PREVALENCE,
CLINICAL CHARACTERISTICS, AND MORTALITY AMONG PATIENTS WITH MYOCARDIAL
INFARCTION PRESENTING WITHOUT CHEST PAIN
Canto
JG, et al. JAMA. 2000;283:3223-3229
CONTEXT:
Although chest pain is widely considered a key symptom in the diagnosis of
myocardial infarction (MI), not all patients with MI present with chest pain.
The extent to which this phenomenon occurs is largely unknown.
OBJECTIVES:
To determine the frequency with which patients with MI present without chest
pain and to examine their subsequent management and outcome.
DESIGN:
Prospective observational study.
SETTING
AND PATIENTS: A total of 434,877 patients with confirmed MI enrolled June 1994
to March 1998 in the National Registry of Myocardial Infarction 2, which
includes 1674 hospitals in the United States.
MAIN
OUTCOME MEASURES: Prevalence of presentation without chest pain; clinical
characteristics, treatment, and mortality among MI patients without chest pain
vs those with chest pain.
RESULTS:
Of all patients diagnosed as having MI, 142,445 (33%) did not have chest pain
on presentation to the hospital. This group of MI patients was, on average, 7
years older than those with chest pain (74.2 vs 66.9 years), with a higher
proportion of women (49.0% vs 38.0%) and patients with diabetes mellitus (32.6%
vs 25.4%) or prior heart failure (26.4% vs 12.3%). Also, MI patients without
chest pain had a longer delay before hospital presentation (mean, 7.9 vs 5.3
hours), were less likely to be diagnosed as having confirmed MI at the time of
admission (22.2% vs 50.3%), and were less likely to receive thrombolysis or
primary angioplasty (25.3% vs 74.0%), aspirin (60.4% vs 84.5%), -blockers
(28.0% vs 48.0%), or heparin (53.4% vs 83.2%). Myocardial infarction patients
without chest pain had a 23.3% in-hospital mortality rate compared with 9.3%
among patients with chest pain (adjusted odds ratio for mortality, 2.21 [95%
confidence interval, 2.17-2.26]).
CONCLUSIONS:
Our results suggest that patients without chest pain on presentation represent
a large segment of the MI population and are at increased risk for delays in
seeking medical attention, less aggressive treatments, and in-hospital
mortality.