Atherogenic index of plasma predicts coronary artery disease severity and major adverse cardiac events in absence of conventional risk factors

Various overlapping risk factors lead to coronary artery disease (CAD). The atherogenic index of plasma (AIP) is a marker for CAD severity and progression. However, little is known about its contribution to the residual risk of CAD observed in the absence of all typical risk factors.A prospective cohort study of 366 Indian patients undergoing coronary computed tomography (CT) angiography and diagnosed with stable CAD. Diabetes, hypertension, hypercholesterolemia, smoking, previous CAD, alcohol or lipid-lowering medication intake, renal, liver or thyroid dysfunction were exclusion criteria. Coronary stenosis was graded using the CAD-reporting and data system (CAD-RADS™) system. Lipid profile, HbA1c, uric acid, highly sensitive C-reactive protein (hsCRP) and anthropometric measurements were taken. AIP, triglyceride/high-density lipoprotein cholesterol (HDLc) and total cholesterol (Tc)/HDLc ratios were calculated. Independent predictors of CAD severity and the occurrence of major adverse cardiac events (MACE) during 2.57 (0.52) years of follow-up were identified using logistic regression and Cox proportional hazards regression.Sixty patients experienced a MACE during a cumulative 887.03 person-years. HbA1c, uric acid, hsCRP, Tc/HDLc and AIP were independent predictors of severe coronary lesions (CAD-RADS 4,5) on multivariate analysis with odds ratio 4.52 (2.37-8.61), 1.41 (1.08-1.84), 1.33 (1.09-1.62), 1.76 (1.27-2.44) and 1.29 (1.11-1.50), respectively. Only AIP and Tc/HDLc were independent predictors of MACE with hazard ratios of 1.41 (1.20-1.65) and 1.78 (1.33-2.39) besides patient age and CAD severity.AIP is associated with both the severity of CAD and the occurrence of MACE within 3 years. It could serve as an effective marker of residual risk of CAD in patients devoid of traditional risk factors. Lipid-profile ratios, such as AIP are cost-effective and accessible parameters suitable for low and middle-income settings.