Functional angiography cuts events, complications after heart attack

On an angiogram, several narrowed coronary arteries can look like candidates for treatment even when not all of them restrict blood flow. The AIR-STEMI trial tested whether measuring that physiological impact could make treatment more selective—and found fewer cardiovascular events in 1,823 patients with STEMI, a serious form of heart attack, and multivessel disease.

The trial ran across 21 centers in Italy and Pakistan. After doctors successfully treated the culprit lesion—the artery responsible for the heart attack—patients were assigned to either conventional angiography or functional coronary angiography. The latter uses the images already taken to reconstruct the artery in three dimensions and estimate blood flow. Its angiography-derived FFR, or fractional flow reserve, guided the decision: values above 0.80 meant treatment could be deferred, while values at or below 0.80 led to PCI, the procedure used to reopen a blocked artery.

That filter changed how much treatment patients received. PCI was performed on 51.9% of non-culprit vessels with functional guidance, compared with 94.9% under conventional angiography. The physiology-guided strategy also involved fewer procedures, fewer treated vessels, shorter treated segments and less contrast agent.

At a median follow-up of 17.9 months, the trial’s combined endpoint—death, myocardial infarction, stroke or ischemia-driven coronary revascularization—occurred in 8.9% of the functional-angiography group, versus 13.7% of the conventional-angiography group. The safety endpoint of contrast-associated acute kidney injury or major bleeding was 4.6%, compared with 7.1%. All-cause mortality was not significantly different: 3.9% versus 5.1%.

For patients, the concrete gain is a narrower intervention: treat the additional lesions that actually impair blood flow, while avoiding procedures on those that do not. That can mean less hardware placed in the coronary arteries and less exposure to contrast, although the mortality result was not significantly different. The findings were presented at ESC Congress 2026 and published in the New England Journal of Medicine; they support a clinical strategy, not proof that every patient will benefit in the same way.