Does Mortality Differ Among Patients With Certain Subtypes of Heart Failure?

May 14, 2020

Patients hospitalized due to acute decompensated heart failure have both a higher rate of annual mortality, compared with patients who have chronic ambulatory heart failure, and of dying within 6 months of hospital release.

Nearly 20% of patients hospitalized due to acute decompensated heart failure (ADHF) die each year as a result of the condition, compared with patients who have chronic ambulatory HF, according to a recent study. The risk of death from this type of HF is considered substantial for 10% to 20% of patients within 6 months after their release from a hospital for this condition.

Drilling down to 3 subtypes—HF with reduced ejection fraction (HFrEF), HF with midrange ejection fraction (HFmrEF), and HF with preserved ejection fraction (HFpEF)—a team from Japan looked to uncover if there were apparent distinctions among these subgroups of patients where death rate and mode of death were concerned. Their findings appeared in a recent issue of JAMA Network Open.

The population of 3717 was culled from data already collected through the multicenter prospective cohort Kyoto Congestive Heart Failure registry, on patients discharged after care for ADHF between October 1, 2014, through March 31, 2016, at 19 sites in Japan. Next, follow-up data were collected in October 2017. Lastly, data were analyzed between April 1 and August 31, 2019. The 3 HF subtypes were defined as follows, based on left ventricular ejection fraction (LVEF) at baseline visit (study entry):

  • HFrEF: less than 40%
  • HFmrEF: 40% to 49%
  • HFpEF: 50% or higher

Overall, the mean (SD) patient age was 77.7 (12.0) years, and 55.1% were male. In addition, close to 27% had HF, with mean (SD) systolic and diastolic blood pressures of 116 (18) and 64 (12) mm Hg, respectively. The mean (SD) LVEF was 46.4% (16.2%), and by HF subtype, 37.2% (1383) had HFrEF; 18.9% (703), HFmrEF; and 43.9% (1631), HFpEF. There was also a median follow-up of 470 days (interquartile range, 357-649), and a 1-year follow-up of 96%.

All-cause mortality was shown to not differ significantly among the subtypes, with all totals coming in at less than 25%:

  • HFrEF: 21.6% (95% CI, 19.5%-23.8%)
  • HFmrEF: 22.5% (95% CI, 19.5%-25.7%)
  • HRpEF: 24.0% (95% CI, 22.0%-26.2%; P = .26)

Similar results were seen when rates of cardiovascular-related and sudden cardiac death (SCD) were investigated:

  1. Cardiovascular-related deaths: HFrEF: 14.7% (95% CI, 12.9%-16.6%) HFmrEF: 13.8% (95% CI, 11.4%-16.5%) HRpEF: 13.7% (95% CI, 12.1%-15.4%; P = .71)
  2. Sudden cardiac death: HFrEF: 3.2% (95%CI, 2.4%-4.2%) HFmrEF: 2.0% (95% CI, 1.2%-3.3%) HRpEF: 2.5% (95% CI, 1.8%-3.3%)

What differed were the origins of the HF. Patients with HFrEF had disease that with an ischemic-related origin, while hypertension and atrial fibrillation were more closely linked to HFpEF.

To make progress in more specialized treatment for these patients, the study authors suggest additional studies are needed “to identify a high-risk subset in this population,” as well as a comprehensive understanding of how and why these patients die.

“The incidences of cardiovascular death and sudden cardiac death were comparable among the heart failure subtypes. Use of β-blockers and ACEIs or [angiotensin receptor blockers] was associated with lower mortality in patients with HFpEF and HFmrEF,” they concluded. “Given the nonnegligible incidence of SCD in patients with HFpEF, an additional study appears to be warranted to identify the high-risk subset in this population.”

Reference

Kitai T, Miyakoshi C, Morimoto T, et al. Mode of Death Among Japanese Adults With Heart Failure With Preserved, Midrange, and Reduced Ejection Fraction. JAMA Network Open. 2020;3(5):e204296. doi:10.1001/jamanetworkopen.2020.4296