Activated clotting time and outcomes of chronic total occlusion percutaneous coronary intervention: insights from the PROGRESS-CTO Registry.

Background: The optimal range of activated clotting time (ACT) in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study.
Methods: We examined the association between ACT and in-hospital ischemic and bleeding outcomes in patients who underwent CTO PCI in the Prospective Global Registry for the Study of CTO Intervention.
Results: ACT values were available for 4377 patients who underwent CTO PCI between 2012 and 2023 at 29 centers. The mean ACT distribution was less than 250 seconds (19%), 250 to 349 seconds (50%), and greater than or equal to 350 seconds (31%). The incidence of ischemic events, bleeding events, and net adverse cardiovascular events (NACE) was 0.8%, 3.0%, and 3.8%, respectively. In multiple logistic regression analysis, increasing nadir ACT was associated with decreasing ischemic events (adjusted odds ratio [aOR] per 50-second increments: 0.69 [95% confidence interval (CI), 0.50-0.94; P=.017]; and increasing peak ACT was associated with increasing bleeding events (aOR per 50-second increments: 1.17 [95% CI ,1.01-1.36; P=.032]). A U-shaped association was seen between mean ACT and NACE, where restricted cubic spline analysis demonstrated that patients with a low ( less than 200 seconds) or high ( greater than 400 seconds) ACT had increasing NACE risk compared with an ACT of 200 to 400 seconds (aOR 2.06, 95% CI 1.18-3.62; P=.012).
Conclusions: Among patients who underwent CTO PCI, mean ACT had a U-shaped relationship with NACE, where patients with a low ( less than 200 seconds) ACT (driven by ischemic events) or high ( greater than 400 seconds) ACT (driven by bleeding) had higher NACE compared with an ACT of 200 to 400 seconds.