Comparison of time of reperfusion during anterior wall acute myocardial infarction to left ventricular volume one month and 20 months later

We studied 95 patients with a first anterior wall acute myocardial infarction who received successful reperfusion within 72 hours after the onset. The patients were divided into 4 groups based on the time required to achieve reperfusion; <3 hours (n = 23), 3 to 6 hours (n = 42), 6 to 24 hours (n = 17), and >24 to 72 hours (n = 13). The infarct size, as evaluated by thallium-201 single-photon emission computed tomography, at 1 month after the infarct was significantly larger (p <0.05) in >24 to 72 hours (1,593 ± 652 U) than that in <3 hours (749 ± 650 U), but was not significantly different from that at 3 to 6 hours (1,353 ± 770 U) or 6 to 24 hours (1,371 ± 561 U). The end-diastolic volume index at 1 month did not differ among the 4 groups. However, the end-diastolic volume index during the follow-up period (20 ± 8 months) in >24 to 72 hours (93 ± 23 ml/m²) was significantly larger than that in the other 3 groups (<3 hours [65 ± 21 ml/m²], 3 to 6 hours [65 ± 22 ml/m²], and 6 to 24 hours [70 ± 25 ml/m²]). Similar findings were observed in end-systolic volume index. In conclusion, although infarct size reduction was not observed by late reperfusion, left ventricular volumes at 1 month were comparable among patients with successful reperfusion within 3 and up to >24 hours. Left ventricular volumes 2 years after acute myocardial infarction were significantly larger in patients who did not under reperfusion for >24 hours.