Design: Systematic review and meta-analysis of randomised trials
Population: 5 trials, 3,315 asymptomatic adults with diabetes and no known coronary disease
Primary outcome: Major adverse cardiovascular events
Effect: Pooled HR/RR 0.76 (95% CI 0.48 to 1.19), four trials

A systematic review identified five randomised trials, 3,315 participants in total, that tested systematic screening for silent ischaemia or occult coronary disease in asymptomatic adults with diabetes, including DIAD, DYNAMIT and FACTOR-64.

Pooling four of them, screening did not significantly reduce major cardiovascular events (HR/RR 0.76, 95% CI 0.48 to 1.19). Screening found disease, but finding it did not translate into fewer events. Harms such as false positives and procedure complications were poorly reported.

The result fits current guidance, which does not recommend routine stress testing in asymptomatic people with diabetes. The money and effort are better spent on what does reduce events: blood pressure, lipids, smoking, and agents with proven cardiovascular benefit such as SGLT2 inhibitors and GLP-1 receptor agonists where indicated.

Testing still has a place when symptoms are atypical, when a resting ECG is abnormal, or when the result would change a specific decision.

Do not order routine stress tests for asymptomatic patients with diabetes and no known coronary disease
Ask specifically about exertional breathlessness and fatigue, which may be the only ischaemic symptoms in diabetes
Test selectively when symptoms, an abnormal ECG or a planned decision would make the result useful
Put the effort into blood pressure, lipid, smoking and glucose-lowering therapy with cardiovascular benefit

Why it matters

Finding hidden coronary disease feels proactive, but in these trials it did not measurably reduce events.

The statistics, in plain English

The pooled estimate of 0.76 leans towards benefit, but the confidence interval runs from a 52% reduction to a 19% increase, so the trials cannot show that screening helps. Most were conducted before modern preventive drugs, which would likely shrink any benefit further.