Differences in heart valve procedures between North American and European centers: A report from the Artificial Valve Endocarditis Reduction Trial (AVERT)

Background and aim of the study: Differences in heart valve procedures between North American (NA) and European (EU) centers were evaluated in a multicenter trial. Methods: Between July 1998 and January 2000, 807 patients from 12 NA (n = 446) and seven EU centers (n = 361) were randomized to receive either Silzone (R) or conventional valves in the Artificial Valve Endocarditis Reduction Trial (AVERT). Subanalysis was performed to compare demographics, patient risk profile, surgical techniques and perioperative management of patients in NA and EU centers. Results: Mean age was significantly younger and body mass index higher in NA. Patients' risk profiles showed significantly higher incidences of previous myocardial infarction, congestive heart failure, angina, prior cardiovascular surgery, and history of smoking in NA. A different distribution of implant position was observed between groups: aortic valve/mitral valve/double valve replacement in 54.0, 35.7 and 10.3% in NA, and 64.5, 27.4 and 8.0% in EU (p <0.01). Concomitant coronary artery bypass grafting was performed in 31.6% of NA patients and 19.4% of EU patients (p <0.001). Timing of surgery showed a higher incidence of urgent procedures in NA centers. Distribution of valve sizes and perioperative complication rate were similar, but length of hospital stay was longer in EU centers. Conclusion: Surprisingly, surgeons in NA and EU centers are faced by different patient populations requiring mechanical heart valve replacement. NA patients were younger, but required more extensive surgery. Surgical technique and perioperative management appear to differ in NA and EU centers. These differences in reporting heart valve procedures might have been influenced by variable interpretations of definitions and different patient expectations, although a uniform study protocol with consistent definitions was used at all sites.