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

Objective

To study gender differences in management and outcome in patients with non‐ST‐elevation acute coronary syndrome.

Design, setting and patients

Cohort study of 53 781 consecutive patients (37% women) from the Register of Information and Knowledge about Swedish Heart Intensive care Admissions (RIKS‐HIA), with a diagnosis of either unstable angina pectoris or non‐ST‐elevation myocardial infarction. All patients were admitted to intensive coronary care units in Sweden, between 1998 and 2002, and followed for 1 year.

Main outcome measures

Treatment intensity and in‐hospital, 30‐day and 1‐year mortality.

Results

Women were older (73 vs 69 years, p<0.001) and more likely to have a history of hypertension and diabetes, but less likely to have a history of myocardial infarction or revascularisation. After adjustment, there were no major differences in acute pharmacological treatment or prophylactic medication at discharge.Revascularisation was, however, even after adjustment, performed more often in men (OR 1.15; 95% CI, 1.09 to 1.21). After adjustment, there was no significant difference in in‐hospital (OR 1.03; 95% CI, 0.94 to 1.13) or 30‐days (OR 1.07; 95% CI, 0.99 to 1.15) mortality, but at 1 year being male was associated with higher mortality (OR 1.12; 95% CI, 1.06 to 1.19).

Conclusion

Although women are somewhat less intensively treated, especially regarding invasive procedures, after adjustment for differences in background characteristics, they have better long‐term outcomes than men.Since the beginning of the 1990s there have been numerous studies on gender differences in management of acute coronary syndromes (ACS). Many earlier studies,^{1,2,3,4,5,6,7,8} but not all,⁹ found that women were treated less intensively in the acute phase. In some of the studies, after adjustment for age, comorbidity and severity of the disease, most of the differences disappeared.^6,7 There is also conflicting evidence on gender differences in evidence‐based treatment at discharge.^{1,3,5,6,8,10,11}After acute myocardial infarction (AMI), a higher short‐term mortality in women is documented in several studies.^{2,5,6,7,12,13,14} After adjustment for age and comorbidity some difference has usually,^2,5,12,13 but not always,^11,14 remained. On the other hand, most studies assessing long‐term outcome have found no difference between the genders, or a better outcome in women, at least after adjustment.^7,10,13,14 Earlier studies focusing on gender differences in outcome after an acute coronary syndrome have usually studied patients with AMI, including both ST‐elevation myocardial infarction and non‐ST‐elevation myocardial infarction (NSTEMI).^{2,5,6,7,12,13,14} However, the pathophysiology and initial management differs between these two conditions,¹⁵ as does outcome according to gender.^11,16 In patients with NSTEMI or unstable angina pectoris (UAP), women seem to have an equal or better outcome, after adjustment for age and comorbidity.^{1,4,8,11,16,17} Studies on differences between genders, in treatment and outcome, in real life, contemporary, non‐ST‐elevation acute coronary syndrome (NSTE ACS) populations, large enough to make necessary adjustments for confounders, are lacking.The aim of this study was to assess gender differences in background characteristics, management and outcome in a real‐life intensive coronary care unit (ICCU) population, with NSTE ACS.