Assessment of left ventricular function before and after a percutanous coronary intervention to chronic total coronary occlusion: Doppler tissue imaging study

BackgroundThe rationale for the recanalization of chronic total occlusion (CTO) is the possible improvement in left ventricular (LV) function through the recovery of hibernating myocardium. Tissue Doppler imaging (TDI) can be used for the assessment of global and regional LV function with high temporal and spatial resolution.PurposeThis study aimed to assess LV function before and after CTO-percutanous coronary intervention (PCI) by pulsed wave (PW)-TDI.Patients and methodsThe present study enrolled 40 patients with CTO; 37 completed the final follow-up: 22 patients did not have infarction in the territories of recanalized CTO vessel (group I), and 15 patients had infarction in the CTO territories of recanalized CTO vessel (group II). All patients were subjected to conventional M-mode and two-dimensional echo-Doppler and TDI examination. PW-TDI was used to assess the velocity curves of basal and mid segments of the septal, lateral, anterior, inferior, posterior, and anteroseptal LV walls. The following indices were measured: Tp, Sv, E0΄, A΄, E΄/ A΄, acceleration of isovolumic contraction (IVC), isovolumic relaxation period, isovolumic contraction time (IVCT), contraction time, and TEI index.ResultsAfter recanalization of the CTO vessel by PCI, the patients in the noninfarction group showed a highly significant improvement in left ventricular ejection fraction% after 3 months of follow-up (P < 0.001), whereas the infarction group did not show any significant improvement (P = NS). In the LAD, left circumflex, and right coronary artery subgroup, noninfarction patients showed a reduction in left ventricular end-systolic volume, and increased fraction shorting% and ejection fraction% after 3 months of follow-up; also, there were improvements in TDI parameters in the form of increased E΄ and acceleration of IVC in all three subgroups and increased E΄/ A΄ in LAD and left circumflex, and an increase in the peak velocity of IVC and a reduction in A΄ and time to peak of IVC in both LAD and right coronary artery; only the S wave velocity increased in the LAD subgroup after 3 months of follow-up.ConclusionIn patients with CTO, acceleration of IVC measured by PW-TDI can differentiate early improvement after successful recanalization of the CTO vessel by PCI. Noninfarction territories might show earlier recovery than that in patients with evident myocardial infarction.