Preventive Angioplasty in Acute Myocardial Infarction - PRAMI

Description:

Current guidelines list a Class III indication for nonculprit vessel percutaneous coronary intervention (PCI) in the setting of primary PCI (PPCI) during ST-segment elevation myocardial infarction (STEMI). However, this is based mostly on data from observational studies. The current trial sought to compare outcomes between nonculprit vessel PCI in addition to PCI of the infarct-related artery (IRA) versus PPCI of the IRA alone in patients with STEMI who had multiple stenoses.

Hypothesis:

Nonculprit vessel PCI in addition to PPCI of IRA (preventive PCI) would be superior to PPCI of IRA alone for reducing ischemic outcomes in STEMI patients with multiple stenoses.

Study Design

  • Randomized
  • Parallel

Patient Populations:

  • STEMI patient undergoing PPCI
  • Successful PCI of IRA
  • Stenosis of 50% or more in one or more coronary arteries other than IRA, which were deemed feasible by PCI

    Number screened: 2,428
    Number of enrollees: 465
    Duration of follow-up: 36 months
    Mean patient age: 62 years
    Percentage female: 22%

Exclusions:

  • Cardiogenic shock
  • Prior CABG
  • Noninfarct IRA of >50% in left main trunk or ostia of left anterior descending/left circumflex artery
  • Noninfarct IRA was a chronic total occlusion

Primary Endpoints:

  • Composite of cardiovascular death/nonfatal MI/refractory angina at 36 months

Secondary Endpoints:

  • Noncardiac death
  • Repeat revascularization (PCI/coronary artery bypass grafting [CABG])

Drug/Procedures Used:

After completion of successful PPCI of IRA, patients were randomized to preventive PCI in noninfarct vessels with >50% stenosis, or to no further PCI. Staged PCI (i.e., at a later date) was discouraged.

Concomitant Medications:

Glycoprotein IIb/IIIa inhibitor (76%), bivalirudin (2.5%), aspirin (100%), statin (96%), thienopyridine (100%), and nitrate (18%)

Principal Findings:

A total of 465 patients were randomized, 234 to preventive PCI and 231 to IRA PCI only. Baseline characteristics were fairly similar between the two arms. Approximately 18% had diabetes mellitus, 8% had prior MI, and 4% had prior stroke. The infarct location was anterior in about a third of the patients, and inferior in 60%. Nearly two thirds of the patients had one other vessel with >50% stenosis; the remainder had three arteries. Approximately 40% of stents in the IRA were bare-metal stents, and 25% in the non-IRA stenoses. The mean number of stents in the non-IRA vessel(s) was 1.29. The percentage of patients receiving medical therapy was similar between the two arms throughout the trial.

The trial was terminated early due to overwhelming benefit with preventive PCI. The primary outcome (cardiovascular death/nonfatal MI/refractory angina) at 36 months was significantly lower in the preventive PCI arm (9% vs. 23%; hazard ratio 0.35; 95% confidence interval 0.21-0.58; p < 0.001). Benefit was noted as early as 6 months, and sustained thereafter. Significant reductions were noted for nonfatal MI (3% vs. 8.7%, p = 0.009) and refractory angina (5.1% vs. 13.0%, p = 0.002); there was a numerical reduction in cardiovascular death (4.7% vs. 11.7%, p = 0.07). Repeat revascularization was also lower (6.8% vs. 19.9%, p < 0.001).

Of the 231 patients in the preventive PCI arm, there were three complications, and five non-IRA PCIs were unsuccessful.

Interpretation:

The results of the PRAMI trial indicate that complete revascularization at the time of PPCI in STEMI, including nonculprit vessel PCI, is associated with significantly lower ischemic outcomes at 3 years as compared with IRA PCI alone (in patients who were otherwise clinically stable). These results are at odds with data from large registries showing a possible harm with non-IRA PCI. These are thus important results, and have the potential to change practice. Another trial on this topic, COMPLETE, is ongoing, and will provide further answers.

How can one reconcile the results of this study with those from studies such as COURAGE? It is possible that the acute MI milieu results in greater inflammation and greater propensity for non-IRA plaque rupture. In the PROSPECT study, recurrent events following index acute MI were equally common due to culprit lesions and nonculprit lesions. Although the majority of nonculprit vessels were angiographically mild, they appeared to have a high plaque burden on intravascular ultrasound (>70%), and had a minimal luminal area of 4.0 mm2 or less. It is possible that fractional flow reserve-guided PCI, as reported in the FAME-2 trial for NSTE-ACS, might further help guide decision making regarding nonculprit vessel PCI.

References:

Wald DS, Morris JK, Wald NJ, et al., on behalf of the PRAMI Investigators. Randomized trial of preventive angioplasty in myocardial infarction. N Engl J Med 2013;369:1115-23.

Presented by Dr. David Wald at the European Society of Cardiology Congress, Amsterdam, Holland, September 1, 2013.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention

Keywords: Inflammation, Registries, Myocardial Infarction, Stroke, Follow-Up Studies, Decision Making, Constriction, Pathologic, Confidence Intervals, Coronary Vessels, Angioplasty, Balloon, Coronary, Diabetes Mellitus, Stents


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