Aortic Valve Replacement: The Influence of Prosthesis-Patient Mismatch for Left Ventricular Remodeling, Cardiac Function and Survival

Sammanfattning: The best valve substitute for aortic valve replacement (AVR) in terms of hemodynamic performance, durability, incidence of complications, and survival remains the subject of much debate. It has been suggested that valve performance is influenced by the potentially modifiable variable prosthesis-patient mismatch (PPM). PPM has been reported to be detrimental for survival and symptom resolution mainly due to the promotion of unfavorable prosthesis hemodynamics with secondary impaired left ventricular remodeling. Nevertheless, an increasing number of studies with various study designs and outcomes present conflicting results. Thus, there is no convincing evidence for PPM’s detrimental effects. The aims of this research were to evaluate the impact of PPM on in-hospital complications and survival, to evaluate whether postoperative heart failure can be detected using brain-type natriuretic peptide (BNP) as a predictive biomarker, to investigate the influence of PPM in bioprostheses with respect to recovery of left ventricular diastolic function and left ventricular mass regression, and to evaluate the influence of prosthesis-patient mismatch on left ventricular remodeling following aortic valve replacement for severe valve insufficiency. The present work demonstrated that PPM was not associated with low cardiac output syndrome, but rather an independent risk factor for a neurological event during the postoperative period after valve replacement. PPM had no impact on either early or late mortality. Postoperative heart failure following AVR was associated with a high early postoperative mortality and was predicted by elevated BNP levels on arrival in the ICU. PPM did not impair left ventricular mass regression or the recovery of diastolic function. Left ventricular remodeling was initiated regardless of preoperative left ventricular ejection fraction or PPM. In conclusion, the clinical relevance and the prevention of PPM seem subordinate and to improve patient outcome, priority should be given to the design of a durable, non-thrombogenic prosthesis permitting easy handling and reducing surgical complexity.