Brazilian Assessment of Technique, Utilization, QRS Response, and Long-term Electrical Performance of the Solia CSP Lead

The CSP Registry is a prospective, multicenter, observational, investigator-initiated study conducted at up to 10 electrophysiology centers in Brazil. The study plans to enroll approximately 300 adult patients with a clinical indication for permanent ventricular pacing in whom the treating physician has independently decided to use the Solia CSP lead (BIOTRONIK) for conduction system pacing (CSP), preferably left bundle branch area pacing (LBBAP).

The decision to implant the device, the selection of the lead and generator, the implantation technique, and device programming are based exclusively on routine clinical practice and are made independently of study participation. The Solia CSP lead is used within its approved indication and conditions of use. No experimental intervention or randomization is introduced by the protocol.

The primary objective is to evaluate the acute feasibility and longitudinal performance of the Solia CSP lead in real-world clinical practice. The primary endpoint is lead success at 12 months, based on a composite technical and electrophysiological outcome including successful implantation with confirmed CSP/LBBAP capture, acceptable electrical parameters, absence of clinically relevant loss of capture, absence of lead revision, dislodgement or abandonment, and absence of major lead-, procedure-, or device-related complications.

Secondary outcomes include acute implantation success, reasons for unsuccessful CSP/LBBAP capture or positioning, procedural characteristics, longitudinal pacing threshold, R-wave sensing and lead impedance, capture classification, heart failure hospitalization, all-cause mortality, changes in left ventricular ejection fraction when echocardiographic assessments are available, and findings from Home Monitoring. Exploratory analyses will evaluate clinical and procedural factors associated with implantation success and longitudinal lead performance.

Participants will be followed for up to 24 months after implantation, with predefined assessments including clinical evaluation, 12-lead electrocardiography, device interrogation, assessment of conduction system capture, electrical lead parameters, adverse events, and remote monitoring.