Prognostic value of Layer-Specific global longitudinal strain in patients undergoing Coronary Artery Bypass Grafting.

purposeTo determine the prognostic value of layer-specific global longitudinal strain (GLS) after coronary artery bypass grafting (CABG).

methodsThis retrospective cohort study comprised 641 patients undergoing isolated CABG between 2006 and 2011. Layer-specific GLS was assessed by echocardiography using two-dimensional speckle tracking. Patients were followed through nation-wide registries for all-cause mortality, heart failure (HF), and the composite endpoint of HF or cardiovascular death (CVD) (HF/CVD).

resultsDuring follow-up (3.8 years [IQR: 2.7; 4.9]), 73 patients died, and 62 developed HF/CVD (HF: n = 30, CVD: n = 38). Patients who died had reduced GLS in all layers; GLSendo (-14.2% vs. - 16.3%, p < 0.001), whole wall GLS (-12.1% vs. - 13.9%, p < 0.001), and GLSepi (-10.6% vs. - 12.2%, p < 0.001). The risk of death increased linearly with decreasing absolute GLS for all layers (p < 0.0002). In multivariable Cox models adjusted for clinical and echocardiographic baseline characteristics, all layer-specific strain parameters remained significantly associated with mortality. However, only GLSepi remained significant after adjusting for European System for Cardiac Operative Risk Evaluation II (EuroSCORE II); (GLSepi: HR = 1.09 (1.00-1.18), p = 0.043, per 1% absolute decrease). For secondary outcomes (HF and HF/CVD), all strain parameters were associated with HF/CVD in fully adjusted models; however, no layer was independently associated with HF after multivariable analysis.

conclusionLayer-specific GLS is an independent prognosticator of all-cause mortality, HF, and HF/CVD. In multivariable models for mortality, GLSepi provided significant prognostic value after adjusting for EuroSCORE II.