The prognostic value of collateral circulation in coronary chronic total occlusion underwent percutaneous coronary intervention.

Background: The prognostic value of coronary collateral circulation (CC) in patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is underdetermined. The purpose of the study was to assess the prognostic value of current two CC grading systems and their association with long-term outcomes in patients with CTO underwent PCI.

Methods: We consecutively enrolled patients with single-vessel CTO underwent PCI between January 2010 and December 2013. All patients were categorized into well-developed or poor-developed collaterals group according to angiographic Werner's CC (grade 2 vs. grade 0-1) or Rentrop (grade 3 vs. grade 0-2) grading system. The primary endpoint was 5-year cardiac death.

Results: Of 2452 enrolled patients, the overall technical success rate was 74.1%. Well-developed collaterals were present in 686 patients (28.0%) defined by Werner's CC grade 2, and in 1145 patients (46.7%) by Rentrop grade 3. According to Werner's CC grading system, patients with well-developed collaterals had a lower rate of 5-year cardiac death compared with those with poor-developed collaterals (1.6% vs. 3.3%, P = 0.02), those with suboptimal recanalization was associated with higher rate of 5-year cardiac death compared with optimal recanalization (4.7% vs. 0.8%, P = 0.01) and failure patients (4.7% vs. 1.6%, P = 0.12). However, the similar effect was not shown in Rentrop grading system.

Conclusions: In patients with the single-vessel CTO underwent PCI, well-developed collaterals by Werner's CC definition were associated with lower rate of 5-year cardiac death. Werner's CC grading system had a greater prognostic value than Rentrop grading system in patients with CTO underwent PCI.