Short- and long-term clinical outcome after Q wave and non-Q wave myocardial infarction in a large patient population.
Prognosis for patients with non-Q wave myocardial infarction is controversial although a number of studies have shown a less favorable outlook after hospital discharge for patients with non-Q wave than for those with Q wave infarction. Therefore, the in-hospital and 1-year prognosis was investigated in a sufficiently large patient population (n = 2,024) to allow stratification by subgroups, in particular by age and previous myocardial infarction. Patients with non-Q wave infarction (n = 444; 22% of the total study population) were somewhat older (65 vs. 63 years, p less than 0.001) and had an increased incidence of previous myocardial infarction (46% vs. 24%, p less than 0.001) and congestive heart failure (21% vs. 8%, p less than 0.001) than patients with Q wave infarction. In-hospital mortality of patients with non-Q wave infarction was lower (8.1% vs. 11.5%; p less than 0.06), whereas their 1-year mortality after hospital discharge was significantly higher (13.7% vs. 9.2%, p less than 0.05) than for patients with Q wave infarction. However, total mortalities at 1 year were nearly equal. When patients were subgrouped by presence or absence of a previous myocardial infarction, patients in both subgroups exhibited mortality patterns typical of the entire population with Q wave or non-Q wave infarction. However, when stratified by age and previous infarction, in-hospital mortality for patients with non-Q wave infarction was significantly lower only in patients older than 70 years of age. Similarly, the higher mortality after hospital discharge in patients with non-Q wave infarction occurred only in patients older than 70 years of age without previous myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)