Sleep Apnea Adds to Risk of Appropriate ICD Shock, Pacing in Heart Failure

Marlene Busko

March 03, 2017

CHARLOTTESVILLE, VA — Patients with heart failure and a reduced ejection fraction who also had sleep-disordered breathing (SDB) showed a 50% increased risk of receiving appropriate ICD therapy, either shocks or pacing, compared with patients without SDB, in a new meta-analysis[1].

The risk was similarly increased for obstructive sleep apnea and central sleep apnea in the analysis encompassing nine studies with a median follow-up time of 22 months.

"These findings infer that SDB may be associated with an increased risk of potentially life-threatening arrhythmias in patients with heart failure," Dr Younghoon Kwon (University of Virginia, Charlottesville) and colleagues write in an article published February 17, 2017 in Circulation: Arrhythmia and Electrophysiology.

Because patients with heart failure commonly have sleep-disordered breathing, these findings "may justify screening for SDB in patients with heart failure undergoing ICD implantation," they write.

However, it's unclear whether treating SDB with, for example, continuous positive airway pressure therapy might reduce the risk of appropriate ICD therapy in patients with heart failure.

SDB in Heart Failure: Common, Potentially Deadly

An estimated 50% to 70% of patients with heart failure have SDB, which is associated with increased cardiovascular mortality, Kwon and colleagues observe. They note that several small, single-center studies used data from ICD interrogation to explore the impact of SDB on the incidence of ventricular arrhythmia in heart failure, with mixed results.

Thus Kwon and colleagues performed a meta-analysis of nine prospective cohort studies conducted between 1999 and 2013 in Germany, Italy, Japan, Israel, and the United Kingdom that compared appropriate ICD shocks or pacing in patients with and without SDB.

The nine studies entered 22 to 255 patients, including 658 with and 616 without SDB, followed for 6 months to 4 years (median 22 months). The proportion of patients in either NYHA class 3 or 4 ranged from one-fourth to three-fourths.

In a pooled analysis, patients who had SDB had a 45% risk of an ICD shock during follow-up, whereas patients without SDB only had a 28% risk (relative risk [RR] 1.55; 95% CI 1.32–1.83).

The increased risk of ventricular arrhythmia among patients with vs without SDB was similar for patients with central sleep apnea (RR 1.50, 95% CI 1.11–2.02; I2=47.2%) or obstructive sleep apnea (RR 1.43, 95% CI 1.01–2.03; I2=0%).

Past Research

The recent Treatment of SDB With Predominant CSA by Adaptive Servo Ventilation in Patients With Heart Failure (SERVE-HF) trial, in which patients with heart failure and central sleep apnea were randomized to receive or not receive adaptive servo-ventilation (ASV, a form of continuous positive airway pressure therapy)—which was not included in the current meta-analysis because it did not include a comparator group with no SDB—unexpectedly found increased all-cause and cardiovascular mortality with this therapy.

Similarly, the recent Sleep Apnea Cardiovascular Endpoints (SAVE) trial failed to show a reduction in cardiovascular events from adding continuous positive airway pressure to usual care in patients with moderate-to-severe obstructive sleep apnea and established cardiovascular disease.

"Future studies should investigate the therapeutic implications of SDB in heart failure patients in the prevention of appropriate ICD therapy and in the context of overall outcome," Kwon and colleagues write.

This research was partly funded by the National Institutes of Health. The authors report no relevant financial relationships.

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