Cardiac Resynchronization Therapy in Congenital Heart Defects

Study Overview
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Brief Summary
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The objective of this multicentre prospective therapeutic study is to evaluate the effects of CRT on the right and left ventricular function of patients with CHD in the medium and long term. Patients who reject the randomization or cannot be paced with right ventricular pacing alone will be enrolled in group C with continuous biventricular pacing, which is the main group in this study. Optional: Immediately after implantation the patients are divided into group A and B (randomized, single blind (for the patient), cross-over design). The treatment and the completing follow-up examination will take approximately 18 months and includes seven visits - one previous to the CRT and six at certain times afterward. At selected time intervals echocardiographic 3D and Tissue Doppler Imaging to evaluate the global and regional ventricular function are performed. Subjective quality of life assessment (questionnaire) will also be performed at the defined follow-up intervals, and if applicable (optional) also objective assessment of the physical performance (VO2 max). 55 patients also including children and adults with CHD are planned to be included in the study. The main target is to provide evidence of the effectiveness of CRT with biventricular stimulation in terms of improved ventricular function (ejection fraction and QRS interval).

Official Title
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Cardiac Resynchronization Therapy in Heart Failure Patients With Congenital Heart Defects

Conditions
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Congenital Heart Defects

Intervention / Treatment
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* Device: Implantation and testing of CRT
* Device: Implantation and testing of CRT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with congenital heart defects Heart failure of the Morphologically right or left system ventricle with an absolute ejection fraction of < 40% in the failed ventricle NYHA classes II-IV Optimal drug therapy for heart failure according to the ESC guidelines QRS interval ≥ 120 ms (demonstrated in at least two relevant ECG derivations, depending on existing bundle branch block symptoms) Patients with chronic stimulation of the subpulmonary ventricle by a 1- or 2-ventricle pacemaker, which also meets the above-mentioned criteria Patients with morphologically right ventricle in system position and significant insufficiency of the systemic atrioventricular valve, if they also meet the criteria listed above Exclusion Criteria: PTCA, cardiomyoplasty or myocardial infarction / unstable angina pectoris or cerebral insult within the 6 weeks preceding the planned cardiac resynchronisation therapy Patients with pulmonary hypertension / Eisenmenger's syndrome Life expectancy < 1 year due to a non-cardiac disease Anticipated poor compliance by the patient Pregnancy and breastfeeding Known or persistent abuse of prescription medicines, recreational drugs or alcohol
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group A<br>Implantation and testing of CRT | Device: Implantation and testing of CRT<br>* Biventricular pacing for 12 weeks (CRT ON) followed by automatic rhythmicity or the original, conventional biventricular stimulation for 12 weeks (CRT OFF), then returning to biventricular pacing (CRT ON).<br>Device: Implantation and testing of CRT<br>* Automatic rhythmicity or original conventional biventricular stimulation for 12 weeks (CRT OFF) followed by biventricular pacing (CRT ON).<br>|
| Experimental: Group B<br>IImplantation and testing of CRT | Device: Implantation and testing of CRT<br>* Biventricular pacing for 12 weeks (CRT ON) followed by automatic rhythmicity or the original, conventional biventricular stimulation for 12 weeks (CRT OFF), then returning to biventricular pacing (CRT ON).<br>Device: Implantation and testing of CRT<br>* Automatic rhythmicity or original conventional biventricular stimulation for 12 weeks (CRT OFF) followed by biventricular pacing (CRT ON).<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ejection fraction |  | 7 visits | 
| QRS-interval |  | 7 visits | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Echocardiographic standard parameters (e.g. LVIDd. FS, RVIDd) |  | 7 visits | 
| Tissue Doppler echocardiography: dyssynchrony parameters, regional myocardiac function |  | 7 visits | 
| 3D echocardiography:LV volumes, LVEF, Dyssynchrony index |  | 7 visits | 
| NT pro-BNP |  | 7 visits | 
| Spiroergometry: performance P (W/kg), incl. VO2,max |  | 6 visits | 
| Walking distance in 6 minutes |  | 6 visits | 
| Decrease of hospitalization |  | 18 months | 
| Decrease of ventricular and atrial arrhythmias |  | 18 months | 
| Prevention or postponement of heart transplantation |  | 18 Months | 
| Quality of life |  | 6 visits | 
| death |  | 18 months |