Recurrent Events Declining, But Remain a Serious Risk for Heart Attack Survivors

September 24, 2020

While rates of recurrent events have declined, the rates of decline have not been equal between sexes and risk of recurrent events still pose a serious risk to heart attack survivors.

New research from a George Institute for Global Health-led team suggests rates of recurrent heart attacks have declined but also revealed the declines seen in recent years were not equal between sexes.

While results indicated rates of recurrent events have declined from 2008-2017, data indicates the decline among men was slower than that among women and the risk for recurrent events and death remain high in heart attack survivors.

"We expected to see a decline in the rate of events, however, we did not expect the rates to differ between the sexes,” said lead investigator Sanne A. E. Peters, PhD, senior lecturer at The George Institute for Global Health, in a statement. “It may be that the improvements in men were achieved before our study period, leaving less room for improvement in the most recent decade. It could also be that the attention paid to heart disease in women over recent years has resulted in the greater gains.”

With significant advances in care and management of cardiovascular health in recent decades, investigators sought to further our understanding of declines in events between men and women who had suffered a previous event. To do so, they designed their study as an analysis of data from the MarketScan and Medicare databases between 2008-2017.

In total, investigators identified 770,408 women and 700,477 men who had a myocardial infarction during the aforementioned time frame for analysis. To avoid including duplicate patients, investigators excluded beneficiaries in the Marketscan database 65 years and younger and beneficiaries 66 years of age or older from the Medicare database. Inclusion criteria for the study were an overnight hospitalization for myocardial infarction of less than 30 days, live in the US, and have continuous coverage from 365 days prior to their admission date through the discharge date.

For the purpose of the analysis, investigators chose recurrent myocardial infarction, recurrent coronary heart disease (CHD) event, heart failure hospitalization, or death within 365 days of hospitalization. Investigators used Poisson regression models to estimate women-to-men risk ratios (RR) for each outcome in each calendar year. Of note, these models were adjusted for age, sex/ethnicity, region of residence, Medicare-Medicaid dual eligible, diabetes and use of insulin, history of CHD, history of stroke, history of heart failure prior to hospitalization, incident heart failure during the hospitalization, and a slew of other factors.

Upon analysis, the age-standardized recurrent myocardial infarction rates per 1000 person-years decreased from 89.2 to 72.3 in women from 2008-2017 and from 94.2 to 81.3 among men during that same time frame (P <.001). For recurrent CHD event rates, investigators noted declines from 166.3 to 133.3 in women and from 198.1 to 176.8 in men during that same time period (P <.001).

For heart failure hospitalization, rates decreased from 177.4 to 158.1 in women and from 162.9 to 156.1 among men (P=.001). For all-cause mortality, investigators observed rates decreased from 403.2 to 389.5 in women and from 436.1 to 417.9 in men (P=.82). Additionally, investigators found rate ratios of 0.90 (0.86-0.93) for recurrent myocardial infarction, 0.80 (0.78-0.82) for recurrent CHD events, 0.99 (0.96-1.01) for heart failure hospitalization, and 0.82 (0.80-0.83) for all-cause mortality when comparing risk for women versus men.

“Regardless of the improvements, the rates of recurrent events in people who survived a heart attack are still very high in both sexes. Patients should speak with their doctors to ensure that the get the right treatments to prevent secondary events and must make sure that they adopt or maintain a healthy lifestyle," added Peters.

This study, “Trends in Recurrent Coronary Heart Disease Following Myocardial Infarction Among US Women and Men Between 2008 and 2017,” was published in Circulation.