Cryoballoon atrial fibrillation ablation: Single-center safety and efficacy data using a novel cryoballoon technology compared to a historical balloon platform.

INTRODUCTION: Catheter ablation is superior to drugs regarding atrial fibrillation (AF) recurrence, symptoms improvement, and mortality reduction in heart failure. POLARx™ is a novel cryoballoon, with technical improvements seeking to improve outcomes. So far, its clinical evidence is restricted to a case report. METHODS: To compare the POLARx™ cryoballoon procedural safety and efficacy to the already established Arctic Front Advance PRO™ (AFAP) in a single-center cohort study, consecutive patients undergoing AF cryoablation with the POLARx™ were enrolled. Data were prospectively gathered. POLARx™ patients were compared with a historical cohort of patients submitted to AF cryoablation with the AFAP. RESULTS: Seventy patients were analyzed, 20 in POLARx™, and 50 in the AFAP group. They all underwent first-time pulmonary vein isolation, 77% were male, 94% had paroxysmal AF, median age was 62.5 years, median CHA2 DS2 -VASc 1, left-atrium size 34 ml/m², and 65% were receiving anticoagulation. The primary end-point, all pulmonary veins isolation, was 100% in both groups. The complication rate was similar (0% POLARx™ vs. 5.7% AFAP, p = .39). The median total procedural time was longer in the POLARx™ group (90 min vs. 60 min, p < .001), but the overall time-to-isolation (TTI; 44.8 s vs. 39 s, p = .253) and ablation time (15 min vs. 13.7 min, p = .122) was similar between POLARx™ and AFAP groups, respectively. Despite equal TTI, the POLARx™ had a lower minimal temperature reached (-57°C vs -47°C, p < .001). CONCLUSION: The novel POLARx™ cryoballoon had similar efficacy and safety compared with the AFAP. It was also associated with longer procedural times, similar TTI, and lower minimum temperature reached.

Trastuzumab-induced cardiotoxicity: clinical and prognostic implications of troponin I evaluation.

PURPOSE: Treatment of breast cancer with trastuzumab is complicated by cardiotoxicity in up to 34% of the patients. In most patients, trastuzumab-induced cardiotoxicity (TIC) is reversible: left ventricular ejection fraction (LVEF) improves after trastuzumab withdrawal and with, or sometimes without, initiation of heart failure (HF) therapy. The reversibility of TIC, however, is not foreseeable, and identification of patients at risk and of those who will not recover from cardiac dysfunction is crucial. The usefulness of troponin I (TNI) in the identification of patients at risk for TIC and in the prediction of LVEF recovery has never been investigated. PATIENTS AND METHODS: In total, 251 women were enrolled. TNI was measured before and after each trastuzumab cycle. LVEF was evaluated at baseline, every 3 months during trastuzumab therapy, and every 6 months afterward. In case of TIC, trastuzumab was discontinued, and HF treatment with enalapril and carvedilol was initiated. TIC was defined as LVEF decrease of > 10 units and below 50%. Recovery from TIC was defined as LVEF increase above 50%. RESULTS: TIC occurred in 42 patients (17%) and was more frequent in patients with TNI elevation (TNI+; 62% v 5%; P < .001). Twenty-five patients (60%) recovered from TIC. LVEF recovery occurred less frequently in TNI+ patients (35% v 100%; P < .001). At multivariate analysis, TNI+ was the only independent predictor of TIC (hazard ratio [HR], 22.9; 95% CI, 11.6 to 45.5; P < .001) and of lack of LVEF recovery (HR, 2.88; 95% CI,1.78 to 4.65; P < .001). CONCLUSION: TNI+ identifies trastuzumab-treated patients who are at risk for cardiotoxicity and are unlikely to recover from cardiac dysfunction despite HF therapy.