Prognostic value of dipyridamole echocardiography early after myocardial infarction in elderly patients

Objectives. This study was conducted to assess the feasibility, safety and prognostic value of dipyridamole echocardiography in elderly patients recovering from an uncomplicated acute nyocardial infarction in a subset analysis performed on the patients entered in the subproject "residual ischemia" of the Echo Persantine Italian Cooperative Study (EPIC). Background. Coronary heart disease accounts for two thirds of all deaths in the age group >65 years, and >50% of all patients admitted to the hospital with acute myocardial infarction are >65 years old. The prognostic value of dipyridamole-induced left ventricular dysfunction was clearly established in patients evaluated early after acute infarction. Methods. In a subgroup analysis of the Echo Persantine Italian Cooperative Study (EPIC), we assessed the value of dipyridamole echocardiography in predicting cardiac events in 190 elderly (≥65 years) patients (age 68.4 ± 3.3 years, range 65 to 78; 147 men and 43 women) evaluated early (mean 10 days) after uncomplicated acute myocardial infarction and followed up for 14 ± 9.8 months. Results. There was no major side effect during dipyridamole echocardiography. A positive test result occurred in 85 patients (44.7%). During follow-up, there were 62 events (14 cardiac deaths, 7 nonfatal reinfarctions, 21 cases of class III or IV angina and 20 revascularization procedures). Of these 62 events, 44 occurred among 85 patients with positive dipyridamole echocardiography and 18 among 105 patients with negative dipyridamole echocardiography (52% vs. 17%, p <0.001). Spontaneous events (death, reinfarction, angina) occurred in 31 patints with positive and in 11 with negative dipyridamole echocardiography (36% vs. 10%, p <0.001). Hard events (myocardial infarction or death) occurred in 14 patients with positive and 7 with negative dipyridamole echocardiography (16% vs. 6%, p <0.05). Death occurred in 11 patients with positive and in 3 with negative dipyridamole echocardiography (13% vs. 3%, p <0.01). The positive predictive value of positive dipyridamole echocardiography and negative predictive value of negative dipyridamole echocardiography as related to the occurrence of all events in the follow-up period (death, reinfarction, angina, revascularization procedures) were 52% and 83%, respectively. The relative risk (that is, the relative risk of occurrence of future cardiac events in the group with positive dipyridamole echocardiography compared with that in those with negative dipyridamole echocardiography) was 3 for all events and 4.4 for death. Conclusions. Dipyridamole echocardiography was well tolerated by elderly patients and proved to be very effective in prognostic stratification early after uncomplicated acute myocardial infarction, even when only survival was considered.