Objectives To evaluate the difference of long-term outcomes of ST-segment elevation acute myocardial infarction (STEMI) treated by immediate PCI and delayed PCI.

Methods 326 patients with STEMI were treated by percutaneous coronary intervention (PCI) in our hospital from January 2006 to January 2010. Among 326 patients 186 patients were treated by immediate PCI and stenting (immediate PCI group) and 140 patients were treated by delayed PCI and stenting (delayed PCI group). All patients were followed 25-72 months with an average 51.6 ± 13.7 months by telephone or outpatient service or in-hospital. The major adverse cardiac events (MACE), the cardiac structure and function estimated by echocardiography and infarct size estimated by the QRS point system were recorded during the follow-up. 107 cases (57.5%) in immediate PCI group and 88 cases (62.9%) in delayed PCI group were followed by echocardiography (MACE included cardiac death, nonfatal myocardial infarction, target lesion revascularisation, late stent thrombosis and rehospitalisation due to heart failure).

Results The rate of MACE was 23.1% (43/140 cases) in immediate PCI group and 38.6% (54/186 cases) in delayed PCI group (P < 0.05). The rate of cardiac death, nonfatal myocardial infarction, target lesion revascularisation and late stent thrombosis in immediate PCI group and delayed PCI group was respectively 5.4% and 6.4% (P > 0.05), 4.8% and 8.6% (P > 0.05), 8.6% and 8.7% (P > 0.05), 2.2% and 2.9% (P > 0.05), but the rate of rehospitalisation due to heart failure in immediate PCI group and delayed PCI group was respectively 4.3% and 11.4% (P < 0.05).

The decrease rate of QRS score-estimated myocardial infarction (MI) size by initial and follow-up electrocardiograms was 0.384 ± 0.167 (initial 16.36 ± 0.08 and follow-up 10.06 ± 5.91) in immediate PCI group and 0.18 ± 0.13 (initial 16.50 ± 8.34 and follow-up 10.44 ± 6.38) in delayed PCI (P < 0.05).

The left ventricular end-diastolic dimension (LVDd) was 46.6 ± 6.7 mm (initial) and 47.4 ± 5.7 mm (follow-up) in immediate PCI group and 47.8 ± 6.1 mm (initial) and 50.1 ± 6.7 mm (follow-up) in delayed PCI group, which were significant difference (P < 0.05) between the two groups. Left ventricular ejection fraction (EF) was 56.7 ± 6.3% (initial) and 59.9 ± 5.9% (follow-up) in immediate PCI group, and 55.0 ± 6.9% (initial) and 51.9 ± 6.4% (follow-up) in delayed PCI group, which was significant difference (P < 0.05) between two groups.

Conclusions The rate of MACE in delayed PCI is higher than that in immediate PCI for patients with STEMI. The rate of rehospitalisation due to heart failure in delayed PCI is higher then that in immediate PCI.