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- Does a left common pulmonary trunk anatomy represent a real limitation for atrial fibrillation cryoablation success?Publication . Brito, Joana; Rodrigues, Tiago; António, Pedro Silvério; Ferreira, Afonso Nunes; Lima Da Silva, Gustavo; Bernardes, Ana; Barreiros, Céu; Ribeiro, João; Carpinteiro, Luís; Cortez-Dias, Nuno; Pinto, Fausto J.; De Sousa, JoãoCryoballoon ablation (CBA) has been increasingly used for atrial fbrillation (AF) ablation. The presence of pulmonary vein (PV) anatomical variants, particularly left common pulmonary trunk (LCPT), may limit the cryoballoon adaptability and performance. To evaluate the impact of the presence of LCPT in CBA, we compared the success, safety, and procedure characteristics in consecutive patients referred for a frst-ever PVI attempt, irrespective of AF type and PV anatomy.
- Anticoagulation after typical atrial flutter ablation: systematic review and meta‐analysisPublication . Ferreira, Afonso Nunes; Alves, Mariana; Lima Da Silva, Gustavo; Cortez-Dias, Nuno; De Sousa, João; Pinto, Fausto J.; Caldeira, DanielBackground: Cavotricuspid isthmus (CTI) ablation in typical atrial flutter (AFL) restores sinus rhythm in 95% of patients, which may lead to the discontinuation of oral anticoagulation during follow-up. Therefore, we aimed to systematically review the clinical impact of oral anticoagulation in the incidence of thromboembolic events (TE) after typical AFL ablation. Methods: We searched for controlled studies evaluating the impact of anticoagulation in the incidence of TE in patients submitted to AFL ablation in MEDLINE, CENTRAL, PsycINFO database (June/2021). The primary outcome was TE events (ischemic stroke or systemic embolism). A meta-analysis was performed deriving risk ratios (RR) and 95% confidence intervals (CI). Statistical heterogeneity was measured through I2 metric. The confidence in the evidence was appraised with Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. Results: Eight observational studies with 4870 patients were included. TE events were not significantly reduced (RR 1.18, 95% CI 0.59-2.36; n = 4870; GRADE very low). A meta-regression showed that for each 10% increase in the prevalence of previous AF in the studied population, anticoagulation reduced TE risk in 32%. There were no significant differences regarding bleeding events (RR 2.16, 95% CI 0.43-10.97, I2 = 0%; GRADE low), but there was a lower all-cause mortality (RR 0.24, 95% CI 0.17-0.32, GRADE low). Conclusion: The best available evidence lacks robustness and the data did not definitely associate anticoagulation after typical AFL ablation with reduced TE.
- Impact of different activation wavefronts on ischemic myocardial scar electrophysiological properties during high‐density ventricular tachycardia mapping and ablationPublication . Lima Da Silva, Gustavo; Cortez-Dias, Nuno; Ferreira, Afonso Nunes; Nakar, Elad; Francisco, Raquel; Pereira, Mariana; Moreno, Javier; Martins, Raphaël P.; Pinto, Fausto J.; De Sousa, JoãoIntroduction: Scar-related ventricular tachycardia (VT) usually results from an underlying reentrant circuit facilitated by anatomical and functional barriers. The later are sensitive to the direction of ventricular activation wavefronts. We aim to evaluate the impact of different ventricular activation wavefronts on the functional electrophysiological properties of myocardial tissue. Methods: Patients with ischemic heart disease referred for VT ablation underwent high-density mapping using Carto®3 (Biosense Webster). Maps were generated during sinus rhythm, right and left ventricular pacing, and analyzed using a new late potential map software, which allows to assess local conduction velocities and facilitates the delineation of intra-scar conduction corridors (ISCC); and for all stable VTs. Results: In 16 patients, 31 high-resolution substrate maps from different ventricular activation wavefronts and 7 VT activation maps were obtained. Local abnormal ventricular activities (LAVAs) were found in VT isthmus, but also in noncritical areas. The VT isthmus was localized in areas of LAVAs overlapping surface between the different activation wavefronts. The deceleration zone location differed depending on activation wavefronts. Sixty-six percent of ISCCs were similarly identified in all activating wavefronts, but the one acting as VT isthmus was simultaneously identified in all activation wavefronts in all cases. Conclusion: Functional based substrate mapping may improve the specificity to localize the most arrhythmogenic regions within the scar, making the use of different activation wavefronts unnecessary in most cases.
- Multielectrode mapping for premature ventricular contraction ablation: a prospective, multicenter studyPublication . Sousa, Pedro A.; Barra, Sérgio; Cortez-Dias, Nuno; Khoueiry, Ziad; Paulo, José; António, Natália; Ferreira, Afonso Nunes; Pereira, Mariana; Lagrange, Philippe; De Sousa, João; Elvas, Luís; Garcia, Fermin C.; Gonçalves, LinoPurpose: We aim to evaluate whether the use of a multielectrode mapping catheter could lead to higher efficacy of premature ventricular contraction (PVC) ablation. Methods: Prospective, multicenter nonrandomized study of consecutive patients referred for PVC ablation from January 2018 to June 2021. Patients were separated into two groups: activation map performed with the PentaRay catheter (Study group) or with the ablation catheter (Control group). PMF software was used in both groups. Procedural endpoints and 1-year freedom from ventricular arrhythmia were assessed. Results: During the enrollment period 136 patients (60% males, mean age of 55 ± 17 years, 60% left-sided origin) fulfilled the inclusion criteria - 68 patients in each group. Patients in the Study Group had a sevenfold higher number of acquired activation points (768 ± 728 vs. 110 ± 79, p < 0.01), a shorter mapping time (28 ± 19 min vs. 49 ± 32 min, p < 0.01) and a quicker procedure time (110 ± 33 min vs. 134 ± 50 min, p < 0.01), compared to patients in the Control Group. While there were no significant differences in the acute success (95.6% in the Study Group vs. 90.1% in Control group, p = 0.49), or adverse events (4% in the Study group vs. 7% in the Control group, p = 0.72), patients in the Study group had a higher freedom from ventricular arrhythmia at 1-year (89.7% vs. 70.6%, p = 0.01). The use of the PentaRay catheter was an independent predictor of success (HR = 6.20 [95% CI, 1.08-35.47], p = 0.003). Conclusions: The use of the PentaRay catheter may improve the outcome of PVC ablation while reducing procedure time.
- Novel “late potential map” algorithm: abnormal potentials and scar channels detection for ventricular tachycardia ablationPublication . Cortez-Dias, Nuno; Lima Da Silva, Gustavo; Ferreira, Afonso Nunes; Nakar, Elad; Francisco, Raquel; Pereira, Mariana; Carpinteiro, Luís; Pinto, Fausto J.; De Sousa, JoãoBackground: Automated systems for substrate mapping in the context of ventricular tachycardia (VT) ablation may annotate far-field rather than near-field signals, rendering the resulting maps hard to interpret. Additionally, quantitative assessment of local conduction velocity (LCV) remains an unmet need in clinical practice. We evaluate whether a new late potential map (LPM) algorithm can provide an automatic and reliable annotation and localized bipolar voltage measurement of ventricular electrograms (EGMs) and if LCV analysis allows recognizing intrascar conduction corridors acting as VT isthmuses. Methods: In 16 patients referred for scar-related VT ablation, 8 VT activation maps and 29 high-resolution substrate maps from different activation wavefronts were obtained. In offline analysis, the LPM algorithm was compared to manually annotated substrate maps. Locations of the VT isthmuses were compared with the corresponding substrate maps in regard to LCV. Results: The LPM algorithm had an overall/local abnormal ventricular activity (LAVA) annotation accuracy of 94.5%/81.1%, which compares to 83.7%/23.9% for the previous wavefront algorithm. The resultant maps presented a spatial concordance of 88.1% in delineating regions displaying LAVA. LAVA median localized bipolar voltage was 0.22 mV, but voltage amplitude assessment had modest accuracy in distinguishing LAVA from other abnormal EGMs (area under the curve: 0.676; p < .001). LCV analysis in high-density substrate maps identified a median of two intrascar conduction corridors per patient (interquartile range: 2-3), including the one acting as VT isthmus in all cases. Conclusion: The new LPM algorithm and LCV analysis may enhance substrate characterization in scar-related VT.
- Anticoagulation after typical atrial flutter ablation: systematic review and meta‐analysisPublication . Ferreira, Afonso Nunes; Alves, Mariana; Lima Da Silva, Gustavo; Cortez-Dias, Nuno; De Sousa, João; Pinto, Fausto J.; Caldeira, DanielBackground: Cavotricuspid isthmus (CTI) ablation in typical atrial flutter (AFL) restores sinus rhythm in 95% of patients, which may lead to the discontinuation of oral anticoagulation during follow-up. Therefore, we aimed to systematically review the clinical impact of oral anticoagulation in the incidence of thromboembolic events (TE) after typical AFL ablation. Methods: We searched for controlled studies evaluating the impact of anticoagulation in the incidence of TE in patients submitted to AFL ablation in MEDLINE, CENTRAL, PsycINFO database (June/2021). The primary outcome was TE events (ischemic stroke or systemic embolism). A meta-analysis was performed deriving risk ratios (RR) and 95% confidence intervals (CI). Statistical heterogeneity was measured through I2 metric. The confidence in the evidence was appraised with Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. Results: Eight observational studies with 4870 patients were included. TE events were not significantly reduced (RR 1.18, 95% CI 0.59-2.36; n = 4870; GRADE very low). A meta-regression showed that for each 10% increase in the prevalence of previous AF in the studied population, anticoagulation reduced TE risk in 32%. There were no significant differences regarding bleeding events (RR 2.16, 95% CI 0.43-10.97, I2 = 0%; GRADE low), but there was a lower all-cause mortality (RR 0.24, 95% CI 0.17-0.32, GRADE low). Conclusion: The best available evidence lacks robustness and the data did not definitely associate anticoagulation after typical AFL ablation with reduced TE.
- Association between the number of altered late potential criteria and increased arrhythmic risk in Brugada syndrome patientsPublication . Brito, Joana; Cortez-Dias, Nuno; Lima Da Silva, Gustavo; Ferreira, Afonso Nunes; Aguiar-Ricardo, Inês; Cunha, Nelson; António, Pedro Silvério; Neves, Irina; Paiva, Sandra; Paixão, Ana; Gaspar, Fernanda; Silva, Adília; Magalhaes, Andreia; Marques, Pedro; Pinto, Fausto J.; De Sousa, JoãoBackground: Brugada syndrome (BrS) is associated with abnormal electrophysiological properties at right ventricular epicardium, consisting of fragmented electrograms extending well beyond QRS termination. We aimed to evaluate the utility of signal-averaged electrocardiogram (SA-ECG) for the noninvasive assessment of late potentials (LP) and risk stratification of BrS patients. Methods: A prospective, observational, single-center study of BrS patients is submitted to SA-ECG with the determination of the total filtered QRS duration (fQRS), root mean square voltage of the 40 ms terminal portion of the QRS (RMS40), and duration of the low-amplitude electric potential component of the terminal portion of the QRS (LAS40). LP were considered positive when above standard cut-offs: fQRS > 114 ms, RMS40 < 20 µV, and LAS40 > 38 ms. The rates of malignant arrhythmic events (MAEs), defined as sudden death or appropriate shocks, were compared in relation to clinical characteristics and SA-ECG findings. Results: A total of 106 BrS patients (mean age, 48 ± 12 years, 67.9% male) were studied, 49% with type-1 spontaneous pattern and 81% asymptomatic. During a median follow up of 4.7 years, 10 patients (7.1%) suffered MAEs, including 4 sudden deaths. The presence of LP was significantly associated with the arrhythmic risk, which increased with the number of altered LP criteria. In comparison to the patients who had none or 1 altered LP criterium, MAE risk was 4.7 times higher in those with 2 altered criteria and 9.4 times higher in those with 3 altered LP criteria. Conclusions: SA-ECG may be a useful tool for risk stratification in BrS. The presence of 2 or 3 abnormal LP criteria could identify a subset of asymptomatic patients at high risk of arrhythmic events.
- Preprocedural imaging guiding ventricular tachycardia ablation in structural heart diseasePublication . Ferreira, Afonso Nunes; Brito, Joana; Cortez-Dias, Nuno; Lima da Silva, Gustavo; Pinto, Fausto J.; De Sousa, JoãoBackground: Integration of preprocedural imaging techniques in ventricular tachycardia (VT) ablation may improve the identification of arrhythmogenic substrates, particularly relevant for patients with nonischemic cardiomyopathy (NICM) with sub-optimal outcomes. We assessed the impact of advanced preprocedural imaging on the safety and long-term efficacy of radiofrequency catheter ablation (RCA) for VT, comparing patients with NICM and ischemic cardiomyopathy (ICM). Methods: In this prospective, single-center study, consecutive patients referred for scar-related VT ablation underwent multidetector computed tomography (MDCT) and late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Images were segmented with ADAS 3D software and integrated into mapping systems. Substrate map collection targeted the imaging-predicted area of interest and the ablation aimed at eliminating all local abnormal ventricular activities. Procedural safety was evaluated with 30-day mortality. Long-term efficacy was assessed by survival free from appropriate ICD shocks at 36 months. Results: 102 patients were included (67 ± 11 years, 94% male; 75 ICM, 27 NICM). All patients underwent MDCT and 35% also underwent LGE-CMR. Procedural safety (4% 30-day mortality, p = .95) and 36-month efficacy were similar in both groups (88.0% vs. 74.1%, HR 2.09; p = .13 in ICM and NICM). Efficacy was higher in patients when VT activation mapping with VT isthmus ablation complemented substrate ablation compared to substrate-based ablation alone (94.5% vs. 80.6%, HR 4.00; p < .05). Conclusion: A preprocedural imaging protocol integrated into the invasive mapping system may improve safety and long-term efficacy, with NICM patients exhibiting outcomes comparable to those with ICM. Activation mapping of the VT on top of substrate ablation may improve prognosis.