Design: International, randomised, open-label trial (AIR-STEMI)
Population: 1,823 adults with STEMI and multivessel disease, culprit lesion already treated
Primary outcome: Death, MI, stroke/TIA, or ischaemia-driven revascularisation at a median 17.9 months
Effect: 8.9% vs 13.7%, hazard ratio 0.62 (95% CI 0.47–0.83), P<0.001

AIR-STEMI randomised 1,823 patients with STEMI and multivessel disease, after the culprit lesion had been treated, to complete revascularisation guided by coronary physiology or by conventional angiography. Median age was 66 and 24% were women; follow-up ran a median 17.9 months.

The physiology-guided strategy lowered the composite of death, myocardial infarction, stroke or transient ischaemic attack, and ischaemia-driven revascularisation to 8.9% from 13.7% (hazard ratio 0.62, 95% CI 0.47–0.83). The safety composite of contrast-associated acute kidney injury or major bleeding also fell, to 4.6% from 7.1% (hazard ratio 0.63, 95% CI 0.43–0.93) — treating fewer non-culprit lesions meant less contrast and fewer bleeds.

The practical point is restraint: deciding non-culprit lesions on measured ischaemia rather than the angiographic appearance treats fewer vessels and still does better. Pressure-wire physiology is available in most Indian cath labs that do primary PCI, so this is implementable where multivessel STEMI is common.

In multivessel STEMI, assess non-culprit lesions by physiology rather than treating on the angiographic appearance alone.
Physiology guidance cut the composite event rate to about 9% from 14% over 18 months.
Fewer lesions treated meant less contrast and fewer major bleeds, not more.
The gain comes from treating fewer, not more, non-culprit lesions — a case for restraint.

Why it matters

It settles how to pick non-culprit lesions for complete revascularisation — physiology, not the eye.

The statistics, in plain English

A hazard ratio of 0.62 is a 38% lower event rate, and the confidence interval (0.47–0.83) sits well below 1.0, so the benefit is secure; the safety composite fell too, so the gain did not come at a bleeding or kidney cost.