Aims: Previous studies have shown that prodromal angina (PA) occurs frequently in acute myocardial infarction (MI) patients. However, the potential benefits of PA on ischaemic myocardial damage remain unknown.
Methods and results: One-hundred and fifty-four patients with acute ST-segment elevation MI successfully treated with primary percutaneous coronary intervention (PPCI) were prospectively evaluated for new-onset PA in the week preceding infarction and other factors known to influence myocardial salvage. Cardiovascular magnetic resonance was performed 8 ± 3 days after MI for the assessment of area-at-risk (AAR), MI size, myocardial haemorrhage (MH), microvascular obstruction (MO), and myocardial salvage index (MSI). Patients with PA (n = 60) compared with those without PA (n = 94) showed similar AAR but significantly smaller MI size leading to larger MSI (0.53 ± 0.27 vs. 0.32 ± 0.26, P < 0.001). Additionally, patients with PA had lower incidence of MH (18 vs. 33%) and MO (22 vs. 46%) than non-PA patients (both P < 0.05). At univariate analysis, higher MSI was associated with new-onset PA, lower myocardial oxygen consumption before PPCI, shorter time-to-PPCI, and higher post-procedural TIMI flow-grade. Neither collateral circulation nor medications administered before PPCI were associated to MSI. After correction for other covariates by multivariate analysis, new-onset PA remained significantly associated with MSI (β-value: 0.352, P < 0.001).
Conclusion: In acute MI patients, new-onset PA is associated with higher MSI independent of others factors known to influence jeopardized myocardium, as well as with less microvascular damage.
Keywords: Cardioprotection; Myocardial infarction; Prodromal angina.