Long-term outcomes with the On-X bileaflet mitral valve: clinical events up to 17 years in 661 patients.

OBJECTIVES: This study reports long-term clinical outcomes-up to 17 years-among patients undergoing mitral valve replacement with the On-X bileaflet mechanical valve. Prior data regarding long-term outcomes with the On-X mitral valve have been limited. METHODS: This retrospective observational study included all patients who underwent mitral valve replacement with the On-X (Standard or Conform-X) valve at 2 major Spanish cardiac surgery centres between 2001 and 2018. The primary study end point was freedom from death. The secondary study end points included surgical mortality and freedom from any valve-related events. Data were obtained from an institutional database, medical records review, direct telephone interviews or the Spanish population registry. Statistical and Kaplan-Meier analyses were performed. RESULTS: A total of 661 patients (mean age 63.1 ± 10.9 years, 63% female) were followed for a mean of 5.6 years (range, 0-17.4 years). Survival at 5, 10 and 15 years was 85%, 71% and 63%, respectively. Surgical mortality was 7.3% (48/661). The linearized rate of global mortality was 1.3% patient-year. Freedom from reoperation was 97%, 95% and 92% at 5, 10 and 15 years, respectively; freedom from anticoagulation-related events was 94%, 89% and 89%, respectively. Multivariable analysis showed that mortality increased with total length of stay, age, smoking history, severe pulmonary hypertension and a permanent pacemaker. Patients who received the On-X 25 -mm valve had decreased long-term survival relative to patients who received other On-X valve sizes, possibly due to underlying risk factors. CONCLUSIONS: Patients in this study showed good long-term survival and freedom from valve-related events.

Outcomes of Aortic Valve Replacement According to Surgical Approach in Intermediate and Low Risk Patients: A Propensity Score Analysis.

BACKGROUND: Previous trials have shown that, among high-risk patients with aortic stenosis, survival rates are similar for transcatheter aortic-valve implantation (TAVI) and surgical aortic valve replacement. The study aimed to compare the outcomes of aortic valve replacement according to the adopted surgical approach in intermediate and low risk patients. METHODS: This is a retrospective, observational, cohort study of prospectively collected data from 421 patients undergoing isolated aortic valve replacement between 2011 and 2015. A multinomial logit propensity score model based on preoperative risk factors was used to match patients 1:1:1 between conventional replacement (CAVR), minimally invasive (MIAVR) and TAVI groups, resulting in 50 matched three cohorts. RESULTS: After multinomial logit propensity score, the three groups were comparable in terms of preoperative characteristics. Mean age and Logistic EuroSCORE I of CAVR, MIAVR and TAVI groups were (84.2±5.1 vs. 82.3±4.8 vs. 85.6±4.9 years; p=0.002) and (11.4±3.6% vs. 8.3±3.4% vs. 15.8±5.4%; p<0.001) respectively. Overall mortality rates were similar for the three patient cohorts at one year. There were no significant differences related to stroke to 30 days. In the TAVI cohort, pacemaker implantation for new-onset total atrioventricular block became necessary in 30% of patients (p<0.001) and 16% of patients had some degree of paravalvular aortic regurgitation, which was more than mild (p<0.001). Total length of stay was shorter in the TAVI group when compared with surgical groups (11.5±5.3 vs. 10.1±6.9 vs 8.5±3.7 days; p=0.023). After discharge, the survival rate follow-up (average follow up: 46.7 months) was 70%, 84% and 72% for three cohorts (log Rank x2=2.40, p=0.3). CONCLUSIONS: In our experience, the three aortic valve replacement approaches offer very good results. Differences in the rate of complications were found between groups. Depending on patient's characteristics the Heart-Team group must offer the best surgical approach for each patient.