Electrical optimization of cardiac resynchronization in chronic heart failure is associated with improved clinical long-term outcome

P>Background Cardiac resynchronization therapy (CRT) is an established treatment option for symptomatic chronic heart failure (CHF) patients with pharmacological baseline therapy, but not all patients benefit from device therapy. One reason for this may be inadequate device settings. In real-world practice, echocardiographic evaluation of atrioventricular (AV) delay is not performed in a high proportion of patients, as the effect of electrical optimization of CRT is an issue open for investigation. Materials and methods We performed a retrospective observational study analysing the effect of AV-interval evaluation with echocardiography on long-term [32 (23?43) months] clinical outcome in 205 CHF patients. A stepwise Cox regression model including a co-morbidity score, failed AV-interval evaluation, satisfactory device function after the first implantation attempt, failure to reach 100% of the recommended renin-angiotensin system inhibitor and beta-blocker dose at follow-up and CRT device implantation compared with CRT in combination with an implanted cardioverter defibrillator (ICD) was applied. Results In the total study cohort, 124 (60 center dot 5%) patients had reached the primary combined endpoint death or cardiac hospitalization and 59 (28 center dot 8%) had died. Cox regression analysis revealed that failed AV-interval evaluation [HR = 1 center dot 72 (1 center dot 19-2 center dot 49), P = 0 center dot 004] non-optimized CHF pharmacotherapy dosages [HR = 2 center dot 12 (1 center dot 32-3 center dot 42), P = 0 center dot 002], the presence of a CRT/ICD combination device [HR = 1 center dot 87 (1 center dot 28-2 center dot 71), P = 0 center dot 001] and satisfactory device function after the first implantation attempt [HR = 0 center dot 44 (0 center dot 25-0 center dot 77), P = 0 center dot 004] were associated with the primary endpoint. Conclusion Echocardiographic evaluation of the AV-interval in patients with CRT was independently associated with improved clinical outcome, impacting on daily clinical practice of HF patient care.