Time to –30°C as a predictor of acute success during cryoablation in patients with atrial fibrillation

Background: Freezing rate of second-generation cryoballoon (CB) is a biophysical parameter that could assist pulmonary vein isolation. The aim of this study is to assess freezing rate (time to reach –30°C ([TT-30C]) as an early predictor of acute pulmonary vein isolation using the CB. Methods: Biophysical data from CB freeze applications within a multicenter, nation-wide CB ablation registry were gathered. Successful application (SA), was defined as achieving durable intraprocedural vein isolation with time to isolation in under 60 s (SA-TTI<60) as achieving durable vein isolation in under 60 s. Logistic regressions were performed and predictive models were built for the data set. Results: 12,488 CB applications from 1,733 atrial fibrillation (AF) ablation procedures were included within 27 centers from a Spanish CB AF ablation registry. SA was achieved in 6,349 of 9,178 (69.2%) total freeze applications, and SA-TTI<60 was obtained in 2,673 of 4,784 (55.9%) freezes and electrogram monitoring was present. TT-30C was shorter in the SA group (33.4 ± 9.2 vs 39.3 ± 12.1 s; p < 0.001) and SA-TTI<60 group (31.8 ± 7.6 vs. 38.5 ± 11.5 s; p < 0.001). Also, a 10 s increase in TT-30C was associated with a 41% reduction in the odds for an SA (odds ratio [OR] 0.59; 95% confidence interval [CI] 0.56–0.63) and a 57% reduction in the odds for achieving SA-TTI<60 (OR 0.43; 95% CI 0.39–0.49), when corrected for electrogram visualization, vein position, and application order. Conclusions: Time to reach –30°C is an early predictor of the quality of a CB application and can be used to guide the ablation procedure even in the absence of electrogram monitoring.

Repeat cryoablation as a redo procedure for atrial fibrillation ablation: Is it a good choice?

Background: Ablation of atrial fibrillation (AF), both cryoablation ablation (CBA) and radiofrequency catheter ablation (RFCA), have demonstrated to be safe and effective. About 1 in 3 patients may face a redo due to recurrence and the best technique is unknown. The aim of this study is to assess the efficacy of CBA as a repeat procedure in patients with prior CBA or RFCA. Methods: A nation-wide CBA registry (RECABA) was analyzed and patients were compared who had previously undergone CBA (Prior-CB) or RFCA (Prior-RF). The primary endpoint was AF recurrence at 12 months after a 3-month blanking period. A survival analysis was performed, univariate and multivariate Cox models were also built. Results: Seventy-four patients were included. Thirty-three (44.6%) were in the Prior-CB group and 41 (55.4%) in the Prior-RF. There were more reconnected pulmonary veins in the Prior-RF than in Prior-CB group (40.4% vs.16.5%, p = 0.0001). The 12-month Kaplan–Meier estimate of freedom from AF recurrence after the blanking period was 61.0% (95% confidence interval [CI] 41.4–75.8%) in the Prior-CB, and 89.2% (95% CI 73.6–95.9%) in the Prior-RF group (p = 0.002).  Multivariate Cox regression pointed Prior-CB as the sole independent predictor of AF recurrence, with an adjusted HR of 2.67 (95% CI 1.05–6.79). Conclusions: Repeat CBA shows higher rates of AF recurrences compared to CBA after a previous RFCA despite presenting less reconnected veins at the procedure. These data suggest that patients with AF recurrence after CBA may benefit from other ablation techniques after a recurrence. RECABA is registered at clinicaltrials.gov with the Unique Identifier NCT02785991

Variaciones de longitud de ciclo y estabilidad de la fibrilación ventricular bajo diversas condiciones clínico-farmacológicas detectadas a través de un desfibrilador automático implantable

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid. Facultad de Medicina, Departamento de Medicina. Fecha de lectura: 9 de Julio de 200

Estimulación multipunto mediante captura anódica del ventrículo izquierdo a través de un electrodo cuadripolar: evaluación hemodinámica no invasiva

Introducción: Un elevado porcentaje de pacientes no responde a la resincronización. La captura anódica izquierda mediante estimulación a alto voltaje, permite una estimulación multipunto que podría aumentar la tasa de respondedores. Objetivo: Evaluar la viabilidad y eficacia hemodinámica aguda de estimulación a alto voltaje mediante el uso del electrodo cuadripolar Quartet 1458Q®. Métodos: Se incluyeron 18 pacientes consecutivos, con electrodo cuadripolar, en quienes se confirmó captura en el modo deseado mediante monitorización electrocardiográfica. Se compararon las diferencias hemodinámicas agudas de captura anódica (electrodos 1-cátodo- y 4-ánodo, máximo voltaje y anchura), biventricular y ventricular derecha. Mediante el Task Force Monitor, se hizo análisis hemodinámico agudo de presión arterial sistólica, diastólica y media, volumen latido e índice, gasto cardiaco e índice. Para cada variable se analizó el valor máximo, mínimo y promedio, durante fases estables de diez minutos. Resultados: Se analizaron 18 pacientes (5 mujeres-27,8%), con edad media de 67,2 años (37-81); 33% con fibrilación auricular permanente y 39% con cardiopatía isquémica (sólo 5,6% ambas). La estimulación anódica aumentó significativamente el volumen latido e índice, así como el gasto cardiaco e índice en comparación con el modo biventricular [76,21 vs. 71,04 ml (p = 0,014); 40,67 vs. 37,88 ml/m2 (p = 0,018); 5,29 vs. 4,89 l/min (p = 0,007); 2,86 vs. 2,65 l/min/m2 (p = 0,007), respectivamente]. En el análisis por subgrupos, se concentró el beneficio en los pacientes en ritmo sinusal. Conclusión: La estimulación multipunto mediante captura anódica a través de un electrodo cuadripolar es factible, demostrándose así diferencias significativas en el volumen latido y gasto cardiaco, aunque limitado a la población en ritmo sinusal

Recurrence of atrial fibrillation after pulmonary vein isolation, should we change the energy and technique?

Background: Pulmonary vein isolation (PVI) is the accepted standard nowadays for atrial fibrillation (AF) ablation. The most widespread ablation techniques are cryoballoon (CB) and point-by-point radiofrequency (RF) ablation. Comparative studies between both techniques have shown their equivalence for the first ablation procedure, but no trial has explored the potential incremental benefit of crossing over the ablation technique after AF recurrence. Objective: To explore the potential incremental benefit of a crossover ablation strategy for AF recurrences, comparatively with repeating the same ablation energy used for the first procedure. Methods: Retrospective analysis of patients undergoing a second AF ablation procedure after documented AF recurrence. Patients were excluded if all 4 PV were isolated at the beginning of the second procedure or extra-PVI ablation was used for the second procedure. Crossover group (n = 16) included patients in which two different techniques were used for the first and second procedure (CB-RF or RF-CB). Control group (n = 23) for those with same ablation procedure (RF-RF of CB-CB). Acute procedure end-point was PVI of all four pulmonary veins. Patients were followed-up at 3, 6, and 12 months with an electrocardiogram and a 24 h-holter. Arrhythmia-free survival at 1 year after the second ablation procedure was studied, comparing efficiency and safety of the two approaches (crossover vs. same energy). Success was defined as freedom from AF or atrial tachycardia lasting > 30 s off antiarrhythmic drugs (AADs) Results: A cohort of 39 paroxysmal and persistent AF patients was analyzed. PVI after the second procedure was 100% in all patients in both groups. There were no baseline relevant differences between the two groups. No deaths or hospitalizations occurred during follow up (data censored at 24h moths). At 1 year, arrhythmia free-survival was significantly higher in the crossover group compared to control group [93,3% vs. 47,8%; HR 0.19 (0.06-0.66);p = 0,009]. Conclusion: Crossing the ablation technique (point-by-point radiofrequency or cryoballoon PVI) after AF recurrence significantly improved arrhythmia free-survival at one year, despite no difference in acute success (PVI isolation). Randomized controlled trials with a higher amount of patients are needed to confirm the results and widespread this approach

Síndrome de Bayés en cirugía cardiaca: prevalencia de bloqueo interauricular en menores de 65 años sometidos a cirugía cardiaca y su asociación con fibrilación auricular en el postoperatorio

Resumen: Objetivo: El bloqueo interauricular (BIA) es una entidad asociada con un mayor riesgo de presentar fibrilación auricular (FA), constituyendo el denominado síndrome de Bayés. El objetivo de nuestro estudio fue definir la prevalencia de BIA en pacientes menores de 65 años sometidos a cirugía cardiaca y determinar si existe una asociación entre la presencia de BIA y la aparición de FA postoperatoria. Método: Se incluyeron un total de 207 pacientes. Se definió BIA parcial como onda P > 120 ms. Se definió BIA avanzado como onda P > 120 ms con morfología bifásica en derivaciones inferiores. Se determinó la frecuencia de aparición de FA postoperatoria y se realizó un análisis comparativo entre los pacientes que presentaron y los que no presentaron esta arritmia. Resultados: La prevalencia de BIA fue del 78.3% (parcial, 66.2%; avanzado, 12.1%). La frecuencia de aparición de FA fue del 28.5% de forma global, siendo mayor en los pacientes con BIA avanzado (44%) comparado con pacientes con BIA parcial (27.7%) y sin BIA (24.4%). Los pacientes que presentaron FA fueron significativamente mayores, con niveles más elevados de NTproBNP y presentaron mayor prevalencia de dilatación auricular y de patología tiroidea. El análisis multivariable demostró una asociación independiente entre BIA avanzado y FA postoperatoria. Conclusiones: El BIA es una entidad frecuente en pacientes sometidos a cirugía cardiaca. En nuestro estudio, el BIA avanzado se asocia de forma independiente con una mayor frecuencia de FA postoperatoria en pacientes menores de 65 años sometidos a cirugía cardiaca. Abstract: Objective: Interatrial block (IAB) is a well-known entity that is associated with an increased risk of atrial fibrillation (AF). This association is called Bayes’ syndrome. The aim of our study was to define the prevalence of IAB among patients younger than 65 years undergoing cardiac surgery and determine whether there is an association between the presence of interatrial conduction delay and postoperative atrial fibrillation (POAF). Method: A total of 207 patients were enrolled. Partial IAB was defined as P-wave > 120 ms. Advanced IAB was defined as P-wave > 120 ms + biphasic morphology in the inferior leads. Ocurrence of POAF was assessed and a comparative analysis was conducted between patients that did and did not develop AF. Results: IAB prevalence was 78.3% (partial 66.2%, advanced 12.1%). POAF occurred in 28.5% of all patients, and was more frequent among patients with advanced IAB (44%) compared to 27.7% and 24.4% of POAF among patients with partial IAB and without IAB, respectively. Patients who developed POAF were significantly older, had significantly higher NTproBNP, higher prevalence of atrial enlargement and thyroid disease. After multivariate analysis, advanced IAB was found to be independently associated with POAF. Conclusions: IAB is a frequent finding among patients undergoing cardiac surgery. According to our results, advanced IAB is independently associated with POAF in younger patients (< 65 years) undergoing cardiac surgery. Palabras clave: Fibrilación auricular, Fibrilación auricular postoperatoria, Cirugía cardiaca, Bloqueo interauricular, Síndrome de Bayés, España, Keywords: Atrial fibrillation, Postoperative atrial fibrillation, Cardiac surgery, Interatrial block, Bayes’ syndrome, Spai