Predictors and outcomes of pulmonary hypertension after mitral valve replacement in severe mitral regurgitation

Background The objective of the study was to determine perioperative clinical and echocardiographic factors associated with pulmonary hypertension (PH) during long-term follow-up of patients with severe primary mitral regurgitation (MR) after mitral valve replacement surgery and its prognostic repercussions. Methods Prospective cohort of consecutive patients undergoing mitral valve replacement between January 2005 and January 2015 and followed for ≥3 years. Main exclusion criteria were receipt of mitral repair surgery and the presence of mitral stenosis. The main outcome was a systolic pulmonary pressure (SPAP) by echocardiography >50 mmHg at least 12 months’ post-surgery. Results 106 patients, 46% male, mean age of 61.7±11 yrs. and median follow-up of 8.8 [6- 16] yrs. SPAP was >50 mmHg in 33% of patients. Predictors identified by multivariate analysis were diabetes (OR 8.3, 95%CI 1.1-73.9), persistent atrial fibrillation (OR 4.2, 95%CI 1.1-20.6), non-rheumatic MR (OR 7.3, 95%CI 1.1-45.5), prosthesis gradient, (OR 2.8, 95%CI 1.3-5.7), patient-prosthesis mismatch (OR 16.9, 95%CI 1.2-234), and preoperative SPAP ≥50 mmHg (OR 19.3, 95%CI 3.4-107). Patients with PH had higher hospitalization (78.8 % vs. 37%, p<0.001) and mortality (72,4% vs. 19,7%, p<0.001) rates. The 10-year survival rate was 83% in patients without PH versus 30% in those with PH (p<0.001). Conclusions Persistent PH is a frequent and serious long-term complication of valve replacement for severe mitral regurgitation. It is associated with a poor prognosis and is related to preoperative pulmonary pressure. Surgery could be considered in candidates for mitral valve replacement with moderate PH, especially in the presence of atrial fibrillation. Clinical perspective What is already known on this topic Pulmonary hypertension is not reversed in an important subset of patients with severe mitral regurgitation after mitral valve replacement surgery and it is associated with a poor prognosis. No prospective study has been published on preoperative factors associated with this condition. The prevalence and prognosis of postoperative PH has not been precisely described. What this study adds Persistent PH after valve replacement for severe mitral regurgitation is common and its prognosis is ominous. Preoperative SPAP ≥50 mmHg and persistent atrial fibrillation are the main predictive factors. The results of this study might affect clinical practice suggesting considering surgery in this population (not only in mitral valve repair) when SPAP ≥50 mmHg, especially if persistent atrial fibrillation.