Image-based left ventricular shape analysis for sudden cardiac death risk stratification.
BACKGROUND
Low left ventricular ejection fraction (LVEF), the main criterion used in the current clinical practice to stratify sudden cardiac death (SCD) risk, has low sensitivity and specificity.


OBJECTIVE
To uncover indices of left ventricular (LV) shape that differ between patients with a high risk of SCD and those with a low risk.


METHODS
By using clinical cardiac magnetic resonance imaging and computational anatomy tools, a novel computational framework to compare 3-dimensional LV endocardial surface curvedness, wall thickness, and relative wall thickness between patient groups was implemented. The framework was applied to cardiac magnetic resonance data of 61 patients with ischemic cardiomyopathy who were selected for prophylactic implantable cardioverter-defibrillator treatment on the basis of reduced LVEF. The patients were classified by outcome: group 0 had no events; group 1, arrhythmic events; and group 2, heart failure events. Segmental differences in LV shape were assessed.


RESULTS
Global LV volumes and mass were similar among groups. Compared with patients with no events, patients in groups 1 and 2 had lower mean shape metrics in all coronary artery regions, with statistical significance in 9 comparisons, reflecting wall thinning and stretching/flattening.


CONCLUSIONS
In patients with ischemic cardiomyopathy and low LVEF, there exist quantifiable differences in 3-dimensional endocardial surface curvedness, LV wall thickness, and LV relative wall thickness between those with no clinical events and those with arrhythmic or heart failure outcomes, reflecting adverse LV remodeling. This retrospective study is a proof of concept to demonstrate that regional LV remodeling indices have the potential to improve the personalized risk assessment for SCD.
Department of Biomedical Engineering, Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland. Electronic address: fijoy@jhu.edu.
Fijoy
F
Vadakkumpadan
Department of Biomedical Engineering, Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland.
Natalia
N
Trayanova
Division of Cardiology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland.
Katherine C
KC
Wu
D009202:Cardiomyopathies / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D003198:Computer Simulation; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000473:pathology* / Q000517:prevention & control; D005260:Female; D006352:Heart Ventricles / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment / Q000379:methods*; D016277:Ventricular Function, Left / Q000502:physiology*
Cardiac magnetic resonance imaging; Computational anatomy; Implantable cardioverter-defibrillator; Risk stratification; Shape analysis; Sudden cardiac death