Multimodality imaging evaluation of functional and clinical benefits of percutaneous coronary intervention in patients with chronic total occlusion lesion

Abstract

Aims: To determine the effects of percutaneous coronary intervention (PCI) on cardiac perfusion, cardiac function, and quality of life in patients with chronic total occlusion (CTO) lesion in left anterior descending (LAD) coronary artery.

Methods and results: Patients (n=99) with CTO lesion in the LAD coronary artery who had successfully undergone PCI were divided into three groups based on the SPECT/CTCA fusion imaging: (a) no severe cardiac perfusion defects (n=9); (b) reversible cardiac perfusion defects (n=40); or (c) fixed cardiac perfusion defects (n=50). No statistical difference of perfusion abnormality was observed at 6 months and 1 year after PCI in group (a). In group (b), SPECT/CTCA fusion imaging demonstrated that cardiac perfusion abnormality was significantly decreased 6 month and 1 year after PCI. Left ventricular ejection fraction (LVEF) increased significantly at 6 months and 1 year follow up. Quality of life improved at 6 months and 1 year after PCI procedure. Moreover, patients in group (c) also benefited from PCI therapy: a decrease in cardiac perfusion abnormality, an increase in LVEF, and an improvement in quality of life. PCI of coronary arteries in addition to LAD did not significantly affect cardiac function and quality of life improvement in each group.

Conclusions: PCI exerts functional and clinical benefits in patients with CTO lesion in LAD coronary artery, particularly in patients with reversible cardiac perfusion defects. SPECT/CTCA fusion imaging may serve as a useful tool to evaluate the outcomes of patients with CTO lesion in LAD coronary artery.

Keywords: CTCA.; CTO; Chronic total occlusion; Computed tomography coronary angiography; PCI; Percutaneous coronary intervention; SPECT; Single-photon emission computed tomography.

Figure 1

Flow chart outlining the study protocol.

Figure 2

Patients enrollment.

Figure 3

Event free survival rate recorded in each group.

Figure 4

SPECT/CTCA fusion imaging and myocardial perfusion imaging. SPECT/CTCA fusion image were indicated in a representative patient in group (b) from baseline to 1 year after PCI. CTCA imaging confirmed LAD lesion (A, B, yellow arrow). SPECT/CT fusion image showed myocardial perfusion defects (C, D, E). Three-dimensional SPECT/CTCA fusion images revealed severe anterior wall perfusion defects (F, red arrow). Myocardial perfusion SPECT after pharmacological stress and at rest showed a reversible anterior perfusion defect. Cardiac perfusion abnormality was significantly improved at 1 year follow up after PCI in group (b) (G, H, I, J). Three-dimensional SPECT/CTCA fusion images visualize improved cardiac perfusion at 1 year follow up after PCI in group (b) (K, L, red arrow). Cardiac perfusion abnormality was not significantly reduced at 6 months and 1 year follow up in group (a). Cardiac perfusion abnormality was significantly improved at 6 months and 1 year follow up after PCI in group (b). The similar trend was found in group (c) (M). Cardiac perfusion abnormality of left ventricular anterior wall was also significantly improved at 6 months and 1 year follow up after PCI in group (b) as well as in group (c) (N). *p<0.05 vs baseline.

Figure 5

Changement of LVEF, ESV, EDV and 6MWD. (A, B) LVEF measured at 6 months and 1 year follow up was found to have increased significantly in group (b) and group (c) compared to their baseline respectively (C, D). ESV were decreased significantly in group (b) and group (c) at 6 months and 1 year follow up (E, F). EDV were decreased significantly in group (b) at 6 months and 1 year follow up. LVEF: left ventricular ejection fraction; ESV: end systolic volume, EDV: end diastolic volume. Solid circles represent the mean, T bars the standard error (SE) in A, C, E, T bars the standard deviation (SD) in B, D, F. Quality of life improved as evidenced by 6-min walk distance (6MWD) at 6 months and 1 year follow up in group (b) and group (c) (G, H). *p<0.05 vs baseline.

Figure 6

Subgroup analysis. No statistical difference of LVEF, ESV, EDV and 6MWD was observed 6 months and 1 year after PCI in group (a) compared with baseline (A). LVEF was significantly enhanced at 6 months and at 1 year after PCI in patients with PCI of the LAD artery in group (b). LVEF was also significantly enhanced at 1 year follow-up in patients with PCI of arteries in addition to the LAD artery in group (b). Similar trend of LVEF change was also recorded in each subgroup in group (c) as group (b) (A). ESV measured at 6 months and 1 year follow up were decreased in patients with PCI of the LAD artery in the group (b) and group (C) as compared with baseline (B). EDV decreased 1 year after PCI procedure in patients with PCI of arteries in addition to the LAD artery in group (b) (C). 6MWD were also significantly increased at 6 months and 1 year follow-up in each subgroup in group (b) and group (c) (D). Solid circles represent the mean, T bars the standard deviation (SD).*p<0.05 vs baseline.