Abstract 8091: Left Ventricular Mechanical Dyssynchrony to Distinguish Hibernating versus Scarred Myocardium in Patients with Cardiomyopathy Undergoing Gated Positron Emission Tomography
Background: We sought to determine whether left ventricular (LV) mechanical dyssynchrony can differentiate predominately hibernating versus scarred myocardium in patients with ischemic cardiomyopathy (ICM) on gated positron emission tomography (PET).
Methods and Results: Stress/rest rubidium-82 gated PET with 18FDG scan performed on consecutive patients with ICM and LV ejection fraction (EF) ≤35% were analyzed. Of 254 patients (age 65±11 years, QRS 108±10 ms, and LVEF 25±6), 25 (10%) had normal rest perfusion, and 229 had a fixed resting perfusion defect (77 (34%) with ≥ 50% hibernating defect (82±21% hibernation) (Group 1) and 152 (66%) with >50% scar (8±12% hibernation) (Group2)). Patients in Group 1 had smaller fixed PDS, more ischemia, and similar LVEF and volumes to those in Group 2. Dyssynchrony indices were derived using Corridor 4DM software (figure 1). Phase SD was lowest in patients with normal perfusion, higher in Group 1, and highest in Group 2 (Figure 2). Using ROC analysis, a phase SD ms cut-off of 120 ms had a 75% specificity to distinguish predominately scarred versus hibernating myocardium (AUC 0.60 [0.52-0.68], P=0.015). By linear regression analysis, phase SD≥120 ms (beta =0.13 [95%CI 0.01;0.25]), implantable cardiac defibrillator (0.23 [0.096;0.36]), beta blockers (-0.17[-0.31;-0.025]), fixed PDS (0.046[0.013;0.079] per 10% increase), and reversible PDS (-0.036[-0.067;-0.005] per 10% increase) were independently associated with predicting scar verus hibernation.
Conclusion: PET LV dyssynchrony analysis can potentially distinguish predominately hibernating from scarred myocardium.
- © 2011 by American Heart Association, Inc.