Abstract
Methods. The sample included 144 patients with complete biomarker data who underwent plaque evaluation with coronary computed tomography angiography; 95 were re-imaged within 6.9±0.3 years. Presence of >5 segments with plaque or coronary artery calcium >100 constituted extensive disease; lesions rendering >50% stenosis were considered obstructive. The Framingham 2008 cardiovascular risk score was included in all models.
Results. Hs-cTnI added to the cardiovascular risk score increased area-under-the curve (AUC) from 0.710 to 0.729 and improved prediction accuracy for baseline plaque presence [Net Reclassification Improvement =0.538 (95% confidence interval 0.143-0.895)] and Integrated Discrimination Improvement (IDI) =0.035 (0.001-0.128). In contrast, a-b2GPI-IgA did not, and the combination offered no added benefit over hs-cTnI alone. While hs-cTnI alone did not predict plaque progression, a-b2GPI-IgA presence did (p=0.005), especially in patients with >median hs-cTnI (p=0.015). In patients with >median hs-cTnI, adding a-b2GPI-IgA to a cardiovascular risk score model predicting progression from non-extensive/non-obstructive to extensive/obstructive plaque increased AUC from 0.796 to 0.878 and improved model precision [IDI=0.277 (0.011-0.946)].
Conclusion. High hs-cTnI significantly improved prediction of baseline plaque presence and may trigger an initial non-invasive coronary atherosclerosis evaluation. A-b2GPI-IgA presence may justify a follow-up interrogation in patients with non-extensive, non-obstructive plaque at baseline.