Impact of calcification length ratio on the intervention for chronic total occlusions

Background: The 64-multislice computed tomography (MSCT) can be used to directly guide the complex percutaneous coronary intervention (PCI) procedure and predict the outcome. This study aimed to determine the possibility of success of angioplasty for chronic total occlusion (CTO) performed on the basis of MSCT results. Methods: In this study, we assessed 82 de novo CTO lesions in 67 patients, who were subjected to 64-MSCT before undergoing PCIs. The lesions were either treated with an antegrade approach or a combined bilateral antegrade and retrograde approach. The clinical characteristics of the patients and the angiographic and 64-MSCT parameters associated with the intervention result were analyzed. Results: In this study, the technical and procedural success rates were 89.0% and 80.5%, respectively. There were significant differences in heavy calcification with the calcification length ratio of > 0.5, proximal stump calcification, and distal stump calcification between the technical-success and technical-failure groups (P < 0.001, P = 0.022, and P = 0.003, respectively) as well as between the procedural-success and procedural-failure groups (P < 0.001, P = 0.042, and P = 0.014, respectively). Multivariate analysis showed that heavy calcification was the strong independent parameter that not only influenced technical success (odds ratio [OR] = 0.040, 95% confidence interval [CI] = 0.006-0.254, P = 0.001) but also procedural success (OR = 0.127, 95% CI = 0.035-0.461, P = 0.002). Conclusions: Calcification length ratio of > 0.5 remains to be the independent negative predictor of both technical and procedural success.