Bottom Line
Chest pain free MI is a very real phenomenon and it is associated with higher mortality - especially in younger women (NRMI study).
Why It's Important for Emergency Medicine
How many times have you seen a relatively normal looking EKG in a young person non-specific symptoms, decided to send off troponins, only for them to come back positive; then the cardiology consult invariably would come down and underplay the severity of the patient because of the absence of chest pain?
In spite of multiple studies demonstrating that our previously held understanding of the patient characteristics MI is actually not accurate, we still seem to under-treat "atypical" presentations of MI. This is an observational study pulling from a very large industry sponsored database (the National Registry of Myocardial Infarction) in 1977 hospitals from 1994 to 2006. The characteristics of 2,160,671 patients were analyzed:
- 481,581 women and 661,932 men
- Almost half (42%) of women with MI present to the ED without chest pain vs 30.7% for males, with younger women experiencing higher numbers of chest pain free MI.
- In addition, younger women who present without chest pain are at an increased risk for death while in the hospital.
- The final study population included 1,143,513 MI (with 481,581 or 42.1% women) patients.
- Age, sex, and presence of chest pain were dichotomized at 65 years
- In both men and women in both age groups, mortality rates were higher in the chest pain free group vs the chest pain group.
- MI patients without chest pain were more likely to have diabetes and delay presentation to the hospital, regardless of sex or age, while MI patients with chest pain were more likely to present with STEMI irrespective of age and sex.
- MI patients without chest pain were less likely to receive any acute reperfusion therapies, or medical management such as aspirin, beta blockers and heparin.
- The in-hospital mortality rate was 14.6% for women and 10.3% for men. Younger women without chest pain had a higher mortality rate than men. The authors' adjustments for morbidity and clinical characteristics at presentation seem to account for the majority of the difference in mortality between the sexes in the younger age cohort. Adjustments based on intervention (reperfusion etc.) seem to only account for a modest difference in mortality between sexes, more pronounced in younger women.
- This study can only shed light into epidemiological factors - it is purely an observational study with no control population
- This study analyzes data from 1994 to 2006. Other recent studies demonstrate that we have achieved dramatic reductions in mortality over the last decade, especially with women.
Reviewed by A Xavier
Reference
Canto JG, Rogers WJ, Goldberg RJ, Peterson ED, Wenger NK, Vaccarino V, Kiefe CI, Frederick PD, Sopko G, Zheng ZJ; NRMI Investigators. Association of age and sex with myocardial infarction symptom presentation and in-hospital mortality. JAMA. 2012 Feb 22;307(8):813-22. Pubmed
MIA 2012 = Most Interesting Articles series of 2012