Under 40, or 10 Years Older: MI Survivors Face Similar Long-term Mortality Risks

Despite being about a decade younger when they had their MIs, patients whose event occurred before age 40 have long-term risks of mortality comparable to MI patients in their 40s, new data from the YOUNG-MI registry show.

Over more than 10 years of follow-up, very young MI survivors did not have significantly lower risks of either all-cause death (HR 0.72; P = 0.056) or CV death (HR 0.83; P = 0.447), Ron Blankstein, MD (Brigham and Women’s Hospital, Boston, MA), reported on a web briefing with reporters.

He noted that even though most baseline risk factors did not differ between patients who were younger than 40 and those who were 40 to 50 years old when they had their MI, the very young patients were less likely to have hypertension (37% vs 49%) but more likely to report use of cocaine or marijuana (18% vs 9%).

The findings—which are scheduled to be presented by Junjie Yang, MD (Brigham and Women’s Hospital), later this month at the American College of Cardiology 2019 Scientific Session in New Orleans, LA—“suggest that we have to be aggressive among individuals who had a myocardial infarction in terms of . . . secondary prevention for lowering their risk of a subsequent MI, and specifically for those under the age of 40, we need to be aware that there [are] unique things that may drive their risk,” Blankstein said, referring to substance abuse and coronary dissections.

Salim Virani, MD, PhD (Baylor College of Medicine and Michael E. DeBakey VA Medical Center, Houston, TX), who moderated the briefing, said that having an MI before age 40 is uncommon but that these very young patients make up “an extremely important subgroup to target [for] preventive efforts.”

He called MI in the very young an important public health issue, adding that there is a need to think about both traditional and unique risk factors in this population. “At the same time,” Virani said, “we have to make sure that the secondary prevention therapies are used as aggressively in these very young patients as one would in any other patient who has had a myocardial infarction.”

Young MI a Growing Problem

Substantial progress has been made in recent decades in terms of reductions in MI and death related to coronary heart disease, but not all demographic groups have reaped the same benefits, Blankstein pointed out. Gains have not been as great in younger adults, particularly women, who are making up a proportionally larger share of MIs over time.

“This is really puzzling,” Blankstein said.

To take a deeper look at young patients with MI, Blankstein’s team designed the YOUNG-MI registry, which retrospectively included patients 50 or younger who had an MI and received treatment at the Brigham or Massachusetts General Hospital between 2000 and 2016. This analysis focused on 2,097 patients with type 1 MI; 20.6% were younger than 40.

Blankstein explained that patients younger than 40 are unlikely to be treated with preventive therapies like statins because risk assessment tools are typically used in populations older than 40. A prior analysis of the YOUNG-MI registry, in fact, showed that only 12.5% of patients who had an MI at age 50 or younger were on statins before the event.

“So this is why we specifically are looking at folks less than 40 knowing that nobody really would think of them as being high risk if you were to see them in the clinic a week before their myocardial infarction,” Blankstein said.

The new analysis showed that there was a 10-year gap in median age between the very young patients and the rest of the cohort (36 vs 46 years). Most other baseline characteristics—except for rates of hypertension and substance abuse—were similar in the two groups.

Renewed Focus on Lifestyle

One would expect that the younger cohort would have had a better long-term prognosis after MI simply based on age, and it’s concerning that that’s not what was observed, commented R. Todd Hurst, MD (Center for Cardiovascular Health, Banner – University Medicine Heart Institute, Phoenix).

Rather than being falsely reassured by their age and [thinking] that because of the benefits of youth that they are going to do well and we don’t need to be as aggressive with them, it’s the opposite. R. Todd Hurst

“Age is far and away the most heavily weighted factor when we look at heart disease and its risk and how people are going to do with that, so it really goes against what we would think intuitively that younger people are going to do better,” Hurst told TCTMD.

There are probably multiple reasons to explain it, he said, highlighting the possibilities that younger patients present later because they are less likely to recognize symptoms of concern, that physicians aren’t immediately thinking about MIs when young patients come in with chest pain, or that patients under 40 are not being as aggressively treated with preventive therapies because of their age.

“Rather than being falsely reassured by their age and [thinking] that because of the benefits of youth that they are going to do well and we don’t need to be as aggressive with them, it’s the opposite,” Hurst said. “We need to be extra aggressive with their prevention regimens and recommendations because they’re not doing as well and they have so much life ahead of them that is at risk.”

As for how to respond to the leveling off or even reversal of declines in mortality related to heart disease in younger age groups, trends driven by a rising burden of risk factors, Hurst said the medical community needs to bring renewed focus to primary prevention.

“Lifestyle issues are becoming the biggest problem that we have in healthcare,” he said. “We’ve been really good about treating acute illness. We are going to have to get better about treating chronic disease and helping people improve their lifestyle choices.”