Cardiac Resynchronization
Therapy (CRT) is known as a highly effective therapy in advanced heart failure
patients with cardiac dyssynchrony. However, still one third of patients do not
respond (or sub-optimally respond) to CRT. Among the many contributors for the
high rate of non-responders, the lack of procedures dedicated to CRT device
settings optimization (parameters to regulate AV synchrony and VV synchrony) is
known as one of the most frequent.
The most recent HF/CRT
Guidelines do not recommend to carry-out optimization procedures in every CRT
patient; they simply state those procedures “could be useful in selected
patients”, even though their role in improving response has not been proven.
Echocardiography techniques
still remain the gold-standard reference method to the purpose of CRT settings
optimization. However, due to its severe limitations in the routine of CRT
patients management (time and resource consuming, scarce reproducibility, inter
and intra-operator dependency), echocardiography optimization is widely
under-utilized in the real-world of CRT follow-up visits. As a consequence,
device-based techniques have been developed to by-pass the need for repeated
echo examinations to optimize CRT settings.
In this report the available device-based optimization
techniques onboard on CRT devices are shortly reviewed, with a specific focus
on clinical outcomes observed in trials comparing these methods vs. clinical
practice or echo-guided optimization methods. Particular emphasis is dedicated
to hemodynamic methods and automaticity of optimization algorithms (making real
the concept of “ambulatory CRT optimization”). In fact a hemodynamic-based
approach combined with a concept of frequent re-optimization has been associated
- although retrospectively - with a better clinical outcome on the long-term
follow-up of CRT patients. Large randomized trials are ongoing to prospectively
clarify the impact of automatic optimization procedures.
Credits: Maurizio LUNATI; Giovanni MAGENTA; Giuseppe CATTAFI; Antonella MOREO; Giacomo FALASCHI; Danilo CONTARDI; Emanuela LOCATI