PO-05-070 ENDOCARDIAL RADIOFREQUENCY ABLATION OF VT STORM IN CARDIOGENIC SHOCK PATIENTS WITH MECHANICAL CIRCULATORY SUPPORT

Abstract

Ventricular tachycardia (VT) storm in the setting of cardiogenic shock requiring mechanical support (MCS) carries a high mortality rate. Limited data exist in the literature using VT ablation as a treatment strategy in this cohort of patients. We aim to evaluate the outcome of patients receiving ablation in VT storm complicated by cardiogenic shock requiring MCS, as well as assess predictors for poor outcomes. This is a single-center, retrospective cohort study in patients with refractory VT and cardiogenic shock on MCS, undergoing endocardial ablation from 2015 to 2022. Complete substrate isolation with high output pacing within the scar, followed by stimulation protocols, was used to confirm substrate isolation and the success of ablation. Patients’ demographic and outcome data was obtained from chart review. The PAINESD score, a scoring system to predict early post-procedural mortality of VT ablation, was calculated for each patient. Peak lactate levels recorded during the procedure and preoperative invasive hemodynamic measurements were also taken into consideration. A total of 37 patients with VT storm and concomitant cardiogenic shock on MCS were included. The average age was 61.7 years old, 94.7% were men, with a mean left ventricular ejection fraction of 17.3%, and the average PAINESD score was 24.9. The type of mechanical support utilized is listed in Table 1. Twenty-one were discharged alive, 8 patients (21.6%) with long-term LVAD support, and 13 (35.1%) after weaning support, while 16 patients (43.2%) didn’t survive the index hospitalization (Figure 1). The PAINESD score between those who survived and those who died was not significantly different (25.3 vs. 24.3, p = 0.31). The survivor group had a significantly higher procedure success rate (76.2% vs. 35.3%, p=0.018), higher mean pulmonary artery pulsatility index (PAPI) (2.7 vs. 1.4, p = 0.005), and lower mean intraoperative peak lactic acid level (1.1 vs. 3.5 mmol/L, p = 0.027). Ablation for medication refractory ventricular arrhythmia in cardiogenic shock is efficacious in facilitating mechanical support weaning in a large proportion of the cohort. The absence of right ventricular dysfunction as measured by PAPI, intraoperative lactic acid level, and acute procedure success, as measured by VT inducibility at the end of the procedure, predict the short-term outcome, while the PAINESD score demonstrated weak differentiating power in this moribund, high-risk cohort.