Oxygen Desaturation Index Predicts AFib Risk in Ischemic Stroke
Investigators observed a significant association between atrial fibrillation and increasing oxygen desaturation index.
Oxygen desaturation index (ODI) was a significant predictor of atrial fibrillation as well as discharge disposition in a study of patients with obstructive sleep apnea and ischemic stroke who underwent high-resolution pulse oximetry (HRPO). The study results were published in the Journal of Stroke and Cerebrovascular Diseases
A total of 115 patients with ischemic stroke who underwent HRPO were enrolled in the study. Investigators collected data on ODI <4%, arterial oxygen saturation (SaO2), pulse rate, and the duration spent at an <88% SaO2 saturation level. Participants received the STOP (S-Snoring, T-Tiredness, O-Observed, P-Pressure) questionnaire; individuals scoring ≥2 were assigned HRPO. National Institutes of Health Stroke Scale (NIHSS), discharge modified Rankin Score (mRS), and discharge disposition data were also collected.
At baseline, patients presented with atrial fibrillation (n=22), type 2 diabetes (n=27), resistant hypertension (n=7), and patent foramen ovale (n=7). A total of 75 participants had an ODI of >10, and the mean ODI was 29±30 across the cohort. In addition, admission and discharge NIHSS scores were 6.14±6.93 and 4.46±4.59, respectively, whereas discharge mRS was 1.70±1.67.
Investigators observed a significant association between atrial fibrillation and increasing ODI (odds ratio [OR] 1.01; 95% CI, 1.00-1.03; P <.001). Patients with an ODI of ≤10 had a significantly increased odds of being discharged home (OR 3.76; 95% CI, 1.49-9.52; P =.005). The odds of patients having atrial fibrillation were 1.01 for each unit increase in ODI (95% CI, 1.00-1.03; P =.056). In addition, for each unit decrease in ODI, the odds of achieving an NIHSS ≤7 were also 1.01 (95% CI, 1.00-1.03; P =.036).
Study limitations include the lack of polysomnography-confirmed cases of OSA and the inclusion of a relatively small number of patients.
OSA continues to be under-recognized in patients with acute stroke, but the study investigators believe that “HRPO will resolve this issue and may lead to increased screening and intervention of sleep apnea in acute ischemic stroke.”
Yaddanapudi SS, Pineda MC, Boorman DW, et al. High-resolution pulse oximetry (HRPO): a cost-effective tool in screening for obstructive sleep apnea (OSA) in acute stroke and predicting outcome [published online August 7, 2018]. J Stroke Cerebrovasc Dis. doi:10.1016/j.jstrokecerebrovasdis.2018.06.030