Pulmonary vein parameters are similar or better predictors than left atrial diameter for paroxysmal atrial fibrillation after cryoablation

Left atrial diameter (LAD) has been considered an independent risk factor for atrial fibrillation (AF) relapse after pulmonary vein isolation (PVI). However, whether LAD or other factors are more predictive of late recurrence in patients with paroxysmal AF remains unclear. We aimed to evaluate the value of pulmonary vein (PV) parameters for predicting AF relapse 1 year after patients underwent cryoablation for paroxysmal AF. Ninety-seven patients with paroxysmal AF who underwent PVI successfully were included. PV parameters were measured through computed tomography scans prior to PVI. A total of 28 patients had recurrence of AF at one-year follow-up. The impact of several variables on recurrence was evaluated in multivariate analyses. LAD and the time from first diagnosis of AF to ablation maintained its significance in predicting the relapse of AF after relevant adjustments in multivariate analysis. When major diameter of right inferior pulmonary vein (RIPV) (net reclassification improvement (NRI) 0.179, CI=0.031-0.326, P<0.05) and cross-sectional area (CSA) of RIPV (NRI: 0.122, CI=0.004-0.240, P<0.05) entered the AF risk model separately, the added predictive capacity was large. The accuracy of the two parameters in predicting recurrence of AF were not inferior (AUC: 0.665 and 0.659, respectively) to echocardiographic LAD (AUC: 0.663). The inclusion of either RIPV major diameter or CSA of RIPV in the model increased the C-index (0.766 and 0.758, respectively). We concluded that major diameter of RIPV had predictive capacity similar to or even better than that of LAD for predicting AF relapse after cryoablation PVI.

Paroxysmal Atrial Fibrillation Catheter Ablation Outcome Depends on Pulmonary Veins Anatomy / O Resultado da Ablação por Cateter da Fibrilação Atrial Paroxística Depende da Anatomia das Veias Pulmonares

Abstract Background: Pulmonary veins (PV) are often the trigger to atrial fibrillation (AF). Occasionally, left PVs converge on a common trunk (LCT) providing a simpler structure for catheter ablation. Objective: To compare the clinical characteristics and outcomes of ablation in paroxysmal atrial fibrillation (PAF) of patients with or without LCT. Methods: Case-control study of patients undergoing first-ever catheter ablation procedure for drug refractory PAF. The information was taken from patients' records by means of a digital collection instrument, and indexed to an online database (Syscardio(r)). Clinical characteristics and procedures were compared between patients with or without LCT (LCT x n-LCT), adopting a level of statistical significance of 5%. The primary endpoint associated with efficacy was lack of atrial arrhythmia over the follow-up time. Results: One hundred and seventy two patients with PAF were included in the study, 30 (17%) LCT and 142 (83%) n-LCT. The clinical characteristics, comorbidities, symptoms scale and risk scores did not differ between the groups. There was AF recurrence in 27% of PAF patients in the n-LCT group and only 10% of patients in the LCT group (OR: 3.4 p: 0.04) after a follow-up of 34 ± 17 months and 26 ± 15 months respectively. Conclusion: Patients with a LCT have a significantly lower recurrence rate when compared to patients without this structure. It is mandatory to report the results of AF catheter ablation as a PV anatomical variation function.

Resumo Fundamento: As veias pulmonares (VP) são frequentemente o local de origem da fibrilação atrial (FA). Ocasionalmente, as VPs esquerdas confluem em um tronco comum (TrCE) proporcionando uma estrutura mais simples para ablação por cateter. Objetivos: Tem-se como objetivo comparar as características clínicas e os resultados da ablação em pacientes portadores de FA paroxística (FAP) com ou sem TrCE. Metódos: Estudo do tipo caso-controle de pacientes submetidos ao primeiro procedimento de ablação por cateter para FAP refratária a drogas antiarrítmicas. As informações foram retiradas dos prontuários dos pacientes por meio de instrumento digital de coleta e indexadas a uma base de dados online (Syscardio(r)). As características clínicas e procedimentos foram comparados entre pacientes com e sem TrCE (TrCE x n-TrCE), sendo adotado nível de significância estatística de 5%. O desfecho primário associado à eficácia foi ausência de arritmia atrial ao longo do seguimento com único procedimento. Resultados: Cento e setenta e dois pacientes foram incluídos no estudo, 30 (17%) TrCE e 142 (83%) n-TrCE. As características clínicas, comorbidades, severidade de sintomas e escores de risco não apresentaram diferença estatística entre os grupos. Houve recorrência da FA em 27% dos pacientes do grupo não-TrCE e em apenas 10% dos pacientes do grupo TrCE (OR: 3,4 p: 0.04) após um seguimento de 34±17 e 26±15 meses respectivamente. Conclusão: Pacientes com TrCE apresentam significativamente menor taxa de recorrência quando comparados a pacientes sem esta estrutura. É imprescindível relatar os resultados da ablação por cateter de FA na vigência de variações anatômicas das VPs.

Pulmonary Vein Anatomy is Associated with Cryo Kinetics during Cryoballoon Ablation for Atrial Fibrillation / A Anatomia da Veia Pulmonar está Associada à Criocinética durante a Ablação por Criobalão da Fibrilação Atrial

Abstract Background: The influence of pulmonary vein (PV) anatomy on cryo kinetics during cryoballoon (CB) ablation is unclear. Objective: To investigate the relationship between PV anatomy and cryo kinetics during CB ablation for atrial fibrillation (AF). Methods: Sixty consecutive patients were enrolled. PV anatomy, including ostial diameters (long, short and corrected), ratio between short and long diameters, ostium shape (round, oval, triangular, and narrow), and drainage pattern (typical, with common trunk, common antrum, ostial branch and supernumerary PV) were evaluated on multi-detector computed tomography (MDCT) images pre-procedure. Cryo kinetics parameters [balloon freeze time from 0 to -30ºC (BFT), balloon nadir temperature (BNT) and balloon warming time from -30 to +15ºC (BWT)] were recorded during procedure. All p values are two-sided, with values of p < 0.05 considered to be statistically significant. Results: 606 times of freezing cycle were accomplished. Moderate negative correlation was documented between BNT and corrected PV diameter (r = -0.51, p < 0.001) when using 23-mm CBs, and mild negative correlation (r = - 0.32, p = 0.001) was found when using 28-mm CBs. Multivariate logistic regression analysis revealed that PV corrected ostial diameter (OR, 1.4; p = 0.004) predicted a BNT < -51ºC when using 23-mm CBs, while PV ostium oval shape (OR, 0.3; p = 0.033) and PV locations (left inferior PV: OR, 0.04; p = 0.005; right superior PV: OR, 4.3; p = 0.025) predicted BNT < -51ºC when using 28-mm CBs. Conclusions: MDCT can provide PV anatomy accurate evaluation prior CB ablation. PV anatomy is associated with cryo kinetics during ablation.

Resumo Fundamentos: A influência da anatomia da veia pulmonar (VP) na criocinética durante a ablação por criobalão (CB) não está clara. Objetivo: Investigar a relação entre a anatomia da VP e a criocinética durante a ablação com CB para fibrilação atrial (FA). Métodos: sessenta pacientes consecutivos foram matriculados. Foram avaliados em imagens de tomografia computadorizada multidetectora (TCMD) pré-procedimento a anatomia da VP, incluindo diâmetros dos óstios (longo, curto e corrigido), relação entre diâmetros curtos e longos, forma do óstio (redondo, oval, triangular e estreito) e padrão de drenagem (típico, com tronco comum, antro comum, ramo ostial e VP supranumerária). Os parâmetros criocinéticos [tempo de congelamento de balão de 0 a -30ºC (TCB), temperatura do nadir do balão (TNB) e tempo de aquecimento do balão de -30 a + 15ºC (TAB)] foram registrados durante o procedimento. Todos os valores de p são bicaudais, com valores de p < 0,05 considerados estatisticamente significativos. Resultados: o ciclo de congelamento foi realizado 606 vezes. Correlação negativa moderada foi documentada entre o TNB e o diâmetro VP corrigido (r = - 0,51, p < 0,001) ao usar CBs de 23 mm e correlação negativa leve (r = - 0,32, p = 0,001) foi encontrada ao usar 28- mm CBs. A análise de regressão logística multivariada revelou que o diâmetro corrigido do óstio da VP (OR, 1,4; p = 0,004) previu um TNB < -51ºC ao usar CB de 23 mm, enquanto a forma oval do óstio VP (OR, 0,3; p = 0,033) e as localizações da VP (VP inferior: OR, 0,04; p = 0,005; VP superior direito: OR, 4,3; p = 0,025) previram TNB < -51ºC ao usar CBs de 28 mm. Conclusões: A TCMD pode fornecer uma avaliação precisa da anatomia da VP antes da ablação por CB. A anatomia da VP está associada à criocinética durante a ablação.