Clinical impact of undersized- versus oversized-stenting approaches in ST-elevation myocardial infarction.

BACKGROUND: Primary percutaneous coronary intervention (PCI) is the standard treatment in patients with ST-elevation myocardial infarction (STEMI). However, some patients still develop ST re-elevation during PCI, resulting in further myocardial damage and a poor outcome. An undersized-stenting approach may prevent ST re-elevation. We aimed to determine the association between final stent area and ST re-elevation during primary PCI for STEMI.

METHODS: Overall, 102 consecutive STEMI patients who underwent primary PCI under integrated backscatter intravascular ultrasound guidance were enrolled. The stent-reference (SR) ratio was defined as the stent cross-sectional area (CSA) divided by the average CSA of the 5-mm proximal and distal reference lumens. The patients were divided into two groups according to the SR ratio: undersize group (SR<1.0, n=62) and oversize group (SR≥1.0, n=40). The incidences of ST re-elevation and total ST resolution (STR) were compared.

RESULTS: The oversize group showed a higher incidence of ST re-elevation (32.5 vs. 9.7%, p=0.004) and a lower total STR (22.4±62.7 vs. 43.4±38.6%, p=0.04). After adjustment, the oversized-stenting approach was independently associated with ST re-elevation [odds ratio: 3.74, 95% confidence interval (CI) 1.27-12.1, p=0.02]. The peak creatine kinase-MB level was higher in the oversize group (341±259 vs. 242±208IU/l, p=0.04). The incidences of stent thrombosis and restenosis were similar between the two groups.

CONCLUSIONS: An oversized-stenting approach in patients with STEMI was associated with a higher incidence of ST re-elevation and a lower total STR, resulting in increased myocardial damage.