Long-Term Survival After Implantable Cardiac Defibrillator Therapy According to Sex: A Propensity Matched Study.

Background: Whether the sex factor influences the benefit of the implantable cardioverter-defibrillator (ICD) for the prevention of sudden death remains a subject of debate. Using a prospective registry, we sought to analyze the survival and time to first ICD therapy according to sex. Materials and Methods: Retrospective analysis of a prospective cohort of patients undergoing an ICD implant from 2008 to 2019. Data about time to first appropriate therapy, type of therapy administered, and incidence and causes of mortality were collected. Results: Among 756 ICD patients, 150 (19.8%) were women. Women were younger (51 ± 15 years vs. 61 ± 14 years; p < 0.001) and showed a lower rate of ischemic cardiomyopathy (23% vs. 54%; p < 0.001) and atrial fibrillation (12% vs. 19%; p = 0.05). Women had higher left ventricular ejection fraction (39% ± 17% vs. 35% ± 13%) and showed more frequently left bundle branch block (39% vs. 28%, p = 0.027). The rate of primary prevention (68% vs. 59.6%; p = 0.058) and cardiac resynchronization therapy (27% vs. 19%, p = 0.02) were higher in women. After a median follow-up of 46 months (3382 patient-years), the incidence of both the primary combined endpoint of mortality/transplant (20% vs. 29%; logrank = 0.031) and ICD therapies (27% vs. 34%; p = 0.138) were lower in women. According to the propensity score-matching analysis, no differences were observed between both sexes with respect to the incidence of mortality/transplant (24.8% vs. 28.6%; logrank = 0.88), ICD therapies (28% vs. 27%; logrank = 0.17), and main cause of death (heart failure [HF]). Conclusions: The clinical characteristics at the moment of ICD implant are different between sexes. After adjusting them, both sexes equally benefit from the ICD. HF is the main cause of mortality both in men and women.

Spanish Results of the Second European Cardiac Resynchronization Therapy Survey (CRT-Survey II).

INTRODUCTION AND OBJECTIVES: We describe the results for Spain of the Second European Cardiac Resynchronization Therapy Survey (CRT-Survey II) and compare them with those of the other participating countries. METHODS: We included patients undergoing CRT device implantation between October 2015 and December 2016 in 36 participating Spanish centers. We registered the patients' baseline characteristics, implant procedure data, and short-term follow-up information until hospital discharge. RESULTS: Implant success was achieved in 95.9%. The median [interquartile range] annual implantation rate by center was significantly lower in Spain than in the other participating countries: 30 implants/y [21-50] vs 55 implants/y [33-100]; P=.00003. In Spanish centers, there was a lower proportion of patients ≥ 75 years (27.9% vs 32.4%; P=.0071), a higher proportion in New York Heart Association functional class II (46.9% vs 36.9%; P <.00001), and a higher percentage with electrocardiographic criteria of left bundle branch block (82.9% vs 74.6%; P <.00001). The mean length of hospital stay was significantly lower in Spanish centers (5.8±8.5 days vs 6.4±11.6; P <.00001). Spanish patients were more likely to receive a quadripolar LV lead (74% vs 56%; P <.00001) and to be followed up by remote monitoring (55.8% vs 27.7%; P <.00001). CONCLUSIONS: The CRT-Survey II shows that, compared with other participating countries, fewer patients in Spain aged ≥ 75 years received a CRT device, while more patients were in New York Heart Association functional class II and had left bundle branch block. In addition, the length of hospital stay was shorter, and there was greater use of quadripolar LV leads and remote CRT monitoring.

Repeated procedures at the generator pocket are a determinant of implantable cardioverter-defibrillator infection.

BACKGROUND: Rates of cardiac-device infections have increased in recent years, but the current incidence and risk factors for infection in patients with implantable cardioverter-defibrillators (ICDs) are not well known. HYPOTHESIS: The increasing number of ICD infections is related to accumulated pocket manipulations over time. METHODS: This single-center, prospective study included patients that underwent ICD implantation from 2008 to 2015. The endpoint was time to infection. Multivariate analysis was performed to identify independent risk factors related to infection. RESULTS: The study included a total of 570 patients, of whom 419 (73.5%) underwent a first implantation. Mean age was 59 ± 14 years, and 80% were male. During a median follow-up of 36 months (interquartile range, 18-61 months; 1887 patient-years), infection was identified in 26 patients (4.56%), an incidence of 14.9 × 1000 patient-years. Median time to infection was 9.7 months (interquartile range, 1.35-23.4 months), and 38.5% were late infections (beyond 12 months of follow-up). In patients with replacement implants, the incidence was 3-fold higher than in first implantations (27.7 vs 9.1 × 1000 patient-years; P = 0.002). Cox regression identified 2 independent predictors of ICD infection: cumulative number of interventions at the generator pocket (hazard ratio: 1.92, 95% confidence interval: 1.42-2.6, P < 0.001) and pocket hematoma (hazard ratio: 7.0, 95% confidence interval: 2.7-17.9, P < 0.0001). CONCLUSIONS: The incidence of infection in ICD patients is greater than previously reported, largely due to late infections. Each new cumulative intervention at the same generator pocket nearly doubles the risk of infection.

Impact of Contact Force Monitoring in Acute Pulmonary Vein Isolation Using an Anatomic Approach. A Randomized Study.

BACKGROUND: The impact of contact force (CF) monitoring in pulmonary vein (PV) isolation after a circumferential anatomic ablation (CAA) is unknown. We analyze the usefulness of CF monitoring in acute PV isolation and procedure parameters using a CAA. METHODS: Fifty patients with paroxysmal atrial fibrillation were randomized into CF-on (CF >10 grams; n = 25) or CF-off (CF blinded; n = 25) groups. We performed a first round of CAA with a ThermoCool(®) SmartTouch(®) catheter blinded to the LASSO(®) catheter (Biosense Webster, Diamond Bar, CA, USA), with radiofrequency (RF) lesions tagged with the VisiTag(™) Module. After the CAA, each PV was reviewed with the LASSO(®) catheter recording the segments with gaps. RESULTS: All the PVs were isolated with a CAA in 20 patients of the CF-on versus eight of the CF-off (P = 0.001). Of the 45 segments with gaps in the left PVs, 38 were from the CF-off (P = 0.0001). Of the eight segments with gaps in the right PVs, seven were from the CF-off (P = 0.06). The CF in the left PVs was higher in the CF-on (16.3 ± 3.2 grams vs 10.5 ± 4.3 grams; P = 0.0001) and similar in the right PVs (17.6 ± 3.6 grams vs 15.2 ± 5.3 grams; P = 0.08). All of the gaps were closed with additional RF LASSO(®) -guided touch-up. Procedure and fluoroscopy times were shorter in the CF-on (139 ± 24 minutes vs 157 ± 32 minutes and 20 ± 6 minutes vs 24 ± 7 minutes; both P = 0.039). At 12 months the patients free of AF recurrence was 84% CF-on versus 75% CF-off (log-rank P = 0.4) [corrected]. CONCLUSIONS: In paroxysmal atrial fibrillation, a CAA guided by CF reduces PV gaps and shortens the procedure parameters at the expense of the left PVs.

A simple surgical technique to prevent atrial reentrant tachycardia in surgery for congenital heart disease†.

OBJECTIVES: To present and test a simple surgical technique that may prevent atrial reentrant tachycardia following surgery for congenital heart disease. This arrhythmia is one of the commonest long-term complications of such a surgery. It may occur many years (even decades) after the operation. It is usually explained as a late consequence of right atriotomy, which is an inherent component of many operations for congenital heart disease. Right atriotomy results in a long scar on the right atrial myocardium. This scar, as any scar, is a barrier to electrical conduction, and macro-reentrant circuits may form around it, causing reentrant tachycardia. However, this mechanism may be counterchecked and neutralized by our proposed method, which prevents reentrant circuits around right atriotomy scars. METHODS: The proposed method is implemented after termination of cardiopulmonary bypass and tying the venous purse-strings. It consists of constructing a full-thickness suture line on the intact right atrial wall from the inferior vena cava (IVC) (a natural conduction barrier) to the atriotomy incision. This suture line is made to cross the venous cannulation sites if these are on the atrial myocardium (rather than being directly on the venae cavae). Thus, the IVC, atriotomy and cannulation sites are connected to each other in series by a full-thickness suture line on the atrial wall. If this suture line becomes a conduction barrier, it would prevent reentrant circuits around right atrial scars. This was tested in 13 adults by electroanatomical mapping. All 13 patients had previously undergone right atriotomy for atrial septal defect closure: 8 of them with the addition of the proposed preventive suture line (treatment group) and 5 without (control group). RESULTS: In all 13 cases, the atriotomy scar was identified as a barrier to electrical conduction with electrophysiological evidence of fibrosis (scarring). In the 8 patients with the proposed suture line, this had also become a scar and a complete conduction barrier. In the 5 patients without this suture line, there was free electrical conduction between the IVC and atriotomy scar. CONCLUSIONS: The proposed suture line becomes a scar and conduction barrier. Therefore, it would prevent reentrant circuits around atrial scars and their consequent arrhythmias.

[Clinical value of N-terminal pro-B-type natriuretic peptide measurement in the follow up of pulmonary vein ablation]. / Utilidad del fragmento N-terminal del péptido natriurético cerebral en el seguimiento de la ablación de venas pulmonares.

BACKGROUND AND OBJECTIVE: N-terminal pro-B-type natriuretic peptide (NT-proBNP) correlates with burden of arrhythmia in atrial fibrillation (AF) patients. Our objective is to validate the usefulness of the measurement of NT-pro-BNP to determine the success of AF ablation in a long term follow up. PATIENTS AND METHODS: Prospective observational study in which 75 patients with preserved systolic function (81% men; mean age (SD) 52 (9) years; 58.7% paroxysmal) underwent circumferential pulmonary vein isolation. Determination of NT-proBNP baseline and one year after the procedure was performed. The relation between NT-proBNP levels and the success of the procedure is analyzed. RESULTS: In the follow up 53 (70.7%) patients remained free of recurrences. A>30% decrease of NT-proBNP levels identified success with a sensitivity of 79.2%, specificity 81.8%, positive predictive value 91.3% and negative 62% (area under ROC curve 0.84, 95% confidence interval 73-95.6). This reduction was associated with a decrease in left atrial volume and pressure and the presence of diastolic dysfunction (all P<.05). CONCLUSIONS: The decrease of NT-proBNP levels in patients undergoing AF ablation is useful as a marker of success in the follow up and is associated with hemodynamic improvement.

Reverse atrial remodeling following pulmonary vein isolation: the importance of the body mass index.

BACKGROUND: Pulmonary vein isolation (PVI) causes a reduction in left atrium size that is attributable to reverse atrial remodeling (RAR). The objective of this study was to identify predictors of RAR and determine its association with other parameters of improvement in cardiac function. METHODS: It is a prospective study with 74 patients (52 ± 9 years old, 81% male), and 51% of patients had paroxysmal atrial fibrillation. Patients were serially assessed with transthoracic echocardiography; plasma N-terminal B-type natriuretic peptide (NT-proBNP); and high-sensitivity C-reactive protein levels at baseline and 3, 6, and 12 months following the PVI. RAR was defined as a reduction in the left atrial volume index (LAV-index) >10% from baseline at the end of follow-up. A multivariate analysis was conducted to identify predictors of RAR. RESULTS: The LAV-index decreased significantly during follow-up in the entire population (P = 0.0005). RAR (experienced by 63.5% of the patients) was more frequent (76% vs. 42%; P = 0.004) and pronounced (reduction 16.65 ± 14% vs. 8 ± 14%; P = 0.015) in patients with a successful ablation (46 of 74 patients, 62.2%). Only patients with RAR showed significant improvement in NT-proBNP levels (P = 0.0001), systolic function (P = 0.035), and diastolic function (P = 0.005). Multivariable analysis revealed that a successful ablation (odds ratio [OR] = 4.6; 95% confidence interval [CI] 1.46-14.68; P = 0.009), LAV-index (OR = 1.15; 95% CI 1.03-1.2; P = 0.021), and patient's body mass index (OR = 0.84; 95% CI 0.74-0.96; P = 0.012) were independent predictors of RAR. CONCLUSIONS: Successful PVI ablation is the main predictor of RAR that is associated with other parameters of improvement in cardiac function. The patient's body mass index may have a negative effect on RAR.

Paroxysmal atrial fibrillation burden before and after pulmonary veins isolation: an observational study through a subcutaneous leadless cardiac monitor.

AIMS: Data on the success rate of ablation in atrial fibrillation (AF) are controversial. Our hypothesis is that the efficacy must be evaluated considering the AF burden (AFB) before the procedure. Moreover, the clinical significance of early recurrence (ERAT) of AF or atrial tachyarrhythmias (AT) is debatable. The aim is to describe the outcome of pulmonary vein isolation in paroxysmal AF through a subcutaneous cardiac monitor (ICM) implanted before the procedure. METHODS: Using CARTO 3, circumferential lesions around the pulmonary veins were placed. The study endpoint was the first documented recurrence of AF/AT by ICM after the blanking period (3 months). AFB (percentage of time in AF/AT) was collected every month before and after the procedure during the 12-month follow-up. RESULTS: The ICM was implanted 94 ± 23 days before the procedure in 35 patients with paroxysmal AF (54 ± 11 years, refractory to 1.8 ± 0.6 antiarrhythmic drugs). Cumulative AFB before the procedure and after the blanking period was 2.5% (1-5%) versus 0% (0-0.25%), P < 0.001. Twenty patients (57.1%) were free of documented AF/AT recurrence, 5 patients (14.2%) reduced the AFB 90%, 6 patients (17.1%) continued the same, and 4 patients (11.4%) increased the AFB 90% for AT. The success rate with second procedure was 71.4%. All 13 patients with ERAT had recurrence after the blanking period. CONCLUSIONS: The outcome of pulmonary vein isolation in patients with paroxysmal AF is well documented by an ICM. The success rate is dependent of the previous AFB that can be randomly variable and lower than expected. ERATs predict late recurrence.

Electroanatomical mapping of the esophagus in circumferential pulmonary vein isolation.

A virtual reconstruction of the geometry of the esophagus was produced using an electroanatomical mapping system and a specially designed catheter in 20 consecutive patients undergoing circumferential pulmonary vein isolation. The course of the esophagus, its motion and its proximity to the predicted lines of application of radiofrequency energy to the left atrium were evaluated. Thirteen (65%) were located centrally (i.e. >10 mm from the ostium), 69 (30%) laterally (i.e. <10 mm from the ostium) and 1 (5%) obliquely. No movements larger than 10 mm occurred during the procedure. Conventionally, the radiofrequency ablation lines are configured such that, in 50% of patients, radiofrequency energy is applied to areas adjacent to the esophagus. In order to decrease the potential risk associated with this procedure, either the position of the ablation lines was altered to bring them closer to the ostium (by 15%) or the power was reduced (by 35%). Although there was no significant movement of the esophagus during the ablation procedure, its course was variable. Consequently, the ablation strategy was altered in a substantial number of cases.

Unusual tachycardia association in a patient without structural heart disease.

We report an unusual association of persistent atrial flutter and bundle branch re-entrant ventricular tachycardia in a young patient without structural heart disease. Atrial flutter masked the infra-Hisian conduction disease, was fundamentally dependent on a long PR interval, and could be a possible trigger of ventricular tachycardia.

Three-dimensional impedance mapping as an aid to circumferential pulmonary vein isolation in paroxysmal atrial fibrillation.

During circumferential pulmonary vein isolation, radiofrequency lesions are created in the transition zone between the left atrium and the pulmonary veins, outside the ostia, to avoid stenosis. Three-dimensional impedance maps were constructed for 25 patients with paroxysmal atrial fibrillation. In the first 15 patients, impedance was measured inside the pulmonary veins (165.4 +/- 7.5 Omega), the ostium (141.6 +/- 7.3 Omega) and the left atrium (131.09 +/- 8.3 Omega). An impedance of 136 Omega identified the outer limit of the atrium (area under the receiver operating characteristic curve, 0.85). In the subsequent 10 patients, a single operator who was blinded to the anatomic position of the catheter tip was able to determine, by impedance measurement alone, whether the point targeted for radiofrequency ablation was in the left atrium or the ostium of the pulmonary vein. The positive predictive value for identifying the left atrium was 91% and the negative predictive value was 73%. In patients with paroxysmal atrial fibrillation, three-dimensional impedance mapping was helpful in guiding circumferential pulmonary vein isolation.

Radiofrequency catheter ablation of an orthodromic tachycardia in a patient with single ventricle.

Radiofrequency catheter ablation of a recurrent orthodromic tachycardia was performed in a 10-year-old child with single ventricle and bidirectional Glenn procedure before a Fontan operation. Identification of a His bundle electrogram was achieved at the postero-inferior atrioventricular (AV) groove by the inferior vena cava route, and electrophysiological demonstration of a concealed accessory pathway-mediated tachycardia was possible when a ventricular extrastimuli given during the His bundle refractoriness showed advancement of the atrium. A single energy application during tachycardia in the right antero-superior region of the AV groove resulted in the definitive interruption of the accessory pathway.

Documented exercise-induced cardiac arrest in a paediatric patient with hypertrophic cardiomyopathy.

A paediatric patient with hypertrophic cardiomyopathy (HCM) presented cardiac arrest due to ventricular fibrillation. Ventricular arrhythmias were not induced in an electrophysiological study, but an implantable cardioverter defibrillator (ICD) was implanted. Nine months later, the child experienced a recurrence of cardiac arrest during exercise, which was successfully treated with a defibrillator shock from the device. Analysis of the stored electrograms demonstrated ventricular fibrillation of abrupt onset following sinus tachycardia. The risk factors and the potential mechanism leading to recurrent cardiac arrest in this case are discussed. This report supports implantation of an ICD as a life-saving therapeutic approach not only for adults but also for children with HCM at high risk.