100: Incremental Value of Global Longitudinal Strain for Predicting Outcome after Cardiac Surgery

Background Global longitudinal strain (GLS) seems accurate for detecting sub-clinical myocardial dysfunction, and may therefore be used improve risk stratification for cardiac surgery. Methods and results Longitudinal strain (by 2D-speckle tracking) was computed in 425 patients (mean age 67±13 years, 69% male, LVEF 51±13%) referred for cardiac surgery (isolated coronary artery bypass graft [CABG, n=155], aortic valve surgery [n=174], mitral surgery [n=96]). Global longitudinal strain (global-e) was assessed for predicting postoperative death. Despite a fair correlation between LVEF and global strain (r=-0.73, p -16%): -12.8±1.7%, range -15% to -8%. In patients with preserved LVEF, NT-proBNP level (983 pg/mL vs. 541 pg/mL, P=0.03), heart failure symptoms (NYHA class, 2.2±0.9 vs. 1.9±0.9, P=0.02) and the need of prolonged (>48H) inotropic support after surgery (33.3% vs. 21.2%, P=0.03) were greater when global-e was impaired. Importantly, despite similar EuroSCORE (9.7±12% vs. 7.7±9%, P=0.2), the rate of post-operative death was 2.4 fold (11.8% vs. 4.9%, p=0.04) in patients with preserved LVEF when global-e was impaired. Multivariate analysis showed that global-e is an independent predictor for postoperative mortality (OR=1.10 [1.01-1.21]) after adjustment to EuroSCORE. Conclusions Global longitudinal strain has an incremental value over LVEF for risk stratification in patients referred for cardiac surgery.