Temporal trends in treatment of ST-elevation myocardial infarction among men and women in Switzerland between 1997 and 2011

Abstract

Background: Few data are available concerning the impact of gender on temporal trends in patients with acute ST-segment elevation myocardial infarction (STEMI).

Methods: All STEMI patients consecutively enrolled in the AMIS (Acute Myocardial Infarction in Switzerland) Plus project from 1997-2011 were included. Temporal trends in presentation, treatment and outcomes were analyzed using multiple logistic regressions with generalized estimations.

Results: Of 21,620 STEMI patients, 5786 were women and 15,834 men from 78 Swiss hospitals. Women were 8.6 years older, presented 48 minutes later with less pain, but more dyspnea, and more frequently had atrial fibrillation (5.5 vs. 3.9%, p<0.001), heart failure (Killip class >2) (9.7 vs. 7.3%, p<0.001), and moderate or severe comorbidities (24.8 vs. 18.2%, p<0.001). Women were less likely to undergo primary reperfusion treatment after adjustment for baseline characteristics and admission year (OR 0.80, 95% CI 0.71-0.90, p<0.001) or receive early and discharge drugs, such as thienopyridines, angiotensin-converting-enzyme inhibitors, angiotensin II receptor antagonists, and statins. In 1997, thrombolysis was performed in 51% of male and 39% of female patients; its use rapidly decreased during the 1990s and has now become negligible. Primary percutaneous coronary intervention increased from under 10% in both genders in 1997 to over 70% in females and over 80% in males since 2006. Patients admitted in cardiogenic shock increased by 8% per year in both genders. The incidence of both reinfarction and cardiogenic shock developing during hospitalization decreased significantly over 15 years while in-hospital mortality decreased from 10 to 5% in men and from 18 to 7% in women. This corresponds to a relative reduction of 5% per year for males (OR 0.95, 95% CI 0.92-0.99, p=0.006) and 6% per year for female STEMI patients (OR 0.94, 95% CI 0.91-0.97, p<0.001). Despite higher crude in-hospital mortality, female gender per se was not an independent predictor of in-hospital mortality (OR 1.07, 95% CI 0.84-1.35, p=0.59).

Conclusion: Substantial changes have occurred in presentation, treatment, and outcome of men and women with STEMI in Switzerland over the past 15 years. Although parallel trends were seen in both groups, ongoing disparities in certain treatments remain. However, these did not translate into worse risk-adjusted in-hospital mortality, suggesting that the gender gap in STEMI care may be closing.

Keywords: Acute myocardial infarction; evidence-based medicine; primary angioplasty; sex; trends.

Figure 1.

Adjusted OR for immediate therapies (A) and discharge drugs (B) received by female patients with acute ST-segment elevation myocardial infarction (reference group: male). Adjusted for age, Killip classes>2, risk factors (smoking, dyslipidemia, hypertension, diabetes) and comorbidities (Charlson weighted index ≥2) and admission year Primary reperfusion, thrombolysis or primary percutaneous coronary intervention; ACE, angiotensin-converting enzyme; AT, angiotensin-II receptor; LMWH, low-molecular-weight heparin.

Figure 2.

Trends in reperfusion therapies in male and female patients with acute ST-segment elevation myocardial infarction in Switzerland between 1997 and 2011 F, female; M, male; PCI, primary percutaneous coronary intervention.

Figure 3.

Trends in immediate (A) and discharge (B) drug therapies in male and female patients with acute ST-segment elevation myocardial infarction in Switzerland between 1997 and 2011 ACE, angiotensin-converting enzyme; AT, angiotensin-II receptor; F, female; GP, glycoprotein; M, male;

Figure 4.

Trends in complications during hospitalization (cardigenic shock, reinfarction, and cerebrovascular events; A) and in crude mortality and major adverse cardiac and cerebrovascular events (B) in male and female patients with acute ST-segment elevation myocardial infarction in Switzerland between 1997 and 2011