Use of cardiac procedures and outcomes in elderly patients with myocardial infarction in the United States and Canada.
BACKGROUND
Acute myocardial infarction is a leading cause of morbidity and mortality in the United States and Canada. We performed a population-based study to compare the use of cardiac procedures and outcomes after acute myocardial infarction in elderly patients in the two countries.


METHODS
We compared the use of invasive cardiac procedures and the mortality rates among 224,258 elderly Medicare beneficiaries in the United States and 9444 elderly patients in Ontario, Canada, each of whom had a new acute myocardial infarction in 1991.


RESULTS
The U.S. patients were significantly more likely than the Canadian patients to undergo coronary angiography (34.9 percent vs. 6.7 percent, P< 0.001), percutaneous transluminal coronary angioplasty (11.7 percent vs. 1.5 percent, P<0.001), and coronary-artery bypass surgery (10.6 percent vs. 1.4 percent, P<0.001) during the first 30 days after the index infarction. These differences in the use of cardiac procedures narrowed but persisted through 180 days of follow-up. The 30-day mortality rates were slightly but significantly lower for the U.S. patients than for the Canadian patients (21.4 percent vs. 22.3 percent, P=0.03). However, the one-year mortality rates were virtually identical (34.3 percent in the United States vs. 34.4 percent in Ontario, P= 0.94).


CONCLUSIONS
Short-term mortality after an acute myocardial infarction was slightly lower in the United States than in Ontario, but these differences did not persist through one year of follow-up. The strikingly higher rates of use of cardiac procedures in the United States, as compared with Canada, do not appear to result in better long-term survival rates for elderly U.S. patients with acute myocardial infarction.
Tu
J V
JV
Institute for Clinical Evaluative Sciences, North York, ON, Canada.
Pashos
C L
CL
Naylor
C D
CD
Chen
E
E
Normand
S L
SL
Newhouse
J P
JP
McNeil
B J
BJ
D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000706:statistics & numerical data*; D015331:Cohort Studies; D017023:Coronary Angiography / Q000706:statistics & numerical data*; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data*; D006801:Humans; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D009864:Ontario / Q000453:epidemiology; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D015996:Survival Rate; D014481:United States / Q000453:epidemiology