Off-pump coronary artery bypass grafting. Excellent results in a group of selected high-risk patients.

BACKGROUND: Off-pump coronary artery bypass grafting (OPCABG) has assumed an increasing role in many surgical practices. The ideal candidate has not been defined, but high-risk patients seem to benefit most when cardiopulmonary bypass (CPB), aortic cross clamping and cardioplegic arrest are avoided. METHODS: Fourteen high-risk patients (age 52 to 81 years, 1 female, EF 44%+/-8, Parsonnet score 23+/-4) were studied. They presented with acute coronary syndroms on platelet glycoprotein IIb/IIIa antagonists, acute myocardial infarction, worsening renal failure, decompensating ischemic cardiomyopathy, religious beliefs and denial of blood transfusion, and severe peripheral/cerebrovascular disease (total bilateral internal carotid artery occlusion and/or >90% stenosis). These patients underwent OPCABG via sternotomy with the intention of complete coronary revascularization. RESULTS: An average of 2.3 grafts/patient were performed and the posterior descending artery (PDA) and marginal branches of the circumflex artery (LCX) were grafted in 79% of the patients. There were 3 events of intraoperative cardiac arrest precipitated by occlusion of right coronary artery (RCA) or positioning a cardiomegaly heart leading to immediate intravascular shunting (2) and/or conversion to CPB (1). One patient was converted to CPB and graft revision (intraoperative ultrasound and probing). The mortality rate was 0% and one stroke was observed on post-operative day 1. Coronary angiography (n=6) showed no significant stenosis. CONCLUSIONS: OPCABG complete revascularization is feasible in high-risk patients with low morbidity and mortality and excellent early RESULTS: OPCABG may be indicated in patients on platelet receptor antagonists preventing bleeding complications. Cardiomegaly can cause difficult off-pump LCX and PDA exposure and stabilization. RCA grafting off-pump is less tolerated and PDA grafting is preferred. High-risk patients for CPB are the ones who may benefit the most from OPCABG.

Percutaneous coronary intervention versus coronary artery bypass graft surgery for patients with medically refractory myocardial ischemia and risk factors for adverse outcomes with bypass: a multicenter, randomized trial. Investigators of the Department of Veterans Affairs Cooperative Study #385, the Angina With Extremely Serious Operative Mortality Evaluation (AWESOME).

BACKGROUND: Percutaneous coronary intervention (PCI) and coronary artery bypass graft surgery (CABG) are being applied to high-risk populations, but previous randomized trials comparing revascularization methods have excluded a number of important high-risk groups. OBJECTIVES: This five-year, multicenter, randomized clinical trial was designed to compare long-term survival among patients with medically refractory myocardial ischemia and a high risk of adverse outcomes assigned to either a CABG or a PCI strategy, which could include stents. METHODS: Patients from 16 Veterans Affairs Medical Centers were screened to identify myocardial ischemia refractory to medical management and the presence of one or more risk factors for adverse outcome with CABG, including prior open-heart surgery, age >70 years, left ventricular ejection fraction <0.35, myocardial infarction within seven days or intraaortic balloon pump required. Clinically eligible patients (n = 2,431) underwent coronary angiography; 781 were angiographically acceptable; 454 (58% of eligible) patients consented to random assignment between CABG and PCI. RESULTS: A total of 232 patients was randomized to CABG and 222 to PCI. The 30-day survivals for CABG and PCI were 95% and 97%, respectively. Survival rates for CABG and PCI were 90% versus 94% at six months and 79% versus 80% at 36 months (log-rank test, p = 0.46). CONCLUSIONS: Percutaneous coronary intervention is an alternative to CABG for patients with medically refractory myocardial ischemia and a high risk of adverse outcomes with CABG.

A multicenter, randomized trial of percutaneous coronary intervention versus bypass surgery in high-risk unstable angina patients. The AWESOME (Veterans Affairs Cooperative Study #385, angina with extremely serious operative mortality evaluation) investigators from the Cooperative Studies Program of the Department of Veterans Affairs.

This multicenter, prospective randomized trial was designed to test the hypotheses that percutaneous coronary intervention (PCI) is a safe and effective alternative to coronary artery bypass grafting (CABG) for patients with refractory ischemia and high risk of adverse outcomes. As a comparison of revascularization strategies, the trial specifically allows surgeons and interventionists to use new techniques as they become clinically available. After 42 months of this 72-month trial, 17,624 patients have been screened and 2022 met eligibility requirements: 341 have been randomized to either CABG or PCI, and the remaining 1681 are being prospectively followed in a registry. The 3-year overall survival of patients in the registry and randomized trial is comparable. To enhance accrual into the randomized trial, site visits were conducted, a few low-accruing hospitals were put on probation and/or replaced, eligibility criteria were reviewed at annual meetings of investigators, and the accrual period was extended by 1 year. These data demonstrate that a prospective randomized trial and registry of coronary revascularization for medically refractory high-risk patients is feasible.

Mortality and need for reoperation in patients with mild-to-moderate asymptomatic aortic valve disease undergoing coronary artery bypass graft alone.

BACKGROUND: Patients presenting for coronary artery bypass graft (CABG) surgery may have concurrent asymptomatic aortic stenosis (AS) or aortic insufficiency (AI). This retrospective study was performed to evaluate outcomes in patients with aortic valve disease undergoing CABG with or without aortic valve replacement (AVR). METHODS: Study groups included 414 patients undergoing combined AVR and CABG (AVR-CABG group) and 62 patients with asymptomatic mild-to-moderate AS, AI, or both undergoing CABG but not AVR (CABG group). End points included 30-day mortality rate, time to cardiac mortality, time to all-cause mortality, and time to aortic valve reoperation. Reoperation refers to surgery for replacement of the native aortic valve in the CABG group or replacement of the prosthetic aortic valve in the AVR-CABG group. Important patient characteristics affecting outcomes were determined by using Cox proportional-hazard analysis. These variables were then included in multivariable analyses by using logistic regression analysis and Cox proportional-hazard modeling to compare outcomes between each patient group. RESULTS: No difference was seen in any of the mortality end points between the CABG group and the AVR-CABG group after controlling for significant differences between the groups. However, the need for reoperation for AVR was significantly higher for the CABG group than the AVR-CABG group. For patients followed for up to 6 years, the estimated need for aortic valve reoperation was 24.3% in the CABG group versus 3% in the AVR-CABG group. CONCLUSION: On the basis of these results, patients with asymptomatic AS or AI should be considered for AVR at the time of CABG.

Results of valve replacement with mechanical and biological prostheses in chronic renal dialysis patients.

BACKGROUND: Whether biological or mechanical valves should be used in patients on chronic dialysis therapy remains to be clearly defined. METHODS: A retrospective review was performed on 19 consecutive patients from our institution with end-stage renal disease on chronic peritoneal or hemodialysis undergoing aortic (n = 12), mitral (n = 5), or aortic-mitral (n = 2) valve replacement. RESULTS: The 9 biological and 10 mechanical valve patients had similar ages (56.5 versus 56.6 years) and cardiovascular risk factors. The overall estimated Kaplan-Meier survival was 60% +/- 12% at 12 months and 42% +/- 14% at 60 months. Mechanical valve patients had a significantly higher rate of postoperative cerebrovascular accidents or bleeding complications (10/10 versus 0/9; chi 2 = 17.0; p < 0.001). No subsequent reoperations were required for biological valve failure at a mean follow-up of 32 +/- 53 months. CONCLUSIONS: These results demonstrate that in patients with end-stage renal disease, use of mechanical valves is associated with significant risk of complications, whereas biological valve failure from prosthetic dysfunction is unusual. Overall survival is poor in both groups of patients. Therefore, preference should be given to biological valve instead of mechanical valve prostheses in patients on chronic renal dialysis.

Analysis of myocardial function in orthotopic cardiac allografts after prolonged storage in UW solution.

The need for a better organ preservative solution in heart transplantation is clear. At the same time, newer techniques in the assessment of cardiac function in the laboratory have made accurate load-independent quantification of myocardial preservation possible. Therefore a study was undertaken to evaluate left ventricular function in transplanted hearts after 14 hours of preservation in the intracellular lactobionate solution. Nine dogs were instrumented with ultrasonic dimension transducers, to measure left ventricular epicardial volume, and with micromanometers, to measure left ventricular pressure. Left ventricular wall volumes were determined from epicardial echocardiograms. To define the extent of organ injury resulting from the transplant procedure and cardiopulmonary bypass alone, four other animals were instrumented in a similar fashion, and left ventricular function was assessed after standard cardioplegic arrest and transplantation. The transplant procedures were performed with a warm ischemic period of 0.75 +/- 0.2 hours. In all experiments, data were collected before graft harvest and 1 hour after separation from cardiopulmonary bypass. Standard cardioplegic arrest and 2.4 +/- 0.1 hours of ischemia resulted in a decrease in left ventricular ejection fraction from 0.43 +/- 0.04 to 0.27 +/- 0.1 (37%) (p less than 0.01), a decrease in the slope of the stroke work/end-diastolic volume relationship from 15.4 +/- 7.9 to 7.9 +/- 2.0 erg X 10(4) (49%; p less than 0.01), and a decrease in the myocardial power output from 19.7 +/- 10.9 to 5.9 +/- 1.9 (70%; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)