Ten year mortality in patients with suspected acute myocardial infarction.

OBJECTIVE--To describe the 10 year mortality in patients with suspected acute myocardial infarction. DESIGN--Follow up of all patients below 76 years of age admitted with acute chest pain to 16 coronary care units participating in the Danish verapamil infarction trial in 1979-81. SUBJECTS--Of the 5993 patients included, 2586 had definite infarction, 402 had probable infarction, and 3005 did not have infarction. MAIN OUTCOME MEASURES--Death and cause of death. Standardised mortality ratio (observed mortality/expected mortality in background population). RESULTS--The estimated 10 year mortalities were 58.8%, 55.5%, and 42.8% in patients with definite, probable, and no infarction, respectively (P < 0.0001). Stratified Cox''s analysis identified a hazard ratio for mortality of 1.25 (95% confidence interval 1.08 to 1.44) for probable infarction compared with no infarction and of 1.15 (1.00 to 1.32) for definite compared with probable infarction. The standardised mortality ratio in the first year was 7.1 (6.5 to 7.8) for definite infarction, 5.0 (3.6 to 6.3) for probable infarction, and 4.7 (4.2 to 5.2) for no infarction. From the second year and onwards the annual standardised mortality ratio in the three groups did not differ significantly. Cardiac causes of deaths were recorded in 89%, 84%, and 71% of the deaths in patients with definite, probable, and no infarction, respectively. CONCLUSIONS--The 10 year mortality of patients with and without infarction is significantly higher than in the background population. Most deaths are caused by coronary heart disease, and these patients should consequently be further evaluated at the time of discharge and followed up closely.