STEMI Patient Population Evolves Over 15 Years

MUNICH, Germany—Patients hospitalized for ST-segment elevation myocardial infarction (STEMI) have changed in the past 15 years, with a shift toward a younger population lacking comorbidities or previous heart disease, according to registry data presented on August 27 at the European Society of Cardiology (ESC) Congress 2012. The results, simultaneously published in the Journal of the American Medical Association, show drastic reductions in mortality directly linked to increased reperfusion use and better medical management.

Nicholas Danchin, MD, PhD, of the Hôpital Européen Georges Pompidou (Paris, France), and colleagues analyzed data from 6,707 STEMI patients admitted to intensive care or coronary care units and recorded in 4 French registries that each conducted 1-month follow-up:

• USIK 1995: 312 centers, 1536 patients
• USIC 2000: 369 centers, 1844 patients
• FAST-MI 2005: 223 centers, 1611 patients
• FAST-MI 2010: 213 centers, 1716 patients 

Mortality Drops Drastically

During the study period, the average age of all patients decreased from 66.2 years to 63.3 years (P < 0.001), with a concomitant decline in history of cardiovascular events and comorbidities. Over time, the proportion of STEMI patients who were women younger than 60 increased from 11.8% to 25.5%, consistent with their increased prevalence of smoking (37.3% to 73.1%) and obesity (17.6% to 27.1%). Younger patients developing STEMI, particularly women, were more likely to be without hypertension, diabetes, or hypercholesterolemia.

All-cause 30-day mortality (primary endpoint) decreased from 13.7% in 1995 to 4.4% in 2010. In men it decreased from 9.8% to 2.6%, while in women it went from 23.7% to 9.8%. Consistent with the decrease in mortality, major hospital complications related to STEMI were also lower. In addition, time from symptom onset to hospital admission decreased, with a shorter time from onset to first call and broader use of mobile intensive care units.

Reperfusion therapy increased from 49.4% to 74.7%, driven by primary PCI (11.9% to 60.8%). Early use of recommended medications also increased, particularly low-molecular-weight heparin and statins.

Multivariable analysis showed a consistent reduction in mortality from 1995 to 2010 after controlling for clinical characteristics plus baseline risk of the population and use of reperfusion therapy, with odds mortality ratios of 0.39 (95%, CI 0.29-0.53; P < 0.001) in 2010 compared with 1995.

Concern Over Obesity

According to the JAMA paper, the French registry results are consistent with others in the United States and Europe. “Within the STEMI population targeted by these sequential registries, the relative proportion of older patients has decreased, while the proportion of younger men and the proportion and numbers of younger women have increased,” they write. “These observations suggest that future reductions in the incidence and mortality related to AMI will need specific targeting of preventative measures toward younger women and possibly younger men.” 

In commentary after the presentation, discussant Filippo Crea, MD, of the Catholic University of the Sacred Heart (Rome, Italy), said the study was “excellent” overall, but noted some “minor weaknesses,” including potential biases related to the prevalent inclusion of large volume hospitals, lack of information on infarct size, microvascular obstruction and ejection fraction at discharge, and lack of follow-up data on recurrence of acute coronary events.

What is most concerning, Dr. Crea said, is the direct relationship between STEMI rates and rising obesity in younger patients. “The prevalence of obesity and its increase over time is higher in English speaking countries, although I don’t think that English is the problem. In France the prevalence is lower, but it keeps increasing over time and we expect it to keep increasing over the coming years. 

“This survey confirms in real life what has been shown in randomized trials,” Dr. Crea observed, crediting more knowledgeable patients, higher statin use, and better overall medical management for making some headway in lowering STEMI mortality. Still, “the battle against risk factors is not over.”

 

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Source:
Puymirat E, Tabassome S, Steg PG, et al. Association of changes in clinical characteristics and management with improvement in survival among patients with ST-elevation myocardial infarction. JAMA. 2012;Epub ahead of print.

 

 

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