Objectives .– Functional MR may occur in heart failure with preserved ejection fraction (HFpEF) as elevated left atrial pressure disrupts normal functioning of the mitral valve apparatus. Whether functional MR contributes to pulmonary hypertension (PH) in HFpEF remains unknown.

Material and methods .– Systolic pulmonary artery pressure (sPAP) was assessed using Doppler echocardiography in 70 ambulatory HFpEF patients and 70 hypertensive controls without organic lesions of the mitral valve.

Results .– sPAP and E/e’ were greater in HFpEF patients than in controls (29 ± 8 vs 35 ± 9, P < 0.0001 and 11 ± 5 vs 13 ± 6, P = 0.018 respectively). While none of controls had more than trivial MR, 21 patients with HFpEF had mild to moderate MR (mean mitral ERO, RV and regurgitant fraction 7 ± 3 mm ² , 15 ± 8 mm ² , and 28 ± 14% respectively). After adjusting for E/e’, sPAP remained greater in HFpEF patients than in controls ( P = 0.002). Pulmonary hypertension was significantly more prevalent in HFpEF patients with functional MR than in HFpEF patients without functional MR (62 vs 22%, P = 0.002). Functional MR remained an independent predictor of PH in HFpEF patients ( P = 0.004) after adjustment on E/e’ ratio ( P = 0.022) and LA volume index ( P = 0.025).

Conclusion .– Besides severity of LV diastolic dysfunction, functional MR appears as a key determinant of pulmonary hypertension in HFpEF.