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


Prognosis

Women had a worse prognosis than men after myocardial infarction

ACP J Club. 1991 May-June;114:89. doi:10.7326/ACPJC-1991-114-3-089


Source Citation

Greenland P, Reicher-Reiss H, Goldbourt U, et al. In-hospital and 1-year mortality in 1,524 women after myocardial infarction. Comparison with 4,315 men. Circulation. 1991 Feb;83:484-91.


Abstract

Objective

To investigate gender differences in 1-year mortality rates after myocardial infarction.

Design

Consecutive patients with acute myocardial infarction were followed for at least 1 year.

Setting

14 of 21 coronary care units in Israel, from November 1981 to August 1983.

Patients

All patients who fulfilled criteria for myocardial infarction based on the presence of symptoms, elevated serum levels of cardiac enzymes, or electrocardiographic findings were included. Of the 1524 women and 4315 men in the study, 2276 were participants in the Secondary Prevention Reinfarction Israeli Nifedipine Trial.

Assessment of prognostic factors

During hospitalization and 1 year later, standard information about demographic variables, medical history, and clinical condition was collected.

Main outcome measures

In-hospital and 1-year mortality.

Main results

Mean age was higher for women than for men (67.3 vs 61.4 y, P < 0.001); all results were adjusted for age. Men were more likely to have been smokers (35.7% vs 19.5%, P < 0.001) or to have had a previous myocardial infarction (26.9% vs 18.5%, P < 0.001). Women were more likely to have had angina, hypertension, or diabetes (29.1% vs 18.0% for diabetes, P < 0.001). During hospitalization, more men than women had a markedly elevated serum level or creatine kinase (65.7% vs 57.6%), but more women had had cardiac arrests (9.8% vs 6.6%) and episodes of cardiogenic shock (11.1% vs 7.4%), P < 0.001 for differences. 401 women (23.1%) and 621 men (15.7%) died in the hospital (risk ratio 1.47, P < 0.001). 142 women (11.8%) and 289 men (9.3%) died within 1 year after discharge (risk ratio 1.27, P = 0.03). After adjustment for age, congestive heart failure, previous myocardial infarction, hypotension, cardiac enzyme level, the location and extent of infarction, and Swan-Ganz catheter use, the relative odds for death in the hospital for women was 1.72 (95% CI 1.45 to 2.04). The adjusted relative odds for death for women in the year after hospitalization was 1.32 (CI 1.05 to 1.66). Strong predictors of 1-year mortality for women were (relative odds in parentheses) congestive heart failure (2.06) and a history of myocardial infarction (1.71) or diabetes (1.67). The need for digitalis at hospital discharge (2.62) was also a strong predictor of 1-year mortality. Sex differences in mortality after hospitalization were not statistically significant among the 3876 nondiabetic survivors (odds ratio 1.11, CI 0.84 to 1.47).

Conclusions

Women had a worse prognosis then men after acute myocardial infarction. Strong predicators of 1-year mortality in women were congestive heart failure, history of myocardial infarction or diabetes, and the need for digitalis at hospital discharge.

Source of funding: Not stated.

Address for article reprint: Professor U. Goldbourt, The Neufeld Cardiac Research Institute, Chaim Sheba Medical Center, Tel Hashomer 52621, Israel.


Commentary

This report of a large study suggests "that women fare worse than men after suffering an acute myocardial infarction, that increased age does not fully account for their increased mortality, and that diabetic women are at particularly high risk after myocardial infarction. As is often the case in secondary data analyses, more questions are raised than answered: Compared with men, did women seek medical care at the same point in the course of their myocardial infarction? Was there differential baseline ascertainment of cardiovascular risk factors and comorbid diseases? Was there differential ascertainment and treatment (both acute and long-term) of myocardial infarction for men and women? What about cholesterol levels and obesity in women compared with men? Were too many subsets analyzed? (For example, what can one make of the finding of more cardiac arrests among women, but of more ventricular arrhythmias among men?)

In summary, multiple referral, diagnostic and treatment biases, and inadequate measurement and adjustment for case mix could easily explain the above findings. Women may fare worse than men with myocardial infarction; future studies, however, will be needed to determine whether women are diagnosed and treated differently or whether they have more severe cardiac and comorbid disease.

Cynthia Mulrow, MD
Audie L. Murphy Memorial Veterans HospitalSan Antonio, Texas


Author's Response

The points raised by the reviewer are valid and worthy of mention. Indeed, we discussed many of them in article. Nevertheless, the cumulative evidence from our study and the many others in the field is strong enough to warrant a shift in future research from whether women have higher mortality in the period immediately after myocardial infarction to why they do.

Philip Greenland, MD