Obstructive Sleep Apnea (OSA) has been linked with coronary artery disease (CAD). Coronary CT angiography (cCTA) is a non-invasive means to evaluate atherosclerotic plaque burden and “Vulnerable plaques” (calcified / mixed plaques) which are implicated in development of acute coronary syndrome. The study investigated the association between OSA and vulnerable plaques.
A total of 95 patients who had undergone 64 slice dual energy CT scan (cCTA) for atypical chest pain and/or prior equivocal physiological testing were included in the study. Patients were screened for presence of OSA by polysomnograpy (45/95) or Berlin questionnaire (50/95). 49 patients were found to have OSA (AHI>15/hr) with mean AHI of 50 (+/− 32) and 45 patients without OSA with mean AHI 5.5 (+/− 4.5). Two experienced radiologists analyzed the cCTA data and were blinded to the results of the polysomnograms. Results of vulnerable plaques (non-calcified and mixed plaques) were analyzed between patients with OSA versus non OSA.
Vulnerable plaques were present in 55 % of patients with OSA as compared to 28 % of non OSA patients (p=0.014). Number of vessel involvement for vulnerable plaques was also higher in OSA patients (20% one vessel, 22% two vessels, 10% three vessels and 4 % four vessels versus 11%, 9%, 4%, 4% in non OSA, P=.05). Patients with OSA also had significantly higher prevalence of stenotic CAD (88%) versus non OSA (59%) (p=0.0013) and higher calcium score (272±422 with OSA versus 241±415 without OSA, p=0.5).There was no statistically significant (p>0.05) difference in baseline demographics (age, gender, body mass index, cardiovascular risk factors) between patients with and without OSA.
Presence of OSA is independently associated with presence and extent of vulnerable plaques and severity of stenotic coronary artery disease.
If above findings are confirmed in a larger prospective trial, identification of OSA would be helpful in risk stratification of patients with atherosclerosis and acute coronary artery syndrome.
Sunil Sharma, No Financial Disclosure Information; No Product/Research Disclosure Information