Computed Tomography Targets for Efficient Guidance of Catheter Ablation in Ventricular Tachycardia (MAP-IN-HEART)
Computed Tomography Targets for Efficient Guidance of Catheter Ablation in Ventricular Tachycardia (MAP-IN-HEART)
The hypothesis of MAP IN HEART is that catheter ablation for post-infarction ventricular
 tachycardia (VT) can be largely improved through a direct definition of primary ablation
 targets from pre-operative CT scan imaging. The objective of is to demonstrate that catheter
 ablation of post-infarction VT targeting left ventricular wall thickness channels as defined
 from CT scan is feasible and associated with favorable efficacy, efficiency and safety
 profiles. A single-arm prospective cohort study will be conducted, including 40 patients over
 3 European centres. Baseline, procedural and 6-month follow-up data will be analyzed
Background: Although catheter ablation is a recommended therapeutic option in patients with
 history of myocardial infarction presenting with sustained ventricular tachycardia (VT),1 the
 current approach relies on lengthy, poorly reproducible and poorly standardized
 identification of targets derived from invasive catheter measurements. As a consequence, the
 rate of VT recurrence remains high, leading to repeat interventions.2 Pre-operative CT scan
 imaging was shown able to identify arrhythmogenic sites within scar through a detailed
 analysis of left ventricular (LV) wall thickness.3,4 This study aims at demonstrating that
 using these as primary targets for ablation is a feasible strategy associated with favorable
 efficacy, efficiency and safety profiles.

 Methods: 40 patients with post-infarction VT referred for catheter ablation will be included
 over 3 European centres. Pre-operative CT scan will be processed to obtain a 3D model of the
 patient heart comprising detailed anatomy and LV wall thickness maps. Channels of relatively
 preserved thickness penetrating within severely thinned scar (i.e. CT-channels) will be
 identified using a proprietary algorithm developed at the IHU LIRYC, University of Bordeaux,
 and used as primary targets for catheter ablation. During the intervention, the 3D model
 along with pre-operatively defined targets will be registered in the 3D mapping space, and
 each CT-channel will be transected by ablation. The inducibility of VT will then be tested
 and any VT remaining inducible after CT-channels ablation will be targeted using conventional
 catheter mapping techniques, with a composite procedural endpoint combining the ablation of
 all CT channels and the non-inducibility of any VT. Procedural and 6-month follow-up data
 will be analyzed to assess the feasibility of the approach and report its efficiency,
 efficacy and safety profiles.

 Expected results: the CT-guided ablation strategy is expected to be feasible in a vast
 majority of post-infarction patients referred for VT ablation, and to be extremely
 time-efficient, the lengthy diagnostic part of the procedure (catheter mapping) being moved
 pre-operatively (imaging). The short procedure duration should translate into a favorable
 safety profile. The strategy should also be associated with a high efficacy in eliminating
 the arrhythmia, thanks to a more comprehensive definition of targets and to the dedication of
 the procedure time almost entirely to therapy. In conclusion, the present study should
 provide solid proof of concept on which randomized controlled trials may be built.
Inclusion Criteria:

 -  Age ≥ 18 years

 -  Indication for catheter ablation intervention with planned preoperative cardiac CT
 scan

 -  Prior myocardial infarction (using the international definition of MI: Q waves or
 imaging evidence of regional myocardial akinesis/thinning in the absence of a non-
 ischemic cause with documentation of prior ischemic injury)

 and

 -  One of the following monomorphic VT events within last 6 months:

 -  A: ≥3 episodes of symptomatic VT treated with antitachycardia pacing (ATP),

 -  B: ≥1 appropriate ICD shocks,

 -  C: ≥3 VT episodes within 24 hr

 -  D: sustained VT below detection rate of the ICD documented by ECG or any cardiac
 monitor

 -  E: Sustained VT recorded on 12 leads ECG in the absence of ICD

 -  Signed informed consent

 -  Affiliated or beneficiary of health insurance

 Exclusion Criteria:

 -  Unable or unwilling to provide written informed consent.

 -  Active ischemia (acute thrombus diagnosed by coronary angiography, or dynamic ST
 segment changes demonstrated on ECG) or another reversible cause of VT (e.g.
 drug-induced arrhythmia), had recent acute coronary syndrome within 30 days thought to
 be due to acute coronary arterial thrombosis, or have CCS functional class IV angina.
 Note that biomarker level elevation alone after ventricular arrhythmias does not
 denote acute coronary syndrome or active ischemia.

 -  Are known to have protruding left ventricular thrombus or mechanical aortic and mitral
 valves.

 -  Have had a prior catheter ablation procedure for VT

 -  Presenting arrhythmia: polymorphic VT or ventricular fibrillation (VF).

 -  Are in renal failure (Creatinine clearance <30 mL/min), have NYHA Functional class IV
 heart failure, or a systemic illness likely to limit survival to <1 year.

 -  Pregnancy, breast feeding women and women who are of childbearing age and not
 practicing adequate birth control. (French HAS criteria or following methods are
 considered adequate):

 -  Combined hormonal contraception

 -  Injected hormonal contraception

 -  Implanted hormonal contraception

 -  Progesterone-only hormonal contraception associated with inhibition of ovulation

 -  Placement of an intrauterine device (IUD)

 -  Placement of intrauterine hormone-realising system (IUS)

 -  Patient under legal protection.