Combined effect of age and right ventricular involvement on acute inferior myocardial infarction prognosis.

BACKGROUND In patients with acute inferior myocardial infarction (AIMI), right ventricular involvement (RVI) is one of the strongest predictors of in-hospital death. We hypothesized that the impact of RVI on AIMI prognosis depends on the patient's age. METHODS AND RESULTS The in-hospital clinical outcome of 798 consecutive patients admitted to the coronary care unit within 48 hours of symptom onset with AIMI was analyzed according to patient age and to the presence of RVI diagnosed by ECG and/or echocardiographic criteria. The total incidence of RVI was 37%, and it increased as age advanced. Patients with RVI had a significantly higher incidence of major complications (45% versus 19%, P<0.0001) and a higher in-hospital mortality rate (22% versus 6%, P<0.0001). The prognostic effect of RVI was independent of sex, smoking, diabetes, shock on admission, left ventricular ejection fraction, and reperfusion therapy, all age-dependent predictors. A multivariate analysis showed a significant (P=0.03) interaction between age and RVI on AIMI mortality. RVI increased mortality risk only in the oldest patients. CONCLUSIONS In patients with AIMI, RVI substantially increases mortality risk in elderly patients, whereas it has a nonsignificant effect in young subjects.