July 8, 2021Circulation JournalOpen Access

Prognostic Implications of Reductions in Heart Rates in Patients With Acute Heart Failure and Atrial Fibrillation

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Why the study?

Heart rate changes significantly over time in acute heart failure, but the prognostic association of heart rate changes in patients with atrial fibrillation is uncertain.

Does a greater percentage heart rate reduction within 48 hours of admission improve 60-day mortality in patients with acute heart failure and atrial fibrillation?

Structured PICO

Does a greater percentage heart rate reduction within 48 hours of admission improve 60-day mortality in patients with acute heart failure and atrial fibrillation?

Population

468 patients with acute heart failure (AHF) and confirmed atrial fibrillation (AF) at both admission and 48 hours after admission, mean age 78±12 years, 51.2% male, mean LVEF 48±16%, from a prospective multicenter registry in Japan (REALITY-AHF). Excluded: acute coronary syndrome, acute myocarditis, and patients showing rhythms other than AF at baseline or 48 hours.

Intervention

Percentage heart rate (%HR) reduction achieved within 48 hours of admission (calculated as [baseline HR - HR at 48 h] / baseline HR × 100).

Comparator

Patients stratified by tertiles of %HR reduction (T1: 25.5–65.8% reduction; T2: 9.4–25.4% reduction; T3: -97.6% to 9.0% reduction).

Outcome

60-day all-cause mortalityhard clinical

In patients with acute heart failure and atrial fibrillation, a greater reduction in heart rate within the first 48 hours of admission is associated with significantly lower 60-day mortality.

Limitations

Heart rate evaluated only at 4 time points, which may have been insufficient to capture precise data
No data collected on heart rate after discharge
Limited number of events did not allow adjustments for all possible confounders
Could not evaluate the prognostic impact according to the etiology of heart failure
Included only patients hospitalized through the emergency department, limiting generalizability
Unable to determine whether %HR reduction achieved by HR-lowering drugs has the same prognostic impact as spontaneous reduction

Implication

HR reduction within 48 h was associated with lower 60-day mortality in AHF with AF; leaves open whether targeted rate control improves prognosis.

Abstract

BACKGROUND: Atrial fibrillation (AF) is a common arrhythmia in patients with acute heart failure (AHF). Heart rate (HR) also changes significantly over time. However, the association between changes in HR in AF patients and prognosis is uncertain. METHODS AND RESULTS: We investigated the association between HR reduction in AF achieved within 48 h of admission and 60-day mortality in patients with AHF from the REALITY-AHF study. The percentage HR (%HR) reduction was calculated as (baseline HR-HR at 48 h) / baseline HR × 100. The primary endpoint was 60-day all-cause mortality. In 468 patients with confirmed AF at both admission and 48 h after admission, the median HR at these time points was 105±31 and 84±18 beats/min, respectively. The median %HR reduction was 15.4% (interquartile range 2.2-31.4%). During the 60 days of admission, 39 deaths (8.3%) were recorded, and the %HR reduction within 48 h was significantly associated with 60-day mortality in the unadjusted model (hazard ratio [HR] 0.85; 95% confidence interval [CI] 0.77-0.95; P=0.005) and after adjusting for other covariates (HR 0.81; 95% CI 0.68-0.96; P=0.016).Furthermore, the %HR reduction was associated with a significant reduction in 60-day mortality in patients with higher baseline HR. CONCLUSIONS: %HR reduction is associated with a better short-term prognosis in patients with AHF presenting with AF, particularly in those with a rapid ventricular response.