Activated rate-response is associated with increased mortality risk in cardiac device carriers with acute heart failure

TL;DR

Patients with heart devices using R-mode stimulation had higher 12-month mortality risk after acute heart failure, suggesting this setting may worsen outcomes.

Contribution

Shows R-mode stimulation in cardiac devices is linked to higher mortality in acute heart failure patients.

Findings

CIED-R patients had a 2.44x higher 12-month mortality risk compared to CIED-0 patients.

R-mode activation was associated with 2.61x higher mortality risk compared to no-CIED patients.

Mortality risk was similar in CIED-R patients with pacemakers or ICDs and across LVEF subgroups.

Abstract

This study investigated whether an activated R-mode in patients carrying a cardiac implantable electronic device (CIED) is associated with worse prognosis during and after an episode of acutely decompensated heart failure (AHF).

Six hundred and twenty-three patients participating in an ongoing prospective cohort study that phenotypes and follows patients admitted for AHF were studied. We compared CIED carriers with activated R-mode stimulation (CIED-R) to CIED carriers not in R-mode (CIED-0) and patients without CIEDs (no-CIED). The independent impact of R-mode activation on 12-month all-cause death was examined using uni- and multivariable Cox proportional hazards regression taking into account potential confounders, and hazard ratios (HR) with their 95% confidence intervals (CI) were reported.

Mean heart rate on admission was lower in CIED-R (n = 37, 16% women) vs. CIED-0 (n = 64, 23% women) or no-CIED (n = 511, 43% women): 70 bpm vs. 80 bpm or 82 bpm; both p<0.001. In-hospital mortality was similar across groups, but age- and sex-adjusted all-cause 12-month mortality risk was differentially affected by R-mode activation; CIED-R vs. CIED-0: HR 2.44, 95%CI 1.25–4.74; CIED-R vs. no-CIED: HR 2.61, 95%CI 1.59–4.29. These effects persisted after multivariable adjustment for potential confounders. Within CIED-R, mortality risk was similar in patients with pacemakers vs. ICDs and in subgroups with left ventricular ejection fraction (LVEF) <50% vs. ≥50%.

In patients admitted with AHF, R-mode stimulation was associated with a significantly increased 12-month mortality risk. Our findings shed new light on “admission heart rate” as a potentially treatable target in AHF. Our data are compatible with the concept that chronotropic incompetence contributes to an adverse outcome in these patients and may not be adequately treated through accelerometer-based R-mode stimulation.

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