Treating Sleep Apnea in HF May Cut 30-Day Readmissions

Marlene Busko

October 23, 2014

PHILADELPHIA, PA — Undiagnosed sleep-disordered breathing (SDB) is common in patients hospitalized for heart failure or other heart issues and should be looked for with in-hospital sleep studies in those showing signs of it, according to a small but prospective study[1]. It further suggests that prescribing continuous-positive-airway-pressure (CPAP) therapy after discharge in such patients who test positive for sleep apnea cuts the risk of 30-day readmission, at least among those who comply fully with CPAP therapy.

The study was publish in the October 2014 issue of the Journal of Clinical Sleep Medicine.

Using a portable sleep monitor, the researchers identified sleep-disordered breathing in 79% of patients with HF, arrhythmias, or acute MI who had not been diagnosed with sleep apnea but showed SDB symptoms, such as snoring. Of the 19 patients discharged with a CPAP machine and confirmed to be fully compliant, none were readmitted within a month. That compared with a readmission rate of 29% for the 17 discharged with the machine who didn't use it. A group that used CPAP only some of the time didn't fare much better.

"The study highlights that sleep apnea is a prominent disorder in hospitalized patients with cardiac disease, specifically heart failure and atrial fibrillation, and diagnosing and treating it can help in their overall health," lead author Dr Shilpa R Kauta (University of Pennsylvania, Philadelphia, PA) told heartwire .

Type 3 Sleep Studies

Kauta et al identified 106 patients who were admitted to the cardiac-care unit at their center with SDB symptoms. Their mean age was 59, with an average body-mass index (BMI) of 34; 62.5% were male. Most patients had been had been diagnosed with heart failure (87.4%) or atrial fibrillation (47.1%), and a few had been admitted for other causes such as chest pain or MI (7.7%).

Sleep apnea was diagnosed at the bedside using a portable, type 3 sleep monitor, "which means there are no EEG leads on the patient and no sleep technician monitoring the patient," unlike a "classic" sleep study using a type 1 monitor where the patient stays overnight in a sleep laboratory, Kauta explained.

A total of 81 patients had an apnea-hypopnea index of at least five events per hour, indicating they had sleep-disordered breathing.

Fifty of these patients were discharged from the hospital and given an automated CPAP machine and a fitted breathing mask. Most of the other 31 patients either refused treatment or required a more extensive sleep study. Thirty-day data on CPAP use were available for 42 patients:

  • 19 patients used the device, on average, 6.4 hours/night for 28 nights (fully compliant).

  • 20 patients used the device, on average, 5.3 hours/night for 9 nights (partially compliant).

  • Three patients did not use the device.

None of the patients who were fully compliant with the CPAP device were readmitted to the hospital or visited the emergency room for a cardiac issue within 30 days of being discharged. However, 30% of those who were partially compliant and 29% of patients who did not use the device either returned to the ER or were readmitted.

A Randomized Trial Is Under Way

Dr Stephen S Gottlieb (University of Maryland, Baltimore), who wasn't involved in the study, pointed out that the patients with sleep apnea who used their CPAP devices "could very likely be very different from the people who didn't use the devices. They are more likely to be more compliant . . . with their medications, diet, and medical follow-up, so it's very difficult to say that it was the treatment of sleep apnea that led to their improved outcome" of a lower 30-day hospital-readmission rate.

While the benefits of treatment are plausible, the results require confirmation. "There are many physiologic and theoretical reasons to believe that treatment of sleep apnea will be beneficial in patients with heart failure," he said. "However, what the effects of treatment turn out to be needs to be evaluated in a randomized trial."

Similarly, in an accompanying commentary[2], Dr Sumnil Sharma (Thomas Jefferson University and Hospitals, Philadelphia, PA) notes the "lack of data on medication compliance, which may significantly influence readmissions."

"Nonetheless, these findings, if confirmed with a randomized control trial, will have significant implications on the role of hospital sleep medicine in addressing the high cost of readmissions in congestive-heart-failure [and] other cardiac patients," Sharma writes.

"Fortunately, there are a few large studies pending looking at this very issue," he continues. One such trial currently recruiting is the Cardiovascular Improvements With Minute Ventilation-Targeted ASV Therapy in Heart Failure (CAT-HF) study, which is investigating whether early diagnosis and intervention in patients hospitalized with decompensated congestive heart failure will improve a composite outcome of six-minute-walk distance, cardiovascular hospitalizations, or death.

Kauta has reported that he has no relevant financial relationships. Disclosures for the coauthors are listed in the article. Sharma has received research support from Resmed.


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