Postoperative hemodynamic evaluation of a new fabric-covered ball-valve prosthesis

Previous in vitro and in vivo experimental studies have indicated that insertion of the Braun-wald-Cutter fabric-covered ball-valve prosthesis results in negligible thromboembolic complications and hemodynamic performance comparable to that of noncovered mitral and aortic ball-valve prostheses. To assess the clinical efficacy of this fabric-covered valve prosthesis, 35 patients have been followed for 4 to 26 months (540 patient-months) after mitral and/or aortic valve replacement, and 13 have had extensive hemodynamic re-evaluation.

In eight patients with the mitral valve prosthesis, the mean diastolic gradient averaged 4.8 mm Hg (range 0 to 8) and the end-diastolic gradient 0.8 mm Hg (range 0 to 2) at a time when the mean heart rate was 75 beats/min (range 50 to 100) and the cardiac output averaged 5.1 L/min (range 3.4 to 8.0). The calculated effective mitral valve orifice size averaged 2.68 cm 2 (range 1.92 to 3.46). In six patients with the aortic valve prosthesis, the average peak systolic gradient was 13 mm Hg (range 0 to 22), and the mean systolic gradient averaged 14.5 mm Hg (range 0 to 24) when the mean heart rate was 82 beats/min (range 64 to 120) and the cardiac output averaged 6.2 L/min (range 3.2 to 9.3). The average effective aortic valve size in the five patients with a mean systolic transvalvular gradient was 1.41 cm 2 (range 1.26 to 1.62).

Only one postoperative thromboembolic complication has been observed, and this occurred in a patient with atrial fibrillation and a large left atrium three weeks after discontinuing anticoagulant therapy because of gingival bleeding.

These data indicate that use of the fabric-covered Braunwald-Cutter ball prosthesis produces few thromboembolic complications and a satisfactory hemodynamic result.

Evaluation of anticoagulant therapy in cloth-covered prosthetic valves

Over a period of four years, a series of 303 patients had prosthetic valve replacement with the Starr-Edwards cloth-covered metallic ball prosthesis. There were 135 aortic replacements, 105 mitral, 42 combined mitral and aortic, and 21 combined mitral and tricuspid. The frequency of thromboembolism and hemorrhage was studied in patients receiving warfarin sodium (Coumadin) and in those not receiving warfarin.

No thromboemboli occurred during 2,052 patient-months of observation in patients with aortic prostheses who were receiving warfarin, but 10 episodes of hemorrhage occurred. By comparison, after anticoagulants were discontinued, there was 1 episode of thromboembolism during 786 months of patient observation.

Among patients with mitral prostheses who were receiving warfarin, 3 episodes of thromboembolism occurred in 2,081 patient-months of observation, during which 5 hemorrhagic episodes also occurred. By comparison, after warfarin was discontinued, there were 3 episodes of thromboembolism during 402 months.

In patients with mitral and aortic prostheses who were receiving warfarin, 1 episode of thromboembolism occurred in 670 patient-months, and no episodes of hemorrhage. Without anticoagulation, 2 episodes of thromboembolism occurred in 130 patient-months.

In patients with mitral and tricuspid prostheses who were receiving warfarin, there were no episodes of thromboembolism during 186 patient-months, but there was 1 episode of hemorrhage. Without anticoagulation, however, there were 3 episodes of thromboembolism during 32 months of patient observation.