Major medical societies released updated guidelines on Oct. 21 regarding multivessel PCI and thrombus aspiration in patients with STEMI undergoing primary PCI.

The guidelines from the American College of Cardiology, American Heart Association and Society for Cardiovascular Angiography and Interventions were published online in the Journal of the American College of Cardiology and Catheterization and Cardiovascular Interventions. They were developed in collaboration with the American College of Emergency Physicians.

The committee reviewed trials presented at major cardiology meetings from 2013 to 2015 and published in peer-reviewed medical journals through August 2015.

The reviewers mentioned approximately 50 percent of patients with STEMI have multivessel disease. Treatment options include culprit artery-only primary PCI with PCI of nonculprit arteries only for spontaneous ischemia or intermediate- or high-risk findings on predischarge noninvasive testing; multivessel PCI at the time of primary PCI; or culprit artery-only primary PCI followed by staged PCI of nonculprit arteries. However, trials have had differing results on which option is the best.

Previous guidelines recommended against PCI of nonculprit artery stenoses at the time of primary PCI in hemodynamically stable patients with STEMI, according to the reviewers. Since then, four randomized controlled trials showed that multivessel PCI may be beneficial and safe in some patients with STEMI.

The updated guidelines upgraded the recommendation from Class III to Class IIb with regard to routine multivessel primary PCI of noninfarct related arteries in hemodynamically stable patients with STEMI. The reviewers mentioned they were not endorsing the routine performance of multivessel PCI in all patients with STEMI and multivessel disease and noted that physicians should integrate clinical data, lesion severity/complexity and risk of contrast nephropathy before determining how to proceed.

“While we knew that treating the culprit artery that is completely blocked by implanting a stent is beneficial, it was previously not considered safe to treat other partially blocked (nonculprit) arteries during the same procedure,” Glenn N. Levine, MD, FACC, FAHA, co-chair of the writing committee, said in a news release.

The guideline recommendations have not changed for PCI of a non–infarct-related artery at a time separate from primary PCI in patients who have spontaneous symptoms and myocardial ischemia or who have intermediate- or high-risk findings on noninvasive testing.

The reviewers also mentioned the optimal timing of nonculprit vessel PCI had not been determined, although observational studies and a meta-analysis found multivessel staged PCI may be associated with better outcomes compared with multivessel primary PCI.

In addition, they changed a prior Class IIa recommendation for aspiration thrombectomy before primary PCI and noted that they did not recommend routine aspiration thrombectomy before primary PCI. They added that there has been no clinical benefit found for routine rheolytic thrombectomy in patients with STEMI undergoing primary PCI.