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Reference: PRAMI trial (N Engl J Med 2013 Sep 19;369(12): 1115) (level 2 [mid-level] evidence)
For patients with ST-elevation myocardial infarction (STEMI) having primary percutaneous coronary intervention (PCI), current guidelines from the American College of Cardiology Foundation and the American Heart Association (ACCF/AHA) recommend PCI of only the culprit vessel for most patients. Performing PCI in noninfarct arteries at the same time as the infarct artery is discouraged except in cases of hemodynamic compromise (Circulation. 2013 Jan 29;127(4):e362). This recommendation was made due to inconsistent and contradictory data with regard to the efficacy of multivessel PCI mostly from observational studies. Recently, the Preventive Angioplasty in Acute Myocardial Infarction (PRAMI) randomized trial compared multivessel PCI vs. culprit-vessel only PCI in 465 patients with STEMI.
Following successful PCI on the culprit vessel, patients were randomized while in the catheterization laboratory to immediate PCI of noninfarct arteries with > 50% stenosis (multivessel PCI) vs. no further PCI procedure. Patients were excluded for previous coronary artery bypass graft (CABG) or for new indication for CABG. Subsequent PCI for angina was recommended only for patients with a confirmed diagnosis of refractory angina (symptoms uncontrolled by medical therapy plus objective evidence of ischemia). Otherwise, any follow-up PCI was discouraged. The primary outcome was a composite of cardiovascular death, nonfatal myocardial infarction, and refractory angina.
The trial was terminated early after an unplanned interim analysis showed a significant reduction in the rate of the primary outcome in the multivessel PCI group. At the time of that analysis, the mean follow-up was 23 months. The primary outcome occurred in 8.8% with multivessel PCI vs. 22.9% with culprit-vessel only PCI (p < 0.001). Multivessel PCI was associated with reduced risks of nonfatal myocardial infarction (3% vs. 8.7% (p = 0.009, NNT 18), refractory angina (5.1% vs. 13%, p = 0.002, NNT 13), and repeat revascularization procedures (6.8% vs. 19.9%, p < 0.001, NNT 8). There was a nonsignificant decrease in cardiovascular mortality with multivessel PCI (1.7% vs. 4.3%, p = 0.07), and no significant difference in noncardiac mortality (3.4% vs. 2.6%).
While the absolute risk difference favoring multivessel intervention was substantial, there were only 74 patients with the primary outcome. The relatively low total number of events in a trial stopped early, especially with an unplanned interim analysis, carries a risk of bias for magnifying the amount of benefit from the intervention.
For more information, see the Revascularization for ST-elevation myocardial infarction (STEMI) topic in DynaMed.