Clinical characteristics of and prognosis in acute transmural anterior, transmural inferior and non-transmural myocardial infarction. A comparative retrospective study.

This retrospective study was undertaken to determine whether there was any difference in the clinical characteristics of and prognosis in white patients admitted to the Intensive Coronary Care Unit (ICCU) at Tygerberg Hospital with acute non-transmural, transmural anterior and transmural inferior myocardial infarction (MI). The three groups were carefully matched, taking into consideration the possible influence of previous MI and congestive cardiac failure (CCF). There were 187 patients with non-transmural MI, and 176 with transmural anterior and 209 with transmural inferior MI. Patients with acute transmural anterior MI had the worst prognosis while at the ICCU, at 3 months' follow-up and at long-term follow-up (mean 22,2 months). This group had the greatest frequency of CCF, cardiogenic shock, acute pericarditis, ventricular premature beats, ventricular tachycardia, left anterior hemiblock and complete left bundle-branch block and the highest mortality. Acute transmural inferior MI was responsible for the highest frequency of ventricular fibrillation in the ICCU and had a worse prognosis than non-transmural MI. Acute non-transmural MI resulted in the highest incidence of early and late myocardial reinfarction; although death in the ICCU was least frequent, mortality among this group had increased dramatically by 3 months' follow-up. Hence, acute non-transmural MI is not benign and an unstable period exists for 3 months thereafter. Because of this, more aggressive diagnostic measures should be instituted during this period in order possibly to improve prognosis in this group. It would appear that this is the first such study undertaken in South Africa.