G-SPECT-derived left ventricular mechanical dyssynchrony parameters, particularly rest phase standard deviation and entropy, were significant predictors of LVEF normalization (11.9%) following CRT.
Cohort (n=100)
Do G-SPECT-derived left ventricular mechanical dyssynchrony parameters predict LVEF improvement following CRT in patients with HFrEF?
G-SPECT imaging can effectively assess left ventricular mechanical dyssynchrony and predict favorable echocardiographic response to cardiac resynchronization therapy in patients with HFrEF.
BACKGROUND: Cardiac resynchronization therapy (CRT) is recommended for patients with heart failure with reduced ejection fraction (HFrEF) who meet specific electrocardiographic (ECG) criteria of electrical dyssynchrony. Gated single-photon emission computed tomography (G-SPECT) is an imaging method that allows for the assessment of left ventricular mechanical dyssynchrony (LVMD); however, its predictive value for CRT response remains uncertain. This study aimed to evaluate the utility of G-SPECT in identifying LVMD and predicting CRT response in patients with HFrEF. METHODS: Patients with HFrEF and a LVEF <35% were prospectively enrolled and stratified into two groups: 60 patients CRT-eligible (Group 1) and 40 CRT-ineligible (Group 2). All patients underwent ECG, echocardiography, and G-SPECT imaging at baseline and at 6-month follow-up. LVMD was assessed using G-SPECT-derived parameters: (a) histogram bandwidth (HBW), (b) phase standard deviation (PSD), and (c) phase entropy, both at rest and under stress. CRT response was evaluated based on changes in LVEF. RESULTS: At baseline, patients in Group 1 exhibited greater LVMD as assessed by both echocardiography and G-SPECT. All G-SPECT-derived parameters, along with septal-to-posterior wall motion delay on echocardiography, were correlated with QRS duration. After CRT, LVMD significantly improved in Group 1. Super-response, defined as EF normalization, was observed in 11.9% of patients. G-SPECT-derived LVMD parameters, particularly rest PSD and entropy measures, were significant predictors of the favorable outcome of LVEF normalization. CONCLUSIONS: LVMD parameters obtained from G-SPECT were significantly correlated with electrical dyssynchrony as measured by QRS duration. Following CRT implantation, LVMD improved in parallel with increases in LVEF.
Stępień-Wroniecka et al. (Sun,) conducted a cohort in Heart failure with reduced ejection fraction (HFrEF) (n=100). Cardiac resynchronization therapy (CRT) and G-SPECT imaging vs. CRT-ineligible patients was evaluated on CRT response evaluated based on changes in LVEF (LVEF normalization). G-SPECT-derived left ventricular mechanical dyssynchrony parameters, particularly rest phase standard deviation and entropy, were significant predictors of LVEF normalization (11.9%) following CRT.