Full-Moon Coronary Calcification as Detected With Computed Tomography Angiography in Chronic Total Occlusion Percutaneous Coronary Intervention

Abstract

"Full moon" is a central calcification that occludes the entire vessel on coronary computed tomography angiography (CCTA). We examined the association of “full moon” calcification as identified by CCTA, on clinical and procedural outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We studied patients who underwent elective CTO PCI in two European centers and had pre-procedural CCTA. The primary endpoint was the inability to cross the lesion and/or the need for extensive debulking techniques. Secondary endpoints were procedural success, in-hospital cardiac mortality, the need for extensive debulking techniques, myocardial infarction (MI), major adverse cardiac events (MACE, defined as in hospital death, MI and clinically driven target vessel revascularization) and stent thrombosis. Secondary procedural endpoints included procedural time, fluoroscopy time, number of guidewires and balloons, stent length, number and diameter and contrast volume. Multivariable logistic regression analysis was performed identifying potential covariates related to the primary outcome according to knowledge and prior studies. Subsequently, a stepwise selection approach was performed to select factors with the greatest predictive value. Among 140 patients included, 28 (20%) had a “full moon” calcified CTO-plaque. Patients in the full moon group were older and had more cardiovascular risk factors. There was not significant difference in the need for retrograde approach and antegrade dissection and re-entry (ADR) techniques in the “full moon” group vs the other groups (32.1% vs 37.5%, p=0.59 and 0% vs 1.7%, p=0.47 respectively). Compared with patients who did not have full moon morphology, full moon patients had higher incidence of the primary outcome (53.5% vs 12.5%;p<0.001). On multivariable analysis that included chronic kidney failure and prior coronary artery bypass surgery, full moon calcification was associated with higher incidence of the primary endpoint; OR 6.5;95% CI 2.1-20.5;p=0.001). Moreover, lower procedural success (71.4% vs 87.5%;p=0.03), higher incidence of coronary perforations (14.2% vs 3.5%;p<0.02) and higher procedural [172.5 (118.0-237.5) vs 144.0 (108.50-174.75); p=0.02] and fluoroscopic time [62.6 (38.1-83.0) vs 42.8 (29.5-65.7); p=0.03] were observed in the “full moon” group. Overall MACE did not differ between the two groups (1 patient in the “full moon” group vs 1 patient in the no “full moon” group; 3.5% vs 0.8%, p=0.29). In conclusion, “full moon” calcification on CCTA was independently associated with procedural complexity and adverse outcomes in CTO-PCI.