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BACKGROUND Detecting early impact of coronary artery bypass grafting (CABG) on left ventricular (LV) function is important because such measures may contribute to meaningful improvement in clinical outcomes. We aimed to gain knowledge about acute changes of LV performance during surgical revascularization using three-dimensional speckle tracking echocardiography (3D STE). METHODS Thirty-five patients scheduled for CABG surgery who underwent intraoperative transesophageal echocardiography (TEE) were enrolled (mean age 68.9 ± 7.3 years). TEE was performed before and after surgery, as well as before and after grafting. 3D LV ejection fraction (LVEF), tissue motion annular displacement (TMAD) of the mitral valves, 3D global longitudinal strain (GLS), global circumferential strain (GCS), twist, and torsion were quantified. Regional longitudinal strain (LS) was calculated based on coronary perfusion territories in a 16-segment LV model. RESULTS Despite the absence of change in TMAD and 3D LVEF, 3D GLS (-18.6 ± 4.3% at baseline vs -16.0 ± 4.0% after surgery, P = .01) was significantly decreased, followed with no significant effect on GCS, twist, and torsion during surgery. 3D GLS correlated significantly with 3D LVEF (r between -0.34 and -0.51, P

Funding Acknowledgements No. OnBehalf No. Background The immediate effect on myocardial function and deformation after coronary revascularization is incompletely studied. Effective revascularization along with perioperative myocardial injury compromises improved regional and global left ventricular function and leads to the risks of adverse perioperative events following coronary artery bypass grafting (CABG) surgery. Global longitudinal strain (GLS) assessed by speckle-tracking echocardiography (STE) has been reported as a better predictor and a more sensitive marker for postoperative ventricular remodeling. Purpose This study aimed to evaluate changes of left ventricular (LV) systolic function and GLS in the perioperative period during CABG and to investigate the value of GLS using two-dimensional STE in predicting short-term outcome. Methods A total of 22 patients who underwent elective CABG surgery (EuroSCORE II 1.84 ± 1.2) were evaluated. Transesophageal echocardiography was performed, 2D and three-dimensional echocardiography (3DE) data was acquired before sternotomy, before cardiopulmonary bypass (CPB), after bypass and after chest closure. LV GLS and tissue motion annular displacements (TMAD) of the mitral valves were quantified by 2D STE using CMQ software. LV volumes and ejection fraction (EF) were evaluated by 3DE at the same timepoints. Short-term outcomes were defined as death, stroke, myocardial infarction, acute kidney dysfunction, rehospitalization and repeated revascularization in a one-month period after surgery. Results Both 2D and 3DE of all patients were analyzed. The cohort had a mean age of 68.2 ± 7.2 years and 9.1% was women. Before sternotomy, GLS was -15.7 ± 2.9%. Despite little change in 3D LVEF, GLS was immediately impaired after coronary artery bypass graft (before bypass vs after chest closure, -15.9 ± 3.6% vs -13.5 ± 4.0%, P = 0.001). There was strong correlation between GLS and 3D LVEF (r=-0.77, P Conclusion Direct effects of myocardial deformation related to revascularization can be characterized by STE during CABG surgery. GLS could be a more sensitive parameter in the perioperative environment, which correlates well with LV global function assessed by 3D LVEF and TMAD. Early impairment of anterior and inferior wall myocardial strain after CABG may contribute to short-term adverse clinical outcome. Abstract P206 Figure.

Background The interaction between baseline kidney function and the performance of biomarkers of acute kidney injury (AKI) on the development of AKI is unclear. Study Design Post hoc analysis of prospective cohort study. Setting & Participants The 1,219 TRIBE-AKI Consortium adult cardiac surgery cohort participants. Predictor Unadjusted postoperative urinary biomarkers of AKI measured within 6 hours of surgery. Outcome AKI was defined as AKI Network stage 1 (any AKI) or higher, as well as a doubling of serum creatinine level from the preoperative value or the need for post-operative dialysis (severe AKI). Measurements Stratified analyses by preoperative estimated glomerular filtration rate (eGFR) ≤ 60 versus > 60mL/min/1.73m 2 . Results 180 (42%) patients with preoperative eGFRs≤60mL/min/1.73m 2 developed clinical AKI compared with 246 (31%) of those with eGFRs>60mL/min/1.73m 2 ( P 2 -transformed biomarker concentrations, there was a significant interaction between any AKI and baseline eGFR for interleukin 18 ( P =0.007) and borderline significance for liver-type fatty acid binding protein ( P =0.06). For all biomarkers, the adjusted relative risk (RR) point estimates for the risk for any AKI were higher in those with elevated baseline eGFRs compared with those with eGFRs≤60mL/min/1.73m 2 . However, the difference in magnitude of these risks was low (adjusted RRs were 1.04 [95% CI, 0.99-1.09] and 1.11 [95% CI, 1.07-1.15] for those with preoperative eGFRs≤60mL/min/1.73m 2 and those with higher eGFRs, respectively). Although no biomarker displayed an interaction for baseline eGFR and severe AKI, log 2 -transformed interleukin 18 and kidney injury molecule 1 had significant adjusted RRs for severe AKI in those with and without baseline eGFRs≤60mL/min/1.73m 2 . Limitations Limited numbers of patients with severe AKI and post-operative dialysis. Conclusions The association between early postoperative AKI urinary biomarkers and AKI is modified by preoperative eGFR. The degree of this modification and its impact on the biomarker-AKI association is small across biomarkers. Our findings suggest that distinct biomarker cutoffs for those with and without a preoperative eGFR≤60mL/min/1.73m 2 is not necessary.

Background:Cognitive and functional impairment increase risk for post-coronary artery bypass graft (CABG) surgery delirium (PCD), but how much impairment is necessary to increase PCD risk remains unclear.Methods:The Neuropsychiatric Outcomes After Heart Surgery (NOAHS) study is a prospective, observational cohort study of participants undergoing elective CABG surgery. Pre-operative cognitive and functional status based on Clinical Dementia Rating (CDR) scale and neuropsychological battery are assessed. We defined mild cognitive impairment (MCI) based on either (1) CDR global score 0.5 (CDR-MCI) or (2) performance 1.5 SD below population means on any cognitive domain on neurocognitive battery (MCI-NC). Delirium was assessed daily post-operative day 2 through discharge using the confusion assessment method (CAM) and delirium index (DI). We investigate whether MCI – either definition – predicts delirium or delirium severity.Results:So far we have assessed 102 participants (mean age 65.1 ± 9; male: 75%) for PCD. Twenty six participants (25%) have MCI-CDR; 38 (62% of those completing neurocognitive testing) met MCI-NC criteria. Fourteen participants (14%) developed PCD. After adjusting for age, sex, comorbidity, and education, MCI-CDR, MMSE, and Lawton IADL score predicted PCD on logistic regression (OR: 5.6, 0.6, and 1.5, respectively); MCI-NC did not (OR [95% CI]: 11.8 [0.9, 151.4]). Using similarly adjusted linear regression, MCI-CDR, MCI-NC, CDR sum of boxes, MMSE, and Lawton IADL score predicted delirium severity (adjusted R2: 0.26, 0.13, 0.21, 0.18, and 0.32, respectively).Conclusions:MCI predicts post-operative delirium and delirium severity, but MCI definition alters these relationships. Cognitive and functional impairment independently predict post-operative delirium and delirium severity.

Using either an angiotensin-converting enzyme inhibitor (ACEi) or an angiotensin receptor blocker (ARB) the morning of surgery may lead to 'functional' postoperative acute kidney injury (AKI), measured by an abrupt increase in serum creatinine. Whether the same is true for 'structural' AKI, measured with new urinary biomarkers, is unknown.The TRIBE-AKI study was a prospective cohort study of 1594 adults undergoing cardiac surgery at six hospitals between July 2007 and December 2010. We classified the degree of exposure to ACEi/ARB into three categories: 'none' (no exposure prior to surgery), 'held' (on chronic ACEi/ARB but held on the morning of surgery) or 'continued' (on chronic ACEi/ARB and taken the morning of surgery). The co-primary outcomes were 'functional' AKI based upon changes in pre- to postoperative serum creatinine, and 'structural AKI', based upon peak postoperative levels of four urinary biomarkers of kidney injury.Across the three levels (none, held and continued) of ACEi/ARB exposure there was a graded increase in functional AKI, as defined by AKI stage 1 or worse; (31, 34 and 42%, P for trend 0.03) and by percentage change in serum creatinine from pre- to postoperative (25, 26 and 30%, P for trend 0.03). In contrast, there were no differences in structural AKI across the strata of ACEi/ARB exposure, as assessed by four structural AKI biomarkers (neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, interleukin-18 or liver-fatty acid-binding protein).Preoperative ACEi/ARB usage was associated with functional but not structural acute kidney injury. As AKI from ACEi/ARB in this setting is unclear, interventional studies testing different strategies of perioperative ACEi/ARB use are warranted.

Objectives: By potentially avoiding the embolic consequences of a side-biting aortic clamp, the single-clamp technique may decrease cerebrovascular accidents in coronary artery bypass grafting. However, this theoretical superiority in stroke prevention has not been conclusively demonstrated and use of this technique may lead to adverse myocardial effects due to longer cross-clamp times. In this study, we sought to determine if the single-clamp technique prevents postoperative stroke in clinical practice. Methods: Of 607 consecutive isolated coronary bypass operations completed over a 3 year period, 301 (50%) were performed by one surgeon using exclusively the singleclamp technique and 306 (50%) were performed by a second surgeon using exclusively the two-clamp technique. Postoperative adverse events were retrospectively compared between these two groups. Results: There were no differences between groups in terms of postoperative stroke (1.7% single-clamp vs. 2.0% two-clamp, Pa 0:78), hospital mortality (2.7% single-clamp vs. 1.6% two-clamp, Pa 0:38), or perioperative myocardial infarction (2.6% single-clamp vs. 0.7% two-clamp, Pa 0:052). The two-clamp technique was not a significant predictor of stroke by logistic regression analysis (Pa 0:72). Conclusions: We conclude that there are no statistically significant differences between clamp techniques with regard to stroke prevention or myocardial protection. We find no compelling evidence for surgeons successfully utilizing one technique to change to the other. q 2001 Elsevier Science B.V. All rights reserved.

Background —Cardiopulmonary bypass (CPB) induces a systemic inflammatory response that causes substantial clinical morbidity. Activation of complement during CPB contributes significantly to this inflammatory process. We examined the capability of a novel therapeutic complement inhibitor to prevent pathological complement activation and tissue injury in patients undergoing CPB. Methods and Results —A humanized, recombinant, single-chain antibody specific for human C5, h5G1.1-scFv, was intravenously administered in 1 of 4 doses ranging from 0.2 to 2.0 mg/kg before CPB. h5G1.1-scFv was found to be safe and well tolerated. Pharmacokinetic analysis revealed a sustained half-life from 7.0 to 14.5 hours. Pharmacodynamic analysis demonstrated significant dose-dependent inhibition of complement hemolytic activity for up to 14 hours at 2 mg/kg. The generation of proinflammatory complement byproducts (sC5b-9) was effectively inhibited in a dose-dependent fashion. Leukocyte activation, as measured by surface expression of CD11b, was reduced ( P P =0.05) in patients who received 2 mg/kg. Sequential Mini-Mental State Examinations (MMSE) demonstrated an 80% reduction in new cognitive deficits ( P P Conclusions —A single-chain antibody specific for human C5 is a safe and effective inhibitor of pathological complement activation in patients undergoing CPB. In addition to significantly reducing sC5b-9 formation and leukocyte CD11b expression, C5 inhibition significantly attenuates postoperative myocardial injury, cognitive deficits, and blood loss. These data suggest that C5 inhibition may represent a novel therapeutic strategy for preventing complement-mediated inflammation and tissue injury.

In the search for alternative conduits, the use of radial artery (RA) grafts has found renewed interest. This study sought to evaluate prospectively the perioperative morbidity, including the postoperative complications in the donor forearm, and mortality in the routine use of RA grafts in coronary artery bypass surgery. Data were obtained prospectively on 200 consecutive patients who underwent coronary revascularization using at least one RA graft from January 1995 to April 1997. The mean age of the patents was 61.9+/-10.5 years (mean+/-standard deviation [SD]). The RA was obtained from one forearm in 197 patients and both forearms in 3 patients. Two patients (1%) required exploration for donor site hematomas, 4 patients (2%) had temporary perioperative dysesthesias in the region of the lateral cutaneous nerve of the forearm, and none had donor site wound infection. Two patients (1%) had a myocardial infarction with electrocardiographic changes in the areas grafted by the RA in the immediate postoperative period, indicating graft failure. The two deaths in the series were due to comorbid factors. Our data suggest that the RA is a safe and suitable conduit for coronary revascularization, and it provides good clinical results. Long-term follow-up of these patients is necessary to confirm the patency of RA conduits. Free RA grafts have the potential for use in other areas of surgery where a conduit is necessary for revascularization procedures.

Ten patients, each with two or more risk factors for morbidity and death, underwent a fenestrated Fontan procedure in which a 4 to 6 mm circular fenestration was left between the systemic and pulmonary venous chambers. None died; a similar group of high-risk patients without fenestration had a mortality rate of 2 of 8. Patients with fenestration had significantly less drainage from the chest tube, less need for inotropic support, and shorter intensive care and hospital stays than did patients without fenestration. Comparison with a group of low-risk patients undergoing the Fontan operation showed no statistical difference in these postoperative parameters. Fenestrations were closed in all 10 patients at from 9 days to 6 months after operation by means of the transcatheter clamshell occluder device. Two patients had left pulmonary artery balloon angioplasty and three patients had other atrial communications closed with additional clamshell devices. During short-term follow-up periods averaging 18 months, all patients were clinically well; however, one patient with mitral atresia required reoperation for obstruction between the left atrium and the tricuspid valve, not related to the clamshell device. These data indicate that fenestration may be one method of achieving lower morbidity and mortality rates among high-risk patients undergoing the Fontan procedure. (J T horac C ardiovasc S urg 1992;103:1039-48)

v a o T n c T t c C i s p f d a 62-year-old diabetic hypertensive female on chronic hemodialysis was admitted from the emergency epartment for progressive marked right-sided heart ailure, fatigue, fever, positive blood cultures for gramositive cocci, and a history of repeated vascular access hromboses with septic thrombophlebitis. She was tachyardic, tachypneic, and hypotensive. Chest x-ray was bnormal and a chest computed tomography (CT) scan as performed. The patient had suffered an acute inferior and right entricular myocardial infarction nearly 7 months earlier ith hypotension and bradyarrhythmias during an adission for Staphylococcus aureus septic thrombophlebitis. rimary angioplasty was performed. Because of a treendous thrombus burden an Angiojet was used, folowed by stenting of the proximal right coronary artery or residual stenosis and dissection. Chest CT demonstrated a 6 7 cm intrapericardial uid collection containing high-density contrast (Fig 1). ransesophageal echocardiography showed a pseudoanurysm surrounding the right coronary artery stent, ante

Use of skeletal muscle for cardiac augmentation is a promising technique for treatment of end-stage cardiac failure. An electrode woven through the latissimus dorsi that recruits nearby nerve fibers is commonly used to pace skeletal muscles both in clinical practice and in the laboratory. A proximally placed nerve cuff electrode offers potential advantages in improved recruitment of muscle fibers and low threshold for stimulation. We tested the effectiveness of a nerve cuff electrode passed directly about the proximal thoracodorsal nerve. Our report looks at the efficacy of nerve cuff electrode stimulation and compares electrical and histologic characteristics of a 180-degree wrap of the thoracodorsal nerve to a 360-degree wrap in dogs over 3 months. Threshold voltage at the commonly used pulse width of 200 microseconds was typically in the range of 400 to 600 mV for each electrode after 3 months. Statistical analysis revealed no significant difference (p < 0.05) in threshold voltage or current between the 180-degree and 360-degree nerve cuff electrode either at acute evaluation or after 3 months. Even contraction of latissimus dorsi was achieved with all implants. Adenosine triphosphatase staining revealed 100% conversion of type II to type I fibers in all stimulated muscles. Histologic examination of the thoracodorsal nerve and latissimus dorsi muscle revealed no abnormalities grossly or by light microscopy. Thus, a carefully applied nerve cuff electrode is an atraumatic, effective method for skeletal muscle stimulation. The 180-degree and 360-degree nerve cuff configurations are equally effective.

The surgical treatment of traumatic injuries of the thoracic aorta is controversial because a number of technical approaches have been recommended. Despite the technique employed, spinal cord ischemia continues to be a persistent problem. Nineteen patients with confirmed aortic injuries secondary to blunt trauma were treated at the Yale-New Haven (Conn) Medical Center from 1984 to 1991. The patients were analyzed in two groups: group 1 (n = 10) underwent repair using mechanical circulatory support and group 2 (n = 9) underwent repair without mechanical circulatory support. Sixteen patients survived. Three patients died of complications of multiple trauma. The groups were comparable with respect to aortic cross-clamp time, preoperative systolic blood pressure, and Injury Severity Score. Three patients in the nonmechanical support group developed neurologic complications (P less than .05). No patient in the mechanical support group had a neurologic complication. We believe that mechanical circulatory support reduces the incidence of neurologic complications following traumatic injuries of the thoracic aorta and should be used whenever clinically feasible.

We studied the feasibility of augmentation of impaired myocardium with synchronously paced skeletal muscle grafts. The short contractile period of skeletal muscle required development of a new stimulator to ensure that the pedicle graft contraction would simulate that of the myocardium. In four dogs each, rectus and diaphragmatic muscles were wrapped around a balloon and electrically stimulated in synchrony with the electrocardiogram, varying stimulation currents and frequency of discharge during systole. For this purpose, a prototype hybrid stimulator was developed which senses the cardiac R wave and modulates the electrical output to the skeletal muscle by delivering a train of impulses of varying frequencies within the systolic intervals. The contraction characteristics in response to such stimulation were similar in rectus and diaphragmatic muscles, but the former developed higher maximum tensions because of the greater muscle bulk. Square-wave output was found to be more effective than sine-wave stimulation, and a single stimulating electrical pulse of 40 msec duration produced a maximum tension of 60 mm Hg lasting for 120 msec, whereas a train of 4 pulses within a 320 msec period was able to achieve a maximum tension of 100 mm Hg lasting nearly 400 msec, the latter approximating that of the myocardium. In six other dogs, the rectus muscle pedicle graft was used to replace a segment of the left ventricle (25.5% +/- 2.1% of left ventricular mass) excised under cardiopulmonary bypass. Left ventricular isometric contraction was studied using a left ventricular balloon with stimulators turned on and off. Significant augmentations of left ventricular maximum tension (+19.3% +/- 2.5%, p less than 0.001, paired t test) and left ventricular contractility (+38.3% +/- 9.4%, p less than 0.001) were achieved when the skeletal muscle grafts were stimulated. Thus, in this preliminary study, skeletal muscle graft properly oriented and stimulated is able to augment the left ventricular isometric contractile function after significant loss of left ventricular myocardial mass.