Mechanical dyssynchrony according to validated cut-off values using gated SPECT myocardial perfusion imaging.
The aim of this study was to establish different degrees of mechanical dyssynchrony according to validated cut-off (CO) values of myocardial perfusion gated SPECT phase analysis parameters (SD, standard deviation; B, bandwidth; S, skewness; K, kurtosis).



Using Emory Cardiac Toolbox™, we prospectively analyzed 408 patients (mean age 64.1 years, 26.7% female), divided into a control group of 150 normal subjects and a validation group of 258 patients (left bundle branch block: 17.8%, right bundle branch block: 8.9%. atrial fibrillation: 16.3%, coronary revascularization: 30%, dilated cardiomyopathy: 7.4%. valvulopathies: 2.7%, ischemic test: 45.3%) with ischemic and non-ischemic cardiac diseases, by means of phase analysis.



Agreement of CO values (SD > 18.4°; B > 51°; S ≤ 3.2; K ≤ 9.3) used to discriminate between normal subjects and patients was strong (c-statistic 0.9; 95% CI 0.98-0.99). Four degrees of dyssynchrony were found according to the number of abnormal phase parameters. All patients with mechanical and electrical criteria for cardiac resynchronization therapy (CCRT) (n: 82) had Grade 2 to 4 (two to four abnormal phase parameters). Agreement of CO values (SD > 40.2°; B > 132°; S ≤ 2.3; K ≤ 4.6) used to discriminate between patients with and without CCRT was strong (c-statistic 0.8; 95% CI 0.79-0.87) but 12% of patients with CCRT did not have any of these abnormal phase parameters.



The discriminatory capacity of gated SPECT phase analysis parameters between normal subjects and patients, and between patients with and without CCRT, is very good, making it possible to define different degrees of mechanical dyssynchrony.
Department of Nuclear Medicine, Hospital Universitari Vall d'Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Paseo Vall d'Hebron 119-129, 08035, Barcelona, Spain. saguade@vhebron.net.
Santiago
S
Aguadé-Bruix
Cardiology Department, Hospital Universitari Vall d'Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain.
Guillermo
G
Romero-Farina
Cardiology Department, Hospital Universitari Vall d'Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain.
Jaume
J
Candell-Riera
Cardiology Department, Hospital Universitari Vall d'Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain.
María N
MN
Pizzi
Cardiology Department, Hospital Universitari Vall d'Hebron, Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Barcelona, Spain.
David
D
García-Dorado
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D003327:Coronary Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006349:Heart Valve Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D009204:Myocardial Revascularization; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon
Gated SPECT myocardial perfusion; cardiac resynchronization therapy; dyssynchrony; phase analysis