Optimization of AV and VV delays in the real-world CRT patient population: an international survey on current clinical practice.

BACKGROUND: Cardiac resynchronization therapy (CRT) is an effective treatment for patients suffering from advanced heart failure and electrical dyssynchrony. Limited data suggest that patients may benefit from routine optimization of the atrioventricular (AV) and interventricular (VV) delays; however, there is scarce information available on how and when optimization should be performed.
OBJECTIVE: The objective of this survey was to characterize the current international standard of care for optimization of the AV and VV delays in CRT devices recipients.
METHODS: Centers participating in the Frequent Optimization Survey Using the QuickOpt Method (FREEDOM) study completed surveys probing into their optimization of AV and VV delays procedures. Probes focused on the methods used to optimizing the delays, visits at which optimization of the delays was performed, percentage of patients that underwent optimization, and factors that limited centers from optimizing the CRT systems.
RESULTS: Few of the 118 investigators from 16 countries who responded to the survey routinely optimized the delays in all patients. At follow-up visits and during hospitalizations, a trend was observed to optimize the delays more often in nonresponders than in responders to CRT. Standard echocardiography was the most common method of optimization. Time availability and lack of qualified staff were the main factors limiting the optimization of CRT systems.
CONCLUSIONS: In real-world practice, AV and VV optimization was not performed in a high proportion of patients. A less time-consuming and easier optimization method might enable a more systematic optimization of the AV and VV delays at routine follow-up visits in all recipients of CRT systems.