Resting echocardiographic parameters to detect patients with less symptomatic primary mitral regurgitation who require exercise stress echocardiography.

Objectives: We aimed to identify which resting echocardiographic parameters can detect asymptomatic or mildly symptomatic patients with primary mitral regurgitation (MR) who require exercise stress echocardiography (ESE) to determine their suitability for surgery.

Methods: We examined 56 consecutive patients with primary moderate/severe MR who underwent ergometer-based ESE. Patients who met the surgical indications at rest were excluded. Eligible patients were divided into Group I (pulmonary artery systolic pressure [PASP] during exercise >60 mmHg; n=11) and Group II (PASP during exercise ≤60 mmHg; n=30).

Results: Forty-one patients were included. Group I was significantly older (65±12 vs. 54±14 years, P=0.042) and had significantly higher serum N-terminal pro-B-type natriuretic peptide concentrations than Group II (351±278 vs. 125±163 pg/mL, P=0.002). The univariate analysis demonstrated that peak E wave velocity (Group I vs. Group II: 125±45 vs. 101±24 cm/sec, P=0.050), left ventricular (LV) end-diastolic diameter index (32±4 vs. 30±3 mm/m², P=0.035), and left atrial volume index (LAVI; 45±14 vs. 30±11 mL/m², P=0.008) were predictors of increased PASP during exercise. In the multivariate analysis, resting LAVI best predicted exercise-induced pulmonary hypertension (hazard ratio 1.081 [95% confidence interval 1.009-1.158], P=0.028), with a cutoff value of 37 mL/m².

Conclusions: In asymptomatic or mildly symptomatic patients with primary moderate/severe MR, increased resting LAVI indicates the requirement for ESE, even without LV dilatation.