Relation of Obstructive Sleep Apnea in Patients with a Coronary Chronic Total Occlusion (CTO) to Coronary Collaterals and Mortality.
A chronic total occlusion (CTO) is frequently identified in patients undergoing coronary angiography. The prognostic implications of intermittent hypoxia from obstructive sleep apnea (OSA) on patients with a CTO, and effects on collateral recruitment are unknown. The aim of this study was to determine the prevalence, vascular effects and prognostic implications of the presence of OSA in patients with a CTO. Patients with a CTO between July 2010 and December 2019 were reviewed. Electronic medical records were accessed to determine documented patient history of OSA, demographics and clinical course. Patients with robust collateral recruitment were defined as Rentrop grade 2 or 3. A total of 948 patients were included in the study, of which 127 (13.4%) had a documented history of OSA. These patients were younger (67.0 years vs 70.6 years, p<0.01), had a higher body mass index (BMI) (29.6kg/m2 vs 26.7 kg/m2, p<0.0001), higher rates of hypertension (91.3% vs 83.2%, p<0.05), higher rates of smokers (63.3% vs 49.0%, p<0.01) and more use of beta blockers (79% vs 68.5%, p<0.05) and statins (92.7% vs 82.1%, p<0.01). A documented history of OSA was independently associated with robust collaterals (OR: 3.0 95%CI: 1.5 – 5.8, p<0.01) and lower mortality (HR: 0.3 95% CI: 0.1 – 0.7, p<0.01) with a mean survival of 10.8 years, as compared to 8.1 years (log rank p<0.0001). In conclusion, in patients with a CTO, documented OSA is independently associated with more robust coronary collaterals and lower mortality. The possible cardioprotective implications of intermittent hypoxia in OSA, as well as treatment effect requires further investigation.
Authors: Usaid K Allahwala, Peter A Cistulli, Avedis Ekmejian, Nadeem Mughal, Hasthi U Dissanayake, Michael Ward, James C Weaver, Ravinay Bhindi