RESUMEN
STUDY OBJECTIVES: To examine the prevalence and clinical significance of sleep-disordered breathing in patients with implantable cardioverter defibrillators (ICD). METHODS AND RESULTS: Overnight sleep studies were performed in 129 ICD recipients who had no history of sleep apnea. The mean left ventricular ejection fraction (LVEF) was 29 +/- 11%. Mild, moderate, and severe sleep apnea was diagnosed in the presence of an apnea/hypopnea index (AHI) of 5-15/h, 15.1-30/h, and >30/h, respectively. No sleep apnea was present in 49 patients (38%), 57 (44%) had central sleep apnea (CSA), and 23 patients (18%) had obstructive sleep apnea (OSA). Mild, moderate, and severe sleep apnea were present in 25%, 31%, and 44% of patients with CSA, compared with 52%, 22%, and 26% of patients with OSA (P < 0.05). LVEF was similar in patients with versus without OSA or CSA. Patients with CSA were significantly older and had a higher prevalence of ischemic cardiomyopathy than patients without sleep apnea. CONCLUSIONS: Previously undiagnosed CSA is common in ICD recipients. Severely disordered breathing during sleep was more prevalent among patients with CSA than patients with OSA. This prospective, observational study will examine the long-term clinical significance of sleep-disordered breathing in ICD recipients.
Asunto(s)
Desfibriladores Implantables/estadística & datos numéricos , Polisomnografía/estadística & datos numéricos , Medición de Riesgo/métodos , Síndromes de la Apnea del Sueño/diagnóstico , Síndromes de la Apnea del Sueño/epidemiología , Femenino , Alemania/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
AIMS OF THE STUDY: To examine the patterns of use, complication rates, and survival in elderly recipients of implantable cardioverter defibrillators (ICD). METHODS AND RESULTS: We followed 500 consecutive patients included in the Marburg Defibrillator database for 48+/-39 months. There were 40 patients (8%) >/= 75 and 460 (92%) < 75 years of age at the time of implant. The 5-year Kaplan-Meier estimate for appropriate treatment of VT or VF by ICD was 49% among patients < 75- versus 57% among patients >/= 75-years-old (P = 0.17). The 5-year sudden death rate was similarly low in both groups of patients (2% versus 3%). The 5-year overall mortality rate was significantly higher in patients >/= 75 than in patients < 75 years of age (55% versus 21%, P = 0.001), due to a higher mortality from heart failure (HF). All procedure-related, lead-related, and pulse generator-related complications were similar in both patient groups (23% versus 25%). CONCLUSIONS: ICD therapy was equally effective in patients >/= 75 and patients < 75 years of age in the prevention of sudden cardiac death. While the complication rates were similar in both age groups, the long-term mortality was considerably higher in elderly patients, due to a higher mortality from HF. The current ICD therapy guidelines appear applicable to elderly patients who are otherwise medically stable and without advanced HF.
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Desfibriladores Implantables/efectos adversos , Desfibriladores Implantables/estadística & datos numéricos , Taquicardia Ventricular/terapia , Fibrilación Ventricular/terapia , Adulto , Factores de Edad , Anciano , Femenino , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Taquicardia Ventricular/mortalidad , Resultado del Tratamiento , Fibrilación Ventricular/mortalidadRESUMEN
INTRODUCTION: We examined whether B-type natriuretic peptide (BNP) levels predict outcome in heart failure patients with implantable cardioverter defibrillators (ICD) using a combined endpoint of malignant tachyarrhythmias, death or heart transplantation. METHODS AND RESULTS: BNP levels were measured in 123 ICD patients with chronic heart failure (age: 63+/-12 years, ejection fraction: 29+/-10%). After a median follow-up of 25 months, the combined endpoint was reached in 28 patients (first tachyarrhythmic event, n=16; death, n=11; heart transplantation, n=1). BNP levels were significantly lower in patients with event-free survival compared to patients reaching the combined endpoint of this study (median: 140 vs. 373 pg/ml; p<0.001). Multivariable Cox regression analysis revealed that BNP levels predict adverse outcome (RR 1.002 per pg/ml increment; 95% CI: 1.001-1.003; p<0.001) and use of beta-blockers was associated with favourable outcome (RR 0.319; 95% CI 0.151-0.670; p=0.004). LV ejection fraction (p=0.66) did not significantly predict event-free survival in multivariable analysis. CONCLUSIONS: BNP plasma levels are useful markers to predict event-free survival in ICD patients with heart failure. Of note, malignant tachyarrhythmias appear responsible for about 50% of fatal outcomes. Our findings suggest that determination of BNP plasma levels is more valuable than determining LV ejection fraction to anticipate event-free survival in this population.
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Desfibriladores Implantables , Insuficiencia Cardíaca/sangre , Péptido Natriurético Encefálico/sangre , Anciano , Biomarcadores/sangre , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Análisis de SupervivenciaRESUMEN
UNLABELLED: This study examined the relation between heart rate variability (HRV) and baroreflex sensitivity (BRS) and subsequent major arrhythmic events (MAE), defined as sustained VT, VF or sudden death, in 263 patients with idiopathic dilated cardiomyopathy (IDC) in sinus rhythm. The predefined measure of HRV was the standard deviation of all normal-to-normal RR intervals (SDNN) on baseline 24-hour ambulatory ECG. BRS was determined by the phenylephrine method. Over 52 +/- 21 months of follow-up, MAE occurred in 38 patients (14%). SDNN at baseline 24-hour ambulatory ECG (106 +/- 46 vs 109 +/- 45, ns) and BRS (7.9 +/- 5.5 vs 7.7 +/- 5.3 ms/mmHg, ns) were both similar in patients with versus without MAE during follow-up. In contrast, left ventricular ejection fraction was significantly lower in patients with versus without MAE (24%+/- 7% vs 31%+/- 10%, P < 0.019. CONCLUSIONS: Neither HRV nor BRS predicted MAE in patients with IDC.
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Arritmias Cardíacas/etiología , Barorreflejo/fisiología , Cardiomiopatía Dilatada/complicaciones , Cardiomiopatía Dilatada/fisiopatología , Frecuencia Cardíaca/fisiología , Arritmias Cardíacas/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Factores de RiesgoRESUMEN
UNLABELLED: Heart Rate Turbulence in Dilated Cardiomyopathy. INTRODUCTION: The aim of this study was to investigate the prognostic significance of heart rate turbulence (HRT) characterized by HRT onset and slope after ventricular premature beats in patients with idiopathic dilated cardiomyopathy (IDC). METHODS AND RESULTS: Blinded HRT analysis was performed in 242 patients with IDC who were enrolled in the Marburg Cardiomyopathy database between 1992 and 2000. During 41 +/- 23 months of follow-up, 54 patients (22%) died or underwent heart transplant. On Cox univariate regression analysis, abnormal HRT onset, HRT slope, HRT onset combined with HRT slope, left ventricular (LV) ejection fraction, LV size, and New York Heart Association (NYHA) functional class III showed a significant association with total mortality or the need for heart transplant. On multivariate analysis, abnormal HRT onset identified patients without transplant-free survival, as did LV size and NYHA class III heart failure. Major arrhythmic events were observed in 42 patients (17%) during follow-up. On univariate analysis, abnormal HRT onset, HRT onset combined with HRT slope, male sex, NYHA class III, LV ejection fraction, and LV size were associated with a higher incidence of major arrhythmic events. On multivariate analysis, only LV ejection fraction remained as a significant arrhythmia risk predictor, with a relative risk of 2.2 per 10% decrease in ejection fraction (95% confidence interval 1.5-3.2). CONCLUSION: In this selected patient population with IDC, HRT onset is a significant predictor of transplant-free survival, as are LV size and NYHA class. For arrhythmia risk stratification, however, only LV ejection fraction remained a significant risk predictor on multivariate analysis.
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Cardiomiopatía Dilatada/diagnóstico , Cardiomiopatía Dilatada/epidemiología , Electrocardiografía Ambulatoria/métodos , Trasplante de Corazón/mortalidad , Complejos Prematuros Ventriculares/diagnóstico , Complejos Prematuros Ventriculares/epidemiología , Distribución por Edad , Cardiomiopatía Dilatada/mortalidad , Cardiomiopatía Dilatada/cirugía , Comorbilidad , Supervivencia sin Enfermedad , Alemania/epidemiología , Trasplante de Corazón/estadística & datos numéricos , Humanos , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Prevalencia , Pronóstico , Reproducibilidad de los Resultados , Factores de Riesgo , Sensibilidad y Especificidad , Distribución por Sexo , Método Simple Ciego , Análisis de Supervivencia , Complejos Prematuros Ventriculares/mortalidad , Complejos Prematuros Ventriculares/cirugíaRESUMEN
BACKGROUND: Heart rate turbulence (HRT) has recently been described as a strong, independent risk stratifier in postinfarct patients. To date, however, the incidence of false positive HRT findings in adults is unknown. Therefore, we performed a blinded, retrospective analysis of HRT in a prospectively collected database of 110 apparently healthy persons to determine the prevalence and clinical significance of abnormal HRT findings in healthy controls using previously published cut-off values. METHODS AND RESULTS: The study included 43 out of 110 apparently healthy adults, in whom a sufficient number of ventricular premature beats were available for HRT analysis on 24-hour Holter recordings. The HRT slope was dichotomized at 2.5 ms per R-R interval and HRT onset was dichotomized at 0% using previously established criteria to define an abnormal HRT analysis in postinfarct patients. Using these definitions, abnormal HRT results were found in 2 out of 43 controls (5%) for HRT slope and in 8 out of 43 controls (19%) for HRT onset without any cardiac deaths during 32 +/- 15 months follow-up. CONCLUSIONS: The incidence of false positive HRT results in healthy middle-aged volunteers is low for HRT slope (5%), but not for HRT onset (19%) when previously published cut-off values are used to define abnormal HRT results. Thus, HRT slope dichotomized at 2.5 ms per R-R interval, but not HRT onset dichotomized at 0%, may be used as a relatively specific tool for risk stratification in middle-aged persons.
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Complejos Cardíacos Prematuros/fisiopatología , Frecuencia Cardíaca , Adulto , Anciano , Electrocardiografía Ambulatoria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Medición de RiesgoRESUMEN
The clinical and electrocardiographic Marburg Cardiomyopathy database was analyzed to identify potential candidates for cardiac resynchronization therapy (CRT) with biventricular or left ventricular pacing among 566 patients with dilated cardiomyopathy (DCM). All of the following restrictive selection criteria were fulfilled by 38 patients (7%): NYHA functional class > or = 3 (n = 193, 34%), left ventricular ejection fraction (LVEF) < 30% (n = 238, 42%), sinus rhythm (n = 437, 77%), left bundle branch block (LBBB, n = 142, 25%), and QRS duration > or = 150 ms (n = 136, 24%). In 78 of the 566 patients (14%) all of the following less restrictive selection criteria were fulfilled: NYHA functional class > or = 3 (n = 193, 34%), LVEF < 35% in presence of any underlying rhythm (n = 326, 58%), QRS duration > or = 120 ms with right or left bundle branch block (n = 223, 39%). Thus, between 7% and 14% of patients with DCM were candidates for CRT depending on the application of strict versus less restrictive selection criteria.