STEMI Complete Revascularization: No Point in Waiting

AMSTERDAM -- When it comes to timing the complete revascularization for heart attack patients with multivessel disease, treating multiple vessels in one session in the catheterization lab proved noninferior to staged angioplasty in the MULTISTARS AMI trial.

Results of immediate multivessel percutaneous coronary intervention (PCI) were at the very least similar to those of staging a follow-up procedure 19-45 days after successful primary PCI of the culprit artery in ST-segment elevation myocardial infarction (STEMI), according to Barbara Stähli, MD, MPH, MBA, of University Hospital Zurich in Switzerland.

The combined rate of all-cause mortality, myocardial infarction (MI), stroke, unplanned ischemia-driven revascularization, or hospitalization for heart failure was 8.5% at 1 year after immediate multivessel PCI and 16.3% with staged multivessel PCI (risk ratio [RR] 0.52, 95% CI 0.38-0.72), allowing the upfront PCI strategy to meet criteria for both noninferiority and superiority, Stähli reported here at the European Society of Cardiology (ESC) Congress.

The results of MULTISTARS, counting over 800 participants, were simultaneously published in the New England Journal of Medicine.

Stähli cautioned against interpreting the noninferiority trial as a win for immediate multivessel PCI in this setting.

"The operator and the patient can now decide [and] we show that for the first time. This was not clear, we had observational data pointing towards increased event rates when you do immediate multivessel PCI in STEMI patients. We show that you can do it, and it's noninferior to staged multivessel PCI," she said during a press conference.

The investigators noted that their study extends the findings of COMPLETE, in which complete revascularization was performed as a staged procedure in all patients, and immediate PCI of nonculprit lesions during the index STEMI procedure was not a comparator. Another trial that favored immediate revascularization was BIOVASC, conducted in the wider setting of acute coronary syndrome.

In MULTISTARS, no between-group differences were observed in mortality, stroke, and heart failure hospitalization rates. However, immediate multivessel PCI was associated with significant reductions in MI (2.0% vs 5.3%; RR 0.36, 95% CI 0.16-0.80) and unplanned revascularization (4.1% vs 9.3%; RR 0.42, 95% CI 0.24-0.74).

Such upfront treatment of nonculprit lesions apparently also reduced total contrast volume (median 250 mL vs 503 mL), total fluoroscopy time (18 min vs 34 min), and total procedure durations (73 min vs 157 min) required for each patient.

Other reasons for this strategy may include avoiding an additional arterial puncture, second hospitalization, and peace of mind for the patient, Stähli's group suggested.

"Of course, the individual patient characteristics need to be incorporated in the decision of whether to apply the MULTISTARS results. A patient with bad kidney function, for example, may not be a good candidate for this immediate approach. Also, if it is the middle of the night and the cath lab team is exhausted, it may not be wise to embark upon a very long case of nonculprit PCI," commented Deepak Bhatt, MD, MPH, of Mount Sinai Heart in New York City.

He told MedPage Today that the trial should influence clinical practice.

An open-label trial conducted at 37 sites in Europe, MULTISTARS AMI randomized STEMI patients to upfront multivessel PCI (n=418) or staged multivessel PCI (n=422).

Notably, patients with cardiogenic shock, need for emergency coronary artery bypass grafting, stent thrombosis, in-stent restenosis, chronic total occlusion of a major coronary artery, left main disease, and those not tolerating antithrombotics post-PCI were excluded.

Between both groups, median age was 64-66, and 77-80% were men. About half were former or current smokers, 15-16% had diabetes, and 5-7% had a previous MI.

Culprit lesions were most commonly the left anterior descending coronary artery and the right coronary artery. Over 80% of the cohort had just one additional vessel with significant nonculprit lesions.

In the staged arm, time to the second procedure took a median 37 days. About 3% of patients crossed over from immediate to staged multivessel PCI, and no patients crossed over from staged to immediate.

Adverse events such as stent thrombosis, acute kidney failure, and major bleeding were similar between the immediate and staged PCI groups.

One study limitation related to its open-label design was the possibility that "patients in the staged group might have been more likely to be referred for earlier ischemia-driven intervention when the coronary anatomy was known," Stähli and colleagues wrote.

"We also acknowledge the challenge that the diagnosis of procedure-related myocardial infarction in patients with STEMI may pose in the immediate and staged groups, and an increased risk of ascertainment bias for procedure-related myocardial infarction in the context of primary PCI as compared with staged elective PCI may have favored the immediate group," they added.

"However, there did not appear to be a substantial difference in the risk of a primary endpoint event in the trial groups after exclusion of procedure-related myocardial infarctions from the analysis," they argued.

Finally, COVID-19 affected patient recruitment in MULTISTARS and likely delayed procedures in some patients.

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