Impact of prosthesis-patient mismatch on exercise capacity in patients after bioprosthetic aortic valve replacement

Objectives: It is presumed that prosthesis-patient mismatch (PPM) influences mortality and regression of left ventricular hypertrophy after aortic valve replacement (AVR). The aim of our study was to determine the impact of PPM on physical ability. Methods: Six months after AVR with a bioprosthesis, stress echocardiography was performed on a bicycle ergometer in 312 patients. Depending on gender, age and weight, the target exercise level for every patient was determined by a reference table. Maximum achieved workload is given as percentage of the target exercise level and termed „relative exercise capacity“. PPM was defined as an effective orifice area index ≤0.85cm 2 /m 2 . Results: PPM was present in 34.3% of the patients. In patients with or without PPM, age (72.5±6.9 vs. 72.7±6.7 years, p=0.806), preoperative ejection fraction (p=0.557) and body surface area (1.85±0.21m 2 vs. 1.84±0.18m 2 , p=0.715) were not significantly different. Male gender was more frequent in patients without PPM (65.4% vs. 45.8%, p=0.001). Patients without PPM achieved 65%±25% relative exercise capacity on the ergometer vs. 57%±24% in patients with PPM (p=0.003). Analysis of variances determined the presence of PPM (p=0.025) as the only parameter influencing the relative exercise capacity, whereas age, gender and preoperative ejection fraction had no significant impact. Conclusion: The present study reveals a significant impact of PPM on physical ability in patients after AVR. Although other factors as training status and comorbidity also influence the achievement of higher exercise levels, our data strengthen the hypothesis that the avoidance of PPM could result in better exercise capacity for patients after AVR.