The atherogenic index of plasma (AIP) is calculated by logarithmic transformation of the ratio of triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) concentrations. Although previous studies have demonstrated that the AIP is associated with coronary artery disease, its association with chronic total occlusion (CTO) requires elucidation.

Coronary artery bypass graft (CABG) accelerates the prevalence of native coronary chronic total occlusion (CTO), and this kind of CTO shows extensive challenging and complex atherosclerotic pathology. As a result, the procedural success rate of percutaneous coronary intervention (PCI) is inferior to another kind of lesions. The present meta-analysis aims to compare the lesion characteristics and procedural complications of CTO-PCI in patients with or without prior CABG. A total of 8 studies, comprising of 13439 patients, published from inception to August 2021 were included in this meta-analysis. Results were pooled using random effects model and are presented as odds ratio (OR) with 95% confidence intervals (95% CIs). From the 13439 patients enrolled, 3349 (24.9%) patients had previous CABG and 10090 (75.1%) formed the control group in our analysis. For the clinical characteristic, compared to the non-CABG patients, prior CABG patients were older (OR, 3.98; 95% CI, 3.19-4.78; p < .001; I2  = 72%), had more male (OR, 1.30; 95% CI, 1.14-1.49; p < .001; I2  = 6%), diabetes mellitus (OR, 1.54; 95% CI, 1.36-1.73; p < .001; I2  = 37%), dyslipidemia (OR, 1.89; 95% CI, 1.33-2.69; p < .001; I2  = 81%), hypertension (OR, 1.88; 95% CI, 1.46-2.41; p < .001; I2  = 71%), previous myocardial infarction (OR, 1.94; 95% CI, 1.48-2.56; p < .001; I2  = 85%), and previous PCI (OR, 1.74; 95% CI, 1.52-1.98; p < .001; I2  = 22%). Non-CABG patents had more current smoker (OR, .45; 95% CI, 0.27-0.74; p < .001; I2  = 91%). BMI (OR, -0.01; 95% CI, -0.07-0.06; p = .85; I2  = 36%) were similar in both groups. For lesions location, the right coronary artery (RCA) was predominant target vessel in both groups (50.5% vs 48.7%; p＝.49), although, the left circumflex (LCX) was more frequently CTO in the prior CABG group (27.3% vs 18.9%; p＜.01), while left anterior descending artery (LAD) in non-CABG ones (16.0% vs 29.1%; p＜0.01). For lesions characteristics, prior CABG patients had more blunt stump (OR, 1.71; 95% CI, 1.46-2.00; p < .001; I2  = 40%), proximal cap ambiguity (OR, 1.45; 95% CI, 1.28-1.64; p < .001; I2  = 0.0%), severe calcifications (OR, 2.91; 95% CI, 2.19-3.86; p < .001; I2  = 83%), more bending (OR, 3.07; 95% CI, 2.61-3.62; p < .001; I2  = 0%), lesion length > 20 mm (OR, 1.59; 95% CI, 1.10-2.29; p = .01; I2  = 83%), inadequate distal landing zone (OR, 1.95; 95% CI, 1.75-2.18; p＜.001; I2  = 0.0%), distal cap at bifurcation (OR, 1.65; 95% CI, 1.46-1.88; p < .001; I2  = 0.0%), and higher J-CTO score (SMD, 0.52; 95% CI, 0.42-0.63; p < .001; I2  = 65%). But side branch at proximal entry (OR, 0.88; 95% CI, 0.72-1.07; p = .21; I2  = 45%), in-stent CTO (OR, 0.99; 95% CI, 0.86-1.14; p = .88; I2  = 0.0%), lack of interventional collaterals (OR, 0.80; 95% CI, 0.55-1.15; p = .23; I2  = 78%), and previously failed attempt (OR, 0.73; 95% CI, 0.48-1.11; p = .14; I2  = 89%) were similar in both groups. For complication, prior CABG patients had more perforation with need for intervention (OR, 1.91; 95% CI, 1.36-2.69; p < 0.001; I2  = 34%), contrast-induced nephropathy (OR, 3.40; 95% CI, 1.31-8.78; p = .01; I2  = 0.0%). Non-CABG patents had more tamponade (OR, 0.25; 95% CI, 0.09-0.72; p = .01; I2  = 0.0%), and the major bleeding complication (OR, 1.18; 95% CI, 0.57-2.44; p = .65; I2  = 0%) were no significant difference in both groups. In conclusion, Patients with prior CABG undergoing CTO-PCI have more complex lesion characteristics, though procedural complication rates were comparable.