Abstract 362: Classification of Severe Left Ventricular Dysfunction Using Global Longitudinal Strain and Outcome
Purpose: The diagnosis of severe left ventricular dysfunction (LVD) has an significant adverse prognostic impact. We have previously shown a cut off of −12% global longitudinal strain(GLS) to be equivalent to EF<35%. We aimed to test the prognostic value of GLS against the EF<35% cut off.
Methods: We studied 546 consecutive individuals (64% male, age 60.9±11.9 years) undergoing echocardiography. EF was calculated using Simpson’s biplane. GLS was calculated using 2D speckle tracking as the mean GLS from 3 apical views. Outcome was expressed using Kaplan-Meier analysis and log-rank tested for significance. Individuals were followed for all-cause mortality for a mean of 5.2±1.5 years. There were 91 deaths.
Results: Overall population mean EF was 57.6±2.1% and mean GLS −16.6±4.3%. 29 individuals (5.3%) had an EF<35%. These individuals had significantly worse outcome compared to those with EF ≥35% (p<0.01). 77 individuals (14.1%) were identified as having GLS>−12%. These individuals also had significantly worse outcome compared to those with GLS≤ −12% (p<0.01). The survival curves for the groups with EF<35% and GLS>−12% almost completely overlay each other as did the curves for EF≥35% and GLS≤ −12% indicating comparable prognostic outlooks for these groups (figure⇓). Log rank testing showed there was no significant difference between the EF≥35% and GLS≤ −12% groups (p=0.6) and the EF≥35% and GLS≤ −12% groups (p=0.45).
Conclusion: A global longitudinal strain cut off value of −12% has an almost identical prognostic influence as an ejection fraction <35%. The measurement of global longitudinal strain may now be the best method to estimate left ventricular function.