Author + information
- Stephen Ellis1,
- Ramy Badawi2,
- M. Nicholas Burke3,
- Bilal Murad4,
- John Graham5,
- Catalin Toma6,
- Henry Meltser7,
- Ravi Nair8,
- Christopher Buller5 and
- Patrick Whitlow1
- 1Cleveland Clinic Foundation, Cleveland, Ohio, United States
- 2Queens Medical Center, Honolulu, Hawaii, United States
- 3Minneapolis Heart Institute Foundation, Minneapolis, Minnesota, United States
- 4United Heart and Vascular Clinic, St. Paul, Minnesota, United States
- 5St. Michael's Hospital, Toronto, Ontario, Canada
- 6UPMC, Pittsburgh, Pennsylvania, United States
- 7Cardiology group of WNY, Williamsville, New York, United States
- 8Cleveland Clinic
Chronic total occlusion (CTO)s are common and often result in referral for bypass surgery without attempted PCI. When PCI is attempted, success rates are variable and current predictive models for success have major limitations. We sought to develop a hybrid approach-specific model to predict CTO success, superior in predictive capacity to commonly used models, useful for experienced CTO operators.
Clinical, procedural and outcomes data were obtained from consecutively attempted patients from 7 clinical sites and 9 operators (mean annual operator CTO volume 61+17 cases). Angiographic analysis of 21 lesion variables was performed centrally. Statistical modeling was performed on a randomly designated training group and tested in a separate validation cohort.
436 patients (456 lesions) met entry criteria. 24.5% of lesions had a prior failed PCI at the CTO site. The RCA was the most common location (56.4%) and occlusion length was 24+20 mm. The initial approach was most often antegrade wire escalation (70%), followed by retrograde (22%). Technical success was achieved in 79.4%. Complications were infrequent but death occured in 0.9% of patients. Failure was most closely correlated with presence of an ambiguous proximal cap (APC), specifically defined collateral score (combination of Werner and Kato scores) and retrograde tortuosity in the presence of an APC; and poor distal target, occlusion length >10 mm, and ostial location with non-APC; and 1 operator variable. Prior failure, Werner and Kato scores alone and circumflex occlusion only weakly correlated with outcome. A 7 item model predicted success with c-statistic = 0.753 in the training cohort and = .738 in the validation cohort, the later superior (p<.05) to that of the J-CTO (0.55) and PROGRESS scores (0.61).
Success can be reasonably well predicted, but that prediction requires modification and combination of angiographic variables. Differences in operator skill sets may make it challenging to create a powerful, generalizable, predictive tool unless individual operator skill sets can be characterized, quantitated, and incorporated.
CORONARY: Complex and Higher Risk Procedures for Indicated Patients (CHIP)