The prognostic value of exercise-induced pulmonary hypertension in asymptomatic patients with primary mitral regurgitation.

Abstract

BACKGROUND\nWe examined whether the early development of exercise-induced pulmonary hypertension (EIPH) and right ventricular dysfunction during exercise stress echocardiography (ESE) may predict clinical deterioration in so-called asymptomatic patients with primary, at least moderate mitral regurgitation (MR).\n\n\nMETHODS\n79 consecutive patients underwent a symptom-limited, graded ESE protocol on semi-supine bicycle at the beginning of the study. During the test, we assessed symptom development, test duration, and the following echocardiographic parameters: MR severity, maximum velocity of the tricuspid regurgitation jet (TR Vmax), pulmonary artery systolic pressure (PASP), and tricuspid annulus systolic excursion (TAPSE). All patients were then followed-up for at least 12 months for clinical end-points (heart failure-related symptoms requiring pharmaceutical therapy, heart failure hospitalization, and/or mitral valve surgery in case of refractory symptoms).\n\n\nRESULTS\nAfter 16 ± 4 months of follow-up, 75 patients completed the study; 26 of them achieved any clinical end-point and were classified as high-risk , while the rest (49 patients) were assigned to the low-risk group. High-risk group showed significantly higher exercise-induced TR Vmax and PASP levels at maximum workload of ESE than low-risk counterparts (p<0.001). Based on receiver operating characteristic analysis, the early (within the first two stages of ESE or up to 50 W) steep rise of calculated PASP ≥51 mmHg (TR Vmax ≥3.4 m/s) had a 92.3% sensitivity and 100% specificity to predict clinical deterioration within the following year. That cut-off value seemed superior predictor than peak value of PASP at the end of ESE. TAPSE levels during ESE did not add prognostic value in our sample.\n\n\nCONCLUSION\nThis is the first study demonstrating that the early development of EIPH has prognostic value in asymptomatic patients with primary at least moderate MR and may become a new valid determinant of mitral valve surgery. Additional larger prospective studies are needed to validate our findings.