Predictors of super-response to cardiac resynchronization therapy: the significance of heart failure medication, pre-implant left ventricular geometry and high percentage of biventricular pacing.

Background: Super-responders (SRs) are defined as patients who show crucial cardiac function improvement after cardiac resynchronization therapy (CRT). The purpose of this study is to identify and validate predictors of SRs after CRT.

Methods: This study enrolled 201 patients who underwent CRT during the period from 2010 to 2014. Clinical and echocardiographic evaluations were conducted before CRT and 6 months after. Patients with a decrease in New York Heart Association (NYHA) functional class ≥ 1, a decrease in left ventricular end-systolic volume (LVESV) ≥ 15%, and a final left ventricular ejection fraction (LVEF) ≥ 45% were classified as SRs.

Results: 29% of the 201 patients who underwent CRT were identified as SRs. At baseline, SRs had significantly smaller left atrial diameter (LAD), LVESV, left ventricular end-diastolic volume (LVEDV) and higher LVEF than the non-super-responders (non-SRs). The percentage of patients using angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEI/ARB) was higher in SRs than non-SRs. Most SRs had Biventricular (BiV) pacing percentage greater than 98% six months after CRT. In the multivariate logistic regression analysis, the independent predictors of SRs were lower LVEDV [odd ratios (OR): 0.93; confidence intervals (CI): 0.90-0.97], use of ACEI/ARB (OR: 0.33; CI: 0.13-0.82) and BiV pacing percentage greater than 98% (OR: 0.29; CI: 0.16-0.87).

Conclusion: Patients with a better compliance of ACEI/ARB and a less ectatic ventricular geometry before CRT tends to have a greater probability of becoming SRs. Higher percentage of BiV pacing is essential for becoming SRs.