Abstract 312: Preprocedural Coronary Computed Tomography Angiography Significantly Enhances Success Rates of PCI in Complex Chronic Total Occlusions
Background: Successful revascularization of Chronic Total Occlusions (CTO) depends on the possibiltiy to cross the complete length of the occlusion with the guidewire. This is often hampered by the inability to detect the true intraluminal passage and the course of the vessel. 3D volume rendering technique (3DVRT) in coronary computed tomography angiography (CTA) enables the complete visualization of the vessel in patent and occluded segments. The tortuosity of the vessel and the degree of calcification can be determined accurately. It was the aim of this study to examine if coronary CTA can significantly enhance procedural success in patients with complex CTOs.
Mehthods: 40 consecutive patients with complex lesions were enrolled in the study and underwent CTA. All patients than had PCI by an experienced interventionalist (GW). Procedural success was defined as the ability to reach the distal vessel with the guidwire. A severity index was derived from the complexity criteria proposed by the EuroCTO club. Patients were compared to a control group of similar severity. All lesions were measured with respect to the complexity criteria on CTA and coronary angioraphy (XA) and tested for significant differences. Each criterion was graded from 0 to 2, a maximum score of 22 was possible. Non parametric Wilcoxon test was used. Continuous variables are presented as mean±SD.
Results: 40 patients underwent PCI for CTO (RCA n=22, LAD n=8, CFX n=10). The mean serverity score was 19.1±2.9 in the study group and 18.8±2.9 among controls, p = 0.72. Success rate was significantly higher in the study group (90%) as compared to controls (73%), p = 0.045. The true course of the occluded vessel segment was visualized by 3DVRT in all of the 40 patients and by XA in only 11 cases, p = 0.0001. The lesion length was underestimated by XA alone (29.5±20.5 mm VRT vs. 21.9±18.1 mm XA, p = 0.001). The degree of calcification of the proximal cap was misjudged by XA alone (mean score 1.0±0.7 VRT vs. 0.41±0.6 XA p = 0.001). A side branch within the occluded segment was detected by VRT in 16 cases and only 8 cases by XA alone, p = 0.034).
Conclusion: Coronary CTA significantly contributed to a higher success rate due to better vessel visualization by VRT.