Patients with suspected Coronary Disease and normal cardiac CT Scan can ‘sleep easy’

Patients with suspected CAD and normal cardiac CT can ‘sleep easy’ December 9,2010 — NEW YORK (Reuters Health) – People with suspected coronary artery disease (CAD) who have a normal coronary CT angiography (CCTA) scan are unlikely to have a major cardiac event anytime soon,cardiologists report in a study released today. The absence of CAD on CCTA “conveys an excellent prognosis for symptomatic patients being evaluated for suspected CAD,” Dr. Edward A. Hulten,from the Cardiology Service,Walter Reed Army Medical Center in Washington,DC,and colleagues write in the December 7 online Journal of the American College of Cardiology. They note in the article that the diagnostic accuracy of CCTA is well defined,but the ability of CCTA to predict future clinical outcomes is less clear. Many of the published studies on the prognostic value of CCTA,they point out,haven’t been adequately powered to detect differences in rates of clinical outcomes such as death,myocardial infarction (MI),and coronary revascularization. A sweep of the literature identified 18 relevant longitudinal studies on the prognostic value of CCTA. In these studies,a total of 9,592 patients (mean age,59 years) with symptoms of possible CAD were followed for a median of 20 months,maximum of 78 months. CCTA findings were normal in 3,557 patients and abnormal (positive) in 6,035. In patients with normal scans,the absolute rate of major adverse cardiac events (MACE),death or MI,during follow-up was low (0.6%),the investigators report. There were no definite CAD-specific events in patients with normal CCTA findings during follow-up. “Patients with normal scans can sleep easy at night knowing that their risk of events is markedly low and not increased from a healthy asymptomatic population,” Dr. Hulten noted in an interview with Reuters Health. CCTA has “excellent” sensitivity (99%) and negative likelihood ratio (0.008) to exclude future coronary clinical events after a normal scan,the authors report. “For predicting prognosis of adverse clinical events,the negative likelihood ratio of CCTA with normal findings is comparable to reported values for stress myocardial perfusion scan and stress echocardiography,” they add. Where CCTA findings were abnormal,there were “incrementally increasing” cardiovascular events (MI and revascularization) and all-cause mortality rates with increasing severity of CAD. Still,the investigators say an abnormal scan isn’t strongly predictive of future major cardiovascular events because the majority of patients with CAD will not have an event over 20 months of follow-up (the annualized incidence rate was only 8.8%). Nonetheless,they say these results are “convincing” for CCTA to “convey risk strata for future adverse cardiovascular events.” “It’s the patients with obstructive disease that are really the ones that need to be followed closely and treated aggressively,” Dr. Hulten told Reuters Health. He also noted that the findings in this large meta-analysis complement data from the CONFIRM registry reported in November at the American Heart Association’s annual meeting. The CONFIRM data showed “a similar finding;that patients with normal CCTA scans do quite well and then there is increasing event rates with increasing burden of disease,” Dr. Hulten said. By Megan Brooks Source: Am Coll Cardiol 2011;57. Last Updated:2010-12-08 17:29:19 -0400 (Reuters Healt