A new 25-year study reveals that mortality after an acute myocardial infarction (AMI) and repeat events are coming down for all older Americans. But it also highlights the need for more work, especially efforts to root out healthcare inequities.
Among 3.9 million Medicare beneficiaries who were alive 30 days after an AMI, the 10-year mortality risk was 13.9% lower for patients hospitalized in 2007 to 2009 compared with those hospitalized in 1995 to 1997.
The 10-year risk of recurrent AMI was 22.5% lower in 2007 to 2009, the last 3 years for which 10-year follow-up data were available.
The reductions continued over the study period (1995 to 2019) and were seen across all demographic subgroups, the investigators reported online in JAMA Cardiology.
“Survival continues to get better over time, year on, year out long-term and so does the risk of a repeat heart attack, so that’s the good news,” Harlan Krumholz, MD, Yale New Haven Hospital and Yale School of Medicine, New Haven, Connecticut, said in an interview. “But there’s also information in the paper that we shouldn’t be complacent.”
He noted that rates of repeat AMI are still quite high, even though they’re coming down, and that there are missed opportunities to get AMI survivors to reduce their risk through proven medications, smoking cessation, and blood pressure control.
“We should be happy with the progress, but we should know we’re not done; we’ve got a ways to go,” he said. “And then this health equity issue is glaring, still.”
The researchers found that being Black or dual eligible for Medicare and Medicaid was independently associated with higher 10-year, all-cause mortality and recurrent AMI risk.
The same was true for patients living in health priority areas, which the investigators previously reported are defined by persistently high adjusted mortality and hospitalization rates and concentrated in the South.
After inverse propensity weighting, the adjusted mortality hazard ratios (HRs) were 1.05 for Black vs white patients, 1.24 for dual-eligible vs noneligible patients, and 1.06 for residents of health priority areas vs other areas.
“Black Americans and Medicare beneficiaries are still lagging behind their white counterparts with regard to their survival experience,” Krumholz said. “We need to accelerate our improvement for Black patients because there’s no biological reason they should be lagging in their outcomes. Race is a social construct and there’s something going on with regard to social determinants.”
Women had higher observed 10-year mortality and recurrence rates (75.2% and 27.8%, respectively) than men (70.6% and 26.6%). But after adjustment, this flipped and men had higher HRs for both outcomes, at 1.13 and 1.07, respectively.
Over the 25-year study period, the observed 10-year mortality rate was 72.7% and the adjusted annual reduction was 1.5% (95% CI, 1.4 – 1.5).
Secondary analyses showed that 10-year mortality was 80.3% for patients with ST-segment elevation MI (STEMI) vs 72.2% for those with non-STEMI. The adjusted 10-year risk of death was 15% higher for patients with STEMI (HR, 1.15; 95% CI, 1.14 – 1.16).
The 10-year recurrent AMI rate was 27.1%. This was threefold higher than the 1-year recurrence rate of 8.9% reported among Medicare beneficiaries in 2010, the authors note.
The adjusted annual reduction in recurrent AMI was 2.7% (95% CI, 2.6 – 2.7). Further, having a recurrent AMI was associated with an 8-percentage point increase in 10-year mortality risk.
The median time to a repeat MI within 10 years was 488 days, suggesting the importance of follow-up for AMI survivors beyond the traditional 1-year period, they suggest.
Krumholz noted that the data will need to be revisited in the wake of the COVID-19 pandemic, which disrupted follow-up care for AMI patients and saw a significant drop in MIs presenting to hospitals.
“There’s a lot to learn about what happened in the pandemic, but it’s likely that whatever inequities and issues that we’re identifying before the pandemic, if anything, are probably only worse now,” he said. “It’s an urgent call for action to try to improve those areas that we’re identifying.”
The authors noted that they were unable to separate Hispanic ethnicity from white, Black, and other race and that diagnostic codes were used to define comorbidities, which could have influenced the results. Other limitations are the inability to evaluate troponin levels and to incorporate the use of secondary prevention medications, post-acute care medication adherence, nursing home stays, home health visits, and physician office visits, which are associated with outcomes.
Krumholz disclosed personal fees from UnitedHealth, Element Science, Reality Labs, Aetna, Tesseract/4Catalyst, F-Prime, the Siegfried & Jensen law firm, Arnold & Porter law firm, and Martin/Baughman law firm; is a cofounder of Refactor Health and HugoHealth; and is associated with grants and/or contracts from the US Centers for Medicare & Medicaid Services through Yale New Haven Hospital and Johnson & Johnson through Yale University. No other disclosures were reported.
JAMA Cardiol. Published online May 4, 2022. Abstract