In ST elevation myocardial infarction women received less evidence-based medicine and had worse outcome during the fibrinolytic era. With the shift to primary percutaneous coronary intervention (pPCI) as preferred reperfusion strategy, the authors aimed to investigate whether these gender differences has diminished.
Design, setting and participants
Cohort study including consecutive ST elevation myocardial infarction patients registered 1998–2000 (n=15 697) and 2004–2006 (n=14 380) in the Register of Information and Knowledge about Swedish Heart Intensive care Admissions.
1. Use of evidence-based medicine such as reperfusion therapy (pPCI or fibrinolysis) and evidence-based drugs at discharge. 2. Inhospital and 1-year mortality.
Of those who got reperfusion therapy, pPCI was the choice in 9% in the early period compared with 68% in the late period. In the early period, reperfusion therapy was given to 63% of women versus 71% of men, p<0.001. Corresponding figures in the late period were 64% vs 75%, p<0.001. After multivariable adjustments, the ORs (women vs men) were 0.86 (95% CI 0.78 to 0.94) in the early and 0.80 (95% CI 0.73 to 0.89) in the late period. As regards evidence-based secondary preventive drugs at discharge in hospital survivors (platelet inhibitors, statins, ACE inhibitors/angiotensin receptor blockers and β-blockers), there were small gender differences in the early period. In the late period, women had 14%–25% less chance of receiving these drugs, OR 0.75 (95% CI 0.68 to 0.81) through 0.86 (95% CI 0.73 to 1.00). In both periods, multivariable-adjusted inhospital mortality was higher in women, OR 1.18 (95% CI 1.02 to 1.36) and 1.21 (1.00 to 1.46). One-year mortality was gender equal, HR 0.95 (95% CI 0.87 to 1.05) and 0.96 (0.86 to 1.08), after adding evidence-based medicine to the multivariable adjustments.
In spite of an intense gender debate, focus on guideline adherence and the change in reperfusion strategy, the last decade gender differences in use of reperfusion therapy and evidence-based therapy at discharge did not decline during the study period, rather the opposite. Moreover, higher mortality in women persisted.
With (1) the focus on treatment guidelines, (2) the attention on gender differences in management and outcome and (3) the change in reperfusion strategy in STEMI in the last decade, we hypothesised
that gender differences in adherence to treatment guidelines would have diminished and
that gender differences in outcome would have decreased.
Management improved and mortality decreased in STEMI patients in the late compared with the early period.
The gender treatment gap did not decrease between the two time periods.
The gender outcome gap did not decrease between the two time periods.
Strengths and limitations of this study
The study included a huge amount of STEMI patients, with enough numbers to assure adequate statistical analyses. Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies register is a unique Swedish National Quality register, with quality control and audit measures, covering all hospitals in Sweden treating STEMI patients and has standardised criteria for defining MI. Mortality data are complete as the vital status of all Swedish citizens is registered in the Cause of Death Register. One limitation is the non-randomised observational nature. Thus, multivariate analyses were used in order to reduce the bias inherent in this type of studies. Adjustments might be influenced by the lack of registration on some possible confounding factors in the database, for example, non-cardiac comorbidities and contraindications for specific treatments.