A new study reveals that while the apnea hypopnea index (AHI) is important, it is not everything. Other less well studied OSA-related variables may be more pathophysiologically relevant and offer better prediction.
The study, published in plos medicine, evaluated the relationship between OSA-related variables and the risk of cardiovascular (CV) events. Obstructive Sleep Apnea and Risk of Cardiovascular Events and All-Cause Mortality: A Decade-Long Historical Cohort Study was conducted using clinical database and health administrative data.
Adults referred for suspected OSA who underwent diagnostic polysomnography at the sleep laboratory at St Michael’s Hospital (Toronto, Canada) between 1994 and 2010 were followed through provincial health administrative data (Ontario, Canada) until May 2011 to examine the occurrence of a composite outcome (myocardial infarction, stroke, congestive heart failure, revascularization procedures, or death from any cause).
Researchers concluded that OSA-related factors other than AHI were shown as important predictors of composite CV outcome, and should be considered in future studies and clinical practice.
“These findings indicate that OSA-related factors other than AHI are important predictors of the composite outcome of a cardiovascular event or all-cause mortality,” wrote researchers in the PLOS Medicine wrap-up. “Indeed, although AHI was significantly associated with the researchers’ composite outcome in an analysis that did not consider other established risk factors for CVD (“confounders”), the association became non-significant after controlling for potential confounders.”