Electrical Stimulation-Guided Approach to Pulmonary Artery Catheter Ablation in Patients with Idiopathic Pulmonary Arterial Hypertension: A Pilot Feasibility Study with a 12-Month Follow-Up

Abstract

Background. Recently, transcatheter pulmonary artery (PA) ablation aiming at sympathetic denervation has been proposed in pulmonary arterial hypertension (PAH). This pilot feasibility study aimed to assess the feasibility of selective radiofrequency PA ablation based on response to high-frequency stimulation mapping. Methods. The study comprised 3 female patients with idiopathic PAH (IPAH). The following reactions to PA stimulation were noted and marked by color points on the three-dimensional map: sinus bradycardia (heart rate decrease ≥15%), tachycardia (heart rate increase ≥15%), phrenic nerve capture, and cough. Since the most appropriate ablation strategy was unknown, two approaches were suggested, according to stimulation results: ablation at points with any heart rate response (either bradycardia or tachycardia)—this approach was applied in patient #1 (IPAH long-term responder to calcium channel blockers); segmental ablation at points with no response and with tachycardia response (one IPAH long-term responder to calcium channel blockers patient and one–IPAH with negative vasoreactive testing). Hemodynamic measurements were performed before and after denervation. Follow-up visits were scheduled at 6 and 12 months. Results. Six-months follow-up was uneventful for patients #1 and 3; patient #2 had one syncope and reduced 6-minute walk test distance and peak VO2 consumption. At 12 months, there was a normalization of mean PA pressure and pulmonary vascular resistance (PVR) in patient #1. Patient #2 had no change in PA pressure and PVR at 12 months. Patient #3 remained in II functional class; however, there was an increase in mean PA pressure and loss of vasoreactivity. Conclusions. Electrical high-frequency stimulation of the PA identifies several types of evoked reactions: heart rate slowing, acceleration, phrenic nerve capture, and cough. The improvement in clinical and hemodynamic parameters following targeted PA ablation in the IPAH patient with positive vasoreactive testing should be confirmed in larger studies.

Extended Renal Artery Denervation Is Associated with Artery Wall Lesions and Acute Systemic and Pulmonary Hemodynamic Changes: A Sham-Controlled Experimental Study

“…We cannot exclude the difference in the stimulation protocols between our study and previous studies. However, a very similar stimulation approach protocol was affective in provoking autonomic reactions when used in other large vessels [18]. We suggest that pain perception during RA stimulation might be Cardiovascular Therapeutics responsible for some BP elevation.…”

An Ovine Model for Percutaneous Pulmonary Artery Laser Denervation: Perivascular Innervation and Ablation Lesion Characteristics

“…By far radiofrequency energy has been extensively employed and studied for denervation procedures [3][4][5]7], although several technical aspects related to device catheters and power settings are under continuous evaluation. Laser energy was introduced in medicine several years ago.…”

“…Pulmonary artery denervation (PADN) is a surgical or interventional procedure aiming to modulate pulmonary artery (PA) pressure in patients with pulmonary arterial hypertension (PAH) of different etiologies [3][4][5][6]. The abatement of perivascular nerves within and around the pulmonary artery (PA) resulting in the decrease of sympathetic neural activity has been suggested as a pathophysiological consequence of PADN procedures [7]. Recently, PA stimulation mapping delineating the phrenic and laryngeal recurrent nerves close to the PA has been demonstrated to be feasible during transcatheter PADN.…”

“…PADN strategies are still not well defined, and radiofrequency energy has been the first energy source employed for PADN in PH subjects and followed by the application of ultrasound energy [3,9]. Furthermore, the recently developed approaches utilized fluoroscopy guidance, and PA three-dimensional electroanatomical reconstruction has been used in a minority of studies [5,7,10]. Technology evolution allowed the manufacture of optical fibers for laser devices and consequently the development of intravascular and intracardiac catheters for medical interventions.…”

Meta-analysis of Pulmonary Artery Denervation for Treatment of Pulmonary Hypertension

“…In 2020, A multi-center clinical trial proved that PADN can reduce PVR as well as increase 6-minute walk distance (6MWD) of PAH patients, and no adverse events related to surgery occurred, con rming the effectiveness and safety of PADN [13]. However, another clinical study found that the effect of PADN on some PAH patients is not obvious [14]. Moreover, the sample size of the current clinical research is too small.…”