FREQUENCY OF PROSTHETIC VALVE-RELATED COMPLICATIONS WITH VERY-LOW LEVEL WARFARIN ANTICOAGULATION COMBINED WITH DIPYRIDAMOLE AFTER VALVE-REPLACEMENT USING ST-JUDE MEDICAL PROSTHESES

The safety of a very low level of anticoagulation combined with dipyri damole in a rheumatic population (mean age 31 +/- 13 years) with ihe S t. Jude Medical (SJM) prosthesis has not yet been tested. Furthermore, no data are available on the safety of relatively infrequent monitori ng of anticoagulation levels and of the necessity for different therap eutic targets according to valve position, number of risk factors, and other base line risk factors for thromboembolism. In this study, the performance of the SIM prosthesis was tested using a target internatio nal normalized ratio (INR) of 2.0 to 2.5 combined with dipyridamole 30 0 mg/day applied uniformly to all patients. Clinical, biochemical, and echocardiographic data were acquired prospectively in 200 consecutive patients at 3-month intervals. Follow-up (mean 27 +/- 13 months) was complete in 95% of patients. Thirteen patients died (2.9%/patient year ). Severe left ventricular dysfunction was the cause of death in 10 of 13 patients. Probability of survival (Kaplan-Meier) was 0.92 at 36 mo nths and of event free survival 0.84 at 36 months. The median INR was 2.0 +/- 0.9. Valve obstruction did not occur, and there were 3 thrombo embolic events (0.6%/patient year). Incidence of bleeding was 1.6%/pat ient year (n = 7) and was major (hemorrhagic stroke) in 1 (0.2%/patien t year). Thus, the SJM prosthesis performs very well despite the use o f very low level warfarin anticoagulation combined with dipyridamole. A 3-month assessment of the anticoagulation level is safe. Left ventri cular dysfunction rather than valve-related complications is the leadi ng cause of mortality in this population.