(245) Percutaneous Transluminal Septal Myocardial Ablation and Common Procedural Complications before and after the approval of Ablysinol

Publication Number: 1236

Background: Percutaneous transluminal septal myocardial ablation (PTSMA) is an alternative to surgery for the treatment of left ventricular outflow tract obstruction in patients with hypertrophic obstructive cardiomyopathy. Ablysinol (dehydrated alcohol), which is used for PTSMA, was first approved by the Food and Drug Administration (FDA) in June 2018. FDA was interested in examining change in the frequency of PTSMA procedures and suspected complications after Ablysinol approval.

Objectives: To estimate the frequency of PTSMA and the procedure’s common suspected complications before and after approval of Ablysinol using the FDA Sentinel System.

Methods: Patients in the Sentinel System who had PTSMA in inpatient (IP) and outpatient (OP) settings in two distinct periods: prior to Ablysinol approval (January 01, 2016 - June 21, 2018) and after Ablysinol approval (June 22, 2018 - June 30, 2022) were identified. Eligible patients were over 18 years old with continuous medical and drug coverage for at least 183 days prior to their index PTSMA. Common post-PTSMA complications: permanent pacemaker placement (PPP), ventricular arrythmia (VA), heart failure (HF), septal myectomy, and repeat PTSMA in the subsequent 90 days and atrioventricular (AV) block in the subsequent 30 days, were assessed.

Results: A total of 307 IP PTSMA and 511 OP PTSMA patients were identified prior to Ablysinol approval, and 1,177 and 1,104 patients respectively post approval. The number of procedures per year increased across time in both settings. For example, inpatient PTSMA procedures increased from 120 in 2016 to 358 in 2021, and outpatient procedures increased from 165 in 2016 to 334 in 2021. The most common post-PTSMA diagnosis was HF, followed by AV block (3rd degree) and PPP in both care settings and time periods. The proportion of IP PTSMA patients with HF increased slightly after Ablysinol approval from 46.3% to 57.9%. Among the same population, the proportion with AV block increased from 26.4% to 33.5%, and the proportion with PPP increased from 25.1% to 34.2%. IP PTSMA patients were more likely to have a repeat procedure in both periods, and the proportion of repeat procedures increased after approval of Ablysinol in both care settings. The most commonly co-occurring diagnoses were HF and VA in the IP setting and AV block and PPP in the OP setting in both periods.

Conclusions: The number of PTSMA procedures increased, especially following approval of Ablysinol. However, the increase was not substantial. Suspected complications of PTSMA, such as heart failure, AV block, and PPP, were common following the procedure in both settings and increased slightly after Ablysinol approval. Claims data may not be ideal for accurately differentiating the setting of PTSMA.