Contractility sensor-guided optimization of cardiac resynchronization therapy: results from the RESPOND-CRT trial

Abstract

AimsAlthough cardiac resynchronization therapy (CRT) is effective in patients with systolic heart failure (HF) and a wide QRS interval, a substantial proportion of patients remain non-responsive. The SonR contractility sensor embedded in the right atrial lead enables individualized automatic optimization of the atrioventricular (AV) and interventricular (VV) timings. The RESPOND-CRT study investigated the safety and efficacy of the contractility sensor system in HF patients undergoing CRT.Methods and resultsRESPOND-CRT was a prospective, randomized, double-blinded, multicentre, non-inferiority trial. Patients were randomized (2:1, respectively) to receive weekly, automatic CRT optimization with SonR vs. an Echo-guided optimization of AV and VV timings. The primary efficacy endpoint was the rate of clinical responders (patients alive, without adjudicated HF-related events, with improvement in New York Heart Association class or quality of life), at 12 months. The study randomized 998 patients. Responder rates were 75.0% in the SonR arm and 70.4% in the Echo arm (mean difference, 4.6%; 95% CI, −1.4% to 10.6%; P < 0.001 for non-inferiority margin −10.0%) (Table 2). At an overall mean follow-up of 548 ± 190 days SonR was associated with a 35% risk reduction in HF hospitalization (hazard ratio, 0.65; 95% CI, 0.46–0.92; log-rank P = 0.01).ConclusionAutomatic AV and VV optimization using the contractility sensor was safe and as effective as Echo-guided AV and VV optimization in increasing response to CRT.ClinicalTrials.gov numberNCT01534234

Real‐world behavior of CRT pacing using the AdaptivCRT algorithm on patient outcomes: Effect on mortality and atrial fibrillation incidence

“…While single‐center studies have demonstrated the benefits of device optimization, the SmartAV randomized clinical trial using static algorithms failed to show a benefit of device‐based algorithms over echocardiographic optimization 24 . However, the Respond CRT randomized study of ambulatory optimization using an accelerometer sensor showed an improvement in clinical response compared with empirical programming, which was consistent across patient subgroups 25,26 . A dynamic algorithm such as aCRT will potentially maintain the benefits of optimal resynchronization during postural changes and exercise.…”

Impact of multipoint pacing on projected battery longevity in cardiac resynchronization therapy. An IRON‐MPP study sub‐analysis

“…Over the years, CRT has shown great potential in improving HF patients' survival, quality of life, symptoms, and exercise capacity, while reducing the need for hospitalizations . Nonetheless, despite significant improvements over the last decade and the introduction of many optimization strategies, 25% to 30% of patient are consistently considered clinical non‐responders across several studies . Multipoint LV pacing (MPP) is a novel LV pacing modality that might increase the magnitude of clinical, hemodynamic, and echocardiographic response to CRT, but uncertainty remains related to increased battery drain due to continuous pacing with an additional LV vector.…”

Cardiac Resynchronization Therapy Optimization: A Comprehensive Approach

“…This allows continuous adaptation of the AV and VV interval setting of the CRT device according to the instantaneous needs of the patient [89]. A comparative study demonstrated that automatic optimization with the SonR sensor is as effective as echo-guided optimization, allowing the primary efficacy end point to be met with a 35% significant reduction in HF hospitalization rates during long-term follow-up [90]. …”