Ventricular assist device support in patients with mechanical heart valves

Background. Due to potential thromboembolic complications, mechanical valve s within the native heart are often considered contraindications to ventric ular assist device (VAD) support. Methods. A retrospective review of VAD cases between June 1982 and March 19 98 showed 8 patients with mechanical valves who were supported with Thorate c (Pleasanton, CA) VADs. Results. There were 6 males and 2 females ranging in age from 20 to 69 year s (mean 49.8 +/- 5.6). Four patients were supported when they could not be weaned from cardiopulmonary bypass after reparative procedures and were tho ught to have reversible injuries. Four patients were supported as a bridge- to-cardiac transplantation. Two patients had mechanical mitral valves, 2 ha d aortic valve replacements, I had an aortic homograft and mechanical mitra l valve, 2 had mechanical aortic and mitral prosthesis, and 1 patient had a ortic, mitral, and triscupid valves. The types of vaIvular prostheses were St Jude (5 patients) and Bjork-Shiley (3 patients). Duration of support ran ged from 3.0 to 150 days (mean 34 days). Four patients were supported with biventricular assist devices and 4 had left VADs. Dextran and intravenous h eparin anticoagulation were used in the shorter duration patients, with war farin being used in the bridge patients. One patient received warfarin and aspirin. At the time of autopsy or device removal, only 1 of the 12 mechani cal intracardiac valves showed any evidence of thrombosis, including the ao rtic valves in 2 patients supported for 2 and 5 months. There were no clini cal thromboembolic events. Four patients (50%) were discharged (1 weaned, 3 transplanted). Conclusions. The 50% (4 of 8) survival rate compares favorably with the 44% (41 of 92) overall survival rate for our Thoratec patients (bridge plus re covery) who did not have mechanical prosthetic valves. These data suggest t hat patients with mechanical intracardiac valves can be supported for short durations with some additional risk, which is yet to be determined. (C) 19 99 by The Society of Thoracic Surgeons.