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.

Cryoballoon Ablation for Persistent and Paroxysmal Atrial Fibrillation: Procedural Differences and Results from the Spanish Registry (RECABA).

Introduction: Cryoballoon ablation (CBA) has become a standard treatment for paroxysmal atrial fibrillation (PaAF) but limited data is available for outcomes in patients with persistent atrial fibrillation (PeAF). Methods: We analyzed the first 944 patients included in the Spanish Prospective Multi-center Observation Post-market Registry to compare characteristics and outcomes of patients undergoing CBA for PeAF versus PaAF. Results: A total of 944 patients (57.8 ± 10.4 years; 70.1% male) with AF (27.9% persistent) were prospectively included from 25 centers. PeAF patients were more likely to have structural heart disease (67.7 vs. 11.4%; p < 0.001) and left atrium dilation (72.6 vs. 43.3%; p < 0.001). CBA of PeAF was less likely to be performed under general anesthesia (10.7 vs. 22.2%; p < 0.001), with an arterial line (32.2 vs. 44.6%; p < 0.001) and assisted transeptal puncture (11.9 vs. 17.9%; p = 0.025). During an application, PeAF patients had a longer time to −30 °C (35.91 ± 14.20 vs. 34.93 ± 12.87 s; p = 0.021) and a colder balloon nadir temperature during vein isolation (−35.04 ± 9.58 vs. −33.61 ± 10.32 °C; p = 0.004), but received fewer bonus freeze applications (30.7 vs. 41.1%; p < 0.001). There were no differences in acute pulmonary vein isolation and procedure-related complications. Overall, 76.7% of patients were free from AF recurrences at 15-month follow-up (78.9% in PaAF vs. 70.9% in PeAF; p = 0.09). Conclusions: Patients with PeAF have a more diseased substrate, and CBA procedures performed in such patients were more simplified, although longer/colder freeze applications were often applied. The acute efficacy/safety profile of CBA was similar between PaAF and PeAF patients, but long-term results were better in PaAF patients.

Long-term prognosis of women with Brugada syndrome and electrophysiological study.

BACKGROUND: A male predominance in Brugada syndrome (BrS) has been widely reported, but scarce information on female patients with BrS is available. OBJECTIVE: The purpose of this study was to investigate the clinical characteristics and long-term prognosis of women with BrS. METHODS: A multicenter retrospective study of patients diagnosed with BrS and previous electrophysiological study (EPS) was performed. RESULTS: Among 770 patients, 177 (23%) were female. At presentation, 150 (84.7%) were asymptomatic. Females presented less frequently with a type 1 electrocardiographic pattern (30.5% vs 55.0%; P <.001), had a higher rate of family history of sudden cardiac death (49.7% vs 29.8%; P <.001), and had less sustained ventricular arrhythmias (VAs) on EPS (8.5% vs 15.1%; P = .009). Genetic testing was performed in 79 females (45% of the sample) and was positive in 34 (19%). An implantable cardioverter-defibrillator was inserted in 48 females (27.1%). During mean (± SD) follow-up of 122.17 ± 57.28 months, 5 females (2.8%) experienced a cardiovascular event compared to 42 males (7.1%; P = .04). On multivariable analysis, a positive genetic test (18.71; 95% confidence interval [CI] 1.82-192.53; P = .01) and atrial fibrillation (odds ratio 21.12; 95% CI 1.27-350.85; P = .03) were predictive of arrhythmic events, whereas VAs on EPS (neither with 1 or 2 extrastimuli nor 3 extrastimuli) were not. CONCLUSION: Women with BrS represent a minor fraction among patients with BrS, and although their rate of events is low, they do not constitute a risk-free group. Neither clinical risk factors nor EPS predicts future arrhythmic events. Only atrial fibrillation and positive genetic test were identified as risk factors for future arrhythmic events.

Sex-Specific Ventricular Arrhythmias and Mortality in Cardiac Resynchronization Therapy Recipients.

OBJECTIVES: The study goal was to examine whether there are sex-related differences in the incidence of ventricular arrhythmias and mortality in CRT-defibrillator (CRT-D) recipients. BACKGROUND: Few studies have evaluated sex-related benefits of cardiac resynchronization therapy (CRT). Moreover, data on sex-related differences in the occurrence of ventricular tachyarrhythmias in this population are limited. METHODS: A multicenter retrospective study was conducted in 460 patients (355 male subjects and 105 female subjects) from the UMBRELLA (Incidence of Arrhythmia in Spanish Population With a Medtronic Implantable Cardiac Defibrillator Implant) national registry. Patients were followed up through remote monitoring after the first implantation of a CRT-D during a median follow-up of 2.2 ± 1.0 years. Sex differences were analyzed in terms of ventricular arrhythmia-treated incidence and death during the follow-up period, with a particular focus on primary prevention patients. RESULTS: Baseline New York Heart Association functional class was worse in women compared with that in men (67.0% of women in New York Heart Association functional class III vs. 49.7% of men; p = 0.003), whereas women had less ischemic cardiac disease (20.8% vs. 41.7%; p < 0.001). Female sex was an independent predictor of ventricular arrhythmias (hazard ratio: 0.40; 95% confidence interval: 0.19 to 0.86; p = 0.020), as well as left ventricular ejection fraction and nonischemic cardiomyopathy. Mortality in women was one-half that of men, although events were scarce and without significant differences (2.9% vs. 5.6%; p = 0.25). CONCLUSIONS: Women with left bundle branch block and implanted CRT have a lower rate of ventricular tachyarrhythmias than men. All-cause mortality in patients is, at least, similar between female and male subjects.

Personalized monitoring of electrical remodelling during atrial fibrillation progression via remote transmissions from implantable devices.

AIMS: Atrial electrical remodelling (AER) is a transitional period associated with the progression and long-term maintenance of atrial fibrillation (AF). We aimed to study the progression of AER in individual patients with implantable devices and AF episodes. METHODS AND RESULTS: Observational multicentre study (51 centres) including 4618 patients with implantable cardioverter-defibrillator +/-resynchronization therapy (ICD/CRT-D) and 352 patients (2 centres) with pacemakers (median follow-up: 3.4 years). Atrial activation rate (AAR) was quantified as the frequency of the dominant peak in the signal spectrum of AF episodes with atrial bipolar electrograms. Patients with complete progression of AER, from paroxysmal AF episodes to electrically remodelled persistent AF, were used to depict patient-specific AER slopes. A total of 34 712 AF tracings from 830 patients (87 with pacemakers) were suitable for the study. Complete progression of AER was documented in 216 patients (16 with pacemakers). Patients with persistent AF after completion of AER showed ∼30% faster AAR than patients with paroxysmal AF. The slope of AAR changes during AF progression revealed patient-specific patterns that correlated with the time-to-completion of AER (R2 = 0.85). Pacemaker patients were older than patients with ICD/CRT-Ds (78.3 vs. 67.2 year olds, respectively, P < 0.001) and had a shorter median time-to-completion of AER (24.9 vs. 93.5 days, respectively, P = 0.016). Remote transmissions in patients with ICD/CRT-D devices enabled the estimation of the time-to-completion of AER using the predicted slope of AAR changes from initiation to completion of electrical remodelling (R2 = 0.45). CONCLUSION: The AF progression shows patient-specific patterns of AER, which can be estimated using available remote-monitoring technology.

Safety threshold of R-wave amplitudes in patients with implantable cardioverter defibrillator.

OBJECTIVE: A safety threshold for baseline rhythm R-wave amplitudes during follow-up of implantable cardioverter defibrillators (ICD) has not been established. We aimed to analyse the amplitude distribution and undersensing rate during spontaneous episodes of ventricular fibrillation (VF), and define a safety amplitude threshold for baseline R-waves. METHODS: Data were obtained from an observational multicentre registry conducted at 48 centres in Spain. Baseline R-wave amplitudes and VF events were prospectively registered by remote monitoring. Signal processing algorithms were used to compare amplitudes of baseline R-waves with VF R-waves. All undersensed R-waves after the blanking period (120 ms) were manually marked. RESULTS: We studied 2507 patients from August 2011 to September 2014, which yielded 229 VF episodes (cycle length 189.6±29.1 ms) from 83 patients that were suitable for R-wave comparisons (follow-up 2.7±2.6 years). The majority (77.6%) of VF R-waves (n=13953) showed lower amplitudes than the reference baseline R-wave. The decrease in VF amplitude was progressively attenuated among subgroups of baseline R-wave amplitude (≥17; ≥12 to <17; ≥7 to <12; ≥2.2 to <7 mV) from the highest to the lowest: median deviations -51.2% to +22.4%, respectively (p=0.027). There were no significant differences in undersensing rates of VF R-waves among subgroups. Both the normalised histogram distribution and the undersensing risk function obtained from the ≥2.2 to <7 mV subgroup enabled the prediction that baseline R-wave amplitudes ≤2.5 mV (interquartile range: 2.3-2.8 mV) may lead to ≥25% of undersensed VF R-waves. CONCLUSIONS: Baseline R-wave amplitudes ≤2.5 mV during follow-up of patients with ICDs may lead to high risk of delayed detection of VF. TRIAL REGISTRATION NUMBER: NCT01561144; results.

Registro Español de Marcapasos. X Informe Oficial de la Sección de Estimulación Cardiaca de la Sociedad Española de Cardiología (2012) / Spanish Pacemaker Registry. 10th Official Report of the Spanish Society of Cardiology Working Group on Cardiac Pacing (2012)

Introducción y objetivos. Se describe el análisis de la actividad con implantes y recambios de marcapasos remitidos en 2012 al Registro Español de Marcapasos, con especial referencia a la selección de los modos de estimulación. Método. Se basa en la información que aporta la Tarjeta Europea del Paciente Portador de Marcapasos. Resultados. Se recibieron datos de 115 centros hospitalarios, con un total de 12.856 tarjetas. Se estima un consumo de generadores convencionales y resincronizadores de 745,8 y 53,1 unidades por millón de habitantes, respectivamente. Se utilizan cables con sistema de fijación activa en más del 70% de los casos, el 20% con protección para resonancia magnética. La indicación electrocardiográfica más frecuente es el bloqueo auriculoventricular (56%). Se estimula en modo VVI /R al 28% de los pacientes con enfermedad del nódulo sinusal. Conclusiones. Se estabiliza el uso de marcapasos convencionales y disminuyen los implantes de resincronizadores. El uso del sistema de fijación activa de los cables ya es mayoritario. Se confirma la mayor incidencia de implantes en los varones y a menor edad por mayor frecuencia de trastornos de conducción. La edad influye en la adecuación del modo de estimulación (AU)

Introduction and objectives. Our aim was to analyze the pacemaker implantations and replacements reported to the Spanish Pacemaker Registry in 2012 with special reference to the selection of pacing modes. Method. The analysis was based on information provided by the European Pacemaker Patient Identification Card. Results. Data were received from 115 hospitals, with a total of 12 856 cards. An estimated 745.8 pacemaker generators and 53.1 resynchronization devices were implanted per million population. Active fixation leads were implanted in more than 70% of the patients; of these leads, more than 20% were safe for use with magnetic resonance. The most common electrocardiographic indication for pacemaker implantation was atrioventricular block (56%). In all, 28% of the patients with sick sinus syndrome were paced in VVIR mode. Conclusions. The use of conventional pacemakers remained stable, whereas the implantation of resynchronization devices increased. Active fixation leads are now employed in most patients. The findings of this study confirm the higher incidence of implantation in men and at an earlier age due to the higher rate of conduction disorders. Age is a factor that influences the choice of the appropriate pacing mode (AU)

Spanish pacemaker registry. 10th official report of the Spanish Society of Cardiology Working Group on Cardiac Pacing (2012).

INTRODUCTION AND OBJECTIVES: Our aim was to analyze the pacemaker implantations and replacements reported to the Spanish Pacemaker Registry in 2012 with special reference to the selection of pacing modes. METHOD: The analysis was based on information provided by the European Pacemaker Patient Identification Card. RESULTS: Data were received from 115 hospitals, with a total of 12 856 cards. An estimated 745.8 pacemaker generators and 53.1 resynchronization devices were implanted per million population. Active fixation leads were implanted in more than 70% of the patients; of these leads, more than 20% were safe for use with magnetic resonance. The most common electrocardiographic indication for pacemaker implantation was atrioventricular block (56%). In all, 28% of the patients with sick sinus syndrome were paced in VVIR mode. CONCLUSIONS: The use of conventional pacemakers remained stable, whereas the implantation of resynchronization devices increased. Active fixation leads are now employed in most patients. The findings of this study confirm the higher incidence of implantation in men and at an earlier age due to the higher rate of conduction disorders. Age is a factor that influences the choice of the appropriate pacing mode.

Experiencia inicial con la extracción de electrodos de marcapasos y desfibrilador asistida con láser excimer / Initial experience with excimer laser-assisted pacemaker and defibrillator lead extraction

La extracción de electrodos de marcapasos y/o desfibriladores de larga evolución puede ser una técnica exigente. Presentamos los resultados de la extracción asistida por láser excimer de los primeros 44 electrodos en 25 pacientes, con una mediana de tiempo de electrodo implantado de 7 (2-20) años. Las indicaciones para la extracción fueron fractura de electrodo en 17 casos, decúbito de bolsa en 4, bacteriemia en 2 y endocarditis sobre electrodo en 2 casos. Se logró la extracción completa de 43 electrodos (97,7%), mientras que en 1 caso se abandonó la porción distal de menos de 4 cm del electrodo. No se produjo mortalidad intrahospitalaria. El láser excimer se presenta como una alternativa segura y eficaz para la extracción de electrodos de marcapasos o desfibrilador, con resultados excelentes en nuestra serie (AU)

Explantation of chronically implanted pacemaker or defibrillator leads can be technically demanding. We present the results of the first 44 leads extracted with excimer laser sheaths in 25 patients with a median lead implantation time of 7 years (range: 2 to 20 years). Indications for extraction were lead fracture in 17 patients, pocket infection in 4, septicemia in 2, and lead endocarditis in 2 cases. Complete extraction was achieved in 43 leads (97.7%), while the lead tip (<4cm) was abandoned in 1 case. There was no in-hospital mortality. The excimer laser-assisted system is a safe and efficient alternative for pacemaker and defibrillator lead extraction. This technology has resulted in excellent outcomes in our series, allowing us to treat remarkably difficult cases (AU)

[Initial experience with excimer laser-assisted pacemaker and defibrillator lead extraction]. / Experiencia inicial con la extracción de electrodos de marcapasos y desfibrilador asistida con láser excimer.

Explantation of chronically implanted pacemaker or defibrillator leads can be technically demanding. We present the results of the first 44 leads extracted with excimer laser sheaths in 25 patients with a median lead implantation time of 7 years (range: 2 to 20 years). Indications for extraction were lead fracture in 17 patients, pocket infection in 4, septicemia in 2, and lead endocarditis in 2 cases. Complete extraction was achieved in 43 leads (97.7%), while the lead tip (< 4 cm) was abandoned in 1 case. There was no in-hospital mortality. The excimer laser-assisted system is a safe and efficient alternative for pacemaker and defibrillator lead extraction. This technology has resulted in excellent outcomes in our series, allowing us to treat remarkably difficult cases.

Severe cardiac conduction disturbances and pacemaker implantation in patients with hypertrophic cardiomyopathy.

The aims of this study were to determine the prevalence of severe cardiac conduction disturbances in a cohort of 451 patients with hypertrophic cardiomyopathy and to describe the characteristics of, and outcomes in, those who required a permanent pacemaker. A pacemaker was implanted in 48 patients (11%): 20 had sinus node dysfunction and 28 had an atrioventricular conduction disturbance. Primary bradyarrhythmia (which was not related to iatrogenic atrioventricular block or therapeutic ablation of the atrioventricular node) was the reason for permanent pacemaker implantation in 36 patients (8%). In 18% of cases, at least one other family member had a permanent pacemaker. In this patient series, a high prevalence of severe cardiac conduction disturbance leading to permanent pacemaker implantation was observed. Severe cardiac conduction disturbance in hypertrophic cardiomyopathy may also have a familial component.

Sudden cardiac death of two heart transplant patients with correctly functioning implantable cardioverter defibrillators.

It is unclear whether the usual criteria for implantation of implantable cardioverter defibrillators in patients at risk of sudden death can be generalized to heart transplant recipients. We describe sudden death in 2 heart transplant recipients despite correctly functioning implantable cardioverter defibrillators. The scant relevant literature is reviewed. We conclude that implantable cardioverter defibrillators are unlikely to assist heart transplant recipients with severe coronary allograft vasculopathy and poor ventricular systolic function, the group with the highest incidence of sudden death.

Clinical effectiveness of antiarrhythmic treatment after electrical cardioversion in patients without structural heart disease.

INTRODUCTION AND OBJECTIVES: The aim was to investigate the clinical effectiveness of using antiarrhythmic drugs after electrical cardioversion in patients without structural heart disease, including their effect on the maintenance of sinus rhythm. METHODS: In total, 528 patients with persistent atrial fibrillation but without significant structural heart disease who underwent successful electrical cardioversion at 96 Spanish hospitals were followed up for 1 year. Patients were assessed at 1, 3, 6 and 12 months. The use and effectiveness of antiarrhythmic drugs for preventing the recurrence of persistent atrial fibrillation was evaluated. RESULTS: Some 80% of patients were receiving antiarrhythmic drugs at discharge, most frequently amiodarone. No specific clinical factor was associated with greater use of antiarrhythmics. Overall, 37% of patients were in sinus rhythm at all follow-up assessments. At the 1-year assessment, 59% of patients who remained in sinus rhythm were still taking antiarrhythmic drugs. Multivariate Cox regression analysis identified weight (hazard ratio [HR]=1.01 per kg; P=.04) and no antiarrhythmic treatment (HR=1.59; P=.001) as being independently associated with the recurrence of persistent atrial fibrillation. Amiodarone tended to be better than other antiarrhythmic drugs. CONCLUSIONS: In routine clinical practice, the large majority of patients without structural heart disease received antiarrhythmic drugs, most frequently amiodarone, after successful electrical cardioversion. Drug use was the principal factor associated with the maintenance of sinus rhythm at 1 year.

Utilidad en la práctica clínica del tratamiento antiarrítmico tras cardioversión eléctrica en pacientes sin cardiopatía estructural / Clinical effectiveness of antiarrhythmic treatment after electrical cardioversion in patients without structural heart disease

Introducción y objetivos. Conocer en la práctica clínica el uso de antiarrítmicos tras cardioversión eléctrica en pacientes sin cardiopatía y su repercusión en el mantenimiento del ritmo sinusal. Métodos. Se realizó un seguimiento a un año de 528 pacientes con fibrilación auricular persistente sin cardiopatía significativa tras una cardioversión eléctrica efectiva en 96 hospitales españoles, con controles clínicos 1, 3, 6 y 12 meses después. Se analizó el uso y la utilidad de los fármacos antiarrítmicos en la prevención de recurrencias de fibrilación auricular persistente. Resultados. Se trató al alta con fármacos antiarrítmicos al 80% de los pacientes, y el más utilizado fue la amiodarona. Ningún factor clínico se relacionó con un mayor uso de antiarrítmicos. El 37% de los pacientes siguió en ritmo sinusal en todos los controles. En el control a los 12 meses, se mantuvo el tratamiento antiarrítmico al 59% de los pacientes que seguían en ritmo sinusal. En el análisis multivariable de la regresión de Cox, el peso (hazard ratio [HR] por cada kilo = 1,01; p = 0,04) y la ausencia de tratamiento antiarrítmico (HR = 1,59; p = 0,001) fueron factores independientes relacionados con la recurrencia de fibrilación auricular persistente. La amiodarona tendía a ser superior a los otros antiarrítmicos. Conclusiones. En la práctica clínica habitual, tras una cardioversión eléctrica efectiva, la gran mayoría de los pacientes sin cardiopatía estructural recibe fármacos antiarrítmicos, especialmente amiodarona, que es el principal factor relacionado con el mantenimiento del ritmo sinusal 1 año más tarde (AU)

Introduction and objectives. The aim was to investigate the clinical effectiveness of using antiarrhythmic drugs after electrical cardioversion in patients without structural heart disease, including their effect on the maintenance of sinus rhythm. Methods. In total, 528 patients with persistent atrial fibrillation but without significant structural heart disease who underwent successful electrical cardioversion at 96 Spanish hospitals were followed up for 1 year. Patients were assessed at 1, 3, 6 and 12 months. The use and effectiveness of antiarrhythmic drugs for preventing the recurrence of persistent atrial fibrillation was evaluated. Results. Some 80% of patients were receiving antiarrhythmic drugs at discharge, most frequently amiodarone. No specific clinical factor was associated with greater use of antiarrhythmics. Overall, 37% of patients were in sinus rhythm at all follow-up assessments. At the 1-year assessment, 59% of patients who remained in sinus rhythm were still taking antiarrhythmic drugs. Multivariate Cox regression analysis identified weight (hazard ratio [HR]=1.01 per kg; P=.04) and no antiarrhythmic treatment (HR=1.59; P=.001) as being independently associated with the recurrence of persistent atrial fibrillation. Amiodarone tended to be better than other antiarrhythmic drugs. Conclusions. In routine clinical practice, the large majority of patients without structural heart disease received antiarrhythmic drugs, most frequently amiodarone, after successful electrical cardioversion. Drug use was the principal factor associated with the maintenance of sinus rhythm at 1 year (AU)

Estimulación cardiaca en situaciones diversas / Cardiac pacing in specific situations

La estimulación cardiaca es un procedimiento terapéutico ampliamente conocido. En la actualidad su utilización óptima depende fundamentalmente de la valoración individualizada de la afección del paciente que precisa un marcapasos y de conocer las múltiples posibilidades de los dispositivos disponibles en el mercado. Existen algunas situaciones especiales que, por su relevancia clínica y las dudas que pueden generar en cuanto a estimulación, merece la pena tratar de forma individualizada. En este trabajo se exponen los conocimientos actuales en cinco de esas situaciones (AU)

Cardiac pacing is a well-known therapeutic approach. In practice, making the best use of the technique depends fundamentally both on accurate disease assessment in the individual patient who requires a pacemaker and on understanding the range of options offered by the devices available on the market. There are a number of specific situations that, because of their clinical significance and the uncertainties associated with the use of pacing in them, are worthwhile treating on an individual basis. This article summarizes current understanding of five of these situations (AU)

[The implantable cardioverter-defibrillator and hypertrophic cardiomyopathy. Experience at three centers]. / Desfibrilador automático en la miocardiopatía hipertrófica. Experiencia de 3 centros.

INTRODUCTION AND OBJECTIVES: Although implantable cardioverter-defibrillators (ICDs) are recommended for high-risk patients with hypertrophic cardiomyopathy (HCM), there is no agreement on their general use. Moreover, little information is available on ICD use in this setting in Spain. Our aims were to describe the characteristics of HCM patients who received ICDs at three hospitals in Spain, and to study indications for device implantation and the results of follow-up in device users. METHODS: We evaluated risk factors for sudden death in HCM patients with ICDs, including family history of sudden death, recurrent syncope, maximum wall thickness > or =30 mm, left ventricular outflow pressure gradient >30 mmHg, abnormal blood pressure response to exercise, and nonsustained ventricular tachycardia. During regular follow-up, appropriate and inappropriate administration of ICD therapy was recorded. RESULTS: Of 726 HCM patients, 45 (6.2%) had an ICD (mean age 43 [20] years). The proportion of patients with ICDs at the three centers studied was highly variable despite patients' clinical characteristics being similar. The indication for implantation was primary prevention in 27 patients and secondary prevention in 18. During follow-up (median 32 months), ICD therapy was administered appropriately in 10 (22.0%) patients (in nine, as secondary prevention and, in one, as primary prevention). The annual appropriate ICD therapy rate was 11.1% for secondary prevention and 1.6% for primary prevention. Two patients received an ICD to treat ventricular fibrillation and eight, to treat sustained ventricular tachycardia. The only significant predictor of appropriate ICD therapy was a history of sustained ventricular tachycardia or ventricular fibrillation (hazard ratio =13.3, P=.014). CONCLUSIONS: The percentage of HCM patients undergoing ICD implantation at Spanish hospitals was highly variable, possibly due to different selection criteria. When used as secondary prevention, ICD therapy was administered appropriately in a high proportion of cases (50% in 3 years).

Desfibrilador automático en la miocardiopatía hipertrófica. Experiencia de 3 centros / The implantable cardioverter-defibrillator and hypertrophic cardiomyopathy. Experience at three centers

Introducción y objetivos. El desfibrilador automático implantable (DAI) es el tratamiento recomendado en la miocardiopatía hipertrófica (MCH) de alto riesgo, aunque no hay acuerdo en sus indicaciones. Hay pocos datos sobre su utilización en nuestro país. El objetivo es describir las características de los pacientes con MCH a los que se les implantó un DAI y analizar los resultados de esta terapia. Métodos. Se analizaron los factores de riesgo de muerte súbita en los pacientes portadores de DAI de 3 centros con consultas dedicadas a la MCH (antecedentes personales y familiares de muerte súbita, síncope recurrente, grosor ≥ 30 mm y gradiente subaórtico > 30 mmHg, respuesta anormal de la presión al esfuerzo y taquicardia ventricular no sostenida) y la indicación del implante. Se realizó un seguimiento periódico y se registraron las terapias adecuadas e inadecuadas. Resultados. De 726 pacientes, 45 (6,2%) eran portadores de DAI (edad de 43 ± 20 años). La proporción de pacientes con DAI en los 3 centros fue muy variable, a pesar de que las características de los pacientes eran similares. La indicación fue prevención primaria en 27 pacientes y secundaria en 18. Con un seguimiento de 32 meses, 10 pacientes (22%) recibieron tratamiento adecuado (9 de prevención secundaria y uno de prevención primaria). La tasa anual de tratamientos adecuados fue del 11,1% en prevención secundaria y del 1,6% en prevención primaria. El único factor asociado con el tratamiento adecuado fue el antecedente de taquicardia ventricular sostenida o fibrilación ventricular (riesgo relativo [RR] = 13,3; p = 0,014). Conclusiones. En consultas dedicadas a la MCH, el porcentaje de pacientes portadores de DAI varía en función del grado de selección de la población de origen. La incidencia de terapias adecuadas es elevada en prevención secundaria (el 50% en 3 años)

Introduction and objectives. Although implantable cardioverter-defibrillators (ICDs) are recommended for high-risk patients with hypertrophic cardiomyopathy (HCM), there is no agreement on their general use. Moreover, little information is available on ICD use in this setting in Spain. Our aims were to describe the characteristics of HCM patients who received ICDs at three hospitals in Spain, and to study indications for device implantation and the results of follow-up in device users. Methods. We evaluated risk factors for sudden death in HCM patients with ICDs, including family history of sudden death, recurrent syncope, maximum wall thickness ≥30 mm, left ventricular outflow pressure gradient >30 mmHg, abnormal blood pressure response to exercise, and nonsustained ventricular tachycardia. During regular follow-up, appropriate and inappropriate administration of ICD therapy was recorded. Results. Of 726 HCM patients, 45 (6.2%) had an ICD (mean age 43 [20] years). The proportion of patients with ICDs at the three centers studied was highly variable despite patients' clinical characteristics being similar. The indication for implantation was primary prevention in 27 patients and secondary prevention in 18. During follow-up (median 32 months), ICD therapy was administered appropriately in 10 (22.0%) patients (in nine, as secondary prevention and, in one, as primary prevention). The annual appropriate ICD therapy rate was 11.1% for secondary prevention and 1.6% for primary prevention. Two patients received an ICD to treat ventricular fibrillation and eight, to treat sustained ventricular tachycardia. The only significant predictor of appropriate ICD therapy was a history of sustained ventricular tachycardia or ventricular fibrillation (hazard ratio =13.3, P=.014). Conclusions. The percentage of HCM patients undergoing ICD implantation at Spanish hospitals was highly variable, possibly due to different selection criteria. When used as secondary prevention, ICD therapy was administered appropriately in a high proportion of cases (50% in 3 years)