Study Analyzes Coronary Artery Spatial Distribution of CTOs
November 14, 2016—A study assessing the spatial distribution of chronic total occlusions (CTOs) within the coronary arteries and describing procedural strategies and outcomes during CTO percutaneous coronary intervention (PCI) was published by Santiago Garcia, MD, et al in Catheterization and Cardiovascular Interventions.
In this study, the investigators examined the clinical and procedural characteristics of 1,348 patients according to lesion location within the coronary tree. The background of the study is that acute occlusions caused by plaque rupture tend to cluster within the proximal third of the coronary artery.
As summarized in Catheterization and Cardiovascular Interventions, the study included a total of 1,369 lesions in 1,348 patients (mean age, 66 ± 10 years; 85% male). CTO PCI of proximal segments (n = 633; 46%) was more common than of mid (n = 557; 41%) and distal segments (n = 179; 13%).
The investigators reported:
- Patients undergoing CTO PCI of proximal segments were more likely to be smokers (P < .01), have previous coronary artery bypass graft surgery (P = .03), and lower ejection fraction (P = .04). CTOs occurring in proximal segments had longer length (P < .01), proximal cap ambiguity (P < .01), and moderate/severe calcification (P < .01) compared to mid or distally located CTOs.
- Interventional collaterals were more often present in CTO PCI of proximal segments (64%, 53%, 56%; P < .01) consistent with the higher use of retrograde approach (47%, 33%, 37%; P < .01) relative to antegrade wire escalation (67%, 82%, 82%; P < .01).
- Procedural complexity was higher in CTO PCI of proximal segments versus mid and distal in terms of contrast volume (275 [200–375] vs 260 [200–350] vs 250 mL [175–350]; P = .01) and fluoroscopy time (53 [32–83] vs 39 [24–65] vs 40 min [22–72]; P < .01). However, procedural success (87% vs 90% vs 85%; P = .1), technical success (89% vs 91% vs 88%; P = .24), and complication rates (2.8% vs 2.5% vs 2.2%; P = .88) were not significantly different.
The study demonstrated that the most common target vessel location for CTO PCI is the proximal coronary segment. PCI of proximal occlusions is associated with adverse clinical and angiographic characteristics and often requires use of the retrograde approach, but can be accomplished with high procedural and technical success and low complication rates, concluded the investigators in Catheterization and Cardiovascular Interventions.