Last year, the SCOT-HEART trial (Scottish COmputed Tomography of the HEART) demonstrated that coronary computed tomography angiography (CCTA) markedly clarified diagnoses for patients with suspected angina due to coronary heart disease (Lancet 2015;385[9985]:2383-91). Whether CCTA-guided changes in diagnoses led to appropriate improvements in invasive coronary angiography and initiation of preventive treatments, and whether these changes could be attributable to an improvement in clinical outcome, were unanswered questions. Now, a sub-analysis of SCOT-HEART has provided answers that may change how coronary artery disease (CAD) is diagnosed and managed (J Am Coll Cardiol 2016;67:1759-68). 

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Post hoc landmark analysis at 50 days to account for the implementation and treatment delay consequent on the conduct, reporting, and communication of the coronary computed tomography angiography (CCTA) findings. HR ¼ hazard ratio.Source: J Am Coll Cardiol 2016;67:1759-68; reprinted with permission.

The SCOT-HEART sub-analysis showed that CCTA-guided therapeutic decision-making ultimately led to a 50 percent reduction in fatal and non-fatal myocardial infarction when compared to usual care, largely including stress testing. Although these findings will require future validation, they suggest that CCTA should be strongly considered as the first-line test for patients presenting with stable chest pain and no known CAD.

“With SCOT-HEART, we have moved beyond studies of diagnostic accuracy,” wrote Michelle C. Williams, MD, MBChB, of the British Heart Foundation Centre for Cardiovascular Science at the University of Edinburgh in Scotland and lead author of the sub-analysis. “This study will certainly change practice.”

Indeed, the identification of both non-obstructive and obstructive coronary artery disease is a major advantage of CCTA. It allows the opportunity to target medical therapy to those patients with CAD before stenoses become severe.

SCCT 2016-17 President Leslee Shaw, PhD, may put it best when she says that the findings of the SCOT-HEART secondary analysis “conclusively demonstrate that CCTA is by far one of the key components to guide accurate diagnosis of and effective treatment for CAD.” While validation is required, she adds, the new findings suggest “that optimal improvements in patient outcomes can best be facilitated by CCTA.” 

Jonathon A. Leipsic, MD, is the chairman of the Department of Radiology for Providence Health Care and the vice chairman of research for the University of British Columbia Department of Radiology; associate professor of radiology and cardiology at the University of British Columbia; and the 2015-16 president of SCCT.