Background: The success rate of percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) is relatively low. Further evaluation of CTO lesion with CT coronary angiography (CT-CA) may help to better select patients that would benefit from percutaneous revascularization. We aimed to test the possible association between failed PCI and transluminal calcification of CTO as assessed by CT-CA.
Methods: Patients with CTO awaiting PCI were scanned with a 16-slice CT. A cardiologist and a radiologist assessed transluminal calcification of CTO lesions on CT images while an interventional cardiologist at a core laboratory assessed conventional variables of invasive fluoroscopic coronary angiography (FCA) associated with failed PCI of CTO. The significance of CT and FCA variables in association with failed PCI were analyzed.
Results: In a cohort of 39 patients with 43 CTO lesions, 24 lesions were successfully revascularized. Transluminal calcification > or =50% as assessed on CT-CA was strongly associated with failed PCI (odds ratio [OR] of PCI success = 0.10, 95% confidence interval [CI]: 0.02-0.47, P = 0.003). Blunt stump as seen on FCA was also associated with failed PCI (OR of PCI success = 0.24, 95% CI: 0.07-0.86, P = 0.029). There was no significant evidence to support that the duration of CTO, presence of side branch and bridging collaterals, and the absence of microchannels as assessed with FCA were associated with failed PCI. On multivariate analysis, transluminal calcification > or =50% on CT-CA was the only significant predictor of failed PCI.
Conclusions: Heavy transluminal calcification as assessed with CT-CA is an independent predictor of failed PCI of CTO. CT-CA may have a role in the work-up of CTO patients prior to PCI.