Heart failure post-MI more frequent in women than men

Women who are hospitalized for myocardial infarction (MI) have a higher risk of long-term negative cardiovascular outcomes compared with men, according to a recent study from Canada.

“[W]omen present with older age and greater burden of comorbidities, have a lower chance of surviving their index MI, and more often developed heart failure (HF) at the time of MI,” said the researchers.

The population comprised 45,064 individuals aged >20 years from Alberta, Canada, who were hospitalized due to a first incidence of MI between April 2002 and March 2016 (30.8 percent female). Of these, 54.9 and 45.1 percent had non–ST-segment–elevation MI (NSTEMI) and STEMI, respectively. Patients were followed up for a median 6.2 years.

Female patients were older than male patients (median age 72 vs 61 years), had more comorbidities, and were less likely to have undergone diagnostic angiography (74 percent vs 87 percent) or received consultation from a cardiovascular specialist while in hospital (72.8 percent vs 84.0 percent; p<0.0001) than men. Revascularization procedures (primary coronary intervention or coronary artery bypass graft) were significantly less frequent in women than men. Women were also less likely to be prescribed β-blockers, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, lipid-lowering therapy, or P2Y12 receptor antagonists. [Circulation 2020;142:2231-2239]

Angiography-detected left main, two-vessel disease with proximal left anterior descending or three-vessel disease was less common in women than men (33.4 percent vs 40.9 percent), while one-vessel disease or nonobstructive coronary artery disease (CAD) was more common in women (39.6 percent vs 29.1 percent; p<0.0001 for both).

The risk of in-hospital mortality was higher among women than men with STEMI (adjusted odds ratio [adjOR], 1.42, 95 percent confidence interval [CI], 1.24–1.64), but not NSTEMI (adjOR, 0.97, 95 percent CI, 0.83–1.13).

In patients with STEMI, post-discharge mortality was higher among women than men (24.6 percent vs 14.5 percent) and remained higher 1 and 5 years after their index MI hospitalization, though the risk reduced over time. Post-discharge mortality was higher in women than men with NSTEMI (29.9 percent vs 20.2 percent), though mortality risk was comparable between men and women at all three time points.

In-hospital development of HF was higher in women than men with STEMI (adjOR, 1.26, 95 percent CI, 1.13–1.4) and NSTEMI (adjOR, 1.2, 95 percent CI, 1.1–1.32), as was post-discharge HF (STEMI: 22.5 percent vs 14.9 percent; NSTEMI: 23.2 percent vs 15.7 percent). This risk remained consistently higher 1 and 5 years after the index MI admission (STEMI: adjusted hazard ratios [adjHRs], 1.21 and 1.18, respectively; NSTEMI: adjHRs, 1.18 and 1.17, respectively).

This higher HF risk in women did not differ by MI type nor reduce over time. However, the effect size of the composite of HF and death decreased over follow-up (STEMI: adjOR, 1.37 at index and adjHRs, 1.26 and 1.2 at 1 and 5 years, respectively; NSTEMI: adjOR, 1.16 and adjHRs, 1.13 and 1.08, respectively).

“Identifying when and how women may be at higher risk for HF after a heart attack can help providers develop more effective approaches for prevention,” noted study lead author Professor Justin Ezekowitz, co-director of the Canadian VIGOUR Centre at the University of Alberta, Edmonton, Alberta, Canada.

“Better adherence to reducing cholesterol, controlling high blood pressure, getting more exercise, eating a healthy diet, and stopping smoking, combined with recognition of these problems earlier in life, would save thousands of lives of women – and men,” he added.

Co-author and co-director of the Canadian VIGOUR Centre, Adjunct Professor Padma Kaul, advocated research into identifying if patients, particularly women, were receiving best care.

“There are gaps across diagnosis, access, quality of care, and follow-up for all patients, so we need to be vigilant, pay attention to our own biases and to those most vulnerable to ensure that we have done everything possible in providing the best treatment,” she said.

The researchers acknowledged several limitations including potential confounding, the lack of information on biomarkers or time to treatment, or patient or physician preferences.