The recanalization of chronic total occlusion leads to lumen area increase in distal reference segments in selected patients: an intravascular ultrasound study

Abstract

Objectives: This study sought to investigate the extent of and factors related to lumen and vessel area change in coronary arteries after total occlusion (TO) recanalization.

Background: TO of a coronary artery promotes negative remodeling in distal reference segments. Recanalization can restore blood flow, potentially leading to positive vascular remodeling.

Methods: From March 2005 to June 2008, 58 consecutive patients with de novo TO lesions of at least 1-month duration were enrolled. We performed intravascular ultrasound after successful percutaneous coronary intervention and at the 6-month follow-up, and we quantified changes in the distal reference segments.

Results: At the 6-month follow-up, there was a significant increase in the mean lumen diameter (+0.21 mm, p = 0.001), the mean external elastic membrane diameter (+0.13 mm, p = 0.010), the lumen area (+0.87 mm(2), p < 0.001), and the external elastic membrane area (+0.85 mm(2), p = 0.001) in the distal reference segments and an increase in the left ventricular ejection fraction (+2.77%, p = 0.010). Overall, 40 of 58 patients (69%) showed lumen area increase; these patients had increase in lumen diameter by 0.40 ± 0.34 mm (p < 0.001) and increase in incomplete stent apposition rate (p = 0.006). A TO duration of longer than 3 months (odds ratio [OR]: 14.8; 95% confidence interval [CI]: 1.28 to 172.8, p = 0.032), a poor collateral flow (OR: 12.0; 95% CI: 1.92 to 74.2, p = 0.008), and statin use (OR: 7.4; 95% CI: 1.03 to 53.6, p = 0.047) were independent predictors of lumen area increase.

Conclusions: Recanalization of TO led to lumen area increase in two-thirds of the patients. Independent predictors of lumen area increase were occlusion duration, a poor collateral flow, and statin use. These factors could be used as guides in choosing the optimal stent size during percutaneous coronary intervention to TO lesions and optimal medical therapy during follow-up.