Pulmonary hypertension after mitral valve surgery

Background Pulmonary hypertension (PH) is predominantly caused by left heart disease. In mitral valve disease, PH is associated with increased mortality and poor prognosis. While generally reported to improve after mitral valve intervention, long-term data on pulmonary artery systolic pressure (PASP) trajectories remain scarce. Purpose This study sought to evaluate the longitudinal changes in PASP after mitral valve intervention and identify clinical and echocardiographic parameters associated with PASP changes over time. Methods This retrospective cohort study included 323 patients who underwent surgical mitral valve intervention at our institution between June 1990 and April 2024, with baseline PH (PASP ≥36 mm Hg). Repeated-measures, mixed-effects linear regression models analysed PASP trajectory over 5 years. A validation cohort of 294 patients from a large regional electronic health database was included. Secondary outcomes included new right ventricular (RV) dysfunction post-surgery and all-cause mortality. Results After surgery, adjusted PASP followed a U-shaped trajectory, decreasing progressively to reach a nadir at 2–3 years (median reduction 17 mm Hg), then progressively increasing in years 4–5. The quadratic term was highly significant (P<0.0001) in both cohorts (Figure 1A - our institution, and Figure 1B - validation cohort). Higher post-operative PASP was associated with higher baseline PASP, older age, female sex, moderate or severe tricuspid regurgitation, and higher mean mitral valve gradient. Latent trajectory analysis (Figure 2) identified four distinct patterns: no or minimal improvement (15.9% and 18.0%, respectively), moderate decline (31.2%), and robust response (34.9%) with subsequent increase (U-shaped pattern). During median follow-up of 8.2 years, PASP (as time-varying covariate) independently predicted RV dysfunction (OR 1.40 per 10 mm Hg, P<0.0001) and mortality (HR 1.19 per 10 mm Hg, P=0.008). Conclusion After mitral valve surgery, PASP demonstrates a biphasic trajectory with initial improvement followed by late deterioration after 2–3 years. This U-shaped pattern suggests that compensatory mechanisms may be exhausted over time or that irreversible pulmonary vascular changes occurred pre-operatively. Latent trajectory analysis revealed distinct PASP trajectories, representing the diverse responses to mitral surgery. Long-term PASP elevation independently predicts RV dysfunction and mortality.