Does subendocardial myocardial infarction compared to transmural infarction affect hospital and one-year mortality in patients under 70 years of age?
Patients with subendocardial myocardial infarction have lower hospital mortality but similar one-year mortality compared to those with transmural infarction, with particularly high risk in those with prior infarction.
Sixty-one consecutive patients with acute subendocardial myocardial infarction (SEAMI) and 223 consecutive patients with transmural infarction (TMI) seen in a coronary care unit were followed for one year. All patients were less than 70 years of age. The patients with SEAMI had a higher frequency of previous infarction (34% vs 21%, p less than 0.025), less cardiac failure (44% vs 65%, p less than 0.005), and were more often free from arrhythmias (61% vs 31%, p less than 0.001) than patients with TMI. Hospital mortality was less in patients with SEAMI (0% vs 8%, p less than 0.05) but total mortality to one year was similar (15% vs 17%). Amongst patients with SEAMI, two died within two weeks of infarction but all other deaths occurred at least six weeks after infarction. Patients with SEAMI and a history of previous infarction had a higher one year mortality than patients without such a history (29% vs 7%, p less than 0.05). Coronary angiography with a view to coronary artery surgery should be considered in the former group.
Bayley et al. (Thu,) studied this question.