Myocardial Infarct Size in Patients on Long-Term Statin Therapy Undergoing Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction

Statin pretreatment has been reported to have a cardioprotective effect in patients undergoing elective or urgent percutaneous coronary intervention (PCI). However, data on patients with ST-elevation myocardial infarction (STEMI) undergoing primary PCI are still controversial. We prospectively evaluated the effect of long-term statin therapy on infarct size (IS), myocardial salvage index (MSI), and microvascular obstruction (MVO) in consecutive patients with STEMI who underwent primary PCI. Two-hundred thirty patients with STEMI (mean age 61 ± 11 years, 183 men) who underwent primary PCI were evaluated with cardiac magnetic resonance (CMR) imaging during hospitalization (median 4 days after primary PCI). In all patients, we measured peak troponin I level, whereas IS, MSI, and MVO were determined by CMR. Fifty patients (22%) were on long-term statin therapy and showed a significantly lower troponin I peak value compared to patients without previous statins (54 ± 47 vs 88 ± 106 ng/ml; p = 0.02). At CMR evaluation, IS related to the index event was significantly smaller (12.5 ± 11.5 vs 18.5 ± 18.5 g, p = 0.05), and MSI was higher (0.68 ± 0.25 vs 0.52 ± 0.30; p <0.01) in patients with previous statin therapy. MVO was also less frequent (10% vs 20%; p = 0.14) in this group. At multivariate analysis, previous statin therapy remained significantly associated with IS and MSI (p = 0.05 and 0.02, respectively). In conclusion, this study suggests that long-term statin therapy before primary PCI in patients with STEMI is associated with smaller IS and higher MSI. Future studies are warranted to confirm these findings and to investigate potential clinical implications.