No Downside to Immediate Complete Revascularization in ACS: BIOVASC

NEW ORLEANS, LA—Operators looking to completely revascularize ACS patients with multivessel coronary artery disease now have additional evidence that doing an immediate procedure is as safe as staging procedures to achieve complete revascularization over the next few days or weeks.

Data from the BIOVASC study, presented Sunday as a late-breaking clinical trial at the American College of Cardiology/World Congress of Cardiology (ACC/WCC) 2023 meeting and published simultaneously in the Lancet, showed that immediate complete revascularization was noninferior to staged complete revascularization in patients with ACS, including those with NSTEMI and unstable angina. In the staged group, the nonculprit vessels were typically treated within 4 to 28 days (mean 15 days).

At 1 year, there was no significant difference in the primary endpoint of all-cause mortality, any MI, unplanned ischemia-driven revascularization, or cerebrovascular events between the two strategies. Immediate revascularization of all coronary lesions was associated with lower rates of MI, as well as lower rates of unplanned ischemia-driven revascularization, when compared with the staged approach.

“The main message is that physicians shouldn’t be concerned about doing everything at once, doing everything during the index procedures, especially if there is two-vessel disease or easy lesions that likely can be treated in a short time with not a lot of contrast,” lead investigator Roberto Diletti, MD, PhD (Erasmus University Medical Center, the Netherlands), told TCTMD. “It is something that is safe and feasible. Also, it’s likely reducing MI and revascularization rates. You’re probably doing them a better service without additional risk.”

Diletti said that patients treated with immediate complete revascularization had a significantly shorter hospital stay than those treated with staged procedures (3 vs 4 days; P < 0.001), adding that there is an economic implication to their study as well.

David Moliterno, MD (University of Kentucky, Lexington), who spoke with the media during a morning press conference, said BIOVASC provides evidence that operators can address all coronary lesions during the index PCI, but “can” does not always mean “should.” While there is an advantage to taking care of everything during the index PCI—namely that operators aren’t left wondering if they took care of the culprit lesion—there are also disadvantages.

“There are several reasons not to,” he told TCTMD. “If [patients] have compromised renal function or if you’ve already used too much contrast, but there are other reasons, too. There’s the fatigue factor. If it’s Saturday night and you’ve already done a couple of cases and the crew is tired, and you’re tired. You may decide we’re going to deal with this in a week or two. Maybe the patient is tired, or uncomfortable. There’s a lot of reasons why a patient might say no. I think you use your best judgement.”

Moliterno said many cath labs are currently tackling all coronary lesions immediately, as opposed to bringing the patient back, but these data provide confidence that it’s not inferior to the staged approach.  

COMPLETE and More

Numerous studies have demonstrated the benefits of complete revascularization, including the COMPLETE trial which showed that complete revascularization of nonculprit lesions in STEMI patients reduced the risk of cardiovascular death or MI. The benefits of complete revascularization were also demonstrated in the DANAMI 3-PRIMULTI study, as well as in CvLPRIT, two studies that included patients with STEMI.  A 2018 meta-analysis that included nine randomized trials of STEMI patients showed that complete revascularization was associated with lower long-term risks of cardiovascular mortality, MI, and repeat revascularization.

Left unclear, Diletti said, is the optimal timing of nonculprit-lesion revascularization.

The BIOVASC trial included 1,525 ACS patients (mean age 65.5 years; 77.8% male) with multivessel coronary artery disease. Of these, 764 underwent complete revascularization during the index procedure and 761 had complete revascularization performed within 6 weeks of the index PCI. Just under 40% presented to hospital with STEMI, while 51.8% had NSTEMI and 8.3% had unstable angina. Additionally, roughly 60% of patients had complex lesions, including 22.6% with type B2 and 37.7% with type C lesions. Immediate complete revascularization was performed off-hours in 27.1% of cases. 

At 1-year follow-up, the primary composite endpoint of all-cause mortality, MI, unplanned ischemia-driven revascularization, or cerebrovascular events occurred in 7.6% and 9.4% of the immediate and staged complete revascularization groups, respectively (P = 0.001 for noninferiority). In terms of MI and unplanned ischemia-driven revascularization alone, outcomes favored the immediate complete revascularization strategy.

BIOVASC Outcomes With Complete Revascularization  

“There was a clear advantage in terms of myocardial infarction for immediate complete revascularization and that advantage was mainly driven by early events,” said Diletti. Of the 15 MIs that occurred between the index and staged PCI, 11 were type 1 MIs while there four cases of stent thrombosis. 

Investigators also reanalyzed the data to exclude periprocedural-related MIs, noting there was an excess of these events in those undergoing staged complete revascularization. Even after excluding these events, immediate complete revascularization was noninferior to the staged strategy in terms of the primary endpoint (7.5% vs 8.7%; P = 0.004 for noninferiority). Additionally, there was still an excess of MI in the staged group compared with the immediate complete-revascularization study arm (1.7% vs 3.3%; P = 0.052).

Dipti Itchhaporia, MD (Hoag Memorial Hospital Presbyterian, Newport Beach, CA), the scheduled discussant during the late-breaking session, questioned the findings, particularly the “remarkably high” rate of MI in patients treated with staged complete revascularization. Diletti agreed that the rate of MI was high, pointing out that nearly half (44%) of MIs in the staged group occurred in the time window between the index and staged procedure. While the study protocol required a clear culprit lesion for randomization, it’s possible that operators misjudged the culprit lesion.

“So, they treated a lesion that wasn’t the actual culprit, and the actual culprit [led to] a second event in the very early phase,” he said. “The other possibility is that there are multiple unstable coronary plaques in acute coronary syndrome. Treating only the culprit doesn’t complete the job, let’s say. It’s not protecting the patient against an event occurring from the other plaques. In both scenarios, immediate complete revascularization would prevent those events.”

Intravascular Imaging and Functional Testing

Itchhaporia also pointed out that the majority of coronary lesions were treated based on visual assessment with angiography. Use of fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) was low—just 15.4% and 23.3% in the immediate and staged complete revascularization groups, respectively—as was the use of IVUS or OCT.

Speaking with the media, Moliterno highlighted the “remarkably” low rates of cardiovascular mortality in the trial: 1.3% and 0.9% with immediate and staged complete revascularization, respectively, a nonsignificant difference. Despite the low rates, he suspects that even better results would have been possible with greater use of functional testing or intravascular imaging.

“It’s a minor criticism of this trial,” he said. “One thing I think you could rethink would be that instead of fixing every blockage up front, spending more time on those blockages that are being dealt with initially, the culprit lesion. We know that optical coherence tomography can look for plaque erosion and plaque rupture so you can be sure you’re getting the appropriate culprit [lesion].” Like Diletti, Moliterno said it’s possible that operators are misjudging the culprit lesion, which would explain the MIs between the index and staged procedures.

Moliterno also pointed to the rate of probable or definite stent thrombosis was 0.8% in the immediate complete revascularization group and 0.9% in the staged group, rates that are too high in the modern era.    

Diletti said that their rate of FFR/iFR, as well as IVUS and OCT, is reflective of current European practice. “Use of imaging or physiology was left to operator discretion,” he said. “What we’re seeing is what we’re doing in everyday practice. In my opinion, it does reduce our ability to correctly detect the culprit lesion and to [optimize] treatment of the coronary lesion.”