Abstract
Background
Recent studies have demonstrated that left ventricular mechanical dispersion (LVMD) assessed by speckle tracking might be a powerful marker in risk stratification for ventricular arrhythmias (VA). We sought to perform a systematic review and meta-analysis to i) assess the prognostic value of this parameter (previous studies were predominantly single-center), ii) define the value relative to other parameters, iii) identify the most appropriate cutoff for designating risk.
Purpose
To assess the association between LVMD and the incidence of VA.
Methods
A systemic review of studies reporting the predictive value of LVMD for VA was undertaken from a search of Medline and Embase. LVMD was defined as the standard deviation of time from Q/R on ECG to peak negative strain from each LV segment. VA events were defined as sudden cardiac death, cardiac arrest, documented ventricular tachyarrhythmia, and appropriate implantable cardioverter defibrillator therapy. Hazard ratios (HRs) were extracted from univariable and multivariable models reporting on the association of LVMD and VA and described as pooled estimates with 95% confidence intervals (CIs). In a meta-analysis, the predictive value of LVMD was compared to that of left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS).
Results
Among 3198 patients (weighted mean, 63 years, 30% female; 82% ischemic heart disease) in 12 published articles, 387 (12%) had VA events over a follow-up (17–70 months). Patients with VA events had a significantly greater mechanical dispersion compared with those without VA events (weighted mean difference, −20.3 ms; 95% CI, −27.3 to −13.2; p<0.01); 60 ms was found to be the optimal cutoff LVMD value for predicting VA events. Each 10 ms increment of LVMD was significantly and independently associated with VA events (HR, 1.19; 95% CI, 1.09 to 1.29; p<0.01). The predictive value of LVMD was superior to that of LVEF or GLS (Figure).
Figure 1
Conclusion
LVMD assessed by speckle tracking provides important predictive value for VA in patients with a number of cardiac diseases and appears to have superior predictive value to LVEF and GLS for risk stratification.
Left Ventricular Speckle Tracking-Derived Cardiac Strain and Cardiac Twist Mechanics in Athletes: A Systematic Review and Meta-Analysis of Controlled Studies
