Catheter Ablation of Atrial Fibrillation in Patients With Pulmonary Hypertension Hypertension: a Randomised Study

Catheter Ablation of Atrial Fibrillation in Patients With Pulmonary Hypertension Hypertension: a Randomised Study

Catheter Ablation of Atrial Fibrillation/Tachycardia in Patients With Pulmonary Hypertension: a Randomised Study

Atrial fibrillation (AF) and atrial tachycardia (AT), including type I atrial flutter, are frequently observed in patients with pulmonary hypertension (PH). Catheter ablation of AF / AT has been established as an effective treatment option in selected patients. However, little is known about the efficacy and safety of this approach in patients with PH. It has also been shown that considerable proportion of patients with PH after acutely successful catheter ablation suffer from the recurrence of clinical or newly manifested arrhythmia. We propose a prospective study to compare two ablation strategies in a randomized fashion: radiofrequency catheter ablation targeting only the clinical arrhythmia versus more extensive substrate-based catheter ablation. This project will investigate the clinical outcome of patients with pulmonary hypertension and symptomatic atrial fibrillation / tachycardia who will be randomly allocated to selective versus complex radiofrequency catheter ablation of arrhythmogenic substrate.

Cinical arrhythmia is fairly documented AF, pulmonary vein isolation will be performed. If AF persists after this step, electrical cardioversion will be performed. If clinical arrhythmia is fairly documented type 1 AFL, cavo-tricuspid isthmus ablation will be performed. If clinical arrhythmia is AT, it will be induced (if not persistent), identified by means of activation and/or entrainment mapping, and ablated. If clinical arrhythmia is AT that is non-inducible during EP study, no ablation will be done. If other incidental (or induced) AT is observed that can be qualified as non-clinical it will not be targeted unless considered important to ablate at discretion of operator. No induction protocols for other, on top of already ablated, arrhythmias will be attempted.

- The initial ablation steps will be identical to those in patients from Group A. Supplemental ablation will consist of: Empirical lesion set within right atrium: superior vena cava isolation, posteroseptal bicaval line, and cavo-tricuspid isthmus ablation (if not already ablated) AND Homogenization of low-voltage zones (if any) in left / right atrium defined by bipolar voltage <0.5 mV in sinus rhythm or <0.2 mV in AF / AT. The threshold can be adapted in severely diseased atria to delineate reasonably smaller zones (<20% of atrial surface) achievable to ablate. Arrhythmia induction protocol by10-second burst atrial pacing with cycle length of 300 ms decremented by 10 ms up to atrial refractoriness or cycle length of 200 ms. Inducible ATs will be mapped and ablated if feasible. In case of inducible persistent (>5 min) AF, pulmonary vein isolation will be performed if not previously done as per protocol.

Catheter ablation of atrial fibrillation or atrial tachykardie related to atrial fibrillation with use of radiofrequency energy.

Documented arrhythmia recurrence >30 s without antiarrhythmic drugs in post-blanking period after the index ablation

Inclusion Criteria: Pre-capillary PH (PAMP ≥25 mmHg; PAWP ≤15 mmHg) or combined post- a pre-capillary PH (PAMP ≥25 mmHg; PAWP >15 mmHg; DPG ≥7 mmHg and/or PVR >3 W.u.) of any etiology. Exclusion Criteria: Complex congenital heart defects (corrected or uncorrected) Isolated post-capillary PH (PAMP ≥25 mmHg; PAWP >15 mmHg; DPG <7 mmHg and/or PVR ≤ 3W.u.) Previous catheter ablation for AF / AT / AFL Previous or scheduled cardiac surgery- NYHA Class IV, cardiogenic shock Life expectancy <1 year Non-compliance