PCI for Prevention of Future Cardiac Events

Percutaneous coronary intervention (PCI) is an effective treatment for patients with acute ST-segment elevation myocardial infarction (STEMI). PCI restores blood flow to the coronary artery that is deemed to be causing the myocardial infarction (MI) (infarct artery, also known as the culprit artery). The patients may have major stenoses in coronary arteries that were not responsible for the MI; the value of performing PCI in those arteries for the prevention of future cardiac events is unknown.

There is debate among clinicians as to whether performing preventive PCI in stenosis in noninfarct arteries could prevent serious adverse cardiac events or whether medical therapy with medications to lower blood pressure and lipids is sufficient; some clinicians feel the risks of preventive PCI outweighs the benefits.

Researchers recently conducted the PRAMI (Preventive Angioplasty in Acute Myocardial Infarction) trial to determine whether performing preventive PCI as part of the procedure to treat the infarct artery would reduce the combined incidence of death from cardiac causes, nonfatal MI, or refractory angina. They reported results online in the New England Journal of Medicine [doi:10.1056/NEJMoa1305520].

The primary outcome of the study was a composite of death from cardiac causes, nonfatal MI, or refractory angina. An intention-to-treat analysis was used.

The researchers enrolled 465 patients at 5 centers in the United Kingdom from 2003 through 2013. Of those, 234 were assigned to preventive PCI and 231 to the group not receiving PCI. Subsequent PCI for angina was recommended only for refractory angina with objective evidence of ischemia. In January 2013, the data and safety committee considered the results conclusive and recommended the trial be stopped early.

At the time of the study closure, the primary outcome had occurred in 21 patients in the preventive-PCI group and 53 in the group not receiving preventive PCI for an absolute risk reduction of 14 percentage points in the preventive group (hazard ratio [HR], 0.35; 95% confidence interval [CI], 0.21-0.58; P<.001).

For the 3 components of the primary outcome, the HRs were 0.34 (95% CI, 0.11-1.08) for death from cardiac causes, 0.32 (95% CI, 0.13-0.75) for nonfatal MI, and 0.35 (95% CI, 0.18-0.69) for refractory angina.

The results were not materially affected by the 5 prespecified covariates (age, sex, the presence or absence of diabetes, infarct location, and the number of coronary arteries with stenosis) or study center. There were 2 events of STEMI and 5 events of non-STEMI in the preventive-PCI group (2 from stent thrombosis) and 9 and 11 events, respectively, in the group receiving no preventive PCI (3 from stent thrombosis).

In conclusion, the researchers stated, “In this randomized trial, we found that in patients undergoing emergency infarct-artery PCI for acute STEMI, preventive PCI of stenosis in noninfarct arteries reduced the risk of subsequent adverse cardiovascular events, as compared with PCI limited to the infarct artery.”