Embolic complications of porcine heterograft cardiac valves.

From January, 1975, until August, 1978, 509 porcine valves were implanted in 465 patients. Patient follow-up was done at 6 to 45 months (mean 20.2 months), for a total observation of 713 patient-years. There were six early embolic events (mitral four, aortic two). Four of these six patients were in atrial fibrillation and none was receiving anticoagulants at the time of the embolism. There were 18 late emboli. Four occurred in patients with aortic prostheses and produced mild, transient symptoms only. Fourteen occurred in patients with mitral or multiple prostheses. These resulted in death in five patients and permanent sequelae in three. The rate of embolic events was 1.32/100 patient-years for aortic prostheses, 3.27/100 patient-years for mitral prostheses, and 4.91/100 patient-years for multiple prostheses. Thirteen of the 14 patients with emboli were in atrial fibrillation and only three were receiving anticoagulants. Anticoagulation is vital in patients with mitral prostheses who remain in atrial fibrillation, but it appears unnecessary in patients with aortic prostheses and those with mitral or multiple prostheses who remain in sinus rhythm.