Risk-benefit analysis of warfarin therapy in Hancock mitral valve replacement.

The purpose of this investigation was to analyze the thromboembolic and/or major bleeding complications of 124 consecutive but nonrandomized patients who had only mitral valve replacement with the Hancock porcine xenograft between September, 1974 and June, 1979. These patients were treated either with or without anticoagulants. Four basic study groups were created: Group 1, warfarin; Group 2, aspirin; Group 3, no anticoagulants; and Group 4, warfarin and aspirin. Group 5 combined Groups 1 and 4 (warfarin and warfarin plus aspirin) and Group 6 combined Groups 2 and 3 (aspirin and no anticoagulants). The cardiac rhythm, history of embolism, and intraoperative findings of a thrombus in the left atrium were examined as risk factors for later thromboembolism . Follow-up time was 3.03 years (range 2.0 to 4.2 years). The embolic rate was not significantly different in any group (n = NS). In Groups 5 and 6 the embolic rate was 2.97 and 3.25 embolisms per 100 patient-years, respectively. Warfarin therapy resulted in significant major bleeding episodes, including two deaths (p less than 0.05). The number of patients with a history of a previous embolism, the finding of an intraoperative left atrial thrombus, or abnormal cardiac rhythm was insufficient to test embolic risk in the four treatment groups. We conclude that long-term warfarin therapy increases the risk of bleeding complications but may not significantly influence the incidence of thromboembolism arising from the Hancock porcine xenograft mitral valve. Other and larger studies are needed to confirm this last point.

Thrombosis and degeneration of Hancock valves: clinical and pathological findings.

Of 415 Hancock valves implanted in 370 patients, 26 valve specimens were recovered at postmortem examination and 8 at reoperation. In 9 of these 34, thrombosis had formed without apparent alteration of the heterograft tissue (Group A). All were mitral prostheses, and the thrombi were attached to the sewing ring. Six of the patients died in the early postoperative period following prolonged low cardiac output syndrome and coagulation disturbances. Three patients had late valve thrombosis 12 to 26 months after operation and were in chronic atrial fibrillation with a very large left atrium. Four valve specimens (Group B) demonstrated degenerative changes of the heterograft leaflets such as shrinkage, perforation, and calcification. The clinical courses and possible pathogenesis are discussed.

Thromboembolic complications after mitral valve replacement with Hancock xenograft.

Case histories of 140 patients who had mitral valve replacement with the Hancock xenograft were reviewed according to the incidence of thromboembolic complications. There were 16 patients with preoperative and/or postoperative low-output syndrome (Group A.) Eight of these patients died, and six had autopsies which showed major thrombi on the heterograft valve. In 126 long-term survivors (followed 1 to 33 months) nine thromboembolic events occurred (thromboembolic incidence 5.3 percent per patient-year). All patients with emboli were in atrial fibrillation. Additional predisposing factors included a history of systemic emboli and the presence of atrial clots at the time of surgery. The majority (7/9) of emboli occurred during the first 3 postoperative months. Two emboli occurred immediately following the operation (before oral anticoagulation therapy could have been begun). Five occurred in patients who were not on anticoagulation (Group B) and two occurred under warfarin treatment (Group C). There was no thromboembolic event in patients taking aspirin (Group D). It is concluded that hemodynamically stable patients have a decreased risk of thromboembolism and do not require anticoagulation. Patients with atrial fibrillation have an increased thromboembolic risk and should be on a regimen of warfarin for 3 months postoperatively and then on aspirin therapy.

The surgical management of bacterial endocarditis: a review.

A total of 239 surgically treated patients with primary endocarditis were reviewed both from the literature and from our own experience. The age range was 10 to 74 years with a male to female ratio of 3:1. A wide variety of organisms was found. However, as a group, gram positive organisms predominate. The onset of congestive failure was the major indication for surgery. The aortic valve was predominantly involved with the mitral valve running a distant second. The hospital mortality rate was 20% and the late mortality rate was 6.7% with an overall mortality of 26.7%. The prognosis in infective endocarditis when congestive failure develops, even in the presence of antibiotic therapy, is poor (79-89% mortality). In view of this poor prognosis, an aggressive attitude with regard to early surgical intervention can greatly improve the outcome of valvular endocarditis.

Acquired ventricular septal defects. Evolution of an operation, surgical technique, and results.

The pathology and treatment of 19 patients with acquired ventricular septal defects (VSD's) secondary to myocardial infarction are presented. A new method of repair is described: suturing the free right ventricular wall against the VSD to support the friable septum on the right side in continuity with the patch on the left side of the septum. This removes the force of the left ventricle contraction from the patch and septum to the healthy right ventricle wall. Distal cardiac amputation was also used in several instances. The hospital survival rate was 64 per cent. The late functional and hemodynamic results were excellent.