The impact of prosthesis-patient mismatch on long-term survival after aortic valve replacement: a systematic review and meta-analysis of 34 observational studies comprising 27 186 patients with 133 141 patient-years.

Aims: Numerous studies have linked prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR) to adverse outcomes. Its correlation with long-term survival has been described but with contradicting results. This systematic review and meta-analysis of observational studies aims to determine the hazard of PPM after AVR.

Methods And Results: The Medline and EMBase databases were searched for English-language original publications. Two researchers independently screened studies and extracted data. Pooled estimates were obtained by random effects model. Subgroup analyses were performed to detect sources of heterogeneity. The search yielded 348 potentially relevant studies; 34 were included comprising 27 186 patients and 133 141 patient-years. Defined by the universally accredited indexed effective orifice area <0.85 cm(2)/m(2), 44.2% of patients were categorized as having PPM. In 34.2 and 9.8% of patients moderate (0.65-0.85 cm(2)/m(2)) and severe (<0.65 cm(2)/m(2)) PPM was present, respectively. Prosthesis-patient mismatch was associated with a statistically significant increase in all-cause mortality (HR = 1.34, 95% CI: 1.18-1.51), but only a trend to an increase in cardiac-related mortality (HR = 1.51, 95% CI: 0.88-2.60) was recognized. Analysis by severity of PPM demonstrated that both moderate and severe PPM increased all-cause mortality (HR = 1.19, 95% CI: 1.07-1.33 and HR = 1.84, 95% CI: 1.38-2.45) and cardiac-related mortality (HR = 1.32, 95% CI: 1.02-1.71 and HR = 6.46, 95% CI: 2.79-14.97). Further analyses showed a consistent effect over separate time intervals during follow-up.

Conclusion: Prosthesis-patient mismatch is associated with an increase in all-cause and cardiac-related mortality over long-term follow-up. We recommend that current efforts to prevent PPM should receive more emphasis and a widespread acceptance to improve long-term survival after AVR.