New recommendations validate the treatment of partially blocked vessels along with the culprit vessel in patients undergoing a primary percutaneous coronary intervention for ST-elevation myocardial infarction (STEMI).
While 2013 guidelines by the American College of Cardiology and the American Heart Association cautioned against multivessel interventions as nonbeneficial in STEMI, evidence from four recent randomized controlled trials now supports the practice as “reasonable,” the updated guidelines say.
Partially blocked vessels may be treated in hemodynamically stable patients at the time of PCI or as a planned staged procedure.
The guidelines, issued Oct 21 by the ACC/AHA and the Society for Cardiovascular Angiography and Interventions, with collaboration from the American College of Emergency Physicians, have been published online in Journal of the American College of Cardiology (2015 Oct 21;10.1016/jacc.2015.10.005), Circulation, and Catheterization and Cardiovascular Interventions.
The guidelines also downgrade a prior recommendation on routine use of manual aspiration thrombectomy before primary PCI to implant a stent, citing evidence from three randomized trials (INFUSE-AMI, TASTE, and TOTAL) in support of the new class III “no benefit” recommendation. Previously, the organizations had considered this treatment strategy reasonable.
For the advice on primary PCI and multivessel treatment, the guideline authors, led by Dr. Glenn N. Levine of Baylor College of Medicine in Houston, identified four trials (PRAMI, CvLPRIT, DANAMI 3-PRIMULTI, PRAGUE-13) in which multivessel PCI, either staged or at the time of primary PCI, was shown to be nonharmful or beneficial in selected patients with STEMI. In three of these trials, multivessel treatment was shown associated with significant reductions in risk of death and other cardiac events compared to culprit-vessel-only treatment.
Previously, “differing inclusion criteria, study protocols, timing of multivessel PCI, statistical heterogeneity, and variable endpoints” made study results on culprit-only vs. multivessel PCI conflicting, Dr. Levine and colleagues wrote.
While the more recent RCTs have helped clarify a benefit or at least lack of harm, “there are insufficient observational data and no randomized data at this time to inform a recommendation with regard to the optimal timing of nonculprit vessel PCI,” the authors wrote, saying further studies were needed. Clinical data, lesion severity and complexity, and the risk of contrast nephropathy should be considered when determining whether to perform primary or staged multivessel PCI.
Earlier recommendations in 2011 and 2013 favoring aspiration thrombectomy before primary PCI had been based largely on the results of one single-center randomized study enrolling about 1,000 patients (Lancet 2008;371:1915-20).
Since then, much larger trials have shown no significant differences in major cardiac events or death in people who received aspiration thrombectomy prior to primary PCI compared with PCI alone, and a meta-analysis of more than 20,000 patients across 17 trials found no significant reduction in death, reinfarction, or stent thrombosis associated with routine aspiration thrombectomy vs. PCI alone (Circ Cardiovasc Interv. 2015;8:e002258).
The guideline authors clarified that the downgraded recommendation of “no benefit” applies only to routine use of aspiration thrombectomy before primary PCI. Current data remain inadequate to determine a benefit for selective or “bailout” aspiration thrombectomy, which is thrombectomy that, though unplanned, had to be used during the procedure because of an unsatisfactory initial result or a complication.
Several of the ACC/AHA/SCAI guideline authors or reviewers, including both vice chairs of the PCI writing committee, disclosed industry relationships.