BiventRicular Pacing in prolongEd Atrio-Ventricular intervaL: the REAL-CRT Study

Study Overview
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Brief Summary
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This study was designed to evaluate the potential benefits of treatment with biventricular device in patients with normal systolic function , indication for pacing and impaired atrio-ventricular conduction , by comparing the treatment with dual-chamber device . The REAL -CRT study is designed to test the hypothesis that, in patients with atrioventricular block of I degree and standard pacing indications , biventricular pacing is superior to single stimulation of the right ventricle (RV) with optimized algorithms for minimization of pacing , as assessed by echocardiography an endpoint defined in terms of maintenance over time of left ventricular ejection fraction (LVEF ) and left ventricular end-systolic volume ( LVESV ) .

Detailed Description
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Clinical data suggest that biventricular pacing is able to preserve the myocardial performance more effectively than the right ventricular pacing in patients with atrioventricular block and mild systolic dysfunction . In particular, some studies have shown that medical therapy in these patients could be responsible for an increase in the cumulative percentage of chronic pacing over the 40% threshold , the threshold associated with a higher incidence of atrial fibrillation and hospitalization for heart failure and ventricular arrhythmias . In addition , patients with pre-existing left ventricular dysfunction and indication for pacing standards have improved left ventricular systolic function , exercise capacity and quality of life as a result of biventricular pacing as compared with Right ventricular pacing . These results suggest that biventricular pacing is a feasible option for permanent pacing in patients who have normal systolic function of the left ventricle and that this can be altered from the adverse effects of conventional Right ventricular pacing on systolic function of the left ventricle . This reality has prompted physicians to assess the value and role of cardiac resynchronization therapy (CRT ) in patients with prolonged Atrio-Ventricular (AV) conduction . Note the deleterious effects of chronic stimulation of the right ventricle , the optimal pacing mode should always be considered in these patients at the time of implantation . This study was designed to evaluate the potential benefits of treatment with biventricular device in patients with normal systolic function , indication for pacing and impaired atrio-ventricular conduction, by comparing it with the treatment with dual chamber device

Official Title
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BiventRicular Pacing in prolongEd Atrio-Ventricular intervaL: the REAL-CRT Study

Conditions
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First Degree Atrioventricular Block

Intervention / Treatment
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* Device: Cardiac resynchronization therapy pacemaker
* Device: Dual chamber pacemaker


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with standard indications to stimulation with a high probability of paced beats according to the clinical evaluation of the investigators: First degree AV block (PR ≥ 220 ms) and indication for pacing Paroxysmal AV block second degree (Type I and Type II) associated with long-PR (PR ≥ 220 ms) Patient must be able to attend all required follow-up visits at the study center. LVEF> 35% Exclusion Criteria : Patient is less than 18 years of age. Patients with a life expectancy less than 12 months Indication for CRT in class I and II Third-degree AV block Patients currently enrolled in other studies / logs Patients who are not able to understand and sign an informed consent State of current or planned pregnancy within 12 months of enrollment Inability to understand and complete the questionnaire QOL

Ages Eligible for Study
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Minimum Age: 18 Years

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: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Right ventricular stimulation<br>patients with conventional Right Ventricular Stimulation (only RV) with optimized algorithms for minimization of pacing | Device: Dual chamber pacemaker<br>* right ventricular stimulation with dual chamber pacemaker<br>|
| Experimental: Biventricular Stimulation<br>Patients with biventricular stimulation (Right Ventricle and Left Ventricle) | Device: Cardiac resynchronization therapy pacemaker<br>* biventricular stimulation with cardiac resynchronization therapy pacemaker (crt-p)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| LVEF | LVEF (Left Ventricular Ejection Fraction: such as the assessment of systolic function of the left ventricle) | 2 years | 
| LVESV | LVESV (Left Ventricular End Systolic Volume: such as the assessment of left ventricular remodeling) | 2 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| echocardiographic left ventricular measures | . Structure and cardiac function: Left ventricular End Systolic Diameter, Left ventricular End Diastolic Diameter Left Ventricular End Systolic | 2 years | 
| Echocardiographic altrial measures | Size of the left atrium (diameter and volume) | 2 years | 
| Clinical outcome | Clinical benefit: 6 minute walking test quality of life questionnaire New York Heart Association class number and duration of hospitalizations | 2 years | 
| Atrial fibrillation (AF) | Incidence of AF: incidence of persistent AF burden of FA new onset of AF | 2 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cardiac Resynchronization therapy, Minimized Right ventricular pacing, Prolonged AV conduction