Periprocedural acute hemodynamic decompensation associated with substrate-based ablation of ventricular tachycardia in patients with structural heart disease - rare and nonpredictable event

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Radiofrequency (RF) catheter ablation is an established treatment method in patients with structural heart disease (SHD) and recurrent ventricular tachycardia (VT). Due to underlying SHD, concomitant heart failure and a high burden of comorbidities, these patients are at considerable risk of periprocedural complications including acute hemodynamic decompensation (AHD) with a reported rate of up to 11%. The PAINESD score [sum of 5, 3, 6, 6, 3, 5, and 3 points for chronic obstructive pulmonary disease (COPD), age >60 years, ischemic cardiomyopathy (ICM), NYHA Class >2, LV ejection fraction (LVEF) <25%, electrical storm (ES), and diabetes mellitus (DM), respectively] was proposed to predict the risk of AHD, and identify the patients who may benefit from pre-emptive use of percutaneous left ventricular assist device (pVAD). PURPOSE: The single-centre, retrospective study investigated the incidence of AHD in large-volume, tertiary referral EP centre and the predictive power of the PAINESD score. METHODS: We included patients who had their first ablation for SHD-related VT between August 2006 and December 2020. The procedure was performed under conscious sedation except for patients who were on mechanical ventilation because of hemodynamical or electrical instability before the ablation. Substrate mapping/ablation was performed primarily during spontaneous rhythm or right-ventricular pacing. Induced VTs were terminated by overdrive pacing or cardioverted. Activation and entrainment mapping were used rarely – only in well-tolerated VTs. The goal of ablation was to abolish all inducible VTs. A purposely established institutional registry for complications of invasive procedures was used to collect all periprocedural complications that were subsequently adjudicated using the source medical records. AHD triggered by ablation procedure was defined as intraprocedural or early post-procedural (<12 h) development of acute pulmonary oedema or refractory hypotension, requiring urgent intervention including (but not limited to) inotropic agents and/or artificial ventilation and/or pVAD implant. RESULTS: The study cohort consisted of 1143 patients (age: 63±13 years, males: 87%, ICM: 67%, ES: 25%, NYHA Class: 2.1±1.0, LVEF: 34±13%, DM: 32%, COPD: 12%). Their PAINESD score was 11.4±6.6 (median: 12, interquartile range: 6–17). The ablation procedure (total duration 187±78 min, RF time: 23±15 min) was complicated by AHD in 13/1143 = 1.1% patients and these adverse events were not predicted by PAINESD score (Figure). CONCLUSIONS: We observed a substantially lower rate (1.1%) of AHD than previously reported (up to 11%). These events did not accumulate in patients with upper-tertile PAINESD score in whom the highest AHD risk was reported (up to 24%). This observation may be explained by careful substrate-based ablation under conscious sedation that prevents prolonged low-output state related to repeated VT induction and mapping in general anaesthesia. [Figure: see text]