Predictors of non-calcified plaque presence and future adverse cardiovascular events in symptomatic rural Appalachian patients with a zero coronary artery calcium score

Background: Coronary artery calcium (CAC) scoring is a proven predictor for future adverse cardiovascular events (CVE) in asymptomatic individuals. Data is emerging regarding the usefulness of non-calcified plaque (NCP) assessment on cardiac computed tomography (CCT) angiography in symptomatic patients with a zero CAC score for further risk assessment.Methods: A retrospective review from January 2019 to January 2022 of 696 symptomatic patients with no known CAD and a zero CAC score identified 181 patients with NCP and 515 patients without NCP by a visual assessment on CCT angiography. The primary endpoint was to identify predictors for NCP presence and adverse CVEs (death, myocardial infarction, or cerebrovascular accident) within two years.Results: Based on logistic regression, age (OR 1.039, 95% CI [1.020-1.058], p < 0.001), diabetes mellitus (OR 2.192, 95% CI [1.307-3.676], p < 0.003), tobacco use (OR 1.748, 95% CI [1.157-2.643], p < 0.008), low-density lipoprotein cholesterol level (OR 1.009, 95% CI [1.003-1.015], p < 0.002), and hypertension (OR 1.613, 95% CI [1.024-2.540], p < 0.039) were found to be predictors of NCP presence. NCP patients had a higher pretest probability for CAD using the Morise risk score (p < 0.001*), with NCP detection increasing as pretest probability increased from low to high (OR 55.79, 95% CI [24.26-128.26], p < 0.001*). 457 patients (66%) reached a full two-year period after CCT angiography completion, with NCP patients noted to have shorter follow-up times and higher rates of elective coronary angiography, intervention, and CVEs. The presence of NCP (aOR 2.178, 95% CI [1.025-4.627], p < 0.043) was identified as an independent predictor for future adverse CVEs when adjusted for diabetes mellitus, age, and hypertension.Conclusion: NCP was identified at high rates (26%) in our symptomatic Appalachian population with no known CAD and a zero CAC score. NCP was identified as an independent predictor of future adverse CVEs within two years.