Two decades of better survival in acute MI was accompanied by changing patient demographics and greater use of certain evidence-based therapies, according to a cohort study of over 4 million Medicare beneficiaries.
From 1995 to 2014, there was a 38% relative decline in hospitalizations for acute MI (914 to 566 per 100,000 person-years), according to Harlan Krumholz, MD, SM, of Yale-New Haven Hospital in Connecticut, and colleagues.
Additionally, there were also observed improvements for those patients who were admitted:
- 30-day all-cause mortality: 20.0% to 12.4%
- 30-day all-cause readmissions: 21.0% to 15.3%
- 1-year recurrent acute MI: 7.1% to 5.1%
“From 1995 through 2014, the Medicare fee-for-service population experienced a remarkable and progressive improvement in the hospitalization rates for acute MI and the 30-day mortality rate after acute MI,” Krumholz’s group concluded in JAMA Network Open. They noted that such improvements held consistent across age, sex, race, and eligibility for Medicaid.
Almost all hospitals and counties showed improvement as well. Yet “health priority areas” — areas with persistently high mortality rates — had slower-than-average declines in acute MI mortality. “These areas may particularly benefit from future improvement activities,” the authors suggested.
The 20-year study period saw the median hospital stay drop from 6 days to 3 days with increased rates of 30-day inpatient catheterization (44.2% to 59.9%) and inpatient percutaneous coronary intervention (18.8% to 43.3%), but not coronary artery bypass graft surgery (14.4% to 10.2%).
This was also a time when the average acute MI patient became older (76.9 years in 1995 vs 78.2 years in 2014, P<0.001), suggestive of "progress in delaying the onset of acute MI," according to the authors.
Other changes included hospitalized patients being less likely to be female (49.5% to 46.1%) or white (91.0% to 86.2%, P<0.001 for both). And despite an increase in general comorbidities over the two decades, the proportions of patients with cerebrovascular disease, stroke, unstable angina, and valvular heart disease declined.
An increase in Medicare inpatient payments per acute MI discharge ($9,282 to $11,031, adjusted according to the 2014 Consumer Price Index) was seen, though the “total cost declined because the number of hospitalizations was greatly reduced,” the authors said.
As the study was based on Medicare fee-for-service patients ages 65 years or older, the results have questionable applicability to the Medicare Advantage population and younger patients, they acknowledged.
The study was restricted to the 1995-2014 period to keep billing codes consistent. However, limitations included the lack of granular data such as troponin or door-to-balloon times for adjustments.
“Previous studies have reported some of these improvements, but not as comprehensively, or over a 20-year period or across the entire United States. As such, this work reveals novel insights about what has been achieved in reducing and mitigating acute MI among Medicare beneficiaries,” they maintained.
“Over the years, the use of evidence-based strategies improved dramatically. The speed of reperfusion therapy for ST-segment elevation acute MI also improved, as did the use of PCI in general,” the group concluded.
Krumholz reported personal fees from UnitedHealth, IBM Watson Health, Element Science, Aetna, Facebook, Arnold & Porter, and the Ben C. Martin Law Firm; grants from CMS, Medtronic, Johnson & Johnson, and the FDA; and founding the personal health information platform Hugo. Co-authors also reported disclosures.