Cardiac Catheterization After CABG With BIMA Grafting: Independent Predictors and Mid-term Bypass Viability

Coronary artery bypass graft (CABG) patency is an important variable, but rarely studied as the main outcome. The best use of bilateral internal mammary artery (BIMA) grafting regarding configuration type or combination with saphenous vein graft (SVG) is still debated.

To find independent predictors for need of cardiac catheterization and for significant lesions in CABG follow-up.

Retrospective cohort including all patients who underwent isolated CABG with BIMA grafts between 2004 and 2013 in a tertiary center. Preoperative, surgical and postoperative data were collected through clinical files and informatics databases. Kaplan-Meier curves, Cox regression and logistic regression were used to find predictors for the need of catheterization and for significant angiographic lesions after CABG. Secondary end-points studied were mid- term survival and need of re-revascularization either surgically or percutaneously.

We included 1030 patients in this analysis. Median follow-up time was 5.5 years and 150 (15%) patients were re-catheterized in that period. Most of these procedures was due to ischemia suspicion (74%) and 61 (41%) were positive for significant angiographic lesions of conduits (IMA: 3.2% and SVG: 3.8%, p=0.488). In multivariate analysis, SVG use was found as an independent predictor of cardiac catheterization on follow-up (HR: 1.610, CI 95%: 1.038-2.499, p=0.034). On the other side, independent predictors of graft lesions were younger age (OR: 0.951, CI 95%: 0.921-0.982, p=0.002), female gender (OR: 2.231, CI 95%: 1.038-4.794, p=0.040), arterial hypertension (OR: 1.968, CI 95%: 1.022-3.791, p=0.043) and 3-vessel disease (OR: 2.820, CI 95%: 1.155-6.885, p=0.023). Among the patients with significant angiographic lesions, 48 underwent repeat revascularization (44 PCI e 4 CABG). Arterial hypertension and younger age were independent predictors of re-revascularization.

In BIMA patients the addition of SVG predicts the need of catheterization; however prevalence of significant angiographic lesions was similar in IMA and SVG. Our results suggest that arterial hypertension is an independent predictor of graft patency and re-revascularization rate.