Co-Morbidities and Cardiac Resynchronization Therapy: When Should They Modify Patient Selection?

Cardiac resynchronization therapy (CRT) improves symptoms, reduces heart failure related hospitalizations and death in selected patients with heart failure. Based on thousands of patients enrolled in major clinical landmark trials, current guidelines describe in relatively precise terms which cardiac patients should receive a device. However, clinical trials often excluded sicker patients leaving clinicians with the dilemma of how to treat real-life patients with major co-morbidities, frailty, and increasing age, who are otherwise candidates for CRT implantation. This review investigates results from clinical trials and available observational data on the influence of co-morbidities on CRT benefit in order to provide better insight of when and why co-morbidities should modify patient selection for CRT.