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

To evaluate the relationship between endothelial progenitor cell (EPC) count and function and collateral circulation in coronary chronic total occlusions (CTOs).

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.

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).

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.