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Background: Electroanatomic voltage mapping (EVM) is a promising modality for guiding endomyocardial biopsies (EMB). However, few data support its feasibility and safety. We now report the largest cohort of patients undergoing EVM-guided EMB in order to show its diagnostic yield and to compare it with a cardiac magnetic resonance (CMR) guided approach. Methods: One-hundred and sixty-two consecutive patients undergoing EMB at our Institution from 2010 to 2019 were included. EMB was performed in pathological areas identified at EVM and CMR. According to EMB results, CMR and EVM sensitivity and specificity regarding the identification of pathological substrates of myocardium were evaluated. Results: Pre-operative CMR showed late gadolinium enhancement (LGE) in 70% of the patients, while EVM identified areas of low voltages in 61%. Right (73%), left (19%) or both ventricles (8%) underwent sampling. EVM proved to have similar sensitivity to CMR (74% vs. 77%), with specificity being respectively 70% and 47%. In 12 patients with EMB-proven cardiomyopathy, EVM identified pathological areas, which had been undetected at CMR evaluation. Sensitivity of pooled EVM and CMR was as high as 95%. EMB analysis allowed to reach a new diagnosis, different from the suspected clinical diagnosis, in 39% of patients. Complications rate was low, mostly vascular access related, with no patients requiring urgent management. Conclusions: EVM proved to be a promising tool for targeted-EMB due to its sensitivity and specificity for identification of myocardial pathological substrates. EVM demonstrated to have an accuracy similar to CMR. EVM and CMR together conferred EMB a positive predictive value of 89%.

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 CHA2DS2‐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.

Diagnosis of Arrhythmogenic CardioMyopathy (ACM) is challenging and often late after disease onset. No circulating biomarkers are available to date. Given their involvement in several cardiovascular diseases, plasma microRNAs warranted investigation as potential non-invasive diagnostic tools in ACM. We sought to identify circulating microRNAs differentially expressed in ACM with respect to Healthy Controls (HC) and Idiopathic Ventricular Tachycardia patients (IVT), often in differential diagnosis. ACM and HC subjects were screened for plasmatic expression of 377 microRNAs and validation was performed in 36 ACM, 53 HC, 21 IVT. Variable importance in data partition was estimated through Random Forest analysis and accuracy by Receiver Operating Curves. Plasmatic miR-320a showed 0.53 ± 0.04 fold expression difference in ACM vs. HC (p < 0.01). A similar trend was observed when comparing ACM (n = 13) and HC (n = 17) with athletic lifestyle, a ACM precipitating factor. Importantly, ACM patients miR-320a showed 0.78 ± 0.05 fold expression change vs. IVT (p = 0.03). When compared to non-invasive ACM diagnostic parameters, miR-320a ranked highly in discriminating ACM vs. IVT and it increased their accuracy. Finally, miR-320a expression did not correlate with ACM severity. Our data suggest that miR-320a may be considered a novel potential biomarker of ACM, specifically useful in ACM vs. IVT differentiation.