The 2017 ACC/AHA Updated Valve Guidelines Regarding Mitral Regurgitation: The Guidelines Get it Right

In a randomized trial comparing mitral-valve repair with mitral-valve replacement in patients with severe ischemic mitral regurgitation, we found no significant difference in the left ventricular end-systolic volume index (LVESVI), survival, or adverse events at 1 year after surgery. However, patients in the repair group had significantly more recurrences of moderate or severe mitral regurgitation. We now report the 2-year outcomes of this trial.

Ischemic mitral regurgitation is associated with a substantial risk of death. Practice guidelines recommend surgery for patients with a severe form of this condition but acknowledge that the supporting evidence for repair or replacement is limited. We randomly assigned 251 patients with severe ischemic mitral regurgitation to undergo either mitral-valve repair or chordal-sparing replacement in order to evaluate efficacy and safety. The primary end point was the left ventricular end-systolic volume index (LVESVI) at 12 months, as assessed with the use of a Wilcoxon rank-sum test in which deaths were categorized below the lowest LVESVI rank. At 12 months, the mean LVESVI among surviving patients was 54.6±25.0 ml per square meter of body-surface area in the repair group and 60.7±31.5 ml per square meter in the replacement group (mean change from baseline, -6.6 and -6.8 ml per square meter, respectively). The rate of death was 14.3% in the repair group and 17.6% in the replacement group (hazard ratio with repair, 0.79; 95% confidence interval, 0.42 to 1.47; P=0.45 by the log-rank test). There was no significant between-group difference in LVESVI after adjustment for death (z score, 1.33; P=0.18). The rate of moderate or severe recurrence of mitral regurgitation at 12 months was higher in the repair group than in the replacement group (32.6% vs. 2.3%, P<0.001). There were no significant between-group differences in the rate of a composite of major adverse cardiac or cerebrovascular events, in functional status, or in quality of life at 12 months. We observed no significant difference in left ventricular reverse remodeling or survival at 12 months between patients who underwent mitral-valve repair and those who underwent mitral-valve replacement. Replacement provided a more durable correction of mitral regurgitation, but there was no significant between-group difference in clinical outcomes. (Funded by the National Institutes of Health and the Canadian Institutes of Health; ClinicalTrials.gov number, NCT00807040.).

Functional mitral regurgitation (FMR) is a common finding in patients with heart failure (HF), but its effect on outcome is still uncertain, mainly because in previous studies sample sizes were relatively small and semiquantitative methods for FMR grading were used. To evaluate the prognostic value of FMR in patients with HF. Patients with HF due to ischaemic and non-ischaemic dilated cardiomyopathy (DCM) were retrospectively recruited. The clinical end point was a composite of all-cause mortality and hospitalisation for worsening HF. FMR was quantitatively determined by measuring vena contracta (VC) or effective regurgitant orifice (ERO) or regurgitant volume (RV). Severe FMR was defined as ERO >0.2 cm(2) or RV >30 ml or VC >0.4 cm. Restrictive mitral filling pattern (RMP) was defined as E-wave deceleration time <140 ms. The study population comprised 1256 patients (mean age 67 ± 11; 78% male) with HF due to DCM: 27% had no FMR, 49% mild to moderate FMR and 24% severe FMR. There was a powerful association between severe FMR and prognosis (HR = 2.0, 95% CI 1.5 to 2.6; p<0.0001) after adjustment of left ventricular ejection fraction and RMP. The independent association of severe FMR with prognosis was confirmed in patients with ischaemic DCM (HR = 2.0, 95% CI 1.4 to 2.7; p<0.0001) and non-ischaemic DCM (HR = 1.9, 95% CI 1.3 to 2.9; p = 0.002). In a large patient population it was shown that a quantitatively defined FMR was strongly associated with the outcome of patients with HF, independently of LV function.