Mitral regurgitation and dyspnoea: The expanding role of mitral effective regurgitant orifice among un-selected patients

Aims Mitral regurgitation is frequent in the general population and among suspected heart failure patients; however, to what extent it contributes to dyspnoea is unclear. We hypothesized mitral regurgitation to have a role in determining dyspnoea in unselected ambulatory patients. Methods Consecutive outpatients referred for echocardiography were retrospectively screened and included. We excluded patients with mitral stenosis or prosthesis, congenital heart disease, cardiac surgery (previous 6 months) and atrial fibrillation. Patients were classified into four dyspnoea grades based on how they perceived their disability. We assessed mitral regurgitation severity through the effective regurgitant orifice area (ERO). Results One hundred and fifty-four patients (58% men; age 67 +/- 14 years; mean ejection fraction 54 +/- 12%) formed the study population; 76 (49%) classified asymptomatic (grade I), 63 (41%) dyspnoea grade II and 15 (10%) grade III; none was in grade IV. Mitral regurgitation was present in 102 patients (66%): primary in 14 (14%) and secondary in 88 (86%); among grades I, II and III patients, mitral regurgitation was present in 35 (46%; ERO 0.05 +/- 0.10 cm(2)), 52 (82%; ERO 0.10 +/- 0.13 cm(2)) and 15 (100%; ERO 0.20 +/- 0.11 cm(2)) patients, respectively (P < 0.0001). After adjusting for clinical (age, hypertension, ischemic heart disease, chronic kidney injury, chronic pulmonary disease) and echocardiographic confounders (ejection fraction, E/e'), ERO remained associated with symptoms presence (grade I versus II - III;P = 0.01 andP = 0.03, respectively). Conclusion Among unselected heterogeneous ambulatory patients, mitral ERO was associated with the presence of dyspnoea and could therefore help in identifying symptomatic patients and in clinical characterization of patients with perceived dyspnoea.