18 results on '"Daley WL"'
Search Results
2. [Untitled]
- Author
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Rizzo M, Christine McLean, Kathryn A. Ryan, J. Theodore Dodge, Mukesh Goel, Christopher P. Cannon, Daley Wl, and C. Michael Gibson
- Subjects
medicine.medical_specialty ,business.industry ,Classification scheme ,Hematology ,Blood flow ,Statistical power ,Surgery ,medicine.anatomical_structure ,Survival benefit ,Flow (mathematics) ,Internal medicine ,medicine ,Cardiology ,Cardiology and Cardiovascular Medicine ,business ,Categorical variable ,TIMI ,Artery - Abstract
The survival benefit following a reperfusion strategy, be it pharmacologic or mechanical, appears to be due to both full and early reperfusion. While the TIMI Flow Grade classification scheme has been a useful tool to assess coronary blood flow in acute syndromes, it has several limitations. A newer method of assessing coronary blood flow called the Corrected TIMI Frame Count method has the following advantages: (1) it is a continuous quantitative variable rather than a categorical qualitative variable; (2) the flow in the non-culprit artery is not assumed to be normal as it is in the assessment of TIMI Grade 3 Flow; (3) there is simplified reporting of reperfusion efficacy through the use of a single number instead of expressing the data in 2 to 4 categories; (4) because a single number rather than 4 categories is used to report the data, there is more efficient use of the dataset by increasing the statistical power; and finally (5) coronary flow can be expressed in intuitive terms (e.g. time or cm/sec for strategy A versus time or cm/sec for strategy B). This paper reviews the history of the open artery hypothesis and recent advances in the field.
- Published
- 1998
3. Angioplasty Guidewire Velocity: A New Simple Method to Calculate Absolute Coronary Blood Velocity and Flow
- Author
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Gibson Cm, Christopher P. Cannon, Dodge Jt, Daley Wl, Rizzo M, Kathryn A. Ryan, Mukesh Goel, Sparano A, Christine McLean, Elliott M. Antman, Eyas N. Al-Mousa, and Susan J. Marble
- Subjects
Male ,medicine.medical_specialty ,medicine.medical_treatment ,Lumen (anatomy) ,Coronary Angiography ,Coronary circulation ,Coronary Circulation ,Angioplasty ,Internal medicine ,medicine ,Humans ,cardiovascular diseases ,Angioplasty, Balloon, Coronary ,medicine.diagnostic_test ,business.industry ,Blood flow ,Middle Aged ,Coronary arteries ,Ostium ,surgical procedures, operative ,medicine.anatomical_structure ,Hemorheology ,Angiography ,Cardiology ,Cardiology and Cardiovascular Medicine ,business ,Blood Flow Velocity ,TIMI - Abstract
The Thrombolysis In Myocardial Infarction (TIMI) frame count is a relative index of coronary flow that measures time by counting the number of frames required for dye to travel from the ostium to a standardized coronary landmark in a cineangiogram filmed at a known speed (frames/s). We describe a new method to measure distance along arteries so that absolute velocity (length divided by time) and absolute flow (area x velocity) may be calculated in patients undergoing percutaneous transluminal coronary angiography (PTCA). After PTCA, the guidewire tip is placed at the coronary landmark and a Kelly clamp is placed on the guidewire where it exits the Y-adapter. The guidewire tip is then withdrawn to the catheter tip and a second Kelly clamp is placed on the wire where it exits the Y-adapter. The distance between the 2 Kelly clamps outside the body is the distance between the catheter tip and the anatomic landmark inside the body. Velocity (cm/s) may be calculated as this distance (cm) divided by TIMI frame count (frames) x film frame speed (frames/s). Flow (ml/s) may be calculated by multiplying this velocity (cm/s) and the mean cross-sectional lumen area (cm2) along the length of the artery to the TIMI landmark. In 30 patients, velocity increased from 13.9 +/- 8.5 cm/s before to 22.8 +/- 9.3 cm/s after PTCA (p
- Published
- 1997
4. Techniques in the Angiographic Analysis of Coronary Flow: Past, Present, and Future
- Author
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Eyas N. Al-Mousa, Susan J. Marble, Theodore Dodge, Christine McLean, C. Michael Gibson, Imran Dotani, Daley Wl, Mukesh Goel, Rizzo M, Ralph Vatner, and Kathryn A. Ryan
- Subjects
Measure (data warehouse) ,business.industry ,medicine.medical_treatment ,Frame (networking) ,Blood flow ,Coronary arteries ,surgical procedures, operative ,medicine.anatomical_structure ,Flow (mathematics) ,medicine ,Radiology, Nuclear Medicine and imaging ,cardiovascular diseases ,Cardiology and Cardiovascular Medicine ,business ,Algorithm ,Categorical variable ,TIMI ,Cardiac catheterization - Abstract
The current method of analyzing coronary flow data is the TIMI flow grade method. This method is convenient and easy to apply, but there are limitations to this categorical method of analyzing coronary artery flow. We have developed a new method of analyzing coronary blood flow called the “TIMI frame count.” Using the TIMI frame counting method, we have shown that the flow in the coronary arteries is in fact distributed as a continuous variable and that there are nondiscrete categories of slow and fast flow. This article discusses the statistical basis for the development of this new, simple, and continuous index of coronary flow and provides a “how-to manual“ describing the practical implementation of the new TIMI frame count method. We also describe simple new techniques for measuring the distance to the landmark used for TIMI frame counting. Knowing the distance and the time from the TIMI frame count, velocity can easily be calculated. Tables are provided that can be used for these calculations on-line in the cardiac catheterization laboratory. If the diameter is known, flow can also be calculated from these tables. We also describe new applications of marker wires to measure distance and velocity.
- Published
- 1996
5. TIMI Frame Count
- Author
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Daley Wl, Dodge Jt, Brian M. Alexander, Eugene Braunwald, W. K. Poole, Terry Fortin, Gibson Cm, Raymond L, Christopher P. Cannon, Carolyn H. McCabe, and Susan J. Marble
- Subjects
Cardiac Catheterization ,medicine.medical_specialty ,medicine.medical_treatment ,Myocardial Infarction ,Anterior Descending Coronary Artery ,Coronary Angiography ,Culprit ,Coronary Circulation ,Physiology (medical) ,Internal medicine ,medicine.artery ,medicine ,Humans ,Thrombolytic Therapy ,Myocardial infarction ,Cardiac catheterization ,business.industry ,Hemodynamics ,Thrombolysis ,medicine.disease ,medicine.anatomical_structure ,Right coronary artery ,Cardiology ,Cineangiography ,Cardiology and Cardiovascular Medicine ,business ,Blood Flow Velocity ,TIMI ,Artery - Abstract
Background Although the Thrombolysis in Myocardial Infarction (TIMI) flow grade is a valuable and widely used qualitative measure in angiographic trials, it is limited by its subjective and categorical nature. Methods and Results In normal patients and patients with acute myocardial infarction (MI) (TIMI 4), the number of cineframes needed for dye to reach standardized distal landmarks was counted to objectively assess an index of coronary blood flow as a continuous variable. The TIMI frame-counting method was reproducible (mean absolute difference between two injections, 4.7±3.9 frames, n=85). In 78 consecutive normal arteries, the left anterior descending coronary artery (LAD) TIMI frame count (36.2±2.6 frames) was 1.7 times longer than the mean of the right coronary artery (20.4±3.0) and circumflex counts (22.2±4.1, P P r =−.05, P =.59). The mean 90-minute CTFC among nonculprit arteries (25.5±9.8) was significantly higher (flow was slower) compared with arteries with normal flow in the absence of acute MI (21.0±3.1, P P =NS). Conclusions The CTFC is a simple, reproducible, objective, and quantitative index of coronary flow that allows standardization of TIMI flow grades and facilitates comparisons of angiographic end points between trials. Disordered resistance vessel function may account in part for reductions in flow in the early hours after thrombolysis.
- Published
- 1996
6. Dose and duration of fenfluramine-phentermine therapy impacts the risk of significant valvular heart disease.
- Author
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Lepor NE, Gross SB, Daley WL, Samuels BA, Rizzo MJ, Luko SP, Hickey A, Buchbinder NA, Naqvi TZ, Lepor, N E, Gross, S B, Daley, W L, Samuels, B A, Rizzo, M J, Luko, S P, Hickey, A, Buchbinder, N A, and Naqvi, T Z
- Published
- 2000
- Full Text
- View/download PDF
7. Effect of angiotensin receptor blockade and antihypertensive drugs on diastolic function in patients with hypertension and diastolic dysfunction: a randomised trial.
- Author
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Solomon SD, Janardhanan R, Verma A, Bourgoun M, Daley WL, Purkayastha D, Lacourcière Y, Hippler SE, Fields H, Naqvi TZ, Mulvagh SL, Arnold JM, Thomas JD, Zile MR, Aurigemma GP, and Valsartan In Diastolic Dysfunction (VALIDD) Investigators
- Published
- 2007
- Full Text
- View/download PDF
8. Comparison of the Efficacy of HSK3486 and Propofol for Induction of General Anesthesia in Adults: A Multicenter, Randomized, Double-blind, Controlled, Phase 3 Noninferiority Trial.
- Author
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Gan TJ, Bertoch T, Habib AS, Yan P, Zhou R, Lai YL, Liu X, Essandoh M, Daley WL, and Gelb AW
- Subjects
- Adult, Humans, Anesthetics, Intravenous adverse effects, Pain drug therapy, Anesthesia, General adverse effects, Double-Blind Method, Propofol adverse effects, Hypotension complications
- Abstract
Background: Propofol is an intravenous anesthetic associated with hypotension, respiratory depression, and injection-site pain. HSK3486 injectable emulsion (ciprofol) is a 2,6-disubstituted phenol derivative with fast onset and quick, stable recovery. Previous studies support HSK3486 as an effective, safe anesthetic with substantially less injection-site pain than propofol. The primary objective of this study was to investigate the noninferiority of HSK3486 compared with propofol in successful general anesthesia induction., Methods: Two hundred fifty-five participants were enrolled in HSK3486-304, a multicenter, randomized (2:1), double-blind, propofol-controlled, phase 3 study evaluating HSK3486 for general anesthesia induction in adults undergoing elective surgery with tracheal intubation. The primary endpoint was successful anesthesia induction, defined as 1 or less on the Modified Observer's Assessment of Alertness/Sedation scale. Key secondary endpoints were proportion of participants with injection-site pain on the Numerical Rating Scale of 1 or greater and a composite endpoint, including the proportion of participants successfully induced while maintaining the desired anesthetic depth and without substantial cardiac and respiratory events. Safety endpoints included adverse events, abnormal vital signs, and injection-site pain., Results: Two hundred fifty-one participants (HSK3486, n = 168; propofol, n = 83) were included in the analyses. General anesthesia was successfully induced in 97.0% versus 97.6% of participants with HSK3486 and propofol, respectively. The difference in success rate was -0.57% (95% CI, -5.4 to 4.2%); the noninferiority boundary of -8% was not crossed. Thirty participants (18.0%) had injection-site pain with HSK3486 versus 64 (77.1%) with propofol (P < 0.0001). Eighty-one participants (48.2%) with HSK3486 versus 42 (50.6%) with propofol (P = 0.8780) satisfied the composite endpoint. When injection-site pain was excluded, the incidence of treatment-emergent adverse events related to study drug was 17.9% for HSK3486 and 14.5% for propofol., Conclusions: The study met its primary objective and endpoint, demonstrating noninferiority of HSK3486 compared with propofol in successful anesthetic induction. Substantially less injection-site pain was associated with HSK3486 than with propofol., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc., on behalf of the American Society of Anesthesiologists.)
- Published
- 2024
- Full Text
- View/download PDF
9. A phase 2 study of interleukin-22 and systemic corticosteroids as initial treatment for acute GVHD of the lower GI tract.
- Author
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Ponce DM, Alousi AM, Nakamura R, Slingerland J, Calafiore M, Sandhu KS, Barker JN, Devlin S, Shia J, Giralt S, Perales MA, Moore G, Fatmi S, Soto C, Gomes A, Giardina P, Marcello L, Yan X, Tang T, Dreyer K, Chen J, Daley WL, Peled JU, van den Brink MRM, and Hanash AM
- Subjects
- Humans, Lower Gastrointestinal Tract, Adrenal Cortex Hormones therapeutic use, Interleukin-22, Hematopoietic Stem Cell Transplantation adverse effects, Graft vs Host Disease drug therapy, Graft vs Host Disease etiology
- Abstract
Graft-versus-host disease (GVHD) is a major cause of morbidity and mortality following allogeneic hematopoietic transplantation. In experimental models, interleukin-22 promotes epithelial regeneration and induces innate antimicrobial molecules. We conducted a multicenter single-arm phase 2 study evaluating the safety and efficacy of a novel recombinant human interleukin-22 dimer, F-652, used in combination with systemic corticosteroids for treatment of newly diagnosed lower gastrointestinal acute GVHD. The most common adverse events were cytopenias and electrolyte abnormalities, and there were no dose-limiting toxicities. Out of 27 patients, 19 (70%; 80% confidence interval, 56%-79%) achieved a day-28 treatment response, meeting the prespecified primary endpoint. Responders exhibited a distinct fecal microbiota composition characterized by expansion of commensal anaerobes, which correlated with increased overall microbial α-diversity, suggesting improvement of GVHD-associated dysbiosis. This work demonstrates a potential approach for combining immunosuppression with tissue-supportive strategies to enhance recovery of damaged mucosa and promote microbial health in patients with gastrointestinal GVHD. This trial was registered at www.clinicaltrials.gov as NCT02406651., (© 2023 by The American Society of Hematology.)
- Published
- 2023
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- View/download PDF
10. An Open-Label, Dose-Escalation Study to Assess the Safety and Efficacy of IL-22 Agonist F-652 in Patients With Alcohol-associated Hepatitis.
- Author
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Arab JP, Sehrawat TS, Simonetto DA, Verma VK, Feng D, Tang T, Dreyer K, Yan X, Daley WL, Sanyal A, Chalasani N, Radaeva S, Yang L, Vargas H, Ibacache M, Gao B, Gores GJ, Malhi H, Kamath PS, and Shah VH
- Subjects
- Adult, Drug Dosage Calculations, End Stage Liver Disease, Female, Humans, Male, Middle Aged, Models, Theoretical, Recombinant Fusion Proteins adverse effects, Severity of Illness Index, Treatment Outcome, Interleukin-22, Hepatitis, Alcoholic drug therapy, Immunoglobulin G, Interleukins agonists, Recombinant Fusion Proteins administration & dosage
- Abstract
Background and Aims: Interleukin-22 has beneficial effects on inflammation and impaired hepatic regeneration that characterize alcohol-associated hepatitis (AH). F-652 is a recombinant fusion protein of human interleukin-22 and immunoglobulin G2 fragment crystallizable. This study aims to assess the safety and efficacy signals of F-652 in patients with moderate and severe AH., Approach and Results: A phase-2 dose-escalating study was carried out. F-652 (10 μg/kg, 30 μg/kg, or 45 μg/kg) administered on days 1 and 7 was tested in 3 patients each with moderate (Model for End-Stage Liver Disease [MELD] scores: 11-20) and severe AH (MELD scores: 21-28). Safety was defined by absence of serious adverse events and efficacy was assessed by Lille score, changes in MELD score, and serum bilirubin and aminotransferases at days 28 and 42. Three independent propensity-matched comparator patient cohorts were used. Plasma extracellular vesicles and multiplex serum cytokines were measured to assess inflammation and hepatic regeneration. Eighteen patients (9 moderate and 9 severe AH) were enrolled, 66% were male, and the mean age was 48 years. The half-life of F-652 following the first dose was 61-85 hours. There were no serious adverse events leading to discontinuation. The MELD score and serum aminotransferases decreased significantly at days 28 and 42 from baseline (P < 0.05). Day-7 Lille score was 0.45 or less in 83% patients as compared with 6%, 12%, and 56% among the comparator cohorts. Extracellular vesicle counts decreased significantly at day 28 (P < 0.013). Cytokine inflammatory markers were down-regulated, and regeneration markers were up-regulated at days 28 and 42., Conclusions: F-652 is safe in doses up to 45 μg/kg and associated with a high rate of improvement as determined by Lille and MELD scores, reductions in markers of inflammation and increases in markers of hepatic regeneration. This study supports the need for randomized placebo-controlled trials to test the efficacy of F-652 in AH., (© 2019 by the American Association for the Study of Liver Diseases.)
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- 2020
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11. The design of an observational study of hypertension management, adherence and pressure control in Blood Pressure Success Zone Program participants.
- Author
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Payne KA, Caro JJ, Daley WL, Khan ZM, Ishak KJ, Stark K, Purkayastha D, Flack J, Velázquez E, Nesbitt S, Morisky D, and Califf R
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- Adolescent, Adult, Aged, Antihypertensive Agents therapeutic use, Clinical Trials as Topic, Female, Humans, Male, Middle Aged, Patient Compliance statistics & numerical data, Patient Satisfaction, Research Design, Treatment Outcome, Young Adult, Hypertension prevention & control, Patient Education as Topic
- Abstract
Aims: The Blood Pressure Success Zone (BPSZ) Program, a nationwide initiative, provides education in addition to a complimentary trial of one of three antihypertensive medications. The BPSZ Longitudinal Observational Study of Success (BPSZ-BLISS) aims to evaluate blood pressure (BP) control, adherence, persistence and patient satisfaction in a representative subset of BPSZ Program participants. The BPSZ-BLISS study design is described here., Methods: A total of 20,000 physicians were invited to participate in the study. Using a call centre supported Interactive Voice Response System (IVRS), physicians report BP and other data at enrolment and every usual care visit up to 12 +/- 2 months; subjects self-report BPs, persistence, adherence and treatment satisfaction at 3, 6 and 12 months post-BPSZ Program enrolment. In addition to BPSZ Program enrolment medications, physicians prescribe antihypertensive medications and schedule visits as per usual care. The General Electric Healthcare database will be used as an external reference., Results: After 18 months, over 700 IRB approved physicians consented and enrolled 10,067 eligible subjects (48% male; mean age 56 years; 27% newly diagnosed); 97% of physicians and 78% of subjects successfully entered IVRS enrolment data. Automated IVRS validations have maintained data quality (< 5% error on key variables). Enrolment was closed 30 April 2007; study completion is scheduled for June 2008., Conclusions: The evaluation of large-scale health education programmes requires innovative methodologies and data management and quality control processes. The BPSZ-BLISS design can provide insights into the conceptualisation and planning of similar studies.
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- 2008
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12. Albuminuria response to very high-dose valsartan in type 2 diabetes mellitus.
- Author
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Hollenberg NK, Parving HH, Viberti G, Remuzzi G, Ritter S, Zelenkofske S, Kandra A, Daley WL, and Rocha R
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- Aged, Albuminuria complications, Antihypertensive Agents administration & dosage, Antihypertensive Agents adverse effects, Diabetes Mellitus, Type 2 complications, Diabetes Mellitus, Type 2 drug therapy, Dose-Response Relationship, Drug, Female, Humans, Hypertension complications, Hypertension drug therapy, Male, Middle Aged, Tetrazoles administration & dosage, Tetrazoles adverse effects, Valine administration & dosage, Valine adverse effects, Valine therapeutic use, Valsartan, Albuminuria drug therapy, Antihypertensive Agents therapeutic use, Tetrazoles therapeutic use, Valine analogs & derivatives
- Abstract
Objective: Renin-angiotensin system blockade is now standard in the management of the patient with type 2 diabetes mellitus. We aimed to investigate whether high doses of valsartan, an angiotensin receptor blocker, are superior to conventional doses to reduce urinary albumin excretion rates (UAER) in such patients., Patients and Methods: Three hundred and ninety-one hypertensive patients with type 2 diabetes mellitus and UAER 20-700 microg/min were randomized to 160, 320 or 640 mg valsartan. All received valsartan 160 mg for the first 4 weeks. Valsartan dose was then increased in two of three groups for 30 weeks. Overnight urine collections at baseline, 4, 16, and 30 weeks in triplicate were used to assess proteinuria., Results: Comparable albuminuria reductions occurred in all groups at week 4 (P<0.001). Subsequently, a highly significant albuminuria fall occurred with valsartan 320 and 640 mg (P<0.001) versus a modest additional change with 160 mg (P=0.03). At week 30, twice as many patients returned to normal albuminuria with valsartan 640 mg versus 160 mg (24 versus 12%; P<0.01). High doses were well tolerated, with no dose-related increases in adverse events, including hypotension and hyperkalemia., Conclusion: High doses of valsartan reduced albuminuria more than the more commonly used 160 mg dose, apparently independent of blood pressure. Thus, at least in type 2 diabetes mellitus, higher doses of valsartan are required to optimize tissue protection than for blood pressure control.
- Published
- 2007
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13. Rationale and design: the VALsartan In Diastolic Dysfunction (VALIDD) Trial: evolving the management of diastolic dysfunction in hypertension.
- Author
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Janardhanan R, Daley WL, Naqvi TZ, Mulvagh SL, Aurigemma G, Zile M, Arnold JM, Artis E, Purkayastha D, Thomas JD, and Solomon SD
- Subjects
- Angiotensin II Type 1 Receptor Blockers administration & dosage, Angiotensin II Type 1 Receptor Blockers therapeutic use, Comorbidity, Double-Blind Method, Echocardiography, Doppler, Humans, Randomized Controlled Trials as Topic, Tetrazoles administration & dosage, Tetrazoles therapeutic use, Valine administration & dosage, Valine pharmacology, Valine therapeutic use, Valsartan, Ventricular Dysfunction epidemiology, Angiotensin II Type 1 Receptor Blockers pharmacology, Diastole drug effects, Hypertension epidemiology, Research Design, Tetrazoles pharmacology, Valine analogs & derivatives, Ventricular Dysfunction drug therapy
- Abstract
Background: Although 50% of hypertensive patients in the community are estimated to have diastolic dysfunction, there is no specific guideline for diastolic dysfunction therapy at present despite the condition's clear association with increased cardiovascular risk. Although the efficacy of angiotensin II receptor blockers (ARBs) in hypertension and left ventricular hypertrophy regression has been established, the effect of angiotensin II receptor blockade on intrinsic parameters of diastolic function has not been evaluated in large-scale studies., Methods: The VALIDD Trial is an investigator-initiated randomized, controlled, double-blind clinical trial on approximately 350 patients designed to explore whether antihypertensive therapy with the ARB valsartan, in addition to standard therapy, would improve intrinsic diastolic properties of the myocardium in patients with hypertension and evidence of diastolic dysfunction. The result of such therapy will be compared with placebo after 38 weeks of treatment. The primary efficacy variable is change in early diastolic lateral mitral annular relaxation velocity measured by tissue Doppler imaging on week 38., Conclusions: We expect the VALIDD Trial to provide novel insights into the specific effects of ARBs on diastolic dysfunction, as assessed by tissue Doppler imaging, in hypertensive patients. The trial may provide clinically useful data on whether such therapy can directly improve diastolic function in patients with hypertension.
- Published
- 2006
- Full Text
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14. Recommendations for evaluating compliance and persistence with hypertension therapy using retrospective data.
- Author
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Halpern MT, Khan ZM, Schmier JK, Burnier M, Caro JJ, Cramer J, Daley WL, Gurwitz J, and Hollenberg NK
- Subjects
- Humans, Retrospective Studies, Behavioral Research methods, Hypertension drug therapy, Hypertension psychology, Patient Compliance
- Published
- 2006
- Full Text
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15. The Open Artery Hypothesis: Past, Present, and Future.
- Author
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Goel M, Dodge JT Jr, Rizzo M, McLean C, Ryan KA, Daley WL, Cannon CP, and Gibson CM
- Abstract
The survival benefit following a reperfusion strategy, be it pharmacologic or mechanical, appears to be due to both full and early reperfusion. While the TIMI Flow Grade classification scheme has been a useful tool to assess coronary blood flow in acute syndromes, it has several limitations. A newer method of assessing coronary blood flow called the Corrected TIMI Frame Count method has the following advantages: (1) it is a continuous quantitative variable rather than a categorical qualitative variable; (2) the flow in the non-culprit artery is not assumed to be normal as it is in the assessment of TIMI Grade 3 Flow; (3) there is simplified reporting of reperfusion efficacy through the use of a single number instead of expressing the data in 2 to 4 categories; (4) because a single number rather than 4 categories is used to report the data, there is more efficient use of the dataset by increasing the statistical power; and finally (5) coronary flow can be expressed in intuitive terms (e.g. time or cm/sec for strategy A versus time or cm/sec for strategy B). This paper reviews the history of the open artery hypothesis and recent advances in the field.
- Published
- 1998
- Full Text
- View/download PDF
16. Thrombolysis in Myocardial Infarction frame count in saphenous vein grafts.
- Author
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Al-Mousa EN, Dodge JT Jr, Rizzo M, McLean C, Ryan K, Moynihan J, Kelley M, Marble SJ, Goel M, Daley WL, and Gibson CM
- Subjects
- Cardiac Catheterization, Cineangiography, Coronary Artery Bypass, Coronary Circulation, Humans, Reference Values, Coronary Angiography methods, Myocardial Infarction diagnostic imaging, Myocardial Infarction surgery, Saphenous Vein transplantation
- Abstract
Background: Although the Thrombolysis in Myocardial Infarction flow grade system is a widely used index of coronary blood flow, it has important limitations. We recently described a new continuous measure of blood flow in native coronary arteries, the Thrombolysis in Myocardial Infarction frame count (TFC), and sought to extend this method to coronary artery bypass grafts., Methods: We retrospectively analyzed cinefilms of patients' status after coronary artery bypass grafting, excluding patients with recent myocardial infarction and grafts with stenoses in the graft or native vessel. We counted the cineframes required for dye to travel from the ostium of the graft to the graft anastomotic site (TFCg) and to a standardized distal coronary landmark (TFC)., Results: For all vein grafts combined, TFCg was 19.2+/-5.7 frames (mean+/-SD, n = 93) and the TFC was 33.9+/-8.0 frames (n = 67). The upper limits for "normal" flow, calculated from the 95% confidence intervals, were 31 frames for TFCg and 50 frames for TFC., Conclusions: The Thrombolysis in Myocardial Infarction frame counting method has now been extended to normal saphenous vein grafts, and normal reference values are provided.
- Published
- 1998
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17. Streptokinase entrapment in interdigitation-fusion liposomes improves thrombolysis in an experimental rabbit model.
- Author
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Perkins WR, Vaughan DE, Plavin SR, Daley WL, Rauch J, Lee L, and Janoff AS
- Subjects
- Animals, Drug Carriers, Liposomes, Rabbits, Drug Delivery Systems, Fibrinolytic Agents administration & dosage, Streptokinase administration & dosage, Thrombosis drug therapy
- Abstract
The successful design of new thrombolytic agents depends on providing these agents with increased clot selectivity. As recently demonstrated (10), entrapment of tissue plasminogen activator into liposomes apparently provided the selective targeting needed to improve the efficacy of this fibrinolytic agent. To test whether liposomal entrapment would benefit streptokinase, a fibrinolytic agent with a different mode of action and inactivation, we compared liposomal streptokinase with free streptokinase in an experimental rabbit model of thrombolysis. First we adapted a new method to produce liposomes of high entrapment efficiency, termed interdigitation-fusion (IF) liposomes, for the encapsulation of streptokinase. This system was then tested in an in vivo rabbit model of thrombolysis where animals with established clots were infused with either free streptokinase (40,000 U/kg), liposomally entrapped streptokinase, free streptokinase+empty liposomes, or the corresponding amount of empty liposomes or saline. Significant differences (p < 0.05) in the percent clot lysis were observed between saline control (22.4 +/- 3.3%; mean +/- S.E.), free streptokinase (36.3 +/- 3.4%), and liposomal streptokinase (47.4 +/- 1.4%). Importantly, animals treated with empty liposomes experienced a level of thrombolysis (32.4 +/- 2.8%) not different to that produced by free streptokinase or empty liposomes plus free streptokinase (38.0 +/- 2.0%). We believe the effect of liposomes alone is due to a transient redistribution or margination of circulating platelets. When tested in rabbits immunized against streptokinase, liposomal (33.8 +/- 1.5%) but not free streptokinase (29.3 +/- 2.1%) showed significant thrombolytic activity compared to saline (22.4 +/- 3.3%) (p < 0.05). The thrombolytic activity was comparable to free streptokinase in non-immunized rabbits. This suggests liposomal streptokinase would have better thrombolytic activity than streptokinase alone and still provide to those patients possessing high levels of anti-streptokinase antibodies (5% of the population) the equivalent degree of therapy expected from free streptokinase.
- Published
- 1997
18. TIMI frame count: a quantitative method of assessing coronary artery flow.
- Author
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Gibson CM, Cannon CP, Daley WL, Dodge JT Jr, Alexander B Jr, Marble SJ, McCabe CH, Raymond L, Fortin T, Poole WK, and Braunwald E
- Subjects
- Blood Flow Velocity, Cardiac Catheterization, Cineangiography, Coronary Circulation physiology, Hemodynamics, Humans, Myocardial Infarction physiopathology, Coronary Angiography methods, Myocardial Infarction diagnostic imaging, Myocardial Infarction drug therapy, Thrombolytic Therapy
- Abstract
Background: Although the Thrombolysis in Myocardial Infarction (TIMI) flow grade is valuable and widely used qualitative measure in angiographic trials, it is limited by its subjective and categorical nature., Methods and Results: In normal patients and patients with acute myocardial infarction (MI) (TIMI 4), the number of cineframes needed for dye to reach standardized distal landmarks was counted to objectively assess an index of coronary blood flow as a continuous variable. The TIMI frame-counting method was reproducible (mean absolute difference between two injections, 4.7 +/- 3.9 frames, n=85). In 78 consecutive normal arteries, the left anterior descending coronary artery (LAD) TIMI frame count (36.2 +/- 2.6 frames) was 1.7 times longer than the mean of the right coronary artery (20.4 +/- 3.0) and circumflex counts (22.2 +/- 4.1, P < .001 for either versus LAD). Therefore, the longer LAD frame counts were corrected by dividing by 1.7 to derive the corrected TIMI frame count (CTFC). The mean CTFC in culprit arteries 90 minutes after thrombolytic administration followed a continuous unimodal distribution (there were not subpopulations of slow and fast flow) with a mean value of 39.2 +/- 20.0 frames, which improved to 31.7 +/- 12.9 frames by 18 to 36 hours (P < .001). No correlation existed between improvements in CTFCs and changes in minimum lumen diameter (r=-.05, P=.59). The mean 90-minute CTFC among nonculprit arteries (25.5 +/- 9.8) was significantly higher (flow was slower) compared with arteries with normal flow in the absence of acute MI (21.0 +/- 3.1, P < .001) but improved to that of normal arteries by 1 day after thrombolysis (21.7 +/- 7.1, P=NS)., Conclusions: The CTFC is a simple, reproducible, objective and quantitative index of coronary flow that allows standardization of TIMI flow grades and facilitates comparisons of angiographic end points between trials. Disordered resistance vessel function may account in part for reductions in flow in the early hours after thrombolysis.
- Published
- 1996
- Full Text
- View/download PDF
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