Objective:

To assess whether CT coronary angiography (CTCA)-guided care reduces subsequent myocardial infarction or cardiovascular death in patients with suspected acute coronary syndrome after MI has been ruled out.

Approach:

• Design and participants: Multicenter, open-label randomized trial at 14 UK hospitals; 3,170 patients with intermediate cardiovascular risk were assigned to CTCA-guided care (1,587) or standard care (1,583).
• Follow-up and outcomes: Median follow-up was 3 years. The primary outcome was myocardial infarction or cardiovascular death; secondary outcomes included other cardiovascular events, mortality, repeat visits, revascularization, and major bleeding.

Key Findings:

• The primary outcome occurred in 112 patients (7%) assigned to CTCA-guided care and 116 (7%) receiving standard care; the difference was not statistically significant.
• Myocardial infarction occurred in 6% of each group; cardiovascular death occurred in 1% with CTCA and 2% with standard care.
• All-cause mortality was 5% with CTCA and 6% with standard care. Much of the difference reflected noncardiovascular deaths; secondary analyses were not adjusted for multiple comparisons.
• CTCA-guided care was associated with higher statin and antiplatelet use. Revascularization occurred in 6% versus 5%, respectively.
• A HEART-score subgroup analysis suggested a possible primary-outcome benefit among low-risk patients, but subgroup findings warrant caution because of multiple comparisons.
• CTCA-related adverse events occurred in 7 patients (0.4%); three were classified as serious, with symptoms resolving without intervention or after antihistamine treatment.

Interpretation:

The trial authors reported that CTCA-guided care did not reduce subsequent myocardial infarction or cardiovascular death compared with standard care. The observed all-cause mortality and subgroup differences require cautious interpretation.

Limitations:

• The primary-outcome event rate was lower than anticipated, and the findings remained compatible with both a reduction and an increase in cardiovascular risk.
• Most participants were men; some had established coronary artery disease or were already receiving preventive treatment.
• The trial was conducted only in the UK, where coronary imaging is used relatively infrequently in routine care.
• Secondary analyses were not adjusted for multiple comparisons.

Conclusion:

In this trial, CTCA-guided care did not significantly reduce the composite of myocardial infarction or cardiovascular death among patients whose initial evaluation ruled out MI.

Sources:

• New England Journal of Medicine