INFARCT SITE-RELATED MORTALITY IN PATIENTS WITH RECURRENT MYOCARDIAL-INFARCTION

PURPOSE: The purpose of this study was to determine the effect of acut e and old myocardial infarction (MI) sites on early (15 days) mortalit y in patients with a second MI. PATIENTS AND METHODS: Data are derived from the SPRINT 2 study population that included 1,161 consecutive pa tients with acute MI, aged 50 to 79 years, recruited from 14 coronary care units in Israel between November 1985 and July 1986. Two hundred twenty-six of these patients (19.5%) had a previous MI prior to the in dex acute MI. Sixty-two patients were excluded from the analysis eithe r because the MI site was not of anterior or inferior location, or bec ause of incomplete data. In the 164 (73%) remaining patients, acute an d old MI locations were determined to be either anterior or inferior a nd were accordingly divided into 4 groups: acute anterior-old anterior (Group 1-23 patients); acute anterior-old inferior (Group 2-86 patien ts); acute inferior-old anterior (Group 3-34 patients); acute inferior -old inferior (Group 4-21 patients). RESULTS: Significant differences in clinical parameters among the four groups included a higher proport ion of Q-wave MI (p = 0.04), severe congestive heart failure during ad mission (p = 0.04), and markedly elevated serum lactate dehydrogenase levels (p = 0.05) in Group 3. High-degree atrioventricular block (p = 0.001) and cardiogenic shock (p = 0.05) also developed more often in t his group during hospitalization. Twenty-three patients (14%) died wit hin 15 days. Death rates in the acute anterior (Group 1 plus Group 2) and the acute inferior (Group 3 plus Group 4) groups were 11% versus 2 0%, respectively (NS). However, death rate variability across the four groups was statistically significant (p = 0.018), with the highest mo rtality observed in Group 3 (old anterior-acute inferior MI-29%). Mult ivariate analysis identified acute inferior MI following old anterior MI as a strong independent predictor of early death (relative odds vis -a-vis other combinations 5.0, 95% confidence interval 1.5 to 16.6). C ONCLUSION: This study identifies a subgroup of patients with acute inf erior MI at high risk for early mortality. It is possible that such pa tients would benefit from early reperfusion therapy.