A Comparison of Two Techniques for Choosing the Best Place to Put a Pacing Lead for Cardiac Resynchronisation Therapy

Study Overview
=================
Brief Summary
-----------------
Cardiac resynchronisation therapy (CRT) using biventricular pacing (BiVP) is established as an effective treatment for heart failure. Unfortunately up to 45% of patients do not respond, with no improvement in symptoms or cardiac size. Reducing the proportion of non-responders has become the key research focus in CRT. Targeting the position of the left ventricular (LV) pacing lead within the coronary vein network has previously been shown to increase the proportion of responders to CRT. Several techniques have been tried for targeting lead position, of which the best investigated are the use of speckle-tracking echocardiography to target the lead position to the site of latest mechanical activation of the left ventricle, and the use of invasive monitoring to select the pacing site at which the greatest acute haemodynamic response (AHR) to BiVP occurs. Both techniques are limited by groups of patients in whom the techniques are not possible or provide limited useful information. The relationship between these two measures is unknown - there are no previous studies that have investigated correlation between the site of latest mechanical activation determined by echo and the site of maximal AHR. It is likely that a hybrid technique using both of these investigations might allow optimal lead positioning in more patients, or that if the information is shown to be equivalent, more streamlined techniques can be designed. This study will also be able to contribute towards several important secondary questions. In particular the investigators will study the possibility of using non-invasive cardiac output monitoring (NICOM) to assess haemodynamic response rather than an intravascular pressure monitor wire. The investigators also wish to assess whether the site of latest mechanical activation is changed by right ventricular pacing.

Official Title
-----------------
Intracardiac Haemo-dynamics and Echocardiographic Assessment to Optimise Lead Placement for CRT

Conditions
-----------------
Heart Failure

Intervention / Treatment
-----------------
* Procedure: Pacing in vein at site of latest mechanical activation
* Procedure: Pacing in other suitable vein


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: With ejection fraction <35% Participant is willing and able to give informed consent for participation in the study. Male or Female, aged 18 years or above. Indication for cardiac resynchronisation therapy Exclusion Criteria: Left Ventricular Ejection Fraction >35% Severe peripheral vascular disease (that would make arterial access more risky) Haemodynamic instability (such that a longer procedure is inadvisable)

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients<br>All included patients, having CRT implant procedure Will have both Pacing in vein at site of latest mechanical activation and Pacing in other suitable vein. | Procedure: Pacing in vein at site of latest mechanical activation<br>* Pacing in vein at site of latest mechanical activation<br>Procedure: Pacing in other suitable vein<br>* Pacing in other suitable vein<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Acute haemodynamic response in area of latest mechanical activation and another vein | To assess whether pacing at the site of latest mechanical activation produces the maximal acute haemodynamic response to biventricular pacing, when compared to other attainable Left Ventricular coronary venous pacing sites. Acute haemodynamic response measured as percentage change in left ventricular dP/dt max (maximum rate of change of left ventricular pressure) recorded by a left ventricular pressure wire, between baseline atrial pacing at 80 beats per minute and biventricular pacing in each vein | Time 0 (during implant procedure) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximum acute haemodynamic response between all available pacing vectors in the vein within the area of latest mechanical response | To assess if further increases in acute haemodynamic response at the site of latest mechanical activation can be achieved with different pacing configurations. | Time 0 (during implant procedure) | 
| Acute haemodynamic response by NICOM and pressure wire | To compare results attained from non-invasive cardiac output monitoring (NICOM) to those from invasive monitoring | Time 0 (during implant procedure) | 
| Area of latest mechanical activation in right ventricular pacing and intrinsic rhythm | To assess the effect of right ventricular pacing on the site of latest mechanical activation. Assessed using speckle-tracking echocardiography. | 1 day post procedure | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Cardiac resynchronisation therapy, Pacing