TARGET-CTCA RCT Shows No Cardiac Event Reduction From Outpatient CTCA After Troponin-Ruled-Out Chest Pain

The randomized trial assigned 1,587 patients with troponin levels above 5 ng/L to early CTCA plus usual care and 1,583 to usual care alone after discharge from 14 UK emergency departments. At three years the composite endpoint occurred in 7.1 percent of the CTCA arm versus 7.3 percent of controls, a non-significant difference despite increased preventive-medication prescriptions in the imaging group. The absolute risk reduction of 0.2 percentage points implies that more than 500 additional scans would be needed to prevent one event.

European guidelines currently recommend noninvasive testing for this intermediate-risk population, yet the trial demonstrates that anatomic imaging alone does not alter hard outcomes when functional risk has already been stratified by troponin. Prior observational data and the earlier PROMISE trial similarly showed limited prognostic impact of routine CTCA in stable or low-risk settings, suggesting that anatomic findings often lead to medication changes without commensurate event reduction.

Implementation of these results could spare radiology and cardiology services roughly 500,000 unnecessary outpatient scans annually in the UK while lowering cumulative radiation exposure. Remaining questions include whether selected subgroups defined by very high troponin or diabetes might still derive benefit and whether functional testing rather than anatomic imaging would change management more effectively.

Future studies should test risk-stratified discharge protocols without imaging against current guideline-directed testing, with cost-effectiveness and quality-of-life endpoints measured at five years.