Incidence and Prevention of Arterial Thromboembolic Complications in Patients With Prosthetic Heart Valves

SUMMARY Early and late arterial thromboembolic complications were evaluated in 253 patients with two types of Starr‐Edwards aortic ball valves on average three years after operation. The incidence is high postoperatively, and in the late course 7.0 episodes were diagnosed per 100 patients per year, 11.1 in patients with the older valve type 1200 and 4.3 with type 2300. The incidence was not reduced by time after operation, and not prevented by adequate anticoagulation. In 196 patients who had received Bjørk‐Shiley or Lillehei‐Kaster disc valves, an equally high early incidence was found. In the late course of implantation the incidence was 5.6 with Bjørk‐Shiley and 6.1 with Lillehei‐Kaster valves. Valve thrombosis with impaired disc movement represented a particularly serious complication for disc valve patients, occurring in four and causing two deaths. In a randomized, prospective double‐blind study 148 patients received either one gm. ASA daily in combination with anticoagulants, or anticoagulants and placebo. In the placebo group, 12 arterial thromboembolic complications occurred in 10 patients, causing three deaths. In the combined group only two slight episodes occurred. Even if the incidence of gastrointestinal bleeding was higher when ASA was used, the much better protection against serious thromboembolic complications makes this an acceptable price to pay. ASA alone was tested in a pilot study in 77 patients for six months, and had a poor preventive effect in patients with fibrillation, but is possible as an alternative to anticoagulation in some patients with sinus rhythm. Arterial thromboembolism represents a serious problem in patients with prosthetic heart valves 0). The thrombi that usually form on the valve itself may disturb valve function (1) and give rise to cerebral emboli (1). While improvement in design has produced valves with very good hemodynamic function arterial thromboembolic complications represent unresolved problems. Therefore the thrombogenic properties constitute a main determinant for valve selction, and evaluation and research in prevention of thromboembolism are important.