Role of Soluble ST2 Biomarker in Predicting Recurrence of Atrial Fibrillation after Electrical Cardioversion or Pulmonary Vein Isolation.

This study aims to determine the predictive value of the soluble suppression of tumorigenicity 2 (sST2) biomarker in atrial fibrillation (AF) recurrence. This prospective, observational study included patients with AF referred for electrical cardioversion (ECV) or pulmonary vein isolation (PVI) procedures. Baseline characteristics were collected, and sST2 was determined at baseline and at 3 and 6 months of follow-up. sST2 was determined at baseline in a matched control group. Left atrial voltage mapping was performed in patients undergoing PVI. The sST2 maximal predictive capacity of AF recurrence was at the 3-month FU in the cohort of patients undergoing ECV with respect to 6-month AF recurrence with an AUC of 0.669, a cut-off point of 15,511 pg/mL, a sensitivity of 60.97%, and a specificity of 69.81%. The ROC curve of the sST2 biomarker at baseline and 3 months in the cohort of patients undergoing PVI showed AUCs of 0.539 and 0.490, respectively. The logistic regression model identified the rhythm (AF) and the sST2 biomarker at 3 months as independent factors for recurrence at 6 months in the ECV cohort. In the logistic regression model, sST2 was not an independent factor for recurrence at 6 months of follow-up in the PVI cohort. In patients who underwent ECV, sST2 values at 3 months may provide utility to predict AF recurrence at 6 months of follow-up. In patients who underwent PVI, sST2 had no value in predicting AF recurrence at 6 months of follow-up.

Circulating miR-451a Expression May Predict Recurrence in Atrial Fibrillation Patients after Catheter Pulmonary Vein Ablation.

Atrial fibrillation is the most prevalent tachyarrhythmia in clinical practice, with very high cardiovascular morbidity and mortality with a high-cost impact in health systems. Currently, it is one of the main causes of stroke and subsequent heart failure and sudden death. miRNAs mediate in several processes involved in cardiovascular disease, including fibrosis and electrical and structural remodeling. Several studies suggest a key role of miRNAs in the course and maintenance of atrial fibrillation. In our study, we aimed to identify the differential expression of circulating miRNAs and their predictive value as biomarkers of recurrence in atrial fibrillation patients undergoing catheter pulmonary vein ablation. To this effect, 42 atrial fibrillation patients were recruited for catheter ablation. We measured the expression of 84 miRNAs in non-recurrent and recurrent groups (45.2%), both in plasma from peripheral and left atrium blood. Expression analysis showed that miRNA-451a is downregulated in recurrent patients. Receiver operating characteristic curve analysis showed that miR-451a in left atrium plasma could predict atrial fibrillation recurrence after pulmonary vein isolation. In addition, atrial fibrillation recurrence is positively associated with the increment of scar percentage. Our data suggest that miRNA-451a expression plays an important role in AF recurrence by controlling fibrosis and progression.

Circulating miR-499a and miR-125b as Potential Predictors of Left Ventricular Ejection Fraction Improvement after Cardiac Resynchronization Therapy.

Cardiac resynchronization therapy represents a therapeutic option for heart failure drug-refractory patients. However, due to the lack of success in 30% of the cases, there is a demand for an in-depth analysis of individual heterogeneity. In this study, we aimed to evaluate the prognostic value of circulating miRNA differences. Responder patients were defined by a composite endpoint of the presence of left ventricular reverse remodelling (a reduction ≥15% in telesystolic volume and an increment ≥10% in left ventricular ejection fraction). Circulating miRNAs signature was analysed at the time of the procedure and at a 6-month follow-up. An expression analysis showed, both at baseline and at follow-up, differences between responders and non-responders. Responders presented lower baseline expressions of miR-499, and at follow-up, downregulation of miR-125b-5p, both associated with a significant improvement in left ventricular ejection fraction. The miRNA profile differences showed a marked sensitivity to distinguish between responders and non-responders. Our data suggest that miRNA differences might contribute to prognostic stratification of patients undergoing cardiac resynchronization therapy and suggest that preimplant cardiac context as well as remodelling response are key to therapeutic success.

Conventional single-chamber pacemakers versus transcatheter pacing systems in a "real world" cohort of patients: A comparative prospective single-center study.

PURPOSE: Despite the developments in conventional transvenous pacemakers (VVI-PM), the procedure is still associated with significant complications. Although there are no prospective clinical trials that compared VVI-PM with transcatheter pacemaker systems (TPS). METHODS: This is a prospective, observational, single-center study that included all patients with an indication for a single-chamber pacemaker implant within a 4-year period. All clinical, ECG and echocardiographic characteristics at implant, electrical parameters, associated complications and mortality were analyzed. A Cox survival model and a Bayesian cohort analysis were performed for differences in complication rates between groups. RESULTS: There were 443 patients included (198 TPS and 245 VVI-PM). The mean age was 81.5 years (TPS group, 79.2 ± 6.6 years; VVI-PM group, 83.5 ± 8.9 years). There was a male predominance in TPS group (123, 62.1% vs. 67, 27.3%; p < 0.001). The presence of systolic dysfunction and renal insufficiency were more frequent in VVI-PM group than in TPS patients. Mean follow-up was 22.3 ± 15.9 months. In a multivariable paired data the TPS group presented fewer complications than VVI-PM group (HR = 0.39 [0.15-0.98], p-value 0.013), but major complications were not different (6, 3% vs 14, 5.6% respectively, p = 0.1761). There was no difference in the mortality rate between the groups. The TPS group had less risk than VVI-PM group to have a complication, with a 96% of probability. CONCLUSIONS: TPS patients had a lower overall complication rate than VVI-PM patients including matched-pair samples using a Bayesian analysis. These results confirm the safety profile of TPS in clinical practice.

Use of an angioplasty wire in transseptal puncture: A new application of an old technique.

OBJECTIVE: We wondered if a modification of the conventional transseptal puncture technique performed with an angioplasty wire could be useful in patients with contrast hypersensitivity or allergy-like reactions. METHODS: This study comprised our initial experience in 22 patients with atrial fibrillation who were scheduled for an electrophysiology study (EPS) and pulmonary vein ablation and who had a contraindication for iodinated contrast administration. RESULTS: Of the 22 patients, 16 were men and ages ranged from 27 to 74 years (mean 56 years). Overall successful transseptal access was achieved in all 22. A control echocardiogram was performed in all patients. There were no complications in any case and no significant differences were found from the conventional transseptal puncture technique regarding procedure or fluoroscopy time. CONCLUSIONS: A modification of the conventional transseptal puncture technique performed with fluoroscopy and EPS catheters for anatomical reference and an angioplasty wire is an option in cases with severe contrast hypersensitivity.

Respuesta al ECG de octubre de 2018 / Response to ECG, October 2018

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ECG de octubre de 2018 / ECG, October 2018

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Cardiac resynchronization therapy response in heart failure patients with different subtypes of true left bundle branch block.

PURPOSE: Left bundle branch block (LBBB) configuration has been described as a predictor of response to cardiac resynchronization therapy (CRT). We investigated whether different subtypes of true LBBB configuration could help select patients with better response and clinical outcome. METHODS: This retrospective study included 198 consecutive LBBB patients implanted with a CRT. True LBBB was defined using the Strauss and the Predict study criteria. Echocardiographic response was evaluated by the reduction in left ventricular end-systolic volume (LVESV) and the increase in left ventricular ejection fraction (LVEF). Clinical response was defined as an improvement in one category of the NYHA functional class. RESULTS: Patients with true LBBB had a greater improvement in both LVESV reduction (median = - 27.6%, interquartile range = [- 4.9, - 50.1]) and LVEF increase (median 10.8 ± 10) than those with non-true LBBB (- 19.7%, [16.7, - 48.0]) p = 0.04 and 5.1 ± 10, p = 0.03, respectively. No differences were exhibited between true LBBB Strauss group (- 26.7%, [- 11.0, - 46.9]) and true LBBB Predict group (- 26.6%, [- 15.9, - 39.4]). There were no statistically significant differences in the percentage of patients with clinical response, assessed by NYHA improvement, among all groups. In the Cox model for death, age, ischemic etiology, and ΔLVESV were independent predictors of mortality. True LBBB (Strauss + Predict) patients had a trend towards lower mortality than non-true LBBB [HR = 0.55, 95% CI = (0.22-1.15)], p = 0.08. In the Cox model for HF hospitalization, age, sex male, prior LVEF, and ΔLVESV were independent predictors. True LBBB (Strauss + Predict) patients had a significantly lower risk of developing HF hospitalization than those with non-true LBBB [0.45 (0.21-0.90)], p = 0.029. CONCLUSIONS: Patients with true LBBB, either Strauss or Predict criteria, had greater echocardiographic response and lower incidence of HF hospitalization than non-true LBBB when implanted with CRT.

Comparison and Validation of Recommended QT Interval Correction Formulas for Predicting Cardiac Arrhythmias in Patients With Advanced Heart Failure and Cardiac Resynchronization Devices.

QT interval prolongation is an important marker for the development of cardiac arrhythmias (CAs). Optimal methods to estimate QT/QTc intervals in patients with ventricular pacing (VP) and its correlation with CA have not been widely investigated. We aimed to validate the currently available formulas for QT determination during VP and to compare their abilities in predicting the occurrence of CA (atrial fibrillation [AF] and malignant ventricular arrhythmias [VAs] in patients with advanced heart failure and cardiac resynchronization therapy). Consecutive patients with advanced heart failure who underwent cardiac resynchronization therapy implantation between August 2001 and April 2015 were included in a retrospective study. Four proposed formulas for QT correction in VP rhythms were evaluated. One hundred eighty patients were enrolled. During 44 months of follow-up, 43 patients (37.7%) developed AF and 16 patients (8.9%) developed VA. There was no correlation between corrected QT increments and AF risk with any of the formulas for paced rhythms. Regarding VA, higher corrected QT values measured with Massachusetts' formula (QTcM) were found to have a higher risk of event (p = 0.036) (Beta = 1.012 [1.001 to 1.023]). Each 1 ms increase in QTc increased the probability of experiencing VA by 12‰. QTcM >444 was found to be a strong predictor of VA. In conclusion, there are significant differences in mean QTc interval measured by the currently advised formulas. QTc interval was not associated with AF in any of the formulas. Only the QTcM formula showed a significant stepwise increase in the risk of experiencing malignant VA.

Marcapasos transcatéter sin cables Micra. Resultados del implante y seguimiento a medio plazo en un centro / The micra leadless transcatheter pacemaker. implantation and mid-term follow-up results in a single center

Introducción y objetivos: Actualmente hay pocos estudios sobre el marcapasos sin cable (Micra) en la práctica clínica, especialmente con seguimientos > 6 meses. El objetivo es evaluar los parámetros eléctricos al implante y en el seguimiento, así como la seguridad de esta nueva técnica. Métodos: Estudio prospectivo y observacional en el que se incluyó a 30 pacientes consecutivos de edad ≥ 65 años con indicación de implante de marcapasos unicameral. Resultados: Se implantó exitosamente el Micra en los 30 pacientes incluidos. La media de edad era 79,4 ± 6,4 (66-89) años; 20 (66,6%) eran varones; 28 (93,3%) presentaban fibrilación auricular permanente; 1, taquicardia auricular y 1, ritmo sinusal. En 5 pacientes (16,6%) se realizó ablación del nódulo auriculoventricular en el mismo procedimiento (4 pacientes en fibrilación auricular rápida y 1 con taquicardia auricular); en 2 pacientes la indicación fue tras el implante percutáneo de válvula aórtica. En 23 (76,6%) el implante se realizó estando en tratamiento anticoagulante oral (INR máximo, 2,4). No hubo complicaciones mayores, salvo un derrame pericárdico moderado sin repercusión hemodinámica. El seguimiento medio fue de 5,3 ± 3,3 meses y 4 pacientes superaron el año de seguimiento. Los parámetros de estimulación fueron excelentes tanto en el implante como en el seguimiento a corto-medio plazo. Conclusiones: El implante de marcapasos sin cables es factible y seguro y presenta potenciales ventajas sobre los sistemas convencionales. Serán necesarios estudios con mayor seguimiento antes de generalizar su uso en la práctica clínica diaria (AU)

Introduction and objectives: Currently, studies on the leadless pacemaker (Micra) have mostly been limited to clinical trials with less than 6 months’ follow-up and they often fail to reflect real population outcomes. We sought to evaluate electrical parameters at implantation and chronologically during follow-up, as well as the safety of this new technique. Methods: This prospective, observational study included 30 consecutive patients, all ≥ 65 years, with an indication for single-chamber pacemaker implantation. Results: Successful implantation was accomplished in all patients referred for leadless implantation. The mean age was 79.4 ± 6.4 years (range, 66-89 years); 20 (66.6%) were men and 28 had permanent atrial fibrillation (93.3%); 1 had atrial tachycardia and 1 had sinus rhythm. Concomitant atrioventricular node ablation was performed immediately after implantation in 5 patients (16.6%), and implantation was performed after transcatheter aortic valve implantation in 2. The procedure was performed under an uninterrupted anticoagulation regimen (maximum INR 2.4) in 23 patients (76.6%). With the exception of 1 moderate pericardial effusion without tamponade, there were no severe complications. The mean follow-up was 5.3 ± 3.3 months and 4 patients had more than 1 year of follow-up. Sensing and pacing parameters were stable both at implantation and during the short- to mid-term follow-up. Conclusions Implantation of leadless pacemakers is feasible, safe and provides advantages over the conventional system. Further studies with longer follow-up periods will be needed before these devices become widely used in routine clinical practice (AU)

The Micra Leadless Transcatheter Pacemaker. Implantation and Mid-term Follow-up Results in a Single Center.

INTRODUCTION AND OBJECTIVES: Currently, studies on the leadless pacemaker (Micra) have mostly been limited to clinical trials with less than 6 months' follow-up and they often fail to reflect real population outcomes. We sought to evaluate electrical parameters at implantation and chronologically during follow-up, as well as the safety of this new technique. METHODS: This prospective, observational study included 30 consecutive patients, all ≥ 65 years, with an indication for single-chamber pacemaker implantation. RESULTS: Successful implantation was accomplished in all patients referred for leadless implantation. The mean age was 79.4±6.4 years (range, 66-89 years); 20 (66.6%) were men and 28 had permanent atrial fibrillation (93.3%); 1 had atrial tachycardia and 1 had sinus rhythm. Concomitant atrioventricular node ablation was performed immediately after implantation in 5 patients (16.6%), and implantation was performed after transcatheter aortic valve implantation in 2. The procedure was performed under an uninterrupted anticoagulation regimen (maximum INR 2.4) in 23 patients (76.6%). With the exception of 1 moderate pericardial effusion without tamponade, there were no severe complications. The mean follow-up was 5.3±3.3 months and 4 patients had more than 1 year of follow-up. Sensing and pacing parameters were stable both at implantation and during the short- to mid-term follow-up. CONCLUSIONS: Implantation of leadless pacemakers is feasible, safe and provides advantages over the conventional system. Further studies with longer follow-up periods will be needed before these devices become widely used in routine clinical practice.

Ablation of Inappropriate Sinus Tachycardia: A Systematic Review of the Literature.

OBJECTIVES: The goal of this study was to describe short- and long-term outcomes in all patients referred for inappropriate sinus tachycardia ablation, along with the potential complications of the intervention. BACKGROUND: Sinus node (SN) ablation/modification has been proposed for patients refractory to pharmacological therapy. However, available data derive from limited series. METHODS: The electronic databases MEDLINE, Embase, CINAHL, Cochrane, and Scopus were systematically searched (January 1, 1995-December 31, 2015). Studies were screened according to predefined inclusion and exclusion criteria. RESULTS: A total of 153 patients were included. Their mean age was 35.18 ± 10.02 years, and 139 (90.8%) were female. All patients had failed to respond to maximum tolerated doses of pharmacological therapy (3.5 ± 2.4 drugs). Mean baseline heart rates averaged 101.3 ± 16.4 beats/min according to electrocardiography and 104.5 ± 13.5 beats/min according to 24-h Holter monitoring. Two electrophysiological strategies were used, SN ablation and SN modification, with the latter being used more. Procedural acute success (using variably defined pre-determined endpoints) was 88.9%. Consistently, all groups reported high-output pacing from the ablation catheter to confirm absence of phrenic nerve stimulation before radiofrequency delivery. Need of pericardial access varied between 0% and 76.9%. Thirteen patients (8.5%) experienced severe procedural complications, and 15 patients (9.8%) required implantation of a pacemaker. At a mean follow-up interval of 28.1 ± 12.6 months, 86.4% of patients demonstrated successful outcomes. The symptomatic recurrence rate was 19.6%, and 29.8% of patients continued to receive antiarrhythmic drug therapy after procedural intervention. CONCLUSIONS: Inappropriate sinus tachycardia ablation/modification achieves acute success in the vast majority of patients. Complications are fairly common and diverse. However, symptomatic relief decreases substantially over longer follow-up periods, with a corresponding high recurrence rate.

Initial experience and treatment of atrial fibrillation using a novel irrigated multielectrode catheter: Results from a prospective two-center study.

BACKGROUND: PV electrical isolation has become the cornerstone of catheter ablation for the treatment of atrial fibrillation (AF). Several strategies have been proposed to achieve this goal. The aim of this study was to assess the efficacy and safety of AF ablation using a new circular irrigated multielectrode ablation catheter designed to achieve single-delivery pulmonary vein (PV) isolation. METHODS: Thirty-five patients with drug refractory paroxysmal AF and normal ejection fraction from two centers were prospectively enrolled in this study. All patients underwent PV isolation with an nMARQ circular irrigated multielectrode ablation catheter guided by an electroanatomic mapping system. Magnetic resonance imaging was performed to exclude PV stenosis. RESULTS: PV isolation was achieved in 138 of 140 (98.57%) targeted veins. The mean procedure time was 79.5 min (SD 39.3 min). During a mean follow up of 16.8±2.8 months, 27 of 35 (77.2%) patients were free of AF. No PV narrowing was observed. One case of pericardial effusion due to perforation of the left atrial free wall during catheter manipulation did occur. CONCLUSIONS: PV isolation with a circular irrigated multielectrode ablation catheter is a feasible technique with a high acute success rate. The majority of patients remained asymptomatic during the midterm follow-up period. PV stenosis was not detected. While only a single serious adverse event occurred, this technique׳s safety profile should be tested in larger studies.

Is HATCH score a reliable predictor of atrial fibrillation after cavotricuspid isthmus ablation for typical atrial flutter?

OBJECTIVE: We determined the effectiveness of the HATCH score in patients with typical atrial flutter (AFl) undergoing cavotricuspid isthmus (CTI) ablation to predict long-term atrial fibrillation (AF). METHODS: We conducted an observational retrospective single-center cohort study including all patients admitted to our hospital for a CTI ablation between 1998 and 2010. The patients were divided into four categories: 1) new-onset AF (no prior AF and AF during follow-up (FU)); 2) old AF (prior AF and no AF during FU); 3) prior and post AF (AF prior and post CTI ablation); and 4) no AF. RESULTS: Four hundred and eight patients were included. In patients without prior AF, the hazard ratio (HR) for new-onset AF during FU was 0.98 (CI 95%: 0.65-1.50; p = 0.95) and 1.00 (CI 95%: 0.57-1.77; p = 0.98) for HATCH ≥ 2 and HATCH ≥ 3, respectively. In patients with prior AF, the HR for AF was 1.41 (CI 95%: 0.87-2.28; p = 0.17) and 1.79 (CI 95%: 0.96-3.35; p = 0.06), for HATCH ≥ 2 and HATCH ≥ 3, respectively. Left atrial enlargement was positively correlated with the occurrence of AF during FU, especially in the subgroup without prior AF, which had a HR of 2.44 (CI 95%: 1.35-4.40; p = 0.003), a HR of 2.88 (CI 95%: 1.36-6.10; p = 0.006) and a HR of 3.68 (CI 95%: 1.71-7.94; p = 0.001), for slight, moderate and severely dilated left atrial dimension, respectively, compared with a normal value. CONCLUSIONS: HATCH score did not predict AF in patients with typical AFl who underwent CTI ablation. Basal left atrium dimension could help predict new-onset AF.

Comparison between CHA2DS2-VASc and the new R2CHADS2 and ATRIA scores at predicting thromboembolic event in non-anticoagulated and anticoagulated patients with non-valvular atrial fibrillation.

BACKGROUND: Accurate risk stratification is considered the first and most important step in the management of patients with non-valvular atrial fibrillation (NVAF). We compared the performance of the widely used CHA2DS2-VASc and the recently developed R2CHADS2 and ATRIA scores, for predicting thromboembolic (TE) event in either non-anticoagulated or anticoagulated patients with NVAF. METHODS: The non-anticoagulated cohort was comprised of 154 patients, whereas 911 patients formed the cohort of patients on vitamin-K-antagonist. The scores were computed using the criteria mentioned in their developmental cohorts. Measures of performance for the risk scores were evaluated at predicting TE event. RESULTS: In the non-anticoagulated cohort, 9 TE events occurred during 11 ± 2.7 months. CHA2DS2-VASc showed significant association with TE occurrence: hazard ratio (HR) = 1.58 (95 % confidence interval [95 % IC] 1.01-2.46), but R2CHADS2 and ATRIA did not (HR = 1.23 (95 % CI 0.86-1.77) and 1.20 (95 % CI 0.93-1.56), respectively. In the anticoagulated cohort, after 10 ± 3 months of follow up, 18 TE events were developed. In that cohort, the three scores showed similar association with TE risk: HR = 1.49 (95 % CI 1.13-1.97), 1.41 (95 % CI 1.13-1.77) and 1.37 (95 % CI 1.12-1.66) for CHA2DS2-VASc, R2CHADS2 and ATRIA, respectively. In both cohorts, no TE event occurred in patients classified in the low risk category according to CHA2DS2-VASc or R2CHADS2. CONCLUSIONS: In this study of NVAF patients, CHA2DS2-VASc has better association with TE events than the new R2CHADS2 and ATRIA risk scores in the non-anticoagulated cohort. CHA2DS2-VASc and R2CHADS2 can identify patients at truly low risk regardless of the anticoagulation status.