Implications of prodromal angina pectoris in anterior wall acute myocardial infarction: acute angiographic findings and long-term prognosis.

OBJECTIVES

This study was undertaken to assess how prodromal angina affects long-term prognosis after acute myocardial infarction.

BACKGROUND

Although it has been reported that prodromal angina occurring shortly before the onset of acute myocardial infarction has protective effects against ischemia, its implication for long-term prognosis remains unclear.

METHODS

We studied consecutive 350 patients with anterior myocardial infarction who underwent coronary angiography within 24 h after the onset of chest pain. Follow-up was achieved for 340 patients (97%).

RESULTS

Eighty-nine patients had one or more episodes of angina within 24 h before infarction. On initial angiography, patients with prodromal angina in the 24 h before infarction had a patent infarct-related artery more frequently than did those without prodromal angina (34% vs. 22%, p = 0.03). Among 213 patients who underwent thrombolytic therapy for an occluded infarct-related artery, reperfusion was more frequently achieved in patients with prodromal angina in the 24 h before infarction (76% vs. 56%, p = 0.01). Prodromal angina in the 24 h before infarction was associated with a lower in-hospital mortality rate (6% vs. 14%, p = 0.02) and better 5-year survival (p = 0.009). There was no significant difference in survival between patients with previous angina at any time (n = 202) and those without. Multivariate analysis showed that prodromal angina in the 24 h before infarction was an independent factor related to 5-year survival after acute myocardial infarction (odds ratio 0.49, p = 0.04).

CONCLUSIONS

Prodromal angina occurring shortly before the onset of infarction, but not previous angina itself, has a beneficial effect on long-term prognosis after infarction, suggesting a relation to ischemic preconditioning.