Risk factor profiling and study of atherosclerotic coronary plaque burden and morphology with coronary computed tomography angiography in coronary artery disease among young Indians.

BACKGROUND

With a decade earlier manifestation of coronary artery disease (CAD) and paucity of data characterizing coronary plaque with coronary computed tomography angiography (CTA) among CAD patients in India, the study aimed to analyze patient characteristics and coronary plaque burden and morphology in young Indian patients with CAD.

METHODS

Serial coronary CTA was performed in 96 CAD patients. Among 60 patients ≤40years, risk factor and coronary plaque analysis done using a 256- slice CT in 33 patients with acute coronary syndrome (ACS) was compared with 27 patients with chronic stable angina (CSA). Univariate and multivariate analysis was performed, for factors predicting ACS as an outcome among young CAD patients. In addition, quantitative and morphologic plaque characteristics were compared among those ≤40years and >40years.

RESULTS

Among 60 subjects ≤40years of age, 77% had dyslipidemia, 70% high lipoprotein(a), 53.33% elevated hs-CRP and 73.33% raised homocysteine. hs-CRP (9.33 vs. 3.33, p value=0.01) and serum triglycerides (178.67 vs. 141.42, p value=0.03) were markedly raised in patients with ACS. Statistically significant number of patients in the ACS group had positive remodelling (ACS, 69.7% vs. CSA, 14.8%; p value<0.001), low attenuation plaque (ACS, 63.6% vs. CSA, 11.1%; p value<0.001), spotty calcification (ACS, 36.4% vs. CSA, 3.7%; p=0.002) and non-calcified plaque (ACS, 69.7% vs. CSA, 11.1%; p<0.001). On multivariate analysis, only lipoprotein (a) >30mg/dL and composite vulnerability score maintained a predictive value for ACS in patients ≤40years. Statistically significant number of patients in the younger age group had higher mean total plaque volume (66.17±41.31mm vs. 44.94±49.07mm; p=0.03), remodelling index (1.5±0.27 vs. 1.08±0.38; p=0.0001). Comparing culprit lesion characteristics of ACS patients in the two age groups, positive remodelling (95.8% vs. 70.5%, p=0.02), spotty calcification (50% vs. 11.7%, p=0.01) and non-calcified plaque (95.8% vs. 70.5%, p=0.02) were significantly more frequent in patients ≤40years.

CONCLUSION

ACS in young Indians is characterized by a higher prevalence of both conventional and newer risk factors. In addition, culprit lesions in young ACS patients are more frequently characterized by coronary plaques with high risk morphological features. This may have implications in terms of preventive strategies to identify this high-risk group.