Factors determining mitral valve dysfunction in patients who underwent surgical mitral valve replacement with bio-prosthetic valves

Abstract

Abstract Background There is increasing Interest in bio-prosthetic MVD as recent advances in transcatheter MV interventions, but there is limited data. Objectives The aim of this study was to identify the factors determining mitral valve (MV) dysfunction (MVD) in patients who underwent MV replacement with bio-prosthetic valves. Also, we sought to investigate clinical outcomes in patients with bio-prosthetic MVD. Methods A total of 233 patients underwent surgical bio-prosthetic MV replacement between June 1996 and May 2015. Finally, 226 patients (mean age 66.9±11.5 years, 74.3% of women) were analyzed, excluding patients who followed-up for less than 5 years and patients whose baseline or follow-up echocardiography could not be analyzed. Clinical, echocardiographic, and laboratory data were collected early after the surgery and during follow-up. MVD was defined as an increase in mean gradient ≥5 mmHg with leaflet motion limitation and/or newly developed MV regurgitation during follow-up. Clinical outcome was defined as a composite of cardiovascular death, redo MV surgery or intervention, and hospitalization for heart failure. Results During a median of 102.0 months (interquartile range 72.0 to 132.0 months), 65 patients (28.8%) revealed MVD. 8 (12.3%) patients revealed predominant MV obstruction, and 57 (87.7%) showed predominant MV regurgitation. Factors associated with bio-prosthetic MVD by multivariate regression analysis were young age at operation (hazard ratio 0.97, 95% CI 0.95–0.99, p=0.001), end-stage renal disease (hazard ratio 4.29, 95% CI 1.45–12.71, p=0.007), elevated mean diastolic pressure gradient>5.5 mmHg across the bio-prosthetic MV early after operation (hazard ratio 1.86, 95% CI 0.97–3.74, p=0.063) and anemia after operation (hazard ratio 0.84, 95% CI 0.74–0.95, p=0.007). However, the presence of hypertension, dyslipidemia, or porcine bio-prosthesis was not related to the bio-prosthetic MVD. Kaplan-Meier curves revealed significant differences in event-free survivals for the occurrence of bio-prosthetic MVD according to each factor (Figure 1). Patients with bio-prosthetic MVD showed significantly poor clinical outcomes compared with those without bio-prosthetic MVD (event-free survival 43.1% vs. 91.9%, log-rank p<0.001) during the follow-up. Conclusions Young age at operation, end-stage renal disease, elevated mean pressure gradient early after the operation, and anemia after operation were associated with bio-prosthetic MVD in patients who underwent bio-prosthetic MV replacement. Funding Acknowledgement Type of funding sources: None.