Age and the Risk of Ventricular Tachyarrhythmia in Patients With an Implantable Cardioverter-Defibrillator.

BACKGROUND: The benefit of implantable cardioverter-defibrillators (ICDs) in elderly patients is controversial. OBJECTIVES: The aims of this study were to evaluate the risk for ventricular tachyarrhythmia (VTA) and ICD shocks by age groups and to assess the competing risk for VTA and death without prior VTA. METHODS: The study included 5,170 primary prevention ICD recipients enrolled in 5 landmark ICD trials (MADIT [Multicenter Automatic Defibrillator Implantation Trial] II, MADIT-Risk, MADIT-CRT [MADIT Cardiac Resynchronization Therapy], MADIT-RIT [MADIT Reduce Inappropriate Therapy], and RAID [Ranolazine in High-Risk Patients With Implanted Cardioverter-Defibrillator]). Fine and Gray regression analysis was used to evaluate the risk for fast VTA (ventricular tachycardia ≥200 beats/min or ventricular fibrillation) vs death without prior fast VTA in 3 prespecified age groups: <65, 65 to <75, and ≥75 years. RESULTS: The cumulative incidence of fast VTA at 3 years was similar for patients <65 years of age and those 65 to <75 years of age (17% vs 15%) and was lowest among patients ≥75 years of age (10%) (P < 0.001). Multivariate Fine and Gray analysis showed a 40% lower risk for fast VTA in patients ≥75 years of age (HR: 0.60; 95% CI: 0.46-0.78; P < 0.001) compared with patients <65 years of age. In patients ≥75 years of age, a risk reversal was observed whereby the risk for death without prior fast VTA exceeded the risk for developing fast VTA. A history of nonsustained ventricular tachycardia, male sex, and the presence of nonischemic cardiomyopathy were identified as predictors of fast VTA in patients ≥75 years of age. CONCLUSIONS: Patients ≥75 years of age have a significantly lower risk for VTA and ICD shocks compared with younger patients. Aging is associated with a higher risk for death compared with the risk for fast VTA, the reverse of what is seen in younger patients.

Sex Differences in the Risk of First and Recurrent Ventricular Tachyarrhythmias Among Patients Receiving an Implantable Cardioverter-Defibrillator for Primary Prevention.

Importance: Current guidelines for primary implantable cardioverter-defibrillator (ICD) therapy do not account for sex differences in arrhythmic risk in ICD candidates. Objective: To evaluate the association between sex and risk of ventricular tachyarrhythmia (VTA) and mortality. Design, Setting, and Participants: This cohort study compared differences in the risk of VTA and mortality between 4506 men and women enrolled in the 4 Multicenter Automatic Defibrillator Implantation Trials (MADIT) between July 1, 1997, and December 31, 2011. Data from prospective randomized controlled multicenter studies were analyzed retrospectively. Men and women with an ICD or cardiac resynchronization therapy defibrillator who were enrolled in all MADIT studies were included. Data were analyzed between January 10 and June 10, 2021. Exposures: ICD implant. Main Outcomes and Measures: The primary end point was sustained VTA, defined as ICD-recorded, treated or monitored VTA at least 170/min or ventricular fibrillation. Secondary VTA end points included VTA at least 200/min, appropriate ICD shocks, and appropriate antitachycardia pacing. All end points were included in a first and recurrent event analysis. Results: Of the 4506 study participants, 3431 were men (76%). Mean (SD) age of the cohort was 64 (12) years. For women vs men, the mean (SD) age (64 [12] years vs 64 [11] years) and left ventricular ejection fraction (24% vs 25%) were similar, but women exhibited a higher frequency of nonischemic cardiomyopathy (454 of 1075 women [42%] vs 2535 of 3431 men [74%]). Women had significantly lower 3-year cumulative probability of sustained VTA (16% vs 26%), fast VTA (9% vs 17%), and appropriate ICD shocks (7% vs 15%) compared with men (P < .001 for all). Multivariable analysis showed that female sex was independently associated with at least 40% lower risk of all first and recurrent VTA end points (P < .001 for all), including the primary end point (first event, HR = 60 [95% CI, 50-73], P < .001; recurrent event, HR = 49 [95% CI, 43-55], P < .001), after accounting for the competing risk of all-cause mortality and nonarrhythmic mortality. The lower VTA risk associated with female sex was consistent in risk subsets but was significantly more pronounced in patients with nonischemic cardiomyopathy (female vs male in the ischemic group: hazard ratio, 0.73 [95% CI, 0.56-0.95], P = .02; nonischemic group: hazard ratio, 0.50 [95% CI, 0.38-0.66], P < .001; P = .03 for interaction between female sex and cardiomyopathy). Conclusions and Relevance: Findings suggest that women display a significantly lower risk of first and recurrent life-threatening VTA events than men, and that it is more pronounced in patients with nonischemic cardiomyopathy, suggesting a need for sex-specific risk assessment for primary prevention ICD therapy.

Comparison of Frequency of Ventricular Tachyarrhythmia in Men-Versus-Women in Patients with Implantable Cardioverter-Defibrillator for Primary Prevention.

Current guidelines do not account for possible sex differences in the risk of ventricular tachyarrhythmia (VTA). We sought to identify specific factors associated with increased risk for VTA in women implanted with a primary prevention implantable cardioverter-defibrillator (ICD). Our study cohort consisted of 4,506 patients with an ICD or cardiac resynchronization therapy-defibrillator who were enrolled in the 4 landmark MADIT studies - MADIT-II, MADIT-RISK, MADIT-CRT and MADIT-RIT (1,075 women [24%]). Fine and Gray regression models were used to identify female-specific risk factors for the primary end point of VTA, defined as ICD-recorded, treated, or monitored, sustained ventricular tachycardia ≥170 beats per minute or ventricular fibrillation. At 3.5 years of follow-up, the cumulative incidence of VTA was significantly lower in women than men (17% vs 26%, respectively; p <0.001 for the entire follow-up). Use of amiodarone at enrollment, Black race, and history of previous myocardial infarction without previous revascularization was found to be independent risk factors of VTA in women. Of these factors, only Black race was associated with a statistically significant risk increase in men. At 3.5 years, the cumulative incidence of VTA in women with one or more of these risk factors was 27% compared with 14% in women with none of the risk factors (hazard ratio [confidence interval] = 2.08 [1.49 to 2.91]). In conclusion, our study, comprising 4 landmark ICD clinical trials, shows that sex and race have the potential to be used for improved risk stratification of patients who are candidates for primary prevention ICD.

Efficacy of intravenous ketamine for treatment of chronic posttraumatic stress disorder: a randomized clinical trial.

IMPORTANCE: Few pharmacotherapies have demonstrated sufficient efficacy in the treatment of posttraumatic stress disorder (PTSD), a chronic and disabling condition. OBJECTIVE: To test the efficacy and safety of a single intravenous subanesthetic dose of ketamine for the treatment of PTSD and associated depressive symptoms in patients with chronic PTSD. DESIGN, SETTING, AND PARTICIPANTS: Proof-of-concept, randomized, double-blind, crossover trial comparing ketamine with an active placebo control, midazolam, conducted at a single site (Icahn School of Medicine at Mount Sinai, New York, New York). Forty-one patients with chronic PTSD related to a range of trauma exposures were recruited via advertisements. INTERVENTIONS: Intravenous infusion of ketamine hydrochloride (0.5 mg/kg) and midazolam (0.045 mg/kg). MAIN OUTCOMES AND MEASURES: The primary outcome measure was change in PTSD symptom severity, measured using the Impact of Event Scale-Revised. Secondary outcome measures included the Montgomery-Asberg Depression Rating Scale, the Clinical Global Impression-Severity and -Improvement scales, and adverse effect measures, including the Clinician-Administered Dissociative States Scale, the Brief Psychiatric Rating Scale, and the Young Mania Rating Scale. RESULTS: Ketamine infusion was associated with significant and rapid reduction in PTSD symptom severity, compared with midazolam, when assessed 24 hours after infusion (mean difference in Impact of Event Scale-Revised score, 12.7 [95% CI, 2.5-22.8]; P = .02). Greater reduction of PTSD symptoms following treatment with ketamine was evident in both crossover and first-period analyses, and remained significant after adjusting for baseline and 24-hour depressive symptom severity. Ketamine was also associated with reduction in comorbid depressive symptoms and with improvement in overall clinical presentation. Ketamine was generally well tolerated without clinically significant persistent dissociative symptoms. CONCLUSIONS AND RELEVANCE: This study provides the first evidence for rapid reduction in symptom severity following ketamine infusion in patients with chronic PTSD. If replicated, these findings may lead to novel approaches to the pharmacologic treatment of patients with this disabling condition. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00749203.

Resilience to meet the challenge of addiction: psychobiology and clinical considerations.

Acute and chronic stress-related mechanisms play an important role in the development of addiction and its chronic, relapsing nature. Multisystem adaptations in brain, body, behavioral, and social function may contribute to a dysregulated physiological state that is maintained beyond the homeostatic range. In addition, chronic abuse of substances leads to an altered set point across multiple systems. Resilience can be defined as the absence of psychopathology despite exposure to high stress and reflects a person's ability to cope successfully in the face of adversity, demonstrating adaptive psychological and physiological stress responses. The study of resilience can be approached by examining interindividual stress responsibility at multiple phenotypic levels, ranging from psychological differences in the way people cope with stress to differences in neurochemical or neural circuitry function. The ultimate goal of such research is the development of strategies and interventions to enhance resilience and coping in the face of stress and prevent the onset of addiction problems or relapse.

Central functions of neuropeptide Y in mood and anxiety disorders.

INTRODUCTION: Neuropeptide Y (NPY) is a highly conserved neuropeptide belonging to the pancreatic polypeptide family. Its potential role in the etiology and pathophysiology of mood and anxiety disorders has been extensively studied. NPY also has effects on feeding behavior, ethanol intake, sleep regulation, tissue growth and remodeling. Findings from animal studies have delineated the physiological and behavioral effects mediated by specific NPY receptor subtypes, of which Y1 and Y2 are the best understood. AREAS COVERED: Physiological roles and alterations of the NPYergic system in anxiety disorders, depression, posttraumatic stress disorder (PTSD), alcohol dependence and epilepsy. For each disorder, studies in animal models and human investigations are outlined and discussed, focusing on behavior, neurophysiology, genetics and potential for novel treatment targets. EXPERT OPINION: The wide implications of NPY in psychiatric disorders such as depression and PTSD make the NPYergic system a promising target for the development of novel therapeutic interventions. These include intranasal NPY administration, currently under study, and the development of agonists and antagonists targeting NPY receptors. Therefore, we are proposing that via this mode of administration, NPY might exert CNS therapeutic actions without untoward systemic effects. Future work will show if this is a feasible approach.