Elsevier

International Journal of Cardiology

Volume 168, Issue 2, 30 September 2013, Pages 1041-1047
International Journal of Cardiology

A gender perspective on short- and long term mortality in ST-elevation myocardial infarction — A report from the SWEDEHEART register

https://doi.org/10.1016/j.ijcard.2012.10.028Get rights and content

Abstract

Background

Previous studies of patients admitted for ST-elevation myocardial infarction [STEMI] have indicated that women have a higher risk of early mortality than do men. These studies have presented limited information on gender related differences in the short term and almost no information on the long term.

Methods and results

We analysed a prospective, consecutively included STEMI population consisting of 54,146 patients (35% women). This population consists of almost all patients hospitalised in Sweden between January 1, 1995 and December 31, 2006 as recorded in the SWEDEHEART register (formerly RIKS-HIA). Follow-up time ranged from one to 13 years (mean 4.6). Women had a lower probability of being given reperfusion therapy, odds ratio [OR] 0.83 (95% confidence interval [CI] 0.79–0.88). During the time these STEMI patients were in the hospital, 13% of the women and 7% of men died, multivariable adjusted OR 1.21 (95% CI 1.11–1.32). During the follow up period, 46% of the women died as compared with 32% of the men. There was, however, no gender difference in age-adjusted risk of long term mortality (hazard ratio [HR] 0.98, 95% CI 0.95–1.01) whereas the multivariable adjusted risk was lower in women (HR 0.92, 95% CI 0.89–0.96). The long term risk of re-infarction was the same in men and women (HR 0.98, 95% CI 0.93–1.03) whereas men in the youngest group had a higher risk than women in that age group (HR 0.82, 95% CI 0.72–0.94).

Conclusion

In STEMI, women had a higher risk of in-hospital mortality but the long-term risk of death was higher in men. More studies are needed in the primary percutaneous coronary intervention (pPCI) era that are designed to determine why women fare worse than men after STEMI during the first phase when they are in hospital.

Introduction

Increased attention has been paid to gender differences in outcomes for patients who have experienced myocardial infarction [MI] in the period 2000–2010. Many studies have indicated higher mortality in women [1], [2], [3], [4], [5], [6], [7], [8], [9] especially during the time when they are in the hospital. Existing studies have not been able to establish if this period of higher mortality might be due to differences in background characteristics, a possible difference in treatment regime for women compared with men, or if it might be related to sex per se. Gender differences in outcome have been reported in some [5], [7], [9], [10] but not all of the published studies even after the researchers had made multivariable adjustments [4], [6]. Discrepancies may be due to differences in patient selection, study population size, covariates in multivariable adjustments and a case mix of ST- and non ST-elevation myocardial infarctions (STEMI and NSTEMI) [3], [7], [8], [11]. The prevalence of both STEMI and NSTEMI differs between men and women [2], [12], and a significant interaction between type of myocardial infarction and gender regarding outcome has been shown [2], [13], [14] with the same or better prognosis in women in NSTEMI [15] but worse in STEMI [14]. STEMI cohorts have often been selected from groups participating in randomised controlled trials [9], [10], so these cohorts may not be representative of an unselected population. There are limited data regarding gender differences in outcome in STEMI based on unselected cohorts, and gender-specific data on long-term prognosis after STEMI are virtually lacking. Thus larger studies with unselected study populations and with more complete adjustments for confounding factors are needed if we are to be able to determine if there are differences in risk between males and females in particular age groups. The main objective of the present study was to evaluate possible gender differences in short and long term outcomes in a large unselected STEMI cohort.

Section snippets

Patients

Data for this study came from the prospective observational register the full name of which is The Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART) [16], which includes the following registers that previously were kept separately: The Registry of Information and Knowledge about Swedish Heart Intensive care Admissions (RIKS-HIA), the Swedish Coronary Angiography and Angioplasty Registry (SCAAR),

Baseline characteristics

A total of 54,146 patients were included in the analyses of which 18,876 (35%) were women. The average age of women on admission was 73.2 and of men 66.3. The median length of the time interval between symptom onset and arrival at CCU was 30 min longer for women than for men. After adjustment for age, female sex was associated with a history of smoking, diabetes mellitus, hypertension, heart failure, chronic obstructive pulmonary disease and dementia, whereas male sex was associated with a

Discussion

Data on the relationship between gender and the long-term prognosis after MI are very limited, especially for STEMI. In this long-term follow-up study covering almost all Swedish STEMI patients hospitalised between 1995 and 2006, we had complete mortality data for these patients for up to a maximum of 13 years and a mean of 4.6 years after admission. To our knowledge this is the first study of possible gender differences in the long term prognosis for re-infarction and death in a multicentre

Conclusion

In the long-term follow-up of STEMI, female gender is correlated with better prognosis after multivariable adjustments. On the other hand, women have approximately a 20% higher multivariable adjusted risk of in-hospital mortality, and this risk is possibly even higher in the youngest age group. Thus there is a need for more studies in the current primary PCI era that are designed to help us understand why women, and perhaps especially young women, fare worse than men after STEMI during the

Acknowledgements

We thank all the participating hospitals for their help and co-operation to contribute with data to the SWEDEHEART register.

References (42)

  • N.C. Chandra et al.

    Observations of the treatment of women in the United States with myocardial infarction: a report from the National Registry of Myocardial Infarction-I

    Arch Intern Med

    (1998)
  • H.D. White et al.

    After correcting for worse baseline characteristics, women treated with thrombolytic therapy for acute myocardial infarction have the same mortality and morbidity as men except for a higher incidence of hemorrhagic stroke. The investigators of the international tissue plasminogen activator/streptokinase mortality study

    Circulation

    (1993)
  • R. Malacrida et al.

    A comparison of the early outcome of acute myocardial infarction in women and men. The third international study of infarct survival collaborative group

    N Engl J Med

    (1998)
  • C. Milcent et al.

    Gender differences in hospital mortality and use of percutaneous coronary intervention in acute myocardial infarction: microsimulation analysis of the 1999 nationwide French hospitals database

    Circulation

    (2007)
  • V. Vaccarino et al.

    Sex-based differences in early mortality after myocardial infarction. National Registry of Myocardial Infarction 2 Participants

    N Engl J Med

    (1999)
  • J.L. Mega et al.

    Outcomes and optimal antithrombotic therapy in women undergoing fibrinolysis for ST-elevation myocardial infarction

    Circulation

    (2007)
  • W.D. Weaver et al.

    Comparisons of characteristics and outcomes among women and men with acute myocardial infarction treated with thrombolytic therapy. GUSTO-I investigators

    JAMA

    (1996)
  • S.C. Gan et al.

    Treatment of acute myocardial infarction and 30-day mortality among women and men

    N Engl J Med

    (2000)
  • K.P. Champney et al.

    The joint contribution of sex, age and type of myocardial infarction on hospital mortality following acute myocardial infarction

    Heart

    (2009)
  • J.S. Berger et al.

    Sex differences in mortality following acute coronary syndromes

    JAMA

    (2009)
  • J. Alfredsson et al.

    Gender differences in management and outcome in non-ST-elevation acute coronary syndrome

    Heart

    (2007)
  • Cited by (77)

    • Few with ST-segment elevation myocardial infarction are diagnosed within 10 minutes from first medical contact, and women have longer delay times than men

      2020, IJC Heart and Vasculature
      Citation Excerpt :

      It could be argued, that since women have a longer patient delay, an even shorter system delay is motivated for women than for men. Even after adjusting for age and other co-morbidities, women seem to have a higher rate of in-hospital mortality [11] and excess mortality compared with men [12]. In the in-hospital setting, door-to-ECG time in the emergency department setting has similarly been found to be longer for women than for men [13].

    View all citing articles on Scopus
    View full text