34 results on '"Gutfinger, D."'
Search Results
2. Modeling of MRI-induced heating in pacemaker patients during 1.5T MRI scans
- Author
-
Mouchawar, G, primary, Sison, S, additional, Chen, S, additional, Min, X, additional, Chen, J, additional, Nyenhuis, J, additional, Gutfinger, D, additional, and Williamson, R, additional
- Published
- 2015
- Full Text
- View/download PDF
3. Integrated microscopy techniques for comprehensive pathology evaluation of an implantable left atrial pressure sensor
- Author
-
Roberts, A, primary, Trainor, K E, additional, Weeks, B, additional, Jackson, N, additional, Troughton, R W, additional, Charles, C J, additional, Rademaker, M T, additional, Melton, I C, additional, Crozier, I G, additional, Hafelfinger, W, additional, Gutfinger, D E, additional, Eigler, N L, additional, Abraham, W T, additional, and Clubb, F J, additional
- Published
- 2013
- Full Text
- View/download PDF
4. Robust curve detection by temporal geodesics.
- Author
-
Gutfinger, D., Nishimura, R., Doi, H., and Sklansky, J.
- Published
- 1990
- Full Text
- View/download PDF
5. Robust classifiers by mixed adaptation
- Author
-
Gutfinger, D., primary and Sklansky, J., additional
- Published
- 1991
- Full Text
- View/download PDF
6. Simplified Parsonnet risk scale identifies limits to early patient discharge.
- Author
-
Ott RA, Gutfinger DE, Alimadadian H, Steedman R, Miller M, Ott WL, Tanner T, Ott, R A, Gutfinger, D E, Alimadadian, H, Steedman, R, Miller, M, Ott, W L, and Tanner, T
- Published
- 2000
7. Rapid recovery of octogenarians following coronary artery bypass grafting.
- Author
-
Ott, Richard A., Gutfinger, Dan E., Miller, Mark, Alimadadian, Hossein, Codini, Michele, Selvan, Arthur, Moscoso, Roberto, Tanner, Teresa, Ott, R A, Gutfinger, D E, Miller, M, Alimadadian, H, Codini, M, Selvan, A, Moscoso, R, and Tanner, T
- Published
- 1997
- Full Text
- View/download PDF
8. Aggressive Preoperative Use of Intraaortic Balloon Pump in Elderly Patients Undergoing Coronary Artery Bypass Grafting
- Author
-
Gutfinger, D. E., Oft, R. A., Miller, M., Selvan, A., Codini, M. A., Alimadadian, H., and Tanner, T. M.
- Published
- 1999
- Full Text
- View/download PDF
9. Prioritization And Classification Of Infrared Detections Using Dynamic Belief
- Author
-
Roberts, G. A., primary, Bradford, L. H., additional, and Gutfinger, D., additional
- Published
- 1989
- Full Text
- View/download PDF
10. Real-Time Analysis of Blobs in Infrared Images Using Dynamic Belief Systems
- Author
-
Gutfinger, D., primary and Sklansky, J., additional
- Published
- 1989
- Full Text
- View/download PDF
11. Robust curve detection by temporal geodesics
- Author
-
Gutfinger, D., primary, Nishimura, R., additional, Doi, H., additional, and Sklansky, J., additional
- Full Text
- View/download PDF
12. Real-world outcomes and management considerations following surgical aortic valve replacement with the Trifecta valve.
- Author
-
Gutfinger D, Sultan I, Ailawadi G, Ramzy D, Kaneko T, Yu Y, Meka G, Prillinger JB, and Bavaria JE
- Abstract
Background: Bioprosthetic surgical aortic valve replacement (SAVR) using the Trifecta valve was frequently chosen because of its large opening area and low transvalvular gradient. However, long-term follow-up revealed the potential for early structural valve deterioration. To further assess the long-term clinical outcomes and management considerations for patients implanted with the Trifecta valve, a real-world study using Medicare fee-for-service claims data was conducted with a focus on Trifecta valve reintervention., Methods: De-identified patients undergoing SAVR with the Trifecta™ valve (Abbott) in the U.S. between 1/1/2011-12/31/2021 were selected by ICD-9/10 procedure codes and then linked to a manufacturer device tracking database. All-cause mortality and freedom from Trifecta valve reintervention with repeat SAVR or valve-in-valve transcatheter aortic valve implantation (ViV-TAVI) were evaluated at 10-years using the Kaplan Meier method. Independent predictors for reintervention and clinical outcomes following reintervention were assessed., Results: Among 242,160 Medicare beneficiaries undergoing SAVR during the study period, 23,197 were implanted with the Trifecta valve. Mean age was 75.2 ± 7.4 years. At 10-years survival was 32.3 % (95 % CI, 31.4 %-33.3 %) and the freedom from valve reintervention was 82.4 % (95 % CI, 81.1 %-83.5 %). Independent predictors for reintervention included younger age, female, obesity, and implants with a small valve size (19 mm, 21 mm). Reintervention with ViV-TAVI (N = 796) was associated with better operative survival (3.8 % vs. 12.5 %, p < 0.001) than repeat SAVR (N = 577)., Conclusion: This real-world nationwide study of Medicare beneficiaries receiving the Trifecta valve demonstrates >80 % freedom from all-cause valve reintervention at 10-years post-implant with reintervention using ViV-TAVI having improved operative survival compared to repeat SAVR., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dan Gutfinger reports financial support was provided by Abbott. Dan Gutfinger reports a relationship with Abbott that includes: employment and equity or stocks. Ibrahim Sultan reports institutional research support from Abbott, Atricure, Artivion, Gore, Edwards, Medtronic, and Terumo Aortic. Gorav Ailawadi reports consulting with Abbott, Anteris, Arthrex, Atricure, Avania, Capstan, Edwards, JenaValve, Johnson & Johnson, Medtronic, Nyra, Philips, and WL Gore. Danny Ramzy reports consulting with Abbott. Tsuyoshi Kaneko reports consulting with Abbott. Yang Yu reports a relationship with Abbott that includes: employment and equity or stocks. Geetanjali Meka reports a relationship with Abbott that includes: employment. Julie B. Prillinger reports a relationship with Abbott that includes: employment and equity or stocks. Joseph E. Bavaria reports consulting with Abbott., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
13. Ten-Year Follow-Up of Mitral Valve Replacement with the Epic Porcine Valve in a Medicare Population.
- Author
-
Rodriguez E, Smith R, Castro L, Baker CJ, Yu Y, Prillinger JB, Gutfinger D, and Starnes VA
- Abstract
Background: Bioprosthetic surgical mitral valve replacement (SMVR) remains an important treatment option in the era of transcatheter valve interventions. We present 10-year clinical outcomes of Medicare beneficiaries undergoing SMVR with a contemporary low-profile mitral porcine valve., Methods: This is a single-arm observational study using Medicare fee-for-service claims data. De-identified patients undergoing SMVR with the Epic™ Mitral valve (Abbott, Minnesota, USA) in the United States between 1/1/2008-12/31/2019 were selected by ICD-9/10 procedure codes and then linked to a manufacturer device tracking database. All-cause mortality, heart failure (HF) re-hospitalization, and mitral valve reintervention (surgical or transcatheter valve-in-valve) were evaluated at 10-years using the Kaplan Meier method., Results: Among 75,739 Medicare beneficiaries undergoing SMVR during the study period, 14,015 were implanted with the Epic™ Mitral valve, of which 76.5% (10,720) had underlying HF. Mean age was 74±8 years. Survival at 10-years in patients without preoperative HF was 40.4% (95% CI 37.4%-43.4%) compared to 25.4% (95% CI 23.8%-27.0%) for patients with HF (p < 0.001). The 10-year freedom from HF rehospitalization was 51.3% (95% CI 49.4%-53.1%). Freedom from mitral valve reintervention was 91.4% (95% CI 89.7%-92.7%) at 10 years., Conclusions: This real-world nationwide study of Medicare beneficiaries receiving the Epic™ Mitral valve demonstrates >90% freedom from all-cause valve reintervention and >50% freedom from HF rehospitalization at 10-years post-implant. Long-term survival and HF rehospitalization in this population with mitral valve disease undergoing SMVR was found to be impacted by underlying HF., (Copyright © 2024. Published by Elsevier Inc.)
- Published
- 2024
- Full Text
- View/download PDF
14. Transcatheter Closure of Postinfarct VSD With the Amplatzer PIVSD Occluder: Results of a US Study.
- Author
-
Iyer V, Weiler C, Merhi W, Kar B, Fudge JC, Seshiah P, Mahadevan VS, Gutfinger D, and Resar J
- Abstract
Background: A postinfarct ventricular septal defect (PIVSD) is associated with high mortality and morbidity, particularly in patients with hemodynamic instability who are not suitable candidates for surgical repair. The Amplatzer PIVSD Occluder (Abbott) is indicated for transcatheter PIVSD closure in patients who are not satisfactory candidates for surgical repair. The objective of this study was to evaluate associated clinical outcomes., Methods: A total of 131 patients underwent transcatheter PIVSD closure using the Amplatzer PIVSD Occluder between 2011 and 2021 as part of a postapproval, multicenter, retrospective, observational study. The patients were analyzed in 2 cohorts. Cohort 1 included 99 patients (age 68.6 ± 11.9 years) implanted from 2011 to 2016 and evaluated technical success, procedure survival, and 6-month survival. Cohort 2 included 32 patients (age 66.4 ± 10.9 years) implanted from 2012 to 2021 with postprocedure echocardiograms and evaluated 24-hour closure, 6-month closure, and 6-month survival., Results: Technical success was achieved in 76.8% (76/99), procedure survival in 84.3% (75/89), and 6-month survival was observed in 37.2% of cohort 1 patients. Twenty-four-hour closure and 6-month closure were achieved in 53.1% (17/32) and 66.7% (4/6) of cohort 2 patients, respectively. Six-month survival was 46.4% of cohort 2 patients. Of the 16 deaths in cohort 2, 11 were cardiac-related, 4 were noncardiac-related, and 1 was of unknown etiology., Conclusions: This study demonstrates high morbidity of patients undergoing PIVSD closure using the Amplatzer PIVSD Occluder and that the device continues to be a safe alternative to medical therapy in patients who are not satisfactory candidates for surgical repair of a PIVSD., (© 2024 The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
15. 3-year follow-up of a prospective, multicenter study of the Amplatzer Piccolo™ Occluder for transcatheter patent ductus arteriosus closure in children ≥ 700 grams.
- Author
-
Morray BH, Sathanandam SK, Forbes T, Gillespie M, Berman D, Armstrong AK, Shahanavaz S, Jones T, Rockefeller T, Justino H, Nykanen D, Weiler C, Gutfinger D, and Zahn EM
- Subjects
- Infant, Humans, Child, Follow-Up Studies, Prospective Studies, Cardiac Catheterization adverse effects, Treatment Outcome, Ductus Arteriosus, Patent surgery, Septal Occluder Device adverse effects
- Abstract
Objective: This study describes 3-year follow-up of 200 infants weighing ≥ 700 grams who underwent transcatheter patent ductus arteriosus (PDA) closure with the Amplatzer Piccolo™ Occluder., Study Design: Between June 2017 and February 2019, 200 children were enrolled in this U.S. study (NCT03055858). PDA closure, survival, and device- or procedure-related events were evaluated. A total of 156 of the available 182 patients (86%) completed the study., Results: The implant success rate was 95.5% (191/200). At 3 years, PDA closure was observed in 100% (33/33) of patients. Survival was >95% with 9 reported deaths. No deaths were adjudicated as device- or procedure-related. Notable events included aortic obstruction (2) requiring stent placement and tricuspid regurgitation (5), for which no interventions were required., Conclusions: This follow-up study demonstrates high rates of PDA closure, low serious complication rates, and survival > 95% at 3 years. The Amplatzer Piccolo™ Occluder is a safe and effective therapy for PDA treatment in premature infants., Clinicaltrials: gov identifier: NCT0305585., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
16. Ten-year outcomes of surgical aortic valve replacement with a contemporary supra-annular porcine valve in a Medicare population.
- Author
-
Wiechmann RJ, Lee LY, Yu Y, Prillinger JB, Gutfinger D, and Blakeman B
- Abstract
Objective: Bioprosthetic surgical aortic valve replacement remains an important treatment option in the era of transcatheter interventions. Real-world outcomes are not well characterized because of limited prospective follow-up studies. We present the 10-year clinical outcomes of Medicare beneficiaries undergoing surgical aortic valve replacement with a contemporary supra-annular porcine valve., Methods: This is a single-arm observational study using Medicare fee-for-service claims data. De-identified patients undergoing surgical aortic valve replacement with the Epic Supra valve (Abbott) in the United States between January 1, 2008, and December 31, 2019, were selected by International Classification of Diseases 9
th and 10th Revision procedure codes and then linked to a manufacturer device tracking database. All-cause mortality, heart failure rehospitalization, and aortic valve reintervention (surgical or transcatheter valve-in-valve) were evaluated at 10 years using the Kaplan-Meier method., Results: Among 272,591 Medicare beneficiaries undergoing surgical aortic valve replacement during the study period, 11,685 received the Epic Supra valve, of whom 51.6% (6029) had underlying heart failure. Mean age was 76 ± 7 years. Survival at 10 years in patients without preoperative heart failure was 43.5% (95% confidence interval, 41.8-45.2) compared with 24.1% (95% confidence interval, 22.6-25.5) for patients with heart failure ( P < .001). The 10-year freedom from heart failure rehospitalization was 64.0% (95% confidence interval, 62.6-65.3). Freedom from aortic valve reintervention was 94.6% (95% confidence interval, 93.8-95.3) at 10 years., Conclusions: This real-world nationwide study of US Medicare beneficiaries receiving the Epic Supra valve demonstrates more than 94% freedom from all-cause valve reintervention and 64% freedom from heart failure rehospitalization at 10 years postimplant. Long-term survival and heart failure rehospitalization in this population with aortic valve disease undergoing surgical aortic valve replacement were found to be impacted by underlying heart failure., (© 2022 The Author(s).)- Published
- 2022
- Full Text
- View/download PDF
17. Hot topics in interventional cardiology: Proceedings from the society for cardiovascular angiography and interventions (SCAI) 2021 think tank.
- Author
-
Naidu SS, Baron SJ, Eng MH, Sathanandam SK, Zidar DA, Feldman DN, Ing FF, Latif F, Lim MJ, Henry TD, Rao SV, Dangas GD, Hermiller JB, Daggubati R, Shah B, Ang L, Aronow HD, Banerjee S, Box LC, Caputo RP, Cohen MG, Coylewright M, Duffy PL, Goldsweig AM, Hagler DJ, Hawkins BM, Hijazi ZM, Jayasuriya S, Justino H, Klein AJ, Kliger C, Li J, Mahmud E, Messenger JC, Morray BH, Parikh SA, Reilly J, Secemsky E, Shishehbor MH, Szerlip M, Yakubov SJ, Grines CL, Alvarez-Breckenridge J, Baird C, Baker D, Berry C, Bhattacharya M, Bilazarian S, Bowen R, Brounstein K, Cameron C, Cavalcante R, Culbertson C, Diaz P, Emanuele S, Evans E, Fletcher R, Fortune T, Gaiha P, Govender D, Gutfinger D, Haggstrom K, Herzog A, Hite D, Kalich B, Kirkland A, Kohler T, Laurisden H, Livolsi K, Lombardi L, Lowe S, Marhenke K, Meikle J, Moat N, Mueller M, Patarca R, Popma J, Rangwala N, Simonton C, Stokes J, Taber M, Tieche C, Venditto J, West NEJ, and Zinn L
- Subjects
- Angiography, Humans, Treatment Outcome, Cardiologists, Cardiology, Heart Defects, Congenital
- Abstract
The Society for Cardiovascular Angiography and Interventions (SCAI) Think Tank is a collaborative venture that brings together interventional cardiologists, administrative partners, and select members of the cardiovascular industry community annually for high-level field-wide discussions. The 2021 Think Tank was organized into four parallel sessions reflective of the field of interventional cardiology: (a) coronary intervention, (b) endovascular medicine, (c) structural heart disease, and (d) congenital heart disease. Each session was moderated by a senior content expert and co-moderated by a member of SCAI's Emerging Leader Mentorship program. This document presents the proceedings to the wider cardiovascular community in order to enhance participation in this discussion, create additional dialog from a broader base, and thereby aid SCAI, the industry community and external stakeholders in developing specific action items to move these areas forward., (© 2021 Wiley Periodicals LLC.)
- Published
- 2021
- Full Text
- View/download PDF
18. Consensus Guidelines for the Prevention and Management of Periprocedural Complications of Transcatheter Patent Ductus Arteriosus Closure with the Amplatzer Piccolo Occluder in Extremely Low Birth Weight Infants.
- Author
-
Sathanandam S, Gutfinger D, Morray B, Berman D, Gillespie M, Forbes T, Johnson JN, Garg R, Malekzadeh-Milani S, Fraisse A, Baspinar O, and Zahn EM
- Subjects
- Humans, Infant, Infant, Extremely Low Birth Weight, Consensus, Ductus Arteriosus, Patent surgery, Postoperative Complications prevention & control, Practice Guidelines as Topic, Septal Occluder Device adverse effects
- Abstract
Transcatheter closure of patent ductus arteriosus (PDA) in premature infants is a feasible, safe, and an effective alternative to surgical ligation and may be performed with an implant success rate of 97%. Major procedural complications related to transcatheter PDA closure in extremely low birth weight (ELBW) infants are relatively infrequent (< 3%) ,but may be associated with a fatality if not optimally managed. Operators performing transcatheter PDA closures should be knowledgeable about these potential complications and management options. Prompt recognition and treatment are often necessary to avoid serious consequences. With strict guidelines on operator training, proctoring requirements, and technical refinements, transcatheter PDA closure in ELBW infants can be performed safely with low complication rates. This article summarizes the consensus guidelines put forward by a panel of physicians for the prevention and management of periprocedural complications of transcatheter PDA closure with the Amplatzer Piccolo Occluder in ELBW infants., (© 2021. The Author(s).)
- Published
- 2021
- Full Text
- View/download PDF
19. Amplatzer Piccolo Occluder clinical trial for percutaneous closure of the patent ductus arteriosus in patients ≥700 grams.
- Author
-
Sathanandam SK, Gutfinger D, O'Brien L, Forbes TJ, Gillespie MJ, Berman DP, Armstrong AK, Shahanavaz S, Jones TK, Morray BH, Rockefeller TA, Justino H, Nykanen DG, and Zahn EM
- Subjects
- Birth Weight, Cardiac Catheterization adverse effects, Coronary Circulation, Ductus Arteriosus, Patent diagnostic imaging, Ductus Arteriosus, Patent physiopathology, Female, Gestational Age, Hemodynamics, Humans, Infant, Newborn, Male, Prospective Studies, Prosthesis Design, Time Factors, Treatment Outcome, United States, Cardiac Catheterization instrumentation, Ductus Arteriosus, Patent therapy, Infant, Extremely Premature, Infant, Very Low Birth Weight, Septal Occluder Device
- Abstract
Objectives: Characterize the safety and effectiveness of the Amplatzer Piccolo Occluder for patent ductus arteriosus (PDA) closure., Background: The presence of a hemodynamically significant PDA has been associated with an increased risk of morbidity and mortality in children born premature., Methods: This was a single arm, prospective, multicenter, non-randomized study to evaluate the Amplatzer Piccolo Occluder to treat PDA in patients ≥700 g. From June 2017 to February 2019, 200 patients were enrolled at nine centers, with 100 patients weighing ≤2 kg. Primary effectiveness endpoint was the rate of PDA closure at 6-month follow-up. Primary safety endpoint was the rate of major complications through 6 months. Secondary endpoint was rate of significant pulmonary or aortic obstruction through 6 months' follow-up., Results: The implant success rate was 95.5% (191/200) overall and 99% in patients ≤2 kg (99/100). The primary effectiveness endpoint was achieved in 99.4% of implanted patients. Four patients experienced a primary safety endpoint event (2 transfusions, 1 hemolysis, and 1 aortic obstruction). There were no branch pulmonary artery obstructions. Five patients, all ≤2 kg, were noted to have worsening of tricuspid regurgitation (TR) after the procedure. None of the TR incidences manifested clinically. The Amplatzer Piccolo Occluder received FDA approval in January 2019 and became the first device approved for PDA closure in patients ≥700 g., Conclusions: This study supports the safety and effectiveness of the Amplatzer Piccolo Occluder, particularly in patients between 700 g and 2 kg where there is currently a significant unmet need in the United States. ClinicalTrials.gov identifier: NCT03055858., (© 2020 The Authors. Catheterization and Cardiovascular Interventions published by Wiley Periodicals, Inc.)
- Published
- 2020
- Full Text
- View/download PDF
20. Thoracic impedance measures tissue characteristics in the vicinity of the electrodes, not intervening lung water: implications for heart failure monitoring.
- Author
-
Charles CJ, Rademaker MT, Melton IC, Gutfinger D, Eigler NL, Qu F, and Troughton RW
- Subjects
- Algorithms, Anesthesia, General, Animals, Blood Pressure Determination methods, Computer Simulation, Edema pathology, Electrodes, Heart Atria pathology, Heart Failure pathology, Monitoring, Physiologic methods, Pulmonary Edema diagnosis, Sheep, Time Factors, Water chemistry, Cardiography, Impedance methods, Electric Impedance, Heart Failure diagnosis, Lung pathology
- Abstract
The rationale for intrathoracic impedance (Z) detection of worsening heart failure (HF) presupposes that changes in Z reflect changes in pulmonary congestion, but is confounded by poor specificity in clinical trials. We therefore tested the hypothesis that Z is primarily affected by tissue/water content in proximity to electrodes rather than by lung water distribution between electrodes through the use of a new computational model for deriving the near-field impedance contributions from the various electrodes. Six sheep were implanted with a left atrial pressure (LAP) monitor and a cardiac resynchronization therapy device which measured Z from six vectors comprising of five electrodes. The vector-based Z was modelled as the summation of the near-field impedances of the two electrodes forming the vector. During volume expansion an acute increase in LAP resulted in simultaneous reductions in the near-field impedances of the intra-cardiac electrodes, while the subcutaneous electrode showed several hours of lag (all p<0.001). In contrast, during the simulated formation of device-pocket edema (induced by fluid injection) the near-field impedance of the subcutaneous electrode had an instantaneous response, while the intra-cardiac electrodes had a minimal inconsistent response. This study suggests that the primary contribution to the vector based Z is from the tissue/water in proximity to the individual electrodes. This novel finding may help explain the limited utility of Z for detecting worsening HF.
- Published
- 2015
- Full Text
- View/download PDF
21. Effects of AV delay and VV delay on left atrial pressure and waveform in ambulant heart failure patients: insights into CRT optimization.
- Author
-
Chan WY, Blomqvist A, Melton IC, Norén K, Crozier IG, Benser ME, Eigler NL, Gutfinger D, and Troughton RW
- Subjects
- Adult, Aged, Feasibility Studies, Humans, Middle Aged, Prospective Studies, Atrial Pressure, Cardiac Resynchronization Therapy methods, Heart Failure physiopathology, Heart Failure therapy
- Abstract
Background: We hypothesized that left atrial pressure (LAP) obtained by a permanent implantable sensor is sensitive to changes in cardiac resynchronization therapy (CRT) settings and could guide CRT optimization to improve the response rate. We investigated the effect of CRT optimization on LAP and its waveform parameters in ambulant heart failure (HF) patients., Methods: CRT optimization was performed in eight ambulant HF patients, using echocardiography as reference. LAP waveform was acquired at each of eight atrioventricular (AV) intervals and five inter-ventricular (VV) intervals. Selected waveform parameters were also evaluated for their sensitivity to CRT changes and agreement with echocardiography-guided optimal settings., Results: Optimal AV and VV intervals varied considerably between patients. All patients exhibited significant changes in waveform morphology with AV optimization. Optimal AV delay determined from echocardiography ranged between 140 ms and 225 ms. Mean LAP tended to be lower at optimal setting 14 ± 3 mmHg compared to shorter (<100 ms) or longer (>160 ms) AV settings (P = 0.16). There were clear trends to smaller peak a-wave (P = 0.11) and gentler positive a-slope (P = 0.15) and positive v-slope (P = 0.09) with longer AV delays. Mean LAP and negative v-wave slope correlated well with echo-guided optimal setting, r = 0.91 (P = 0.001) and 0.79 (P = 0.03), respectively. No significant effects on LAP or waveform were seen during VV optimization., Conclusions: LAP and its waveform changes considerably with AV optimization. There is good agreement between echo-guided optimal setting and LAP. LAP could provide an objective guide to CRT optimization. (Clinical Trial Registry information: URL: http://www.clinicaltrials.gov. Unique Identifier: NCT00632372)., (©2014 Wiley Periodicals, Inc.)
- Published
- 2014
- Full Text
- View/download PDF
22. Monitoring of heart failure: comparison of left atrial pressure with intrathoracic impedance and natriuretic peptide measurements in an experimental model of ovine heart failure.
- Author
-
Rademaker MT, Charles CJ, Melton IC, Richards AM, Frampton CM, Siou J, Qu F, Eigler NL, Gutfinger D, and Troughton RW
- Subjects
- Animals, Biomarkers blood, Cardiac Pacing, Artificial, Cardiography, Impedance, Disease Models, Animal, Feasibility Studies, Heart Atria physiopathology, Heart Failure etiology, Heart Failure physiopathology, Sheep, Domestic, Atrial Function, Left physiology, Heart Failure diagnosis, Natriuretic Peptides blood
- Abstract
Monitoring of HF (heart failure) with intracardiac pressure, intrathoracic impedance and/or natriuretic peptide levels has been advocated. We aimed to investigate possible differences in the response patterns of each of these monitoring modalities during HF decompensation that may have an impact on the potential for early therapeutic intervention. Six sheep were implanted with a LAP (left atrial pressure) sensor and a CRT-D (cardiac resynchronization therapy defibrillator) capable of monitoring impedance along six lead configuration vectors. An estimate of ALAP (LAP from admittance) was determined by linear regression. HF was induced by rapid ventricular pacing at 180 and 220 bpm (beats/min) for a week each, followed by a third week with daily pacing suspensions for increasing durations (1-5 h). Incremental pacing induced progressively severe HF reflected in increases in LAP (5.9 ± 0.4 to 24.5 ± 1.6 mmHg) and plasma atrial (20 ± 3 to 197 ± 36 pmol/l) and B-type natriuretic peptide (3.7 ± 0.7 to 32.7 ± 5.4 pmol/l) (all P<0.001) levels. All impedance vectors decreased in proportion to HF severity (all P<0.001), with the LVring (left ventricular)-case vector correlating best with LAP (r2=0.63, P<0.001). Natriuretic peptides closely paralleled rapid acute changes in LAP during alterations in pacing (P<0.001), whereas impedance changes were delayed relative to LAP. ALAP exhibited good agreement with LAP. In summary, impedance measured with an LV lead correlates significantly with changes in LAP, but exhibits a delayed response to acute alterations. Natriuretic peptides respond rapidly to acute LAP changes. Direct LAP, impedance and natriuretic peptide measurements all show promise as early indicators of worsening HF. ALAP provides an estimate of LAP that may be clinically useful.
- Published
- 2011
- Full Text
- View/download PDF
23. Usefulness of monitoring congestive heart failure by multiple impedance vectors.
- Author
-
Panescu D, Naware M, Siou J, Nabutovsky Y, Holmstrom N, Blomqvist A, Shah R, Gutfinger D, and Khoury D
- Subjects
- Animals, Dogs, Reproducibility of Results, Sensitivity and Specificity, Sheep, Algorithms, Diagnosis, Computer-Assisted methods, Heart Failure diagnosis, Heart Failure etiology, Plethysmography, Impedance methods, Pulmonary Edema diagnosis, Pulmonary Edema etiology
- Abstract
Introduction: We investigated trends in intrathoracic impedance measured between multiple implanted electrodes for monitoring pulmonary edema secondary to congestive heart failure (CHF) in an experimental model., Methods: Biventricular ICDs were implanted in 16 dogs and 5 sheep. Continuous RV pacing (230- 250 bpm) was applied over several weeks. Meanwhile, impedance was measured every hour along 4 intrathoracic and 2 intracardiac vectors. Four cardiogenic impedance vectors were also monitored. Cardiac function was assessed biweekly by catheterization and echocardiography. Left atrial (LA) pressure was measured daily by an implanted LA pressure sensor., Results: All animals developed CHF after 2-4 weeks of pacing as evidenced by changes in function (EF, 52 vs. 34%; LV end-diastolic volume, 65 vs. 97 ml; LV end-diastolic pressure, 7 vs. 16 mmHg; LA volume, 17 vs. 33 ml; LA pressure, 7 vs. 26 mmHg), clinical symptoms, or autopsy. Steady state impedance decreased during CHF: LV-Can, 17+/-9%; LV-RV, 15+/-8%; LV-RA, 13+/-6%; RV-Can, 13+/-8%; RVcoil-Can, 8+/-6%; RA-Can, 6+/-6%. Change in LV-Can impedance was greater than that of RA-Can, RV-Can, and RVcoil-Can (P0.05). LV-Can impedance correlated well with LA pressure (r(2)=0.73), while RV-Can and RVcoil-Can were weakly correlated (r(2)=0.43 and r(2)=0.52, respectively). Changes in LV-RV and LV-RA impedances were also larger than those of RVcoil-Can and RA-Can (P0.05). Meanwhile, all impedances were associated with circadian variability at baseline (5+/-2%) which diminished during CHF (2+/-1%); P=0.02. Furthermore, significant variations were observed in cardiogenic impedances during progression into CHF as evidenced by reduced peak-to-peak amplitude and increased fractionation of the signals., Conclusions: All impedance vectors decreased during CHF. Impedance measurement employing left heart sensors correlated well wit- - h LA pressure, and may improve detection of CHF onset compared to sensing by RA or RV leads alone. This approach has important clinical implications for managing heart failure patients in the ambulatory setting.
- Published
- 2008
- Full Text
- View/download PDF
24. Conventional coronary artery bypass grafting: why women take longer to recover.
- Author
-
Ott RA, Gutfinger DE, Alimadadian H, Selvan A, Miller M, Tanner T, Hlapcich WL, and Gazzaniga AB
- Subjects
- Age Factors, Aged, Aged, 80 and over, Atrial Fibrillation mortality, Cause of Death, Comorbidity, Female, Humans, Intra-Aortic Balloon Pumping statistics & numerical data, Male, Myocardial Infarction mortality, Myocardial Infarction surgery, Risk Assessment, Sex Factors, Survival Rate, Coronary Artery Bypass mortality, Length of Stay statistics & numerical data, Postoperative Complications mortality
- Abstract
Background: Recovery following successful coronary artery bypass grafting (CABG) has been dramatically improved with the use of fast-track methods. Although data exist that demonstrate a significant gender difference in survival following CABG, little is known about factors influencing gender-specific recovery. This report describes a series of consecutive patients undergoing isolated CABG to determine gender-associated factors that may impact outcomes and recovery., Methods: Five hundred and seventeen consecutive patients underwent isolated CABG utilizing cardiopulmonary bypass and were retrospectively reviewed. The outcomes of 351 men in the study were compared to the group of 160 women. A rapid recovery protocol focused on reduced cardiopulmonary bypass time, aggressive preoperative intra-aortic balloon pump use, early extubation, perioperative administration of corticosteroids and thyroid hormone, aggressive diuresis and atrial fibrillation prevention was applied to all patients., Results: The 30-day mortality rate for the women was 4.2% (Parsonnet risk 16.3+/-9.0) compared with 3.4% (Parsonnet risk 9.9+/-7.5) for the men. There were no statistically significant differences in the 30-day mortality rates or postoperative complication rates between the women and men. The women, however, were found to be older (71+/- years versus 65+/- years, p<0.001), and to have a higher incidence of acute myocardial infarction (31% versus 20%, p<0.05), obesity (23% versus 10%, p <0.05), diabetes (31% versus 22%, p<0.05), hypertension (65% versus 48%, p<0.001), and symptomatic vascular disease (20% versus 12%, p<0.05). The women required fewer bypass grafts (2.9 versus 3.5 grafts, p<0.001), and consequently, had shorter cross and cardiopulmonary bypass times. Rapid recovery with discharge before the fifth postoperative day was achieved in 30% of the women, in comparison to 44% of the men (p<0.01). The postoperative hospital length of stay was longer for the women in comparison to the men (7.2+/-7.1 versus 5.8+/-5.2 days, p<0.05)., Conclusions: Women had similar operative mortality and postoperative complication rates to men under a rapid recovery protocol. However, women have a longer recovery interval compared to men, which may be a reflection of their higher preoperative risk profile.
- Published
- 2001
25. Initial experience with beating heart surgery: comparison with fast-track methods.
- Author
-
Ott RA, Gutfinger DE, Steedman R, Tanner TM, and Hlapcich WL
- Subjects
- Aged, Female, Humans, Male, Middle Aged, Minimally Invasive Surgical Procedures, Retrospective Studies, Treatment Outcome, Coronary Artery Bypass methods, Myocardial Revascularization methods
- Abstract
Cardiopulmonary bypass (CPB) in coronary artery bypass grafting (CABG) may increase postoperative complications in high-risk patients. The goal of this study is to retrospectively review a series of consecutive patients undergoing conventional CABG using a fast-track recovery method and to compare this series with the initial series of patients undergoing beating heart surgery using either the single-vessel minimally invasive approach or the off-pump multivessel bypass technique with a median sternotomy. One hundred fifty-eight consecutive patients underwent CABG. One hundred four patients underwent conventional CABG using CPB with a short-pump fast-track recovery method (Group A). Twenty-nine patients underwent a single-vessel bypass via a left anterior thoracotomy off pump [Group B, minimally invasive direct coronary artery bypass (MIDCAB)]. Twenty-five patients underwent multivessel CABG with a median sternotomy off pump (Group C). Short-pump fast-track (Group A) patients exhibited minimal complications and expedient recovery and received extensive revascularization. Off-pump multivessel patients (Group C) received fewer bypass grafts, had more preoperative comorbidity, and recovered as quickly as lower-risk fast-track short-pump patients (Group A). Single-vessel off-pump patients (Group B, MIDCAB) were younger elective patients and demonstrated no recovery advantage. The overall mortality was 1.8 per cent. The conversion rates from beating heart surgery to CPB for groups B and C were 10.3 and 16 per cent, respectively. The postoperative hospital length of stay for groups A, B, and C were 4.8+/-2.4, 3.9+/-1.8, and 5.2+/-2.3 days, respectively. Eliminating CPB is not as important as reducing exposure for minimizing operative risk. Beating heart surgery is an adjunct to conventional CABG with CPB. The off-pump multivessel bypass technique is best suited for high-risk patients requiring three grafts or fewer, whereas MIDCAB is best suited for single-vessel bypass that cannot be managed using interventional percutaneous techniques; however, the recovery advantage with MIDCAB is not apparent. Patients requiring more than three bypass grafts should undergo conventional CABG with CPB.
- Published
- 1999
26. Reduced postoperative atrial fibrillation using multidrug prophylaxis.
- Author
-
Ott RA, Gutfinger DE, Alimadadian H, Miller M, Selvan A, Weinberg D, Hlapcich WL, and Tanner TM
- Subjects
- Aged, Anti-Arrhythmia Agents adverse effects, Atrial Fibrillation diagnosis, Atrial Fibrillation mortality, Dose-Response Relationship, Drug, Drug Administration Schedule, Drug Therapy, Combination, Electrocardiography drug effects, Female, Humans, Magnesium administration & dosage, Magnesium adverse effects, Male, Metoprolol administration & dosage, Metoprolol adverse effects, Middle Aged, Postoperative Complications diagnosis, Postoperative Complications mortality, Procainamide administration & dosage, Procainamide adverse effects, Prospective Studies, Survival Rate, Thyroxine administration & dosage, Thyroxine adverse effects, Triiodothyronine administration & dosage, Triiodothyronine adverse effects, Anti-Arrhythmia Agents administration & dosage, Atrial Fibrillation prevention & control, Coronary Artery Bypass, Postoperative Complications prevention & control
- Abstract
Background: Atrial fibrillation (AFIB) is the most common complication following coronary artery bypass grafting (CABG). Despite three decades of recognition, efforts to reduce the high incidence reported (15%-30%) have been largely unsuccessful. Reasons for postoperative AFIB are likely multifactorial. As a result, we defined a multidrug prophylaxis based on agents known to be individually effective. This method was applied prospectively to a series of consecutive CABG patients with the goal of reducing the incidence of new-onset postoperative AFIB., Methods: Isolated CABG with cardiopulmonary bypass was performed on 517 consecutive patients. A rapid recovery protocol emphasizing AFIB multidrug prophylaxis was applied to all patients. All patients received 10 microg of triiodothyronine intraoperatively when the clamp on the aorta was released. Immediately following CABG, parenteral magnesium was administered to assure a serum magnesium > 2.2 mEq/dL. Thyroxine 200 microg was administered parenterally to all patients on postoperative days 1 and 2. Metoprolol (25 mg to 100 mg/day) was begun on all patients after extubation provided: heart rate > 85 beats/min and systolic blood pressure > 130 mmHg. Parenteral procainamide (12 mg/kg) loading dose, followed by a maintenance dose (2 mg/min), was used for patients who developed premature atrial contractions (> 1/min), nonsustained supraventricular tachycardia, or any episodes of atrial fibrillation. All patients also received postoperative digitalization, steroids, and aggressive diuresis., Results: The 30-day operative mortality was 3.7%. The overall incidence of new-onset postoperative AFIB was 10.3% (53 patients). There was no major difference in operative mortality (7.5% vs 3.2%, p = 0.23), Parsonnet risk score, or intraoperative variables between AFIB patients and the non-AFIB patients. Patients presenting with a preoperative acute myocardial infarction (p < 0.05), left main stenosis > or = 70% (p < 0.01), and advanced age > or = 70 years (p < 0.05) were at increased risk of developing AFIB. The length of stay for patients with AFIB was 9.9 +/- 9.6 days versus 5.9 +/- 5.2 days (p < 0.001)., Conclusion: Application of a multidrug prophylaxis can reduce postoperative AFIB to a low incidence. Identification of associated clinical features can help predict patients at risk for postoperative AFIB. Additional strategies to target postoperative AFIB may include treatment at the earliest recognition of atrial rhythm instability.
- Published
- 1999
27. Coronary artery bypass grafting "on pump": role of three-day discharge.
- Author
-
Ott RA, Gutfinger DE, Miller MP, Selvan A, Codini MA, Alimadadian H, and Tanner TM
- Subjects
- Aged, Female, Humans, Male, Middle Aged, Postoperative Care, Postoperative Complications, Retrospective Studies, Cardiopulmonary Bypass, Coronary Artery Bypass mortality, Length of Stay
- Abstract
Background: A new emphasis has been directed toward "off-pump" coronary artery bypass grafting to avoid the morbidity of cardiopulmonary bypass and further reduce the postoperative hospital length of stay. With the intent of achieving a hospital discharge for "on-pump" coronary artery bypass grafting procedures comparable with the same procedures "off pump," we applied a rapid-recovery protocol with particular attention paid to patients eligible for discharge on the third postoperative day., Methods: The cases of 104 consecutive patients who underwent isolated coronary artery bypass grafting using cardiopulmonary bypass were retrospectively reviewed. A rapid-recovery protocol emphasizing reduced cardiopulmonary bypass time, an anesthesia protocol for early extubation, perioperative administration of corticosteroids and thyroid hormone, and aggressive diuresis was applied to all patients. The goal during the first 24 hours postoperatively was to achieve early extubation as well as a mild state of negative fluid balance and to ensure absence of postoperative bleeding and a safe transfer from the intensive care unit to a monitored floor. On the second postoperative day, chest drains were discontinued, and aggressive ambulation therapy was instituted. If at 72 hours postoperatively the patient was walking without assistance, had return of normal bowel function, and had no atrial fibrillation, a 3-day discharge home was planned., Results: The 30-day mortality rate for the entire group was 1.9%. The average postoperative hospital length of stay for the entire series was 4.8 +/- 2.4 days. Of the 102 survivors, 30 patients (29%) were discharged within 3 days postoperatively (group 1), and 72 patients (71%) were discharged after the third postoperative day (group 2). Patients in group 1 were younger and had fewer comorbid conditions. Compared with group 2, group 1 had fewer patients with diabetes (7% versus 28%; p < 0.05), congestive heart failure (7% versus 18%), symptomatic vascular disease (0% versus 11%), chronic obstructive pulmonary disease (0% versus 10%), ambulatory difficulties (0% versus 10%), and the requirement of an intraaortic balloon pump preoperatively (13% versus 35%). Group 1 patients also had almost no complications and a lower readmission rate (3.3% versus 6.9%)., Conclusions: With the application of a rapid-recovery protocol to patients undergoing "on-pump" coronary artery bypass grafting, discharge home within 3 days postoperatively is attainable and safe for patients who have minimal comorbid conditions.
- Published
- 1997
- Full Text
- View/download PDF
28. Rapid recovery after coronary artery bypass grafting: is the elderly patient eligible?
- Author
-
Ott RA, Gutfinger DE, Miller MP, Alimadadian H, and Tanner TM
- Subjects
- Aged, Anti-Arrhythmia Agents therapeutic use, Atrial Fibrillation drug therapy, Atrial Fibrillation epidemiology, Cardiopulmonary Bypass, Case-Control Studies, Digitalis Glycosides therapeutic use, Female, Humans, Intra-Aortic Balloon Pumping, Length of Stay statistics & numerical data, Male, Middle Aged, Patient Discharge, Postoperative Complications drug therapy, Postoperative Complications epidemiology, Procainamide therapeutic use, Retrospective Studies, Survival Rate, Thyroxine therapeutic use, Time Factors, Triiodothyronine therapeutic use, Convalescence, Coronary Artery Bypass rehabilitation
- Abstract
Background: Rapid recovery protocols after coronary artery bypass grafting have been applied successfully to young patients with normal ventricular function. However, the success of such protocols when applied to the elderly population has not been thoroughly validated, and at some centers there is still reluctance in allowing elderly patients to be discharged early from the hospital., Methods: One hundred fifty-two consecutive younger patients (< 70 years) were compared retrospectively with 167 consecutive elderly patients (> or = 70 years) who underwent isolated coronary artery bypass grafting using cardiopulmonary bypass. A rapid recovery protocol emphasizing an anesthetic protocol for early extubation, reduced cardiopulmonary bypass time, and perioperative administration of corticosteroids and thyroid hormone was applied to all patients. The protocol also emphasized early identification and management of postoperative atrial fibrillation, a proactive negative fluid balance, rapid return of bowel function, mobilization of the patient, and aggressive use of the intraaortic balloon pump preoperatively., Results: The 30-day mortality rate for the younger group of patients was 3.3% (Parsonnet risk 7.2 +/- 6.2), compared with 4.2% (Parsonnet risk, 17.7 +/- 6.8) for the elderly group of patients. There were no statistically significant differences in the 30-day mortality rates or postoperative complications between the elderly and younger patient groups. Rapid recovery with discharge before the fifth postoperative day was achieved in 19% of the elderly, in comparison with 48% of the younger patients (p < 0.001). The younger patients were discharged earlier after operation than the older patients (5.7 +/- 5.2 versus 8.0 +/- 8.5 days; p < 0.01)., Conclusions: Application of the rapid recovery protocol helped expedite recovery for all patients regardless of age, acuity of illness, or associated conditions. Although younger patients had a significantly shorter postoperative length of hospital stay, older patients performed well and are suitable candidates for rapid recovery protocols.
- Published
- 1997
- Full Text
- View/download PDF
29. In vitro atherosclerotic plaque and calcium quantitation by intravascular ultrasound and electron-beam computed tomography.
- Author
-
Gutfinger DE, Leung CY, Hiro T, Maheswaran B, Nakamura S, Detrano R, Kang X, Tang W, and Tobis JM
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Cadaver, Female, Humans, Iliac Artery pathology, In Vitro Techniques, Male, Microscopy, Electron, Scanning, Middle Aged, Models, Theoretical, Arteriosclerosis pathology, Calcium analysis, Iliac Artery chemistry, Tomography, Emission-Computed, Ultrasonography, Interventional
- Abstract
The purpose of this investigation was to compare the accuracy of intravascular ultrasound (IVUS) and electron-beam computed tomography (EBCT) in quantitating human atherosclerotic plaque and calcium. In experiment 1, 12 human atherosclerotic arterial segments were obtained at autopsy and imaged by using IVUS and EBCT. The plaque from each arterial segment was dissected and a volume measurement of the dissected plaque was obtained by water displacement. The plaque from each arterial segment was ashed at 700 degrees F, and the weight of the remaining ashes was used as an estimate of the calcium mass. In experiment II, 11 calcified arterial segments were obtained at autopsy and imaged by using IVUS at one site along the artery. A corresponding histologic cross section stained with Masson's trichrome was prepared. In experiment I, the mean plaque volume measured by water displacement was 165.3 +/- 118.4 microliters. The mean plaque volume calculated by IVUS was 166.1 +/- 114.4 microliters and correlated closely with that by water displacement (r = 0.98, p < 0.0001). The mean calcium mass measured by ashing was 19.4 +/- 15.8 mg. The mean calculated calcium mass by EBCT was 19.9 mg and correlated closely with that by ashing (r=0.98, p<0.001). The mean calculated calcium volume by IVUS was 18.6 +/- 11.2 microliters and correlated linearly with the calcium mass by ashing (r = 0.87, p < 0.0003). In experiment II, the mean cross-sectional area of the calcified matrix was 1.71 +/- 0.66 mm2 by histologic examination compared with 1.44 +/- 0.66 mm2 by IVUS. There was a good correlation between the calcified cross-sectional area by histologic examination and IVUS (r = 0.76, p < 0.007); however, IVUS may underestimate the amount of calcium present depending on the intralesional calcium morphologic characteristics. In conclusion, IVUS accurately quantitates atherosclerotic plaque volume as well as the cross-sectional area and volume of intralesional calcium, especially if the calcium is localized at the base of the plaque. IVUS underestimates the amount of calcium present because of signal drop-off when the calcium is too thick for the ultrasound to completely penetrate. In comparison, EBCT accurately quantitates calcium mass regardless of the intralesional calcium morphologic characteristics; however, EBCT does not accurately quantitate plaque volume and will miss noncalcified atherosclerotic lesions.
- Published
- 1996
- Full Text
- View/download PDF
30. Intravascular ultrasound appearance of normal and mildly diseased coronary arteries: correlation with histologic specimens.
- Author
-
Maheswaran B, Leung CY, Gutfinger DE, Nakamura S, Russo RJ, Hiro T, and Tobis JM
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Coronary Artery Disease diagnostic imaging, Coronary Artery Disease pathology, Coronary Disease pathology, Coronary Vessels pathology, Female, Humans, Hyperplasia, Male, Middle Aged, Tunica Intima diagnostic imaging, Tunica Intima pathology, Coronary Disease diagnostic imaging, Coronary Vessels diagnostic imaging, Ultrasonography, Interventional
- Abstract
Intravascular ultrasound imaging was performed in vitro on six histologically normal and 104 minimally diseased arteries in patients aged 13 to 83 years. This study tested the hypothesis that normal coronary arteries produce a three-layer image that corresponds to the histologic layers of intima, media, and adventitia. The results showed a very good correlation between area of the echolucent ultrasound layer with the media and the inner echogenic layer with intimal area. In addition, a three-layer appearance was consistently seen when the internal elastic membrane was present with or without intimal hyperplasia. If the internal elastic membrane was absent, a three-layer appearance was still seen if the collagen content of the media was low. However, a two-layer appearance was observed when there was absence of the internal elastic membrane as well as a high collagen content of the media.
- Published
- 1995
- Full Text
- View/download PDF
31. Accurate coronary calcium phosphate mass measurements from electron beam computed tomograms.
- Author
-
Detrano R, Tang W, Kang X, Mahaisavariya P, McCrae M, Garner D, Peng SK, Measham C, Molloi S, and Gutfinger D
- Subjects
- Algorithms, Calcium analysis, Chemical Precipitation, Coronary Angiography, Coronary Artery Disease diagnostic imaging, Coronary Artery Disease metabolism, Durapatite analysis, Electrons, Humans, Image Processing, Computer-Assisted, Models, Structural, Regression Analysis, Tomography Scanners, X-Ray Computed, Calcium Phosphates analysis, Coronary Vessels chemistry, Tomography, X-Ray Computed
- Abstract
Precipitates of calcium phosphate in coronary arteries always indicate the presence of atherosclerosis. The mass of these precipitates is related to the severity of atherosclerosis. To determine the accuracy of electron beam computed tomographic (CT) mass estimates, we imaged 21 human hearts inside an anthropomorphic chest phantom using an Imatron C-100 electron beam CT scanner (Imatron, San Francisco, CA). We then incinerated the 63 imaged coronary arteries and weighed the mineral ash. We calculated the mass estimates from the images using an algorithm derived from a model that assumes simple radiographic properties of the coronary arteries. We also calculated the currently used coronary calcium score for each artery. Although both the mass estimates and the scores correlated with the actual mass of the incinerated specimens (r = .97 and r = .93), the correlation with the mass estimates was better (P = .02; William's test). The regression equation relating the actual mass to the mass estimates was y = 1.37 x + 14, indicating that the CT mass estimates consistently underestimate actual coronary calcium phosphate mass. We conclude that relative mass estimates using electron beam CT scanning are accurate and that both these and the currently employed calcium scores reflect the actual mass of precipitated calcium phosphate in diseased coronary arteries.
- Published
- 1995
32. Intracoronary ultrasound imaging before and after directional coronary atherectomy: in vitro and clinical observations.
- Author
-
Nakamura S, Mahon DJ, Leung CY, Maheswaran B, Gutfinger DE, Yang J, Zelman R, and Tobis JM
- Subjects
- Aged, Angiography, Digital Subtraction statistics & numerical data, Arteriosclerosis diagnostic imaging, Arteriosclerosis pathology, Arteriosclerosis surgery, Coronary Angiography statistics & numerical data, Coronary Artery Disease diagnostic imaging, Coronary Artery Disease surgery, Evaluation Studies as Topic, Female, Humans, Iliac Artery diagnostic imaging, Iliac Artery pathology, Iliac Artery surgery, In Vitro Techniques, Male, Middle Aged, Recurrence, Ultrasonography, Interventional methods, Ultrasonography, Interventional statistics & numerical data, Atherectomy, Coronary instrumentation, Atherectomy, Coronary methods, Atherectomy, Coronary statistics & numerical data, Coronary Vessels diagnostic imaging
- Abstract
The rate of restenosis after directional coronary atherectomy (DCA) is higher than expected. To elucidate why, the current study used intravascular ultrasound (IVUS) imaging to investigate the mechanism of DCA. An in vitro validation study was performed to determine the accuracy of the measurement of plaque removal by IVUS. DCA was performed in eight human atherosclerotic artery segments. The volume of removed plaque was measured by water displacement and was compared with the volume calculated from IVUS images. A clinical study of DCA was performed in 32 lesions. IVUS was performed in 28 lesions after successful DCA. Measurements of lumen dimensions from digital angiograms before and after DCA were compared with observations of lumen and plaque size from the cross-sectional IVUS images. In the in vitro study, the mean plaque volume removed by DCA was 19.9 +/- 8.5 microliters. The calculated estimate of removed plaque volume by IVUS was 18.6 +/- 7.9 microliters and correlated closely with the volume by water displacement (r = 0.92). The calculated volume of plaque removed from histologic sections was 14.3 +/- 6.0 microliters and was linearly correlated with plaque volume by water displacement (r = 0.81). In the clinical study, the angiographic mean minimum lumen diameter increased from 1.0 +/- 0.4 to 2.7 +/- 0.5 mm and the percentage stenosis decreased from 70% to 19% (p < 0.0001). The IVUS images before and after DCA showed that the lumen DCA improved from 2.9 +/- 1.5 to 7.0 +/- 1.5 mm2 (p < 0.0001). In addition the vessel cross-sectional area (CSA) increased from 17.1 +/- 5.9 to 18.7 +/- 5.5 mm2. The atheroma CSA was reduced from 14.2 +/- 5.0 to 11.7 +/- 4.8 mm2. This combined effect of reduction in atheroma CSA and stretching of the outer vessel diameter resulted in an improvement in percentage plaque area stenosis from 83% +/- 7% to 61% +/- 9%. It is concluded that despite a successful angiographic appearance, DCA removed an average of 2.5 mm2 from the atheroma, which corresponds to only 18% of the atheroma CSA. The total lumen CSA increased 4.1 mm2; 61% of the new lumen was created by cutting and removal of plaque, whereas 39% of the new lumen was made by stretching the external wall of the artery. Despite an excellent angiographic result, IVUS imaging reveals that after DCA a significant amount of residual atheroma remains. As in balloon dilatation, a stretching effect is a significant component of DCA.
- Published
- 1995
- Full Text
- View/download PDF
33. Concepts in the application of pneumatic ventricular assist devices for ischemic myocardial injury.
- Author
-
Gutfinger DE, Ott RA, Eugene J, and Gazzaniga AB
- Subjects
- Blood Pressure physiology, Cardiac Output physiology, Electrocardiography, Humans, In Vitro Techniques, Mathematics, Models, Biological, Oxygen Consumption physiology, Heart-Assist Devices, Myocardial Reperfusion Injury therapy
- Abstract
The clinical results of "bridge-to-recovery" from ischemic myocardial injury using pneumatic ventricular assist devices (VADs) have been disappointing, because no significant improvement in the hospital discharge rate (25%) has been observed during the past 10 years. Interestingly, similar results have been reported using the less sophisticated and more widely available centrifugal pumps. It is well recognized that appropriate patient selection and early device implantation are important determinants of patient survival; however, it is less clear why there is a lack of difference in the results between pneumatic VADs and the centrifugal pumps. The reasons for the lack of difference in the results between pneumatic VADs and centrifugal pumps are multifactorial, and to some extent may be due to a conservative approach in the application of the more capable pneumatic VADs. In an effort to provide a more effective approach to the clinical application of pneumatic VADs for bridge-to-recovery, two pneumatic devices (the Jarvik 7-70 total artificial heart and the Symbion acute VAD) were functionally characterized using an in vitro mock circulatory system. The performance under pneumatic VAD asynchronous pumping compared to electrocardiogram synchronous counterpulsation was also evaluated. Based upon the results obtained, a two phase approach was developed. In the initial phase (i.e., the first 12-48 hrs), device output is maximized through asynchronous pumping to rapidly reverse the effects of cardiogenic shock. During the second phase (i.e., after hemodynamic stabilization and early evidence of end-organ recovery), electrocardiogram synchronous counterpulsation is used to focus more specifically on recovery of the heart.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1995
34. An explanation for discrepancy between angiographic and intravascular ultrasound measurements after percutaneous transluminal coronary angioplasty.
- Author
-
Nakamura S, Mahon DJ, Maheswaran B, Gutfinger DE, Colombo A, and Tobis JM
- Subjects
- Aged, Constriction, Pathologic, Coronary Disease diagnostic imaging, Coronary Disease therapy, Coronary Vessels diagnostic imaging, Female, Humans, Male, Middle Aged, Ultrasonography, Angioplasty, Balloon, Coronary, Coronary Angiography, Coronary Disease pathology, Coronary Vessels pathology
- Abstract
Objectives: This study attempted to determine why there is a discrepancy between angiographic and intravascular ultrasound measurements after coronary balloon angioplasty., Background: Previous studies have shown a poor correlation between angiographic and intravascular ultrasound measurements after percutaneous coronary balloon angioplasty., Methods: After successful balloon angioplasty, 91 lesions in 84 patients were studied by intravascular ultrasound. Plaque morphology on intravascular ultrasound was classified as demonstrating a superficial injury if there was either no fracture or only a small tear that did not extend to the media versus a deep injury defined as the presence of a plaque fracture that reached the media. Measurements of minimal lumen diameter were compared between angiography and intravascular ultrasound., Results: On ultrasound imaging, a superficial injury pattern was observed in 44 lesions, whereas a deep injury was seen in 47 lesions. There were no statistical differences at baseline in patient or lesion characteristics. In the superficial injury group there was a significant correlation between angiography and intravascular ultrasound for minimal lumen diameter (r = 0.67) and lumen cross-sectional area (r = 0.69). In the deep injury group there was a poor correlation for minimal lumen diameter (r = 0.05) and lumen cross-sectional area (r = 0.28). After balloon angioplasty, the angiographic appearance showed a normal contour in 34%, the presence of dissection in 38% or a hazy appearance in 23%. On ultrasound imaging after angioplasty, the superficial injury group comprised 65% of lesions with a normal angiographic appearance and 67% of lesions with a hazy appearance, whereas 77% of lesions with an angiographic diagnosis of dissection were in the deep injury group by ultrasound (p = 0.0005)., Conclusions: These observations suggest that the discrepancies between angiographic and ultrasound measurements are due to differences in plaque morphology created by balloon dilation. Superficial injuries demonstrate similar results by angiography or ultrasound, whereas a deep injury to the plaque produces a difference in measurements between angiography and ultrasound. When angiography reveals a dissection, there is a high probability that intravascular ultrasound will demonstrate a plaque fracture extending to the media.
- Published
- 1995
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.