Frailty Extra Risky in Young Patients With Acute MI

Frailty manifests differently by age among patients who’ve experienced acute MI, a population-based study shows. While it is consistently linked to worse outcomes, people younger than 55 feel the strongest effects.

Using national administrative data from England and Wales, researchers found that younger adults with severe frailty had a more than threefold higher risk of 1-year all-cause mortality compared with similarly frail peers ages 75 and up. Importantly, too, the main drivers of their frailty were cardiometabolic in origin, whereas for older patients, frailty tends to manifest more conventionally.

Muhammad Rashid, MBBS, PhD (University of Leicester and Keele University, England), senior author of the new report, told TCTMD that it challenges the notion that frailty is restricted to the elderly. Simply put, he noted, frailty can be defined as a “state of heightened vulnerability where the body doesn’t bounce back from the stressor,” in this case acute MI.

“When you say frail, then instantaneously in your head what clicks is you’re talking about an 80-year-old [who has] typical geriatric syndrome, or limited mobility, limited function, and limited physiological reserves,” he said, noting that this is the first study to introduce the idea of frailty in the younger acute MI population. “We wanted to basically look a little bit deeper into this: how, as you get older, the frailty health deficits accumulate in patients and how they’re different [for the young].”

What they found—much worse outcomes when frailty develops in younger versus older acute MI patients—came as a surprise, Rashid noted. The disparate phenotypes between the age groups, he added, give clues as to what’s driving that higher risk.

For clinicians, the takeaway is “don’t trust the age on the wrist band,” he stressed. “If you’re seeing a young patient with the cluster of metabolic conditions—that high-risk, phenotypically different patient—then treat them as high risk. Don’t think: ‘This is a 40-year-old who’s going to be a bread-and-butter patient for me.’” In these patients, standard care may not produce the expected outcome, he noted. “We need to be aware of that.”

Led by Hasan Mohiaddin, MBBS (University of Leicester and Keele University), the study was published online recently in the European Heart Journal.

Outsized Impact on Mortality

The analysis included 931,133 acute MI patients (34.1% female) in England and Wales who were stratified into three age groups—up to 55 years, 55-74 years, and 75 years or older. Patients were also categorized as being fit (29%) or having mild (36%), moderate (22%), or severe frailty (13%) as defined by the Secondary Care Administrative Records Frailty (SCARF) index. Just 2.4% of the youngest group was severely frail, as compared to 21.7% of the oldest group.

Patients younger than 55 tended to have the highest median body mass index, were more likely to smoke, and were more likely to undergo angiography followed by PCI, while those ages 55-74 years were more apt to undergo CABG. The oldest group had the highest prevalence of women, comorbidities, and NSTEMI.

The analyses were adjusted for numerous confounders, including year of admission, age, sex, ethnicity, smoking, creatinine, LV function, Killip class, ST-segment elevation, biomarkers of myocardial injury, hypercholesterolemia, cardiac arrest, family history of CAD, in-patient revascularization, in-hospital pharmacotherapy, and referral for cardiac rehabilitation on discharge.

With these factors accounted for, all-cause mortality was higher across the board for severely frail versus fit patients, with the strongest association seen in the youngest group. Risks of other outcomes, including cardiovascular mortality, MACE, heart failure, reinfarction, and bleeding, also rose alongside frailty.

All-Cause Mortality Risk at 1 Year After Acute MI: Severely Frail vs Fit Patients

Among patients with severe frailty, the risk of all-cause mortality was nearly four times higher for younger versus older individuals (HR 3.51; 95% CI 3.11-3.96). Even with mild frailty, people younger than 55 versus 75 or older had a higher risk (HR 1.32; 95% CI 1.20-1.47).

The greatest loss of life-years due to premature mortality was seen in the youngest patients, whose lifespan was, on average, 6.1 years shorter compared with the general population.

Don’t trust the age on the wrist band. Muhammad Rashid

The difference in phenotypes between younger versus older individuals is “a distinction crucial for clinical interpretation” of their findings, Mohiaddin et al stress.

For younger people, frailty in this dataset was “driven by an accelerated accumulation of cardiovascular and metabolic comorbidities,” the authors explain, specifying that cancer doesn’t appear to be a big driver of early-onset frailty. Instead, the study suggests key contributors for young adults are diabetes, hypertension, heart failure, and prior ischemic heart disease.

“This contrasts with frailty in older patients, who more frequently exhibit traditional geriatric syndromes such as falls and arthritis, aligning more closely with the conventional concept of frailty,” they point out.

Thus, frailty appears not to be “solely an age-related syndrome of physical decline,” the investigators say. They advise it should be defined not by the “specific type of health problem, but by the quality of accumulative deficits [that] collectively erode physiological reserve and confer a state of heightened vulnerability to stressors.”

Rashid said that, in terms of research, the next step is determining how best to assess frailty in the younger acute MI population, since currently available tools are based on older patients. With this pinned down, it also will be important to evaluate what specific interventions—apart from standard secondary prevention—can help improve outcomes for the young. These might include an extra emphasis on cardiac rehabilitation or closer follow-up, he suggested.