While a multicenter trial demonstrated that SonR contractibility sensor was as effective as echo-guided optimization at improving response to cardiac resynchronization therapy (CRT), an association between SonR values and clinical endpoints has never been established. The primary objective was to assess the predictive value of the SonR signal evolution (SSE) regarding cardiovascular events. The secondary objective was to evaluate whether SSE was associated with cardiovascular death.

All patients with a CRT SonR system implanted between 2012 and 2016 were included in this retrospective study. SSE during 6 months ((month 6 value–month 1 value)/month 1 value *100) after implantation was calculated. The primary endpoint (cardiovascular events) was a composite of cardiovascular death, hospitalization for acute heart failure and ventricular arrhythmia. Seventy-four patients (67 years old; 81% males) were followed up over a median 20 [13; 29] months. Cumulative incidence function showed that SSE was predictive of cardiovascular events (threshold≤10.70%; P=0.023) and predictive of cardiovascular death (P=0.0018). After multivariate analysis, SSE was independently associated with the onset of cardiovascular events (HR=4.03; 95% CI [1.31–12.43]; P=0.015) even after adjustment on left bundle branch block and chronic kidney disease.

In this first study publishing data regarding SonR signal in real-life settings, SSE within the first 6 months after implantation was an independent predictor of cardiovascular events at follow-up, suggesting that this parameter could be useful to identify patients at higher risk of further adverse events after CRT implantation.