Impact of prophylactic cavotricuspid isthmus ablation in atrial fibrillation recurrence after a first pulmonary vein isolation procedure João Mesquita a, ⁎, António Miguel Ferreira a,b , Diogo Cavaco a,b , Pedro Carmo a,b , Márcio Madeira c , Pedro Freitas a , Francisco Moscoso Costa a,b , Francisco Morgado a , Miguel Mendes a , Pedro Adragão a,b a Cardiology Department, Hospital de Santa Cruz, Lisbon, Portugal b Cardiology Department, Hospital da Luz, Lisbon, Portugal c Cardiothoracic Surgery Department, Hospital de Santa Cruz, Lisbon, Portugal abstract article info Article history: Received 2 December 2017 Received in revised form 6 January 2018 Accepted 8 January 2018 Introduction: PVI is a well-established therapy for patients with drug refractory atrial fibrillation (AF). However, it remains unclear whether prophylactic cavotricuspid isthmus (CTI) ablation at the time of PVI improves long- term freedom from AF. Objective: To compare the outcomes of patients who underwent PVI alone vs. PVI + prophylactic CTI ablation. Methods: Propensity score (PS) matching analysis based on a registry dataset of 1931 consecutive patients who underwent a first AF catheter ablation. After excluding those with documented/inducible atrial flut- ter (n = 233), 1698 individuals were available for matching. Following adjustment for age, gender, body mass index (BMI), hypertension, smoking, diabetes, LA volume, type of AF, and type of navigation (magnetic vs. manual), PS matched 411 patients who underwent PVI + CTI ablation with 411 receiving PVI alone. Results: PS analysis yielded a study population of 822 matched patients (58 ± 11 years, 69% males, 64% with paroxysmal AF). Over a median 2 years follow-up period there were 278 AF recurrences (34%). Survival free of AF (Log rank p = .965) and annual relapse rates were similar in the two groups - 10.9%/year vs 10.1%/year (PVI vs PVI + CTI, respectively, p = .97). CTI ablation remained unassociated with AF-free survival (HR 1.09, 95%CI: 0.84–1.41, p = .54) after Cox regression adjustment for age, sex, type of AF, LA volume, hypertension, diabetes, BMI and center. Female gender, current smoking, indexed LA volume and non-paroxysmal AF were identified as independent predictors of relapse after matching. Conclusions: Prophylactic CTI ablation at the time of a first PVI does not seem to improve long-term freedom from AF. © 2018 Published by Elsevier B.V. Keywords: Atrial fibrillation Cavotricuspid isthmus Pulmonary vein isolation Radiofrequency catheter ablation Prognosis Acronyms ACGME – Accreditation Council on Graduate Medical Education REDUCE-AF TRIPLE-A Ethical standards All human and animal studies have been approved by the appropri- ate ethics committee and have therefore been performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. The patients signed an informed consent both for the procedure and publication of any relevant data. 1. Introduction Pulmonary vein isolation (PVI) is a well-established treatment for patients with drug-refractory atrial fibrillation (AF) [1,2]. However, recurrence rates after a first catheter ablation procedure are still significant [3,4]. An increasing body of research has shown that PV reconnection is an important mechanism of AF relapse following catheter ablation [5]. Nevertheless, some patients remain free from AF despite showing PV re- connection, while others present with AF relapse regardless of complete PV isolation, prompting the question of whether pulmonary vein trig- gers are the only culprits in AF and if additional ablation sites should be targeted [6,7]. Several strategies to reduce AF recurrence after abla- tion have been proposed, such as performing additional lines [8,9] or International Journal of Cardiology 259 (2018) 82–87 Abbreviations: AAD, antiarrhythmic drug; AF, atrial fibrillation; AFL, atrial flutter; BMI, body mass index; CAD, coronary artery disease; CI, confidence interval; CT, computerized tomography; CTI, cavotricuspid isthmus; ESC, European Society of Cardiology; HR, hazard ratio; IQR, interquartile range; LA, left atrium; LV, left ventricle; LVSD, left ventricular sys- tolic dysfunction; PS, propensity-score; PSM, propensity-score matching; PV, pulmonary vein; PVI, pulmonary vein isolation; RF, radiofrequency; SDM, standardized difference of the means; USA, United States of America. ⁎ Corresponding author at: Av. Prof. Reinaldo dos Santos, 2790-134 Carnaxide, Portugal. E-mail address: jpmesquita@chlo.min-saude.pt (J. Mesquita). https://doi.org/10.1016/j.ijcard.2018.01.025 0167-5273/© 2018 Published by Elsevier B.V. Contents lists available at ScienceDirect International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard