PRAMI: Strong Showing for Complete Revascularization in Acute STEMI Patients

AMSTERDAM, The Netherlands—Patients with multivessel disease who experience ST-segment elevation myocardial infarction (STEMI) fare substantially better when they undergo immediate percutaneous coronary intervention (PCI) in not only the infarct-related artery but also any other diseased arteries. Data released September 1, 2013, at the European Society of Cardiology Congress and simultaneously published online ahead of print in the New England Journal of Medicine show that ‘preventive’ PCI reduces the risk of adverse cardiovascular events by two-thirds.

For the PRAMI (Preventive Angioplasty in Acute Myocardial Infarction) trial, David S. Wald, MD, of the Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry (London, United Kingdom), and colleagues at 5 centers planned to enroll 600 STEMI patients with multivessel disease and randomly assign them to PCI in the infarct-related artery with or without immediate treatment of other stenosed vessels. All other aspects of patient management were at physician discretion, and subsequent PCI was reserved only for patients with documented refractory angina.

The study was halted early in January 2013, when interim results showed a “clear” advantage for the preventive strategy after only 465 patients were treated, Dr. Wald reported.

Nonfatal MI, Refractory Angina Both Reduced

Over a mean follow-up period of 23 months, the combined rate of cardiac death, nonfatal MI, and refractory angina (primary endpoint) was 9% in patients who received complete revascularization (n = 234) and 23% in those who had infarct-only PCI (n = 231). Nonfatal MI and refractory angina each were lower with the preventive strategy, as was the secondary outcome of repeat revascularization (table 1).

Table 1. Preventive vs. No Additional PCI: Clinical Outcomes

Procedure time, fluoroscopy dose, and contrast volume all were higher when patients underwent PCI in all diseased arteries, though complication rates were similar between the 2 groups (P = 0.86).

More Options to Explore

Kaplan-Meier curves, Dr. Wald noted, “indicate that the effect [on the primary endpoint] is seen relatively early on. In fact, the curves start to emerge almost immediately, within days, and the full effect is evident within months. This may be important because preventive angioplasty may need to be done immediately to secure the full benefit. A staged or deferred approach may not achieve a similar magnitude of effect.” Notably, the benefit continued out to 36 months, he added.

In an editorial accompanying the NEJM paper, Laura Mauri, MD, of Brigham and Women’s Hospital also raises the possibility of staged PCI. “The PRAMI study did not examine whether preventive PCI is best performed during the emergency procedure,” she writes. “Although the risks of recurrent myocardial infarction were highest in the first few days, it is unknown whether the risk-benefit ratio would be preserved in preventive PCI were performed soon after, rather than during, the initial procedure.”

Another unanswered question, according to Drs. Wald and Mauri, is how functional assessment would change the equation. “Although it is possible that this tool would improve lesion selection in acute myocardial infarction, it is also plausible that the risk conferred by the non-infarct lesion is independent of hemodynamic severity,” Dr. Mauri notes.

STEMI a Unique Situation

With improvements in techniques, devices, and medications, Dr. Mauri explains, complete revascularization is reasonable but represents a departure from current guidelines, which caution “against treating multiple vessels during acute STEMI, particularly when the secondary sites are not clearly causing ongoing hemodynamic instability. This recommendation is based on concern that treating non-infarct-causing stenosis could jeopardize healthy areas of myocardium when the recovering areas of injured myocardium are at their weakest.”

Medical therapy has thus far been important but preventive PCI appears promising, she concludes. “During acute myocardial infarction, there is no healthy vessel, even in case in which thrombosis is absent. We can no longer assume that secondary lesions . . . are innocent until proven guilty.”

Discussant George D. Dangas, MD, PhD, of Mount Sinai Medical Center (New York, NY), also agreed that PRAMI “directly challenges some thoughts [on clinical practice] derived from the guidelines.” He highlighted the high risk of the cohort, however, and suggested that this quality may have been partially responsible for magnitude of the statistical significance.

Note: Dr. Dangas is a faculty member of the Cardiovascular Research Foundation, which owns and operates TCTMD.

Sources:

1. Wald DS, Morris JK, Wald NJ, et al. Randomized trial of preventive angioplasty in myocardial infarction. N Engl J Med. 2013;Epub ahead of print.
2. Mauri L. Nonculprit lesions: Innocent or guilty by association [editorial]. N Engl J Med. 2013;Epub ahead of print.

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