Clinical Risk Stratification for Primary Prevention Implantable Cardioverter Defibrillators.

BACKGROUND: A conceptualized model may be useful for understanding risk stratification of primary prevention implantable cardioverter defibrillators considering the competing risks of appropriate implantable cardioverter defibrillator shock versus mortality. METHODS AND RESULTS: In a prospective, multicenter, population-based cohort with left ventricular ejection fraction ≤35% referred for primary prevention implantable cardioverter defibrillator, we developed dual risk stratification models to determine the competing risks of appropriate defibrillator shock versus mortality using a Fine-Gray subdistribution hazard model. Among 7020 patients referred, 3445 underwent defibrillator implant (79.7% men, median, 66 years [25th, 75th: 58-73]). During 5918 person-years of follow-up, appropriate shock occurred in 204 patients (3.6 shocks/100 person-years) and 292 died (4.9 deaths/100 person-years). Competing risk predictors of appropriate shock included nonsustained ventricular tachycardia, atrial fibrillation, serum creatinine concentration, digoxin or amiodarone use, and QRS duration near 130-ms peak. One-year cumulative incidence of appropriate shock was 0.9% in the lowest risk category, and 1.7%, 2.5%, 4.9%, and 9.3% in low, intermediate, high, and highest risk groups, respectively. Hazard ratios for appropriate shock ranged from 4.04 to 7.79 in the highest 3 deciles (all P≤0.001 versus lowest risk). Cumulative incidence of 1-year death was 0.6%, 1.9%, 3.3%, 6.2%, and 17.7% in lowest, low, intermediate, high, and highest risk groups, respectively. Mortality hazard ratios ranged from 11.48 to 36.22 in the highest 3 deciles (all P<0.001 versus lowest risk). CONCLUSIONS: Simultaneous estimation of risks of appropriate shock and mortality can be performed using clinical variables, providing a potential framework for identification of patients who are unlikely to benefit from prophylactic implantable cardioverter defibrillator.

Predictors of short-term complications after implantable cardioverter-defibrillator replacement: results from the Ontario ICD Database.

BACKGROUND: Complications after implantable cardioverter-defibrillator (ICD) replacement are often clinically devastating, particularly when infection or reoperation occurs. Identifying factors contributing to complications may permit identification of high-risk individuals that warrant incremental monitoring and therapy to attenuate risk. In addition, replacement may be a discretionary decision in the context of an advisory or borderline device performance and patient, device, and implanter factors that predict adverse outcome may assist in clinical decision-making. METHODS AND RESULTS: In a prospective, multicenter, population-based registry of all ICD patients at 18 centers in Ontario, Canada, we examined 45-day complication and all-cause mortality rates from February 2007 to August 2009 in patients undergoing ICD generator replacement. Complications were determined longitudinally and were categorized as major or minor. ICD replacement was performed in 1081 of 5176 patients (20.8%) undergoing ICD implantation (age, 64.3±12.7 years; 78.5% men). In patients undergoing ICD replacement, 47 patients (4.3%) had a complication within 45 days, with 47 major complications in 28 patients (2.6%), most commonly infection (n=23), lead revision (n=35), electrical storm (n=14), and pulmonary edema (n=13). Minor complications occurred in 2.3% of patients, most commonly incisional infection (n=10) and pocket hematoma (n=10). On multivariable analysis, risk factors associated with major complications were Canadian Cardiovascular Society angina class (adjusted hazard ratio [HR], 3.70 for class 2 to 4 versus 0 to 1; P=0.027) and multiple previous procedures on the pocket (adjusted HR, 3.35 for >1 versus 1; P=0.058). Risk factors associated with any complication were the use of antiarrhythmic therapy (adjusted HR, 6.29; P=0.001), implanter volume (adjusted HR 10.4 for <60/y versus >120/y, P=0.026), and Canadian Cardiovascular Society angina class (adjusted HR, 3.00 for class 2 to 4 versus 0 to 1; P=0.031). In a Cox model with a time-dependent variable of major complication within 45 days after replacement, major complications after ICD replacement were associated with an increased risk of mortality at 45, 90, and 180 days (adjusted HR, 9.61, 12.69, and 6.41, respectively; P=0.002 to 0.039). CONCLUSIONS: Risk factors associated with complications after ICD replacement include the presence of angina, antiarrhythmic therapy, increased number of previous procedures, and low implanter volume. Major complications may be associated with increased risk of subsequent mortality.

Who cares? A profile of people who care for relatives with a mental disorder.

OBJECTIVE: To profile the Australian adults who are caring for a relative with a mental disorder. METHOD: Data came from the 2007 National Survey of Mental Health and Wellbeing 2007 (NSMHWB), a nationally representative household survey of 8841 individuals aged between 16 and 85 years. RESULTS: Many people act as carers: 15% of the Australian adult population, or nearly 2.4 million individuals. The strongest predictors of being a carer are being female and being in a relatively older age bracket. Carers provide a range of emotional and practical supports to close relatives with a range of mental disorders, most notably high prevalence disorders. Their relatives' health problems cause them considerable worry, anxiety and depression, and their caring role can be associated with high financial costs. CONCLUSIONS: Carers are significant stakeholders in the mental health system. Providing support for carers is crucial, particularly because their own mental health and well-being may be affected by their care-giving role. The nature of this support should take into account their large numbers, their profile and the role they perform.

Evaluation of early complications related to De Novo cardioverter defibrillator implantation insights from the Ontario ICD database.

OBJECTIVES: This study examined the predictors of early complications after defibrillator implantation. BACKGROUND: Although implantable cardioverter-defibrillators are widely used, predictors of procedural complications and the consequences of these events have not been determined. METHODS: In a prospective, multicenter, population-based clinical outcomes registry of all newly implanted defibrillator patients at 18 centers in Ontario, Canada, we examined 45-day complications and all-cause mortality from February 2007 to May 2009. Complications were determined longitudinally and were categorized as direct implant-related or indirect events. RESULTS: Among 3,340 patients (mean age 63.8 +/- 12.5 years, 78.5% men), major complications occurred in 4.1% of de novo procedures. Compared with those undergoing a single-chamber device, implantation of a cardiac resynchronization defibrillator (adjusted hazard ratio [HR]: 2.17, 95% confidence interval [CI]: 1.38 to 3.43, p < 0.001) or dual-chamber device (adjusted HR: 1.82, 95% CI: 1.19 to 2.79, p = 0.006) was associated with increased risk of major complications. Major complications were increased in women (adjusted HR: 1.49, 95% CI: 1.02 to 2.16, p = 0.037) and when left ventricular end-systolic dimension exceeded 45 mm (adjusted HR: 1.54, 95% CI: 1.08 to 2.20, p = 0.018). Major complications (excluding death) occurring early after defibrillator implantation were associated with increased adjusted risk of subsequent death up to 180 days after defibrillator implant (adjusted HR: 3.70, 95% CI: 1.64 to 8.33, p = 0.002). Direct implant-related complications were associated with increased risk of early death (adjusted HR: 24.89, p = 0.01), whereas indirect clinical complications conferred increased risk of near-term death (adjusted HR: 12.35, p < 0.001) after defibrillator implantation. CONCLUSIONS: Complications after de novo defibrillator implantation were strongly associated with device type. Major complications were associated with increased risk of mortality.

Design and implementation of a population-based registry of Implantable Cardioverter Defibrillators (ICDs) in Ontario.

BACKGROUND: There are scarce population-based data on the use, complication rates, and outcomes of patients receiving implantable cardioverter defibrillators (ICDs). OBJECTIVE: This study sought to describe the methodology of the Ontario ICD Database, a prospective study of all ICD recipients in Ontario, Canada. METHODS: In this registry, web-based data collection will be performed in all patients referred to a cardiac electrophysiologist for consideration of an ICD. The variables included in the database were determined by consensus. Outcomes to be assessed will include defibrillator device therapies (e.g., shock or antitachycardia pacing), morbidity, and death. Preliminary statistics are reported after the first 6 months of data collection. RESULTS: Of 208 total variables selected by consensus, 111 (53.4%) were referral/patient characteristics, 12 (5.8%) were implant-related, and 85 (40.9%) were outcome variables. Among 990 referred patients, 902 were accepted, with the following ICD indications: primary prevention (63.3%), secondary prevention (21.6%), and generator replacement (15.1%). The mean (SD) age of patients with implants was 63.9 +/- 12.6 years, and 79% were men. Among accepted ICD patients, 66% had ischemic heart disease, 23% had nonischemic dilated cardiomyopathy, and 11% had other cardiac conditions. Left ventricular (LV) systolic dysfunction was highly prevalent, with 82% of primary and 44% of secondary prevention patients having LV ejection fraction