Impact of recanalization of chronic total occlusion on left ventricular electrical remodeling

Successful percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is associated with reduction of cardiac mortality, as well as reducing fatal ventricular arrhythmias. The aim of this study was to evaluate the effect of recanalization of CTO on endocardial left ventricular voltages by paired electrophysiological studies.

Sixteen consecutive patients who underwent PCI for de novo CTO lesions were included. High-density mapping was performed during sinus rhythm before and 8 months after PCI. According to the amplitude of bipolar electrograms, the left ventricular endocardium was classified into a preserved normal voltage (>1.5 mV), border zone (0.5-1.5 mV), and dense scar areas (<0.5 mV).

The border zone area had a significant positive correlation with CTO length, as well as a significant negative correlation observed in the preserved voltage region. In the successful PCI patient, the median dense scar area did not change significantly (reported as [median difference: 95% confidence interval]) between baseline and after PCI (0.1 cm² : -2.8 to 2.9). However, the area of the border zone decreased (-10.5 cm² : -16.8 to -4.1) and the preserved voltage area increased significantly (19.2 cm² : 7.7-30.6). In addition, successful PCI was related to slight, but significant, increase in the amplitude of unipolar and bipolar voltage (1.55 mV: 0.88-3.33, 0.23 mV: 0.08-0.36).

Recanalization of CTO may promote reverse electrical remodeling in the border zone of the left ventricle, without affecting the dense scar tissue.