Influence of prosthesis-patient mismatch on exercise-induced arrhythmias: A further aspect after aortic valve replacement

Objectives: The influence of prosthesis-patient mismatch on outcome after aortic valve replacement is controversial. This study analyzed the impact of prosthesis-patient mismatch on survival, the extent of left ventricular mass, and physical capacity after replacement with a small-size prosthesis. Patients and Methods: A total of 157 patients who underwent valve replacement for pure aortic stenosis were reviewed. Late mortality, morbidity, left ventricular mass regression, transprosthetic gradient at rest and after exercise, exercise capacity, and occurrence of arrhythmias were evaluated. Results: Prosthesis-patient mismatch, defined as an indexed effective orifice area of 0.75 cm(2)/m(2) or more, occurred in 96 (61.1%) patients and had no significant impact on early and late mortality. The only independent predictor of mortality was age greater than 65 years. At follow-up, multivariate analysis of prosthetic gradient at rest of 35 mm Hg end exercise capacity or more revealed that both these evidences were associated with high left ventricular mass (P < .001), female gender (P < .001), and follow-up time (P< .001). Arrhythmias occurred during exercise in 34.1% of patients (40/117). Multivariate analysis of occurrence of arrhythmias revealed that they were associated with high mean transprosthetic gradients: values of 50 mm Hg or more during exercise had 95% sensitivity and 72% specificity for predicting arrhythmias. Conclusion: Prosthesis-patient mismatch failed to demonstrate any significant impact on early and late mortality and morbidity and in left ventricular mass regression. High transprosthetic gradients influence exercise capacity and occurrence of arrhythmias.