HBR Common, Impactful Among All-Comer Acute MI Patients

One-third of all patients with acute MI are at high bleeding risk (HBR) and, regardless of if they are managed medically or with PCI, end up with noticeably higher rates of both MACE and major bleeding over time, according to new registry data from England, Wales, and Sweden.

With limited data on how HBR patients fare over the long term, the data indicate that “perhaps these patients do have more to benefit from invasive procedures, albeit a slightly increased risk of bleeding complications,” senior author Mamas Mamas, BMBCh, DPhil (Keele University/Royal Stoke University Hospital, Stoke-on-Trent, England), told TCTMD. “The thing that should happen is that we need to think about bleeding risk more broadly, not just in the PCI population, but in the medically treated AMI population, and particularly for NSTEMI and patients who are medically managed.”

Moreover, Mamas said he was surprised by “the consistency of the results across the healthcare systems,” especially given that patients from Sweden and the UK have some differences, including in rates of anemia and moderate chronic kidney disease (CKD).

“I think we were expecting far fewer patients to be high bleeding risk,” he said, adding that the magnitude of the adverse outcomes seen in HBR patients was also unexpected.

The Academic Research Consortium (ARC)-HBR criteria, comprised of 20 major and minor clinical variables, were originally introduced in 2019 and have come to be incorporated into clinical practice as well as many studies, especially for the PCI population. However, HBR criteria may also overlap with frailty since they capture systemic vulnerability, say researchers.

The data, published online recently in European Heart Journal: Acute Cardiovascular Care with first author Nicholas Weight, MBChB (Keele University), illustrate how common HBR is among individuals who are not treated with PCI and what types of risks they face with medical management, researchers say.

Marco Valgimigli, MD, PhD (Cardiocentro Ticino Institute, Lugano, Switzerland), who was not involved in the study, said the findings aren’t new but rather confirmatory of other studies showing HBR rates ranging from 30 to 45%. As for why HBR patients might not be treated with PCI, he told TCTMD this is likely because of a higher comorbidity burden as well as frailty, with clinicians likely erring on the side of conservative practice.

“These patients, of course, by definition are very elderly patients, very fragile, and of course in approaching these patients, you always ask yourself the question whether this patient would benefit from a minimally invasive yet still invasive procedure,” Valgimigli said. “The answer is that they do benefit, perhaps not in terms of mortality, but they do benefit in terms of prevention of recurrent risk of nonfatal events, nonfatal MI.”

Such patients, he added, are often left out of studies, not necessarily because they aren’t approached but potentially because they decline.

As such, “it’s completely true that there is some uncertainty regarding if and how much these very elderly and very frail patients do benefit from invasive procedures,” Valgimigli said. “I would say [this study] is, in a way, reflective of the fact that we try to be good medical doctors and we try to offer invasive procedures to those who can tolerate them. [This] information is praising the quality of the clinical care more than criticizing it.”

MINAP and SWEDEHEART Findings

For the analysis, researchers looked at 563,251 and 189,102 patients with acute MI between 2005 and 2019 from England and Wales (MINAP registry) and Sweden (SWEDEHEART registry), respectively. In both cohorts, 39% of patients met ARC-HBR criteria. HBR patients were typically older than non-HBR patients in both the MINAP (mean age 81 vs 63 years) and SWEDEHEART registries (80 vs 66 years; P < 0.001 for both). They also had lower body mass index on average and presented with STEMI less frequently (P < 0.001 for all).

Medically managed patients were more likely to be older than 75 years and have cancer, anemia, or moderate/severe CKD than their invasively managed counterparts.

The 5-year risks of MACE and major bleeding (co-primary endpoints) were higher for HBR patients compared to non-HBR patients in both cohorts.

Primary Endpoints: HBR vs Non-HBR Patients With Acute MI

Additionally, increased risks of both MACE and major bleeding were observed for HBR compared with non-HBR patients regardless of if they were medically or invasively managed, a pattern seen across both registry cohorts.

Broader Thinking Needed

Given the results, Mamas said physicians will need to take a proactive approach in questioning why HBR patients aren’t undergoing revascularization. “Is it because of our own biases?” he asked. “Are we thinking that these patients perhaps are too high risk [so] we’re not offering them the same evidence-based interventions and the potential benefits that go along with them?”

With evidence lacking on antiplatelet therapy strategies in nonrevascularized patients, clinicians are limited in how they might prescribe these drugs to this population, he continued. “[We don’t know] whether they would also gain the same benefit from short DAPT [dual antiplatelet therapy] durations,” Mamas said. “There’s no reason to me why they wouldn’t, but again, we don’t have the trial data.”

He added: “This is a call for more evidence generation in this population.”

Valgimigli, who led the MASTER DAPT trial showing that a short course of DAPT in HBR patients receiving PCI lowers the risk of recurrent events, agreed that the antiplatelet conversation is an important one for this population.

“For [HBR] patients, anything beyond 1 month of dual antiplatelet therapy duration is clearly harming patients and still if you look into the guidelines, and still if you look into practice, this notion is not widespread,” he said. “These patients are receiving in clinical practice a much longer than a 1-month [course of] dual antiplatelet therapy.”

He also called for more and larger studies in this space. “The more we have, the more that is convincing to people. . . . There is absolutely need to design and conduct studies in specifically those patients [with HBR],” Valgimigli said.