Aims: Significant mitral regurgitation (MR) is an important predictor for all-cause mortality and heart failure (HF) hospitalizations independent of left ventricular ejection fraction (LVEF). The aims of this study were to investigate (i) in how many patients referred to a tertiary outpatient HF clinic HF therapy could be optimized, (ii) the effect of optimized treatment on MR severity, and (iii) whether a reduction in MR resulted in improvement of symptoms.
Methods and results: Forty-seven referred patients with therapy-resistant symptomatic chronic HF with an LVEF <40% and at least moderate MR were analysed on admission and after optimization of HF treatment after 6-18 months. The patients were classified as a volume responder when LV end-systolic volume (LVESV) decreased ≥15%, as LVEF responder when LVEF increased by ≥5% points, as clinical responder when New York Heart Association (NYHA) class improved at least one category, and as MR responder when MR severity improved at least one category to maximally moderate. After 14 ± 4 months of treatment optimization, optimal doses of angiotensin-converting enzyme inhibitors/angiotensin receptor blocker were seen in 18 (38%) patients compared with three (6%) at baseline (P < 0.001), and optimal doses of beta-blockers were seen in 14 (30%) patients compared with four (9%) at baseline (P < 0.001). In total, 68% of the patients were clinical responders, 57% MR responders, 34% volumetric responders, and 49% LVEF responders. NYHA class improved from 2.9 ± 0.6 to 2.0 ± 0.9 (P < 0.001), MR class from 5.2 ± 0.8 to 3.6 ± 1.5 (P < 0.001), LVEF from 24% ± 9% to 31% ± 12% (P < 0.01), and LVESV non-significantly improved. The positive predictive value of MR response to NYHA response was 88%; the negative predictive value was 53%, agreement 69%, and kappa 0.39. The positive predictive value of LVEF response to NYHA response was 76%; the negative predictive value was 44%, agreement 60%, and kappa 0.21. The positive predictive value of LVESV volume response to NYHA response was 75%; the negative predictive value was 39%, agreement 51%, and kappa 0.12.
Conclusions: Although this study was limited by a small number of patients, initiation and up-titration of recommended HF therapy in patients referred to our tertiary HF outpatient clinic resulted in significant MR reduction in over half of the patients, emphasizing the importance of optimal medical treatment in these very sick cardiac patients with otherwise grave prognosis. MR reduction was best correlated to NYHA improvement.
Keywords: Echocardiography; Heart failure; Mitral regurgitation.