Current issues of ACP Journal Club are published in Annals of Internal Medicine


Therapeutics

Women with acute myocardial infarction had worse prognosis than men

ACP J Club. 1996 Sept-Oct;125:43. doi:10.7326/ACPJC-1996-125-2-043


Source Citation

Weaver WD, White HD, Wilcox RG, et al., for the GUSTO-I Investigators. Comparisons of characteristics and outcomes among women and men with acute myocardial infarction treated with thrombolytic therapy. JAMA. 1996 Mar 13;275:777-82.


Abstract

Objective

To compare baseline characteristics, complications, and outcomes in men and women with acute myocardial infarction (MI).

Design

Randomized controlled trial with 30-day follow-up (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries [GUSTO-I] trial).

Setting

1081 hospitals in 15 countries.

Patients

30 706 men (mean age 59 y) and 10 315 women (mean age 66 y) who had acute MI and were treated with thrombolytic therapy within 6 hours of symptom onset.

Intervention

Patients were allocated to streptokinase plus subcutaneous heparin, streptokinase with intravenous heparin, streptokinase plus accelerated tissue plasminogen activator (tPA) and intravenous heparin, or tPA plus intravenous heparin.

Main outcome measures

All-cause mortality, stroke, and complications at 30 days.

Main results

At baseline, women compared with men were older (66 vs 59 y); had longer mean times from symptoms to admission (2.0 vs 1.8 h) and treatment (3.3 vs 3.0 h); lower rates of previous MI (14% vs 17%), coronary artery bypass surgery (3% vs 5%), and smoking (38% vs 45%); higher rates of hypertension (50% vs 34%) and diabetes mellitus (21% vs 13%); lower systolic blood pressure (137 vs 139 mm Hg); and a higher heart rate (77 vs 75 mean beats/min) (P < 0.001 for all comparisons). Women had a higher unadjusted mortality rate than did men (11.3% vs 5.5%, P < 0.001). After adjusting for all differences in baseline characteristics, the risk for mortality remained higher (relative risk [RR] 1.15; 95% CI 1.0 to 1.31). Women also had more nonfatal complications: shock (9% vs 5%), congestive heart failure (22% vs 14%), serious bleeding (15% vs 7%), and reinfarction (5.1% vs 3.6%) (P < 0.001 for all comparisons).

Conclusion

Women who received thrombolytic therapy after acute MI were more likely to die or have nonfatal complications (shock, congestive heart failure, serious bleeding, and reinfarction) than were men.

Sources of funding: Bayer; CIBA-Corning; Genentech; ICI Pharmaceuticals; Sanofi Pharmaceuticals.

For article reprint: Dr. W.D. Weaver, MITI Coordinating Center, Division of Cardiology, University of Washington, 1 910 Fairview Avenue East, Suite 205, Seattle, WA 98102 USA. FAX 206-548-4469.


Commentary

This subgroup analysis is the most recent and the largest addition to a growing body of literature describing a "gender gap" in acute MI. Consistent with previous studies (1, 2), Weaver and colleagues found that women were older, more likely to have unfavorable baseline characteristics, and at greater risk for both fatal and nonfatal complications. After adjustment for differences in baseline characteristics, the RR for death remained 15% higher but was no longer statistically significant. This result is supported by a previous GUSTO-I multivariable analysis that identified age as the most important prognostic factor, whereas sex was only a marginal predictor (3). Previous studies have also described increased in-hospital and 6- to 12-month mortality rates that diminished in women after adjustment for age (1, 2).

Weaver and colleagues correctly point out that their data do not provide insight into the outcomes for women who do not receive thrombolytic therapy after MI. Although placebo-controlled trials have clearly shown that women and men of all ages benefit from thrombolytic therapy (4), a report of an unselected group of patients found that such therapy was underused in eligible women (5). Thus, eligibility criteria in GUSTO-I would tend to limit enrollment to only 20% to 30% of all women with MI and would decrease possible differences in baseline characteristics and outcomes in women and men.

Other important sex differences included longer delays after symptom onset to hospitalization and from arrival to treatment initiation in women, even after age adjustment. These brief (10 to 20 min each) but substantial delays may translate into a loss of approximately 1 life/1000 patients treated (4) and further highlight the importance of rapid diagnosis and treatment of women with acute MI.

Shaun G. Goodman, MD
University of TorontoToronto, Ontario, Canada


References

1. White HD, Barbash GI, Modan M, et al. Circulation. 1993;88:2097-103.

2. Becker RC, Terrin M, Ross R, et al. Ann Intern Med. 1994;120:638-45.

3. Lee KL, Woodlief LH, Topol EJ, et al. Circulation. 1995;91:1659-68.

4. Fibrinolytic Therapy Trialists' (FTT) Collaborative Group. Lancet. 1994;343:311-22.

5. Maynard C, Althouse R, Cerqueira M, Olsufka M, Kennedy JW. Am J Cardiol. 1991;68:529-30.