In patients with ST-elevation myocardial infarction (STEMI), current guidelines support PCI of the infarct related artery and medical management of flow-limiting lesions in non-infarct related vessels (so-called bystander disease). This paradigm is challenged in the Preventive Angioplasty in Acute Myocardial Infarction (PRAMI) study. In this single-blind trial performed at five UK centres, patients presenting with STEMI were randomly assigned to preventive PCI or no further PCI of non-infarct related vessels with >50% stenosis, immediately following reperfusion of the infarct related artery. The primary outcome was a composite of death from cardiac causes, nonfatal myocardial infarction, or refractory angina and the mean follow-up was 23 months. The trial was stopped early by the data and safety monitoring committee following enrolment of 465 out of a planned 600 patients due to a highly significant result favouring preventive PCI;  the primary outcome occurred in 21 patients assigned to preventive PCI and in 53 patients assigned to no preventive PCI.  This translates into an absolute risk reduction of 14% in the preventive PCI group (HR 0.35; 95% CI, 0.21 to 0.58; NNT 8; P<0.001). The hazard ratios were 0.34 (95% CI, 0.11 to 1.08) for death from cardiac causes, 0.32 (95% CI, 0.13 to 0.75) for nonfatal myocardial infarction, and 0.35 (95% CI, 0.18 to 0.69) for refractory angina.  Although procedure times and contrast loads were significantly higher in the preventive PCI group, this did not translate into an increase in procedure-related adverse events.

Conclusions:

In patients with STEMI and multivessel coronary artery disease undergoing infarct-artery PCI, preventive PCI of bystander lesions significantly reduced the risk of adverse cardiovascular events, as compared with PCI limited to the infarct artery. This important study contrasts directly with studies of PCI for stable CAD and suggests a different paradigm in the management of STEMI patients.  Future investigation is needed to optimize the identification of true bystanders versus those lesions lying in wait in the setting of STEMI.

• Wald DS, Morris JK, Wald NJ, Chase AJ, Edwards RJ, Hughes LO, Berry C and Oldroyd KG. Randomized trial of preventive angioplasty in myocardial infarction. N Engl J Med. 2013 Sep 19;369(12):1115-23.