Glenn W. Laub

Aprotinin for coronary bypass operations: Efficacy, safety, and influence on early saphenous vein graft patency. A multicenter, randomized, double- blind, placebo-controlled study

The purpose of this study was to evaluate the efficacy and safety of aprotinin in a U.S. population of patients undergoing coronary artery bypass grafting. Early vein graft patency rates were assessed by ultrafast computed tomography. A total of 216 patients at five centers were randomized to receive either high-dose aprotinin or placebo during the operation; 151 patients underwent primary operation, and 65 underwent repeat procedures. Total blood product exposures in the primary group were 2.2 per patient receiving aprotinin as compared with 5.7 per patient receiving placebo (p = 0.010). The repeat group had 0.3 exposures per patient receiving aprotinin as compared with 10.7 per patient receiving placebo (p = < 0.001). Consistent reductions in the percent of patients requiring donor red blood cells and in the number of units of platelets, fresh frozen plasma, and cryoprecipitate required were associated with the use of aprotinin in both primary and repeat groups. Mortality was 5.6% in the aprotinin group and 3.7% in the placebo group (p = 0.517). In the primary group, clinical diagnoses of myocardial infarction were made in 8.9% of patients receiving aprotinin as compared with 5.6% of the patients receiving placebo (p = 0.435). In the repeat group, infarctions occurred in 10.3% of patients receiving aprotinin and 8.3% of patients receiving placebo (p = 1.000). Secondary analysis of electrocardiograms and available enzyme data showed no significant difference in infarction rates between the treatment groups. There was no difference in clinically significant renal dysfunction. The early vein graft patency rates were 92.0% in the aprotinin group and 95.1% in the placebo group (p = 0.248). In this study, aprotinin was effective in reducing bleeding and blood product transfusion rates, and its use was not associated with an increase in complications. An adverse effect on early vein graft patency rates was not demonstrated, but the number of grafts assessed was insufficient for absolute conclusions in this regard.

Coronary Artery Bypass Grafting in Patients with Chronic Congestive Heart Failure: A 10‐Year Experience with 203 Patients

Abstract From 1983 to 1992, 203 patients with chronic congestive heart failure and no angina underwent primary coronary artery bypass. This represented 3% of patients undergoing coronary artery bypass grafting. Ninety‐two percent of the patients were in New York Heart Association (NYHA) functional class III or IV prior to undergoing coronary artery bypass grafting. Thallium perfusion imaging was performed in 21% of the patients, with a reversible defect present in 88%. An internal mammary artery graft was used in 70% of the patients. The hospital mortality was 6.0% and the actuarial survival at 5 years was 59%. An improvement in NYHA functional class occurred in 75% of the surviving patients with a mean improvement of 1.6 ± 0.6 functional classes. Univariate analysis identifed risk factors for hospital death as emergency operation, recent myocardial infarction (< 30 days), and the need for an intra‐aortic balloon pump. A trend emerged for nonuse of an internal mammary artery to predict hospital death. A positive thallium perfusion scan was not a predictor of early or late survival, nor did it influence NYHA functional class. The use of the internal mammary artery signifcantly enhanced late survival (p = 0.01), however, did not affect the functional class of survivors. We conclude that coronary artery bypass grafting is effective in ameliorating symptoms of chronic congestive heart failure in patients suffering from chronic ischemic cardiomyopathy and can be performed with acceptabie early and late mortality.

Perioperative risk factors affecting hospital stay and hospital costs in open heart surgery for patients≥65 years old

OBJECTIVE Demographic changes, associated with increased demands for open heart surgery in the elderly, place increased burden on financial resources. To evaluate perioperative risk factors affecting incidence of hospital events and estimation of hospital charges, 2577 patients > or = 65 years (range 65-91), operated on from January 1991 to December 1994, were compared with a concurrent cohort of 2642 younger patients. METHODS Statistical analysis, by surgical procedure, focused on hospital mortality, key postoperative complications affecting length of hospital stay and hospital charges. RESULTS Overall hospital mortality was 4.7%, 3.5% in younger patients versus 6.1% in the older group (P << 0.01). Mortality was significantly lower in patients less than 65 years undergoing coronary artery bypass grafting (3% versus 5%, P < 0.01) and valve replacement (4% versus 9%, P = 0.01). Significant risk factors for hospital death in the elderly: diabetes (P < 0.01), hypertension (P < 0.01), myocardial infarction (P < 0.01) and congestive heart failure (P < 0.01). Significant postoperative events, more common in older patients, included prolonged ventilation (P << 0.01), congestive heart failure (P << 0.01), infection (P << 0.01), cerebrovascular accident (P < 0.01), and intra aortic balloon pump (P < 0.01). Incremental risk factors for morbidity in the elderly were: higher New York Heart Association class, congestive heart failure, emergent operation, and female gender. Mean length of hospital stay for the < 65 group was 15.3 versus > 19.5 days for the > 65 group (P << 0.01). Length of stay over 18 days positively correlated with increased morbidity in both age groups. For patients > or = 65 years of age, the average hospital charge for open heart surgery was 172% higher for patients with a length of stay greater than 18 days compared with 165% for patients less than 65 years of age. CONCLUSIONS Higher operative mortality and longer length of stay in elderly patients, resulting in increased health care costs, was associated with more co-morbidities. These results suggest interventions designed to reduce congestive heart failure and other co-morbidities may improve patients recovery and reduce costs.

Perioperative events in patients with failed mechanical and bioprosthetic valves

From 1963 through 1991, 1037 patients underwent reoperative valvular procedures. The 478 patients having reoperations for either failed bioprosthetic (n = 212) or mechanical (n = 266) valves were evaluated. There were 210 male (44%) and 268 female (56%) patients. The mean age at reoperation of the patients in the bioprosthesis group was 59.7 years and and that in the mechanical valve group was 56.1 years (p = 0.0006). The mean interval to the time of reoperation was 84.7 months in the mechanical valve group and 74 months in the bioprosthesis group. There was no difference between the two groups in the functional class at reoperation. More severe mitral valve stenosis and incompetence, more severe aortic valve stenosis, and higher right ventricular and pulmonary arterial pressures were noted in the bioprosthesis group than in the mechanical valve group. Hemolysis (p = 0.05) was more prevalent in the patients with mechanical valves than in the ones with bioprostheses. A longer aortic occlusion time (p = 0.0001) and longer cardiopulmonary bypass time (p = 0.0001) were required for the reoperations in the bioprosthesis group. The operative mortality was 13.2% for the bioprosthesis patients and 12.4% for the mechanical valve patients. The risk factors for hospital death included the cross-clamp time (p = 0.0001), the functional class (p = 0.00001), the presence of ascites (p = 0.02), hepatomegaly (p = 0.002), and decreasing ejection fraction (p = 0.05). We conclude that mechanical valve failures do not produce catastrophic events resulting in poor reoperative results.

Actuarial survival and other events following valve surgery in octogenarians : comparison with an age-, sex-, and race-matched population

From January 1973 to December 1989, 54 patients over 80 years of age underwent an intracardiac repair which included a cardiac valve operation. There were 21 males and 33 females. Mean age at operation was 82 years, range 80-89 years. Fifty-two patients (96%) were in New York Heart Association functional class III or IV preoperatively. Six patients had undergone previous valve surgery (11%). There were eight hospital deaths (14.8%). Risk factors for hospital death included older age at repair (p = 0.008), increased total cardiopulmonary bypass time (p = 0.06), and, possibly, smaller aortic valve prosthesis (p = 0.10). All 46 hospital survivors were followed up at a mean of 28.8 months after hospital discharge. There were 11 late deaths (23.9%), occurring at a mean of 32.3 months postoperatively. Survival analysis indicated that increased age (p = 0.06) and increased pulmonary artery diastolic pressure preoperatively (p less than 0.07) were multivariate risk factors for overall mortality. Actuarial survival at 5 years was 44%, with no difference from survival in an age-, sex-, and race-matched population. We conclude that octogenarians in the modern era have good chance for survival following valvular surgery. As hazards for full anticoagulation were low in this series, if valve repair is not feasible, we presently recommend the use of mechanical valves in the elderly to reduce the requirement for late reoperation due to bioprosthesis degeneration.

Valve-related events and valve-related mortality in 340 mitral valve repairs. A late phase follow-up study.

To assess the early and late valve-related events, 340 consecutive patients undergoing mitral valve repair from 1969 to 1988 were evaluated. Follow-up was complete, with a mean of 7.5% years and range from 2 to 22 years (cumulative 2456 patient-years). There were 221 (65%) female patients. Rheumatic valvular disease was present in 246 (68%) patients. The remaining patients had ischemic or congenital valve disease, floppy valve or infective endocarditis. At surgery, 47% of the patients had pure mitral incompetence, 43% had mixed mitral stenosis and incompetence and 10% had predominant mitral stenosis. Seventy-three percent of the patients were in functional class III or IV. Twelve percent had had prior heart surgery. Concomitant valve procedures including coronary revascularization were performed in 62.3%. There were 23 hospital deaths (6.8%) but only 3 of these (0.8%) were valve-related in patients who died at reoperation for valve repair failure. There were 4 other early repair failures who survived early reoperation. Of the 317 hospital survivors, there were 127 late deaths, and an actuarial survival of 44 +/- 3.7% (70% CL) at 14 years. Of these, 13 were valve-related or 0.5% patient-year. Late events included thromboembolism (TE) 1% patient-year, anticoagulant bleeding 0.4% patient-year, infective endocarditis (IE) 0.2% patient-year and late reoperation for mitral valve repair failure in 63 patients or 2.8% patient-year. At the late follow-up, 88% of the hospital survivors were in functional class I or II.(ABSTRACT TRUNCATED AT 250 WORDS)

Tracheal Homograft as Aortic Conduit: Early Phase Results

The aim of this study was to evaluate the performance of tracheal homografts as aortic conduits. Fourteen tracheal grafts freshly procured from rats were preserved by the following two methods: cryopreservation (n = 6) and treatment with glutaraldehyde 0.2 % (n = 8). The explanted tracheae were stored for ten to twenty days prior to implantation. They were subsequently implanted into the infrarenal aorta of the recipient rats. The average length replaced was 1 to 1.5 cm. The grafts were then evaluated after a period of one (n = 6, 2 cryopreserved, 4 gluteraldehyde), two (n = 4, 2 cryopreserved, 2 glutaraldehyde), and three (n = 4, 2 cryopreserved, 2 gluteraldehyde) weeks for their performance, morphol ogy, and histopathology. The rats did well postoperatively with adequate distal perfusion. Two of the 6 rats with cryopreserved grafts had reduced flow as evidenced by lack of pulsation in the aorta distal to the graft, and histologic examination revealed incompletely occluding thrombus adherent to the luminal surface. The remaining cyropreserved and glutaraldehyde-fixed grafts had good flow and did not show any radiologic evidence of narrowing at the site of anastomosis or in the region of the graft. Histopathologic examination showed that the glutaraldehyde-treated homografts had better morphology, intact carti lage, and no or mild inflammatory response. The cryopreserved tracheal homo grafts showed degenerative changes in the cartilage. The inflammatory response was moderate, and the mucosa was either ruptured or absent. In the 2 that had reduced flow, there was marked cartilage necrosis and inflammatory response with thrombus formation in the lumen. This early phase study shows that tracheal homografts functioned well as conduits in the aortic position and gluaraldehyde treated homografts have better morphology than cryopreserved homografts.

Aortic valve disruption after percutaneous aortic balloon valvoplasty

Severe disruption of the aortic valve cusps in patients with aortic valve stenosis can occur during percutaneous aortic balloon valvoplasty. We report such a case treated successfully by aortic valve replacement.

Experimental Use of Fluorescein for Visualization of Coronary Arteries

Intraoperative delineation of the coronary anatomy during coronary bypass operations is critical for suc cessful revascularization. Two tech niques utilizing fluorescein to en hance the visualization of the coro nary arteries were evaluated in a ca nine model. A previously described method using fluorescent cardiople gia to arrest the heart produced sub- optimal contrast. Excellent visualiza tion of the coronary circulation was obtained when the heart was arrested with crystalline cardioplegia and then reinjected with fluorescein cardiople gia.