25 ASSOCIATION OF CORONARY COMPUTED TOMOGRAFY ANGIOGRAPHY AND STRESS-ECHOCARDIOGRAPHY WITH LONG-TERM CARDIAC OUTCOME: A COMPARISON STUDY


 
 
 The study aims to assess which variables on coronary computed tomography angiography (CTA) and vasodilator stress-echocardiography (SE) are best associated with long-term cardiac outcome in patients presenting for suspected chronic coronary syndrome (CCS).
 
 
 
 There is no published data regarding how CTA and SE variables compare regarding the association with long-term cardiac outcome in patients with suspected CCS who performed both tests.
 
 
 
 From the prospectively-collected SE we selected all patients (n=397) who underwent both SE and CTA within 30 days, in the period between 2007 and 2019, performed with the clinical indication of suspected CCS, independently from which of the two tests was performed first. Coronary artery calcium score (CACS) and the number of coronary arteries with diameter stenosis >50% were assessed on CTA. The presence of reversible regional wall motion abnormalities (RWMA) and reduced Doppler coronary flow velocity reserve in the left anterior descending coronary artery (CFVR) were assessed on SE. The association of SE and CTA variables with cardiac outcome (cardiac death or myocardial infarction) was assessed using Fine and Gray competing risk models.
 
 
 
 During a median follow-up of about 10 years (median 3783 days, lower-upper quartile, 1470-4653), 38 patients (10%) experienced a non-fatal myocardial infarction, 19 (5%) died because of cardiac cause and 26 (7%) died from causes other than cardiac. Four patients had first a non-fatal myocardial infarction, and later died because of cardiac cause during follow-up, so that finally the number of cardiac events was 53. RWMA (HR 7.189, p<0.001) and a lower CFVR (HR 0.034, p<0.001) on SE, CACS (HR 1.004, p<0.001) and the number of >50% stenosed coronary vessels (HR 1.975, p<0.001) on CTA were each associated with cardiac events. After adjusting for covariates, only CACS and CFVR remained associated (both p<0.001) with cardiac outcome, while this was not the case for the number of stenosed vessels on CTA or RWMA on SE. When considering CVFR as a categorical parameter (<2) and CACS in the usual 4 categories, only CFVR<2 remained significantly and independently associated with the risk of cardiac events (HR 13.890, 95% CI 4.154 to 46.445, p<0.001).
 
 
 
 Our data suggest that only CFVR on SE and CACS on CTA are independently and strongly associated with long-term cardiac outcome, unlike RWMA or the number of stenosed coronary arteries, usually considered the hallmarks of coronary artery disease on each test. Coronary artery calcium score and CFVR, although they originate from two different types of tests (anatomical or functional) share a higher sensitivity for milder or early-stage atherosclerotic disease when compared with their respective traditional, theoretically “ischemia-hallmarks” counterparts (obstructive CAD on CTA and reversible RWMA on SE). We speculate that the tighter association of CACS and CFVR with outcome in this study confirms the capability of these two markers to detect those early and possibly pre-clinical signs of CAD, which may turn into clinical events in the very long run.
