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Comparison of CRT-D and CRT-DX Systems (CRT-NEXT)

Non-inferiority Randomized Clinical Investigation of CRT-DX Versus CRT-D Systems

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03587064
Acronym
CRT-NEXT
Enrollment
640
Registered
2018-07-16
Start date
2018-10-22
Completion date
2025-05-07
Last updated
2026-07-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cardiac Resynchronization Therapy, Heart Failure

Keywords

CRT-D, CRT-DX, Atrial pacing

Brief summary

The principal objective is to test non-inferiority of the CRT-DX system as compared to a conventional CRT-D system, in terms of the combined endpoint of mortality, hospitalizations due cardiovascular causes, any complication leading to loss of lead functionality, in the subset of patients without evidence of sinus dysfunction on optimal therapy.

Detailed description

Resting heart rate is strongly associated with incident worsening Heart Failure (HF) and mortality. Current devices for cardiac resynchronization (CRT-D) normally provide atrio-ventricular (AV) sequential pacing modes during resynchronization, but the best pacing programming strategy is not clear. On the one hand a basic rate of 50 to 70 bpm (optionally with some rate-responsive function) could be considered for therapy up-titration, specifically betablockers; on the other hand, increasing pacing rates may partially reduce benefits from resynchronization, reducing filling time and contractility reservoir. The Pegasus investigation is the only large randomized investigation comparing DDD with 70 bpm basic rate to DDD(R) @40 bpm. Results showed no difference in investigation endpoints, including mortality and HF-hospitalization. These results may support the use of a device implementing both a CRT function and a right ventricular single-lead with and an atrial sensing dipole (CRT-DX system). This system can track ventricular pacing and resynchronization following atrial sensing, even if it cannot provide atrial pacing support. It should be assessed whether such limitation is counterbalanced by the advantages related to the reduced number of necessary leads, with simplified implantation and less complications. The objective of the investigation is to assess whether atrial pacing support is really necessary in the subset of patients with indication to CRT-D and no evidence of sinus dysfunction on optimal therapy. The investigation will test the hypothesis that a CRT-DX system is not inferior to a conventional CRT-D system in this class of subjects.

Interventions

DEVICEConventional 3-lead CRT defibrillator system implantation

Conventional 3-lead(1 atrial and 2 ventricular leads) system implantation

DEVICE2-lead CRT defibrillator system implantation

2-lead (2 ventricular leads with dipole for atrial sensing) DX system implantation

Sponsors

Associazione Portatori Dispositivi Impiantabili Cardiaci
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

1. Male and female patients ≥ 18 years old 2. Patients willing to participate in the investigation and signing the Patient Informed Consent (PIC) Form; 3. Indication to CRT-D implant according to current ESC Guidelines on cardiac pacing and cardiac resynchronization therapy 4. Sinus rhythm at time of implant; 5. Optimized medical therapy according to current ESC Guidelines 6. Rest heart rate (HR) \>45 bpm at baseline ECG, with betablocker therapy at optimal medical dosage; or, if rest HR\<45 bpm: maximum heart rate at the 6- minute walking test \>85 bpm.

Exclusion criteria

1. Any indication to atrial pacing according to current guidelines; 2. Both: resting heart rate \<45 bpm at baseline ECG, with betablocker therapy at optimal medical dosage and maximum heart rate at the 6-minute walking test \<85 bpm; 3. NYHA Class IV; 4. Permanent Atrial Fibrillation 5. Replacement of/upgrading from previously implanted pacing system; 6. Dialysis patients; 7. Pregnant or breast-feeding women.

Design outcomes

Primary

MeasureTime frameDescription
Combined endpoint of Mortality, hospitalization due to cardiac causes and lead-related complications1 yearIt includes number of patients who experienced death, hospitalization due to cardiac causes, or any lead-related complication leading to loss of functionality (including lead dislodgement, conduction or insulation failure, loss of sensing or capture that couldn't resolved by reprogramming)

Secondary

MeasureTime frameDescription
Rate of implant revisions1 yearRate of implant revisions to add, replace, reposition, and remove an atrial pacing lead.
Rate of inappropriate therapy of the device1 yearInappropriate detections and interventions of high rate ventricular episodes.
Atrial pacing percentage1 yearIn the conventional CRT-D group, atrial pacing percentage.
Exercise test1 yearSix minute walking test distance at one year
Device detected AT1 yearIncidence of atrial tachyarrhythmias (AT)
Incidence of appropriate Ventricular therapy1 yearIncidence of Ventricular Arrhythmias (VA) requiring therapy delivery
Incidence of events due to short-long-short sequence1 yearIncidence of both VA and AT due to bradycardia or short-long-short sequence
Implant failure1 yearImpossibility to implant any component (leads and device) of the initially planned system
Procedure times1 yearSkin-to-skin and fluoroscopy time
Atrial sensing amplitude measured by device1 yearAtrial sensing amplitude measured by devices in both investigation arms
Far field oversensing incidence1 yearIncidence of far field oversensing episodes in both investigation arms

Countries

Italy

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 7, 2026