Mitral regurgitation in acute decompensated HF varies by LVEF, race, sex
In acute decompensated HF, moderate or severe mitral regurgitation occurred in nearly half of patients with ejection fraction below 50%, and its overall prevalence in this population varied by race/ethnicity and sex, researchers reported.
According to an analysis of the Atherosclerosis Risk in Communities (ARIC) study published in JACC: Heart Failure, higher severity of mitral regurgitation (MR) was independently associated with 1-year mortality in patients with acute decompensated HF with left ventricular EF less than 50%.
“Our study is the largest to date in the United States that examines MR in acute decompensated HF and provides strong evidence for an independent contribution of MR to increased all-cause 1-year mortality in acute decompensated HF patients with an LVEF < 50%,” Sameer Arora, MD, preventive medicine resident in the division of cardiology at the University of North Carolina School of Medicine in Chapel Hill, and colleagues wrote. “We also report that in acute decompensated HF patients with an LVEF 50%, there is no increased likelihood of all-cause 1-year mortality in those with higher as opposed to lower MR severity. Thereby, we add evidence against a significant prognostic role of MR in acute decompensated HF patients with an LVEF 50%.”
The researchers analyzed 17,931 patients aged at least 55 years from four U.S. communities who were hospitalized with acute decompensated HF. The cohort was stratified by LVEF (49.2% with LVEF < 50%; 50.8% with LVEF 50%).
Mitral regurgitation and LVEF
Moderate or severe MR was prevalent in 44.5% of patients with LVEF less than 50% and 27.5% in those with an LVEF of 50% or more.
Researchers observed that women with acute decompensated HF were more likely to experience moderate or severe MR compared with men, regardless of LVEF (LVEF < 50%: OR = 1.21; 95% CI, 1.11-1.33; LVEF 50%: OR = 1.52; 95% CI, 1.36-1.69).
Among individuals hospitalized with acute decompensated HF and a LVEF of at least 50%, moderate or severe MR was less likely among Black patients compared with white patients (OR = 0.72; 95% CI, 0.64-0.82), but there was no difference between Black and white patients with LVEF less than 50%.
Moreover, greater MR severity was independently associated with increased 1-year mortality among patients with reduced LVEF (OR = 1.3; 95% CI, 1.16-1.45).
The ‘burden’ of mitral regurgitation
In a related editorial, Paul A. Grayburn, MD, cardiologist at Baylor Scott & White Heart and Vascular Hospital in Plano, Texas, discussed some of the echocardiographic limitations of this study.
“The timing of echocardiography in this report from ARIC relative to hospitalization is unknown. The two prior studies of MR in acute decompensated HF reported findings from discharge echocardiograms. Secondary MR is notoriously dynamic and can resolve after intravenous diuresis or inotropes,” Grayburn wrote. “It has not been shown whether mortality differences are present between patients for whom secondary MR does or does not improve with standard therapy for acute decompensated HF, although it seems clinically intuitive that those with persistent severe secondary MR are likely to have a worse prognosis.
“The authors conclude that ‘there was a considerable burden of MR in this sample of acute decompensated HF hospitalizations.’ This is a very interesting term that merits consideration. The authors use the term in an epidemiological sense to reflect the prevalence of moderate/severe secondary MR in acute decompensated HF within the ARIC population. However, the ‘burden’ of disease in an individual patient is contextually different,” Grayburn wrote. “In terms of studies of secondary MR, a single echocardiogram at a given point in time does not define the ‘burden’ of MR. Future studies in secondary MR should consider longitudinal echocardiographic evaluation of secondary MR severity in trying to better understand this complex and dynamic condition such that we can develop optimal strategies for identifying and treating patients who are most likely to benefit from therapies targeted to the mitral valve.”