Impact of OSA on future cardiovascular events differs by BMI

Key takeaways:

• Those without obesity faced a high risk for major cardiovascular events after acute coronary syndrome due to obstructive sleep apnea.
• Researchers recommend sleep apnea screening in this patient population.

Among adults with acute coronary syndrome not classified as having obesity, obstructive sleep apnea raised the risk for major cardiovascular and cerebrovascular events, according to results published in CHEST.

“This study showed that OSA significantly increased the risk of cardiovascular events after [acute coronary syndrome (ACS)], particularly among patients without obesity,” Wen Hao, MD, PhD, of the Center for Coronary Artery Disease in the division of cardiology at Beijing Anzhen Hospital, and colleagues wrote. “This finding promotes us to evaluate the interrelationships of OSA and obesity with risk of adverse events in patients with ACS and the possible benefits of suitable OSA treatment for this high-risk subset.”

In a prospective cohort study, Hao and colleagues assessed 1,920 adults (mean age, 56.4 years; 84.5% men) with ACS to determine if the risk for major adverse cardiovascular and cerebrovascular events (MACCE) linked to OSA differs by obesity status.

Researchers found that a little over half of the total cohort (52.8%) had OSA, whereas fewer patients had a BMI of 28 kg/m² (37.4%), which the researchers defined as having obesity. OSA appeared in more patients with vs. without obesity (67.5% vs. 43.9%; P < .001).

Within the study population, 388 patients reported a MACCE. When divided by obesity status, patients with obesity experienced more MACCEs (HR = 1.29; 95% CI, 1.06-1.58) over the 2.9-year median follow-up period vs. those with a BMI that did not suggest obesity.

Five events are encapsulated within the MACCE classification, but researchers noted two frequently reported in this cohort: hospitalization for ACS (310 events) and ischemia-driven revascularization (158 events).

When factoring in OSA for patients without obesity, researchers found that more MACCEs occurred in patients with vs. without OSA (HR = 1.42; 95% CI, 1.09-1.84). For those with obesity, the difference in MACCE incidence was not significant between those with vs. without OSA.

Notably, for those without obesity, OSA was independently linked to a higher risk for MACCE (adjusted HR = 1.34; 95% CI, 1.03-1.75) in a confounder-adjusted model. Researchers did not find this link among those with obesity.

Potential reasons for the OSA-associated risk observed among those without obesity include the higher adjusted risk for hospitalizations for ACS (aHR = 1.353; 95% CI, 1.003-1.825) and ischemia-driven revascularization (aHR = 1.522; 95% CI, 1.001-2.314) found in this group, according to researchers.

“These findings highlight the importance of screening for OSA in ACS patients without obesity,” Hao and colleagues wrote.

“Measures of sleep apnea-specific hypoxic burden, which reflects hypoxemia caused specifically by sleep apnea, are not available in this cohort,” Hao and colleagues added. “Further studies are needed to evaluate the prognostic value of sleep apnea-specific hypoxic burden compared with other hypoxic metrics in an ACS-dominant cohort.”