Impact of septal flash and left ventricle contractile reserve on positive remodeling during 1 year cardiac resynchronization therapy: the multicenter ViaCRT study

Introduction: Cardiac resynchronization therapy (CRT) has been shown to improve outcomes in patients with systolic heart failure (HFREF). However, the relatively high non-responder rate results in a need for more precise qualification for CRT. The ViaCRT study was designed to determine the role of contractile reserve and dyssynchrony parameters in predicting CRT response. The purpose of this analysis was to determine the effect of baseline septal flash and contractile reserve (CR) on clinical and echocardiographic parameters of response to CRT in 12-month follow-up. Material and methods: One hundred thirty-three guideline-selected CRT candidates (both ischemic and non-ischemic heart failure with reduced ejection fraction) were enrolled in the study. Baseline study population characteristics were: left ventricle ejection fraction (LVEF) 25 6%, QRS 165 25 ms, NYHA class III (90%) and IV (10%). Results: In subjects with septal flash (SF) registered before CRT implantation improvement in LVEF (14 2% vs. 8 1%, p < 0.05) and left ventricle (LV) systolic (63 10 ml vs. 36 6 ml, p < 0.05) and diastolic (46 10 ml vs. 32 7, p < 0.05) volumes was more pronounced than in patients without SF. In patients with CR (defined as LVEF increase by 20% or 4 viable segments) improvement in echo parameters was not significantly different then in the CR-group. Neither SF nor CR was associated with improvement in NYHA class. Subgroup analysis revealed that only in non-ischemic HF patients is presence of septal flash associated with LV function improvement after CRT. Conclusions: In non-ischemic HF patients septal flash is a helpful parameter in prediction of LV remodeling after 12 months of resynchronization therapy.