Influence of prosthesis – patient mismatch on long-term results in patients after aortic valve replacement with a biological prosthesis: retrospective single center study

Background. Despite numerous studies, ambiguity remains at present regarding the impact of prosthesis-patient mismatch (PPM) on long-term outcomes after aortic valve (AV) replacement. Objective. This study evaluates the effect of PPM on long-term results in patients after AV replacement with a biological prosthesis. Material and methods. We retrospectively analyzed the data of 231 patients who underwent AV replacement with a biological prosthesis from 2010 to 2018 at the Penza Federal Center of Cardiovascular Surgery. Patients were implanted with the following biological prostheses: Medtronic Mosaic, Edwards PERIMOUNT, Biocor. Results. Moderate PPM was present in 131 patients (56%), and severe PPM in 1 patient (0.7%). The mean follow-up was 78.832 months. There were no significant differences in hospital mortality in patients with and without PPM, 4 (3%) and 3 (2,9%), respectively, p=0.9. In the long-term period, patients with PPM showed a slower regression of left ventricle (LV) mass and recovery of LV contractile function than patients without PPM, p=0.05. There was no significant difference in survival in the long-term follow-up period between patients with and without PPM long-term survival, 77.7% and 79%, respectively, p=0.6. Also, there were no significant differences in major adverse cardiac events and the freedom from adverse events was 90% and 91%; p=0.7. However, there was a tendency to more frequent hospitalization for chronic heart failure (CHF) exacerbation in the patient group with PPM than in those without PPM, 63.8% and 78%; HR 1.6; 95% CI 0.932.1, p=0.007. There was also a tendency for an increased biological valve structural degeneration in the group with PPM than in the group without PPM 76% and 87%, HR 1.4; 95% CI 1.43.1, p=0.01 According to the Cox regression, the overall postoperative mortality predictors were diabetes mellitus, vascular atherosclerosis HR 5; 95% CI 1.222, p=0.04 and HR 2.9; 95% CI 1.46.6, p=0.01 respectively. Predictors of the risk of hospitalization due to CHF exacerbation were previous myocardial infarction and PPM HR 0.4; 95% CI 0.20.9, p=0.04 and HR 1,5; 95% CI 0.92; p=0.005, respectively PPM HR 2; 95% CI 0.854.1, p=0.01. Conclusion. PPM is a common complication after AV replacement with a biological prosthesis. It is associated with a slower regression of LV mass, an increased risk of structural valve degeneration, and hospitalizations for exacerbated heart failure.