Preventive PCI Improves Patient Outcomes
The recent single-blind, randomized PRAMI (Preventive Angioplasty in Acute Myocardial Infarction) trial found that in individuals undergoing emergency infarct-artery percutaneous coronary intervention (PCI) for acute ST-segment elevation myocardial infarction (STEMI), preventive PCI of noninfarct coronary artery stenoses significantly lowered the risk of subsequent major adverse cardiovascular events. Results were presented on September 1, 2013 at the 2013 European Society of Cardiology Congress.
Study Outcome
The study results demonstrated that this approach “conferred a substantial advantage over not performing this additional procedure,” according to the authors. The researchers aimed to determine whether performing preventive PCI in noninfarct coronary arteries with major stenoses in individuals undergoing PCI of the infarct artery would lower the combined incidence of death from cardiac causes, nonfatal myocardial infarction, or refractory angina.
The study enrolled 465 patients with acute STEMI (including 3 patients with left bundle branch block) who were undergoing PCI of the infarct artery from 2008 until 2013; patients were randomized to either preventive PCI (n=234) or no preventive PCI (n=231). Participants were considered eligible after undergoing successful PCI of the infarct artery if they had a stenosis of at least 50% in at least one other coronary artery that was treatable by PCI. Both treatments had to be deemed acceptable options by the treating cardiologist.
A composite of death from cardiac causes, nonfatal myocardial infarction, or refractory angina was the primary outcome. Death from noncardiac causes and repeat revascularization procedures (PCI or coronary artery bypass grafting) were the secondary outcomes.
Follow-up information was first at 6 weeks and then yearly; the mean follow-up was 23 months. The results showed that 21 patients who underwent preventive PCI and 53 patients who underwent culprit-only PCI during follow-up experienced a primary outcome event. There was an absolute risk reduction of 14% in individuals in the preventive PCI group. Further, hazard ratios for the three individual components of the primary outcome were 0.34 (95% confidence interval [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.
The authors found that the death from noncardiac causes rate did not vary significantly between the preventive PCI group and the culprit-only PCI group.
Future Research
Current guidelines on the management of STEMI recommend infarct artery–only PCI in those with multivessel disease, based on a lack of evidence regarding the benefits of preventive PCI. This uncertainty has led to variations in practice.
“The results of this trial help resolve the uncertainty by making clear that preventive PCI is a better strategy than restricting a further intervention to those patients with refractory angina or a subsequent myocardial infarction,” the authors write. “However, our findings do not address the question of immediate versus delayed (staged) preventive PCI, which would need to be clarified in a separate trial.”
The authors noted several other remaining questions that require further research, including whether the benefits of preventive PCI are applicable to patients with non-STEMI, whether these benefits extend to stenosis of less than 50%, and whether a physiological measure of blood flow offers any advantages over angiographic visual assessment in guiding preventive PCI.
A complete report on the study findings and an accompanying editorial by Laura Mauri, MD, the Center for Clinical Biometrics and Harvard Clinical Research Institute, Brigham and Women’s Hospital, Boston, MA, are available published online in The New England Journal of Medicine.
- Meredith Edwards White
References
1. Wald DS, Morris JK, Wald NJ, et al; the PRAMI Investigators. Randomized trial of preventive angioplasty in myocardial infarction. N Engl J Med. 2013 Sep 1. [Epub ahead of print]
2. Mauri L. Nonculprit lesions—innocent or guilty by association. N Engl J Med. 2013 Sep 1. [Epub ahead of print]