Long-term outcome of patients with heart failure and dynamic functional mitral regurgitation

Abstract

AIMS: In patients with heart failure and chronic ischaemic mitral regurgitation (MR), the mortality risk is related to the quantified severity of MR at rest and its dynamic changes during exercise. The impact of dynamic MR on long-term mortality, hospital admission for heart failure, and major adverse cardiac events has never been investigated. METHODS AND RESULTS: We prospectively studied 161 patients with chronic ischaemic left ventricular (LV) dysfunction and at least mild MR who underwent quantitative measurement of the effective regurgitant orifice (ERO) of MR at rest and during semi-supine exercise test and who were followed up for 35+/-11 months. The 20 patients who underwent surgery were censored at the time of operation. Of the 141 patients who were treated medically, 23 died, 22 required hospitalization for heart failure, 4 had nonfatal myocardial infarction, and 11 developed unstable angina. By multivariate analysis, an exercise-induced increase in ERO by > or =13 mm(2) and a greater increase in transtricuspid pressure gradient during exercise emerged as predictors of mortality and of hospital admission for heart failure. MR severity under basal conditions (ERO> or =20 mm(2)) was an independent predictor of only cardiac death. Greater LV volumes at rest and lack of contractile reserve during exercise were additional independent markers of poor outcome. CONCLUSION: In patients with ischaemic heart disease and LV dysfunction, large exercise-induced increases in MR identify patients at high risk of morbidity and of death.