The New England Journal of Medicine, 1999;341:217-25. This study analyzed data from 384,878 patients (155,565 women and 229,313 men) aged 30-89 years enrolled in the National Registry of Myocardial Infarction 2. It found that women had a higher mortality rate during hospitalization (16.7%) compared to men (11.5%). However, this difference varied by age. Women under 50 had more than twice the mortality rate of men in the same age group, while the difference decreased with age and was no longer significant after 74 years. Logistic regression showed that women had 11.1% higher odds of death than men for every five-year decrease in age, even after adjusting for medical history, clinical severity, and early management. The study concluded that younger women, but not older women, had higher mortality rates during hospitalization after myocardial infarction. The risk increased with younger age, indicating that younger women with myocardial infarction represent a high-risk group. The study highlights the importance of considering age when assessing sex-based differences in mortality after myocardial infarction.The New England Journal of Medicine, 1999;341:217-25. This study analyzed data from 384,878 patients (155,565 women and 229,313 men) aged 30-89 years enrolled in the National Registry of Myocardial Infarction 2. It found that women had a higher mortality rate during hospitalization (16.7%) compared to men (11.5%). However, this difference varied by age. Women under 50 had more than twice the mortality rate of men in the same age group, while the difference decreased with age and was no longer significant after 74 years. Logistic regression showed that women had 11.1% higher odds of death than men for every five-year decrease in age, even after adjusting for medical history, clinical severity, and early management. The study concluded that younger women, but not older women, had higher mortality rates during hospitalization after myocardial infarction. The risk increased with younger age, indicating that younger women with myocardial infarction represent a high-risk group. The study highlights the importance of considering age when assessing sex-based differences in mortality after myocardial infarction.