Abstract
The effect of percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) on left ventricular dyssynchrony was unclear. Patients with one CTO vessel were included. Tissue Doppler imaging (TDI) was used to assess the left ventricular dyssynchrony index (DI) in twelve segments before and after successful CTO PCI. Multiple regression was used to identify independent correlates of DI reduction. Ninety one patients were included with the mean age of 62.04 years. 88(96.70%) had left ventricular DI more than 33. It decreased from 69.58 ± 28.35 to 43.38 ± 17.34 (P < 0.001) after successful CTO PCI. PCI of infarct-relative CTO was associated with less percentage of DI reduction (Coefficient [Coef.], 11.13; 95% confidence interval [CI], 2.33-19.93; P = 0.01). Higher initial DI was associated with more percentage of DI reduction (Coef., - 0.38; 95% CI - 0.52 to - 0.23; P < 0.001). Percentage of DI reduction was associated with ejection fraction (EF) improvement (Coef., - 1.45; 95% CI - 2.58 to - 0.33; P = 0.01). CTO PCI led to significant reduction in DI and improvement of EF, particularly in patients without myocardial infraction and severe dyssynchrony. CTO patients with evident left ventricular dyssynchrony or without a history of myocardial infarction may benefit from a more proactive revascularization strategy. The association between dyssynchrony reduction and long-term benefits of CTO PCI warrants further investigation.