Traditional Criteria of Mechanical and Electrical Dyssynchrony as a Predictor of Super-Response in Patients with Cardiac Resynchronization Therapy

Aim: To evaluate clinical and morpho-functional predictors of super-response to cardiac resynchronization therapy (CRT) in patients with heart failure and reduced ejection fraction (HFrEF) in the short-term period after implantation. Material and Methods. The study enrolled 86 patients (88.4% men, 54.0 ± 8.9 years mean age, New York Heart Association (NYHA) class II–IV). Patients were examined at baseline and in dynamics (mean follow-up was 10.6 ± 3.6 months). According to the change in left ventricular (LV) end-systolic volume (ESV) patients were divided into two groups: Group I (n = 19) with a decrease in LV ESV ≥ 30% (super-responders (SR) and Group II (n = 67) – decrease in LV ESV < 30% (non-super-responders (non-SR). Parameters of mechanical dyssynchrony (MD) were assessed in the two groups including LV pre-ejection period, interventricular mechanical delay (IVMD), intraventricular delay (IVD). Results. At baseline, traditional parameters of MD were higher in SR: LV pre-ejection period (156.8 ± 35.4 ms vs 135.0 ± 35.6 ms; p = 0.021) and IVMD (73.0 [43.0; 108.0] ms vs 47.0 [19.5; 70.0] ms; p = 0.017). Logistic regression results showed that female gender (HR 7.048; 95% CI 1.496–33.206; p = 0.014) and QRS width (HR 1.017; 95% CI 1.000–1.034; p = 0.048) had an independent association with super-response. Conclusion. In patients with HFrEF, more severe mechanical and electrical dyssynchrony is associated with super-response to CRT in a short-term follow-up period.