Regional Strain Pattern Index—A Novel Technique to Predict CRT Response

Abstract

Background: Cardiac resynchronization therapy (CRT) improves outcome in patients with heart failure (HF) however approximately 30% of patients still remain non-responsive. We propose a novel index—Regional Strain Pattern Index (RSPI)—to prospectively evaluate response to CRT. Methods: Echocardiography was performed in 49 patients with HF (66.5 ± 10 years, LVEF 24.9 ± 6.4%, QRS width 173.1 ± 19.1 ms) two times: before CRT implantation and 15 ± 7 months after. At baseline, dyssynchrony was assessed including RSPI and strain pattern. RSPI was calculated from all three apical views across 12 segments as the sum of dyssynchronous components. From every apical view, presence of four components were assessed: (1) contraction of the early-activated wall; (2) prestretching of the late activated wall; (3) contraction of the early-activated wall in the first 70% of the systolic ejection phase; (4) peak contraction of the late-activated wall after aortic valve closure. Each component scored 1 point, thus the maximum was 12 points. Results: Responders reached higher mean RSPI values than non-responders (5.86 ± 2.9 vs. 4.08 ± 2.4; p = 0.044). In logistic regression analysis value of RSPI ≥ 7 points was a predictor of favorable CRT effect (OR: 12; 95% CI = 1.33–108.17; p = 0.004). Conclusions: RSPI could be a valuable predictor of positive outcome in HF patients treated with CRT.

Risk scores in cardiac resynchronization therapy–A review of the literature

“…Park et al (17) were the first who developed a risk score, the EchoCG score, by using echocardiographic strain analysis to predict the reverse remodeling after CRT implantation. Strain analysis was included in many models later (11,(18)(19)(20). Similarly, to strain analysis, electrophysiologic modalities were also used in risk score development, such as sophisticated ECG analysis (21)(22)(23), vectorcardiography (24), or heart rate histogram analysis (25).…”

The Value of Left Ventricular Mechanical Dyssynchrony and Scar Burden in the Combined Assessment of Factors Associated with Cardiac Resynchronization Therapy Response in Patients with CRT-D

“…Some studies have shown that the ventricular MD assessment using transthoracic echocardiography (TTE), magnetic resonance imaging (MRI), computed tomography (CT), and single-photon emission computed tomography (SPECT) can play a key role in the prediction of CRT response [ 15 , 16 , 17 , 18 , 19 ]. However, according to other studies, TTE indicators are not reliable CRT response predictors [ 20 ].…”