Global Constructive Work is associated with ventricular arrythmias after cardiac resynchronization therapy

Aim Non-invasive left ventricular (LV) pressure-strain loops provide a novel method for quantifying myocardial work by incorporating LV pressure in measurements of myocardial deformation. Early studies suggest that myocardial work parameters such as Global Constructive Work (GCW) could be useful and reliable in arrhythmia prediction particularly in patients undergoing cardiac resynchronization therapy. The aim of this study was to evaluate whether the magnitude of GCW was associated with occurrence of ventricular arrhythmias in patients after cardiac resynchronization therapy. Method and results Patients on guideline-recommended treatment with a cardiac resynchronization therapy defibrillator (CRT-D) were evaluated by 2D speckle-tracking echocardiography including measurements of GCW at least six months after implantation. The primary outcome was a composite of appropriate defibrillator therapy and sustained ventricular arrhythmia under the monitor zone. A total of 162 patients (mean age 66 years (±10), 122 males (75%)), were included. 16 (10%) patients experienced the primary outcome during a median follow-up of 18 months (IQR: 12-25) after the index echocardiography. Patients with below-median GCW (<1,473 mmHg%) had a hazard ratio for the outcome of 8.14 [95% CI: 1.83-36.08], P=0.006 compared to patients above the median in a univariate model and remained an independent predictor after multivariate adjustment for eGFR and QRS duration (hazard ratio 4.75 [95% CI: 1.01 – 22.28], P<0.05. Conclusion In patients treated with CRT-D, GCW below median level was associated with a 5-fold increase in risk of ventricular arrhythmias.