Collateral filling efficiency of comorbid chronic total occlusion segment on short-term mortality in ST-elevation myocardial infarction.

Background: Collateral filling of chronic total occlusion (CTO) segments is considered to affect hemodynamic stability in primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) with CTO, however its value as a prognostic indicator for mortality is uncertain. The present study examined the relationship between collateral filling of CTO segments and short-term mortality in patients with STEMI with a comorbid CTO lesion.

Methods: Among 829 STEMI patients who underwent primary PCI, 74 patients with CTO were identified. Collateral filling of their CTO segment was assessed by Rentrop grade (0; n=10, 1; n=13, 2; n=31, 3; n=20) in their initial angiogram and whether the origin of the feeding collateral donor artery was infarct-related artery (IRA) was evaluated using their final angiogram in primary PCI; IRA (n=26) and non-IRA group (n=48). The relationship between these classifications and 30-day all-cause mortality was examined retrospectively.

Results: The 30-day mortalities were 4.5% in single-vessel disease, 18.3% in multi-vessel disease (MVD) without CTO and 25.7% in MVD with CTO. Mortality of MVD with CTO reduced with increasing Rentrop grade from 0 to 3 (80.0%, 30.8%, 19.4%, and 5.0%, respectively). IRA was associated with a significant higher mortality than those of non-IRA (50.0% vs. 12.5%, P=0.0004). Low Rentrop grade 0 or 1 was extracted as an independent predictor of 30-day death (HR 3.28, 95% CI 1.20-9.96, P=0.0203).

Conclusions: Poor collateral filling of the CTO segment assessed by Rentrop grade was an independent angiographic predictor for 30-day death in patients with STEMI combined with CTO.