For patients with rheumatic mitral stenosis and pulmonary hypertension (PH) who undergo mitral valve replacement (MVR), proper control of systolic pulmonary arterial pressure (sPAP) and right ventricular systolic pressure (RVSP) may help prevent tricuspid regurgitation progression, according to study results published in the Annals of Thoracic Surgery.
The aim of this retrospective study was to assess the effect of PH on long-term survival and late-onset tricuspid regurgitation in patients with rheumatic mitral stenosis who underwent a MVR. Patients were categorized into either a non-PH cohort with a sPAP ≤50 mm Hg or a PH cohort with a sPAP >50 mm Hg.
Preoperative measurements of systolic, diastolic, and mean arterial pressure were taken after general anesthesia was administered, and a postoperative measurement of pulmonary arterial pressure was taken 48 hours after surgery. Echocardiography was completed preoperatively, postoperatively, and ≥6 months after discharge. Tricuspid regurgitation was visualized using a Doppler technique and categorized as none, mild, moderate, and severe. Patients were followed for 9.6±4 years.
Of the 394 patients included in this study, 322 were categorized into the non-PH cohort and 72 were categorized into the PH cohort. These 2 cohorts differed on mean diastolic pressure gradient, RVSP, tricuspid regurgitation velocity, and systolic, diastolic and mean pulmonary arterial pressure at baseline (P <.001, for all).
Changes from preoperative to postoperative measurements and postoperative measurements for RVSP and pulmonary arterial pressure were significantly higher in the PH cohort when compared with the non-PH cohort (P <.001, for all). At late follow-up, 23.8% of patients in the non-PH cohort and 29.9% of the patients in the PH cohort experienced tricuspid regurgitation progression.
The 10-year survival rate was higher in the non-PH cohort, (90.7% vs 79.7%; P =.043), and the 10-year rate of freedom from tricuspid regurgitation was higher in patients with sPAP reductions (P =.003) and RVSP reductions (P <.001). Cox multivariate analysis indicated that a substantial reduction after surgery in sPAP (hazard ratio [HR] 0.966; 95% CI, 0.942-0.991; P =.008) and RVSP (HR 0.973; 95% CI, 0.960-0.986; P <.001) was found to prevent tricuspid regurgitation progression.
Limitations of this study include potential selection or heterogeneity bias because of the nonrandomized, retrospective study design, the limited number of patients in the PH cohort, the lack of preoperative pulmonary arterial pressures collected, and not accounting for preoperative symptoms of right heart failure or postoperative vasodilator medications.
The researchers concluded that “[a]lthough concomitant PH at MVR is associated with poor long-term survival, adequate sPAP and RVSP reduction can prevent [tricuspid regurgitation] progression even in patients with severe PH preoperatively.”
Kim DJ, Lee S, Joo HC, et al. Effect of pulmonary hypertension on clinical outcomes in patients with rheumatic mitral stenosis [published online June 20, 2019]. Ann Thorac Surg. doi:10.1016/j.athoracsur.2019.05.077