Endothelial Progenitor Cell Function in Patients With Coronary Chronic Total Occlusion and its Relationship With Collateral Circulation.

ABSTRACT

AIM: To evaluate the relationship between endothelial progenitor cell (EPC) count and function and collateral circulation in coronary chronic total occlusions (CTOs). METHODS: A total of 20 consecutive patients with successfully treated CTO lesions were included during a period of 12 months. EPC count and function were evaluated by flow cytometry and colony-forming unit (CFU) analysis at baseline (before percutaneous coronary intervention) and at 1-year follow-up. Patients were classified, according to Rentrop classification at the baseline angiography, as group 1 (Rentrop 3; n = 7) and group 2 (Rentrop <3; n = 13). Differences in EPC count and function were compared between groups. RESULTS: The EPC count did not differ between the 2 groups, either at baseline or at follow-up. CFU was significantly lower at follow-up compared with baseline in the overall population (16.6 10^6/mL (IQR, 10.2-29.4 10^6/mL) vs 7.1 10^6/mL (IQR, 5.3-25.0 10^6/mL); P=.046). Group 1 had both higher basal and follow-up CFU values compared with group 2 (35.4 10^6/mL (IQR, 21.5-41.8 10^6/mL) vs 13.3 10^6/mL (IQR, 6.9-17.5 10^6/mL) and 32.1 10^6/mL (IQR, 13.9-40.5 10^6/mL) vs 5.9 10^6/mL (IQR, 4.4-9.8 10^6/mL), respectively; P=.01 for both). By linear regression analysis, Rentrop grade 3 flow was an independent predictor of both basal and follow-up CFU levels (odds ratio, 3.66; 95% confidence interval, 6.41-29.69; P<.01; and odds ratio, 5.24; 95% confidence interval, 9.78-25.85; P<.01, respectively). CONCLUSION: Patients with Rentrop grade 3 collateral circulation exhibited higher EPC activity at baseline and at 1-year follow-up compared with those who had reduced collateral circulation. The role of this higher EPC activity in determining clinical endpoint should be investigated in a larger study.