Primary percutaneous angioplasty, thromobolysis and conservative treatment in low-risk patients with ST-elevation myocardial infarction: effects on short- and long-term mortality

Background: Although primary coronary intervention (PCI) is currently regarded as the preferred reperfusion strategy in ST-elevation myocardial infarction (STEMI), its superiority over thrombolysis has been documented mainly in high-risk patients. In low-risk patients, the difference seems to be not so significant. Aim: To evaluate the early and late mortality in low-risk STEMI patients treated with thrombolysis, PCI, or conservatively. Methods: From a total of 3,780 consecutive STEMI patients presenting within 24 h from symptom onset, 990 low-risk patients (age < 70 years old, Killip-Kimball class 1 at admission, non-anterior STEMI) were selected. The median follow-up duration was 18.3 (14.2-25.0) months. The patients were subdivided into three groups: group A (n = 465) - treated with PCI; group B (n = 289) - treated with thrombolysis; and group C (n = 236) - treated conservatively. Results: In the whole study group 12 (1.21%) patients died; 30-day mortality in group A was 0.65%. In group B five out of 289 (1.73%) patients died, and in group C four out of 236 (1.69%) patients died. No significant differences in 30-day mortality between these three groups were found (p = 0.3). During the long-term follow-up, 37 (3.7%) of 990 patients died. In group A 18 (3.9%) patients died, in group B ten (3.4%) patients died, and in group C nine (3.8%) patients died (p = 0.96). Conclusions: No significant differences in 30-day or long-term mortality rates between conservative therapy, PCI or thrombolysis groups in low-risk STEMI patients were observed.