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.
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).
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.