Abstract 5749: Prognostic Value of Stenosis Severity and Atherosclerotic Plaque Burden at Coronary CT Angiography for Major Adverse Cardiac Events (MACE) - A Population Based Outcome Study
Multiple previous investigations have demonstrated the accuracy of coronary CT angiography (cCTA) for diagnosing or excluding coronary artery stenosis. Recent studies have established the prognostic value of cCTA for all-cause mortality. However, the predictive value of cCTA specifically for cardiac events is less well documented. We assessed the hypothesis that the extent and severity of coronary artery disease (CAD) as defined at cCTA are predictive of major adverse cardiac events (MACE). We examined a consecutive cohort of 454 patients (233 women, mean age 57±years) who had undergone contrast medium enhanced cCTA using either 64-slice or dual-source CT for atypical chest pain. Stenosis at cCTA was scored as minimal (<30%), mild (30% to 49%), moderate (50% to 69%), or severe (≥70%) for each coronary artery. Atherosclerotic plaque burden was assessed by the global Agatston score and based on the degree of vessel involvement with calcified, non-calcified, and mixed plaque. A>12-month follow-up of MACE was assessed using Cox proportional hazards models adjusted for pretest CAD likelihood and risk factors. MACE were determined using the Social Security Death Index, medical record review and phone calls to patients and referring physicians. 2 patients were lost to follow-up. Of the 452 remaining patients, 198 patients did not show any atherosclerosis at cCTA. Of these, none had a MACE during follow-up (100% NPV). 254 patients had atherosclerosis at cCTA (28 purely non-calcified, 254 purely calcified, 180 mixed). 87/254 patients had stenosis >50%. 26 patients had a MACE during 12 month follow-up. The presence of stenosis >50% was significantly (p=0.003) associated with MACE during follow-up. MACE rates were not significantly (p>0.05) associated with different plaque types or the global calcium score. Our results suggest that in individuals presenting with atypical chest pain a normal cCTA has 100% NPV for ruling out MACE during follow-up. Stenosis >50% determined at cCTA significantly predicts the risk of MACE, while we did not observe a significant correlation of MACE with the calcium score or different plaque types.