Early Recurrent Events After Acute MI: Clues to Origins Hint at Solutions

Nearly half of patients with acute MI who return to the hospital with a recurrence die within 5 years, underscoring the need to identify predictors of these events and the means to prevent them, Cleveland Clinic researchers say.

For their study published in the Journal of the American Heart Association, Raunak Nair, MD (Cleveland Clinic, OH), and colleagues tracked the “timing of reinfarction, etiology, and outcome for all patients admitted with an early recurrent MI within 90 days of discharge” at their hospital over a 7-year time period.

“What we wanted is for our study to act as a benchmark of where we’ve reached now in our effort to provide the best care for MI patients,” with an eye toward areas with room for improvement, Nair told TCTMD.

The good news is that recurrent MIs were so rare—with an incidence of just 2.5%, he said. “However, the interesting part is that most of these reinfarctions were occurring in the very, very early period [within] 2 weeks and most of them in the first 2 days after discharge.”

This “reiterates how aggressive we need to be in educating our patients, in telling them how important it is to take their medications, to follow through,” Nair continued, adding that it emphasizes “shared responsibility between the provider and the patient” when it comes to risk factor control and lifestyle changes.

Kamil Faridi, MD (Yale School of Medicine, New Haven, CT), said looking at this real-world experience is valuable. “It can be a difficult question to sort out with national data, but I like what they did in this study. They really went into the details on patients within their health system,” he told TCTMD. And because of that “deep dive,” they found revealing information that offers lessons for clinical practice, Faridi commented.

Risk Peaks Just After Discharge

Nair et al analyzed 6,626 acute MI admissions at their center between January 1, 2010, and January 1, 2017. There were 2,051 readmissions (by 1,389 patients) within 90 days of discharge; 168 were due to recurrent MI (traced back to 155 index admissions).

“The instantaneous risk of readmission with an early recurrent MI peaked at 2 days after hospital discharge and the vast majority occurred within the first 2 weeks after hospital discharge,” they report.

Among the 168 recurrences, two-thirds underwent diagnostic left-heart catheterization. PCI was performed in 46% of patients with recurrent MI, while another 46% continued medical management and just 8% underwent CABG surgery.

The most common etiologies were stent thrombosis (17%), disease progression (12%), unchanged CAD (11%), new vessel obstruction (10%), and multivessel disease (10%). A minority were related to type 2 MI, in-stent restenosis, a planned procedure, or nonobstructive disease. For 21%, the cause was unknown.

Patients readmitted for another MI were less likely to be white (60% vs 72%), more likely to be Black (37% vs 24%), and more apt to have chronic kidney disease (32% vs 24%) than those who didn’t return to the hospital. Their index event was more likely to be NSTEMI (78% vs 71%), and they were less commonly treated with CABG (8% vs 16%) but more often with medical management (46% vs 34%). Nearly half had PCI during their initial hospital stay.

Independent predictors of these early recurrences on multivariate analysis were Black race, higher peak troponin T, shorter index hospital stay, lower hemoglobin during admission, and medical management.

Seventy-eight out of 168 patients (46%) with early recurrent MI died. Morality was 30% at 1 year, then rose steadily thereafter to reach 44% at 3 years and 49% at 5 years. Patients readmitted with NSTEMI were more likely to survive than those who returned with STEMI, as were those whose recurrences could be attributed to stent thrombosis versus other causes. By comparison, patients without early recurrent MI had all-cause mortality rates of 5%, 13%, and 22%, respectively, at 1, 3, and 5 years.

How to Make It Better

“Though these are uncommon recurrences, when these happen, [they have] significant implications for long-term mortality,” said Nair. Prevention will require a team-based approach, he added. “It’s not just the proceduralist: it’s [also] the general cardiologist, it’s the [primary care physician], it’s the patient. Everybody has their part to play.”

As to why a third of the index MIs had been managed medically, Nair pointed out that “these patients might be inherently more sick,” with characteristics that deter intervention, or might have expressed their preference to not undergo revascularization.

Faridi, too, drew attention to this subgroup, noting that patients at the highest risk of poor outcomes are those who potentially stand to gain the most from revascularization.

“But in clinical practice, it can be tough to decide about whether to have patients undergo a procedure. Generally, left-heart catheterization is a safe procedure for most patients, [though] there are certainly some absolute contraindications,” he said. Clinicians also may be reluctant to send patients with poor long-term prognoses (eg, those with end-stage cancer or active bleeding) for catheterization, explained Faridi. “It’s really a patient-by-patient decision.”

Additionally, Nair and colleagues urge close attention to transitions of care as a path toward better outcomes, given that the first 2 days after discharge are a vulnerable time. “This signifies that factors that promote reinfarction are probably in play even before patients leave the hospital,” they say, adding that “predischarge planning, patient education with readback, incorporating health information technology, proper medication reconciliation, scheduling appropriate follow-up appointments before discharge, follow-up telephone calls, and postdischarge home visits are all effective methods.”

Faridi agreed that this is a key takeaway. “This is really a time period where it’s easy to drop the ball with medical management, just because the healthcare system can be very complicated,” he observed.

“It’s always important when we take care of patients in the hospital to make sure [they] have their medications, or at least have a really good plan for getting them right after they leave the hospital, so that they can make sure they take their dual antiplatelet therapy and reduce the risk of in-stent thrombosis,” Faridi advised. “Not only do they need them, they also need to be able to afford them.”