Major changes in acute ST elevation myocardial infarction (STEMI) management prompted a comprehensive rewriting of the American College of Cardiology/American Heart Association Guidelines. The Canadian Cardiovascular Society (CCS) participated in both the writing process and the external review. Subsequently, a Canadian Working Group (CWG), formed under the auspices of the CCS, developed a perspective and adaptation for Canada. Herein, accounting for specific realities of the Canadian cardiovascular health system, is a discussion of the implications for prehospital care and transport, optimal reperfusion therapy and an approach to decision making regarding reperfusion options and invasive therapy following fibrinolytic therapy. Major recent developments regarding indications for implantable cardioverter defibrillator(s) (ICDs) also prompted a review of indications for ICDs and the optimal timing of implantation given the potential for recovery of left ventricular function. At least a 40-day, preferably a 12-week, waiting period was judged to be optimal to evaluate left ventricular function post-STEMI. A recommended algorithm for the insertion of an ICD is provided. Implementation of the new STEMI guidelines has substantial implications for resources, organization and priorities of the Canadian health care system. While on the one hand, the necessary incremental funding to provide tertiary and quaternary care and to support revascularization and device implantation capability is desirable, it is equally or more important to develop enhanced prehospital care, including the capacity for early recognition, risk assessment, fibrinolytic therapy and/or triage to a tertiary care centre as part of an enlightened approach to improving cardiac care.
Aerobic interval training (AIT) has been shown to be superior to moderate continuous exercise training in improving exercise capacity and endothelial function in patients with both coronary artery disease and heart failure (HF). The objective of this study was to evaluate this training modality in patients with HF and an implantable cardioverter defibrillator (ICD) with regard to feasibility, safety, and effect.
We prospectively included 38 patients with an ICD: 26 patients participated in an AIT programme for 3 months, while 12 patients served as controls. At baseline and 12-week follow up, patients were assessed with a maximal ergospirometry stress test, echocardiography, endothelial function testing, and ICD interrogation.
No exercise-related adverse events occurred during or soon after the training sessions. ICD interrogation revealed no sustained arrhythmias, antitachycardia pacing, or ICD discharge related to exercise sessions. The AIT programme led to a significant increase in peak oxygen uptake, cycle ergometer workload, and endothelial function compared to the control group. The training programme was safe and not associated with any adverse events or ICD-related complications.
An AIT programme is feasible and seems safe in a well-treated, stable ICD population. Further, AIT for 3 months results in significantly increased aerobic capacity and endothelial function in this population.
Ventricular arrhythmia is a significant cause of sudden death. Implantable cardioverter-defibrillators (ICDs) offer at-risk patients a prophylactic treatment option. This prophylaxis is largely responsible for growth in utilization of ICDs. Identification of factors that may impact device-specific quality of life (QOL) is warranted. The influence of preimplant patient variables on postimplant device-specific QOL is unknown. The study aimed to determine whether preimplant psychosocial, generic health-related quality of life (HRQOL), personality disposition, or demographic factors predicted early postimplant device-specific QOL.
A prospective cohort study design was employed in 70 adults receiving an ICD for primary prevention. Preimplant, we measured generic HRQOL, personality disposition, depressive symptoms, age, and sex. The primary outcome was 3-month ICD device-specific QOL as measured by the Florida Patient Acceptance Scale (FPAS). We applied hierarchical multivariate regression analysis.
Mean age was 64.8 ± 9.4 years; 12.9% were women. Most had ischemic heart disease (77%) and a heart failure history (54.3%). Preimplant prevalence of elevated depressive symptoms was 30%. Three months post implant, the mean adjusted FPAS score was 76.8 ± 12.98. Of the variance in FPAS scores, 37% was explained by the independent variables. Younger age and poor preimplant mental HRQOL contributed most to lower FPAS scores.
Patient support and psychosocial interventions should target younger ICD candidates and those reporting poor preimplant mental HRQOL; these patients may be at risk for poor postimplant device-specific QOL.
Division of Cardiology, Department of Medicine and Cardiovascular Research Group, Faculty of Medicine, 2C2 Walter MacKenzie Health Sciences Centre, University of Alberta, Edmonton, AB T6G 2R7, Canada. email@example.com
The elderly population (age > or =65) is increasing and with it morbidity, hospitalizations, costs and mortality due to heart failure (HF). HF is a progressive disorder that is superimposed on an on-going aging process. The two broad categories of HF, HF with left ventricular (LV) systolic dysfunction or low ejection fraction (HF/low-EF) and HF with preserved ejection fraction (HF/PEF) are equally prevalent in the elderly. Trials of therapy for HF/low-EF in primarily non-elderly patients showed mortality benefit in elderly patients. In contrast, trials for HF/PEF have not shown mortality benefit in elderly or non-elderly patients. HF pharmacotherapy in the elderly is challenging and needs to be individualized and consider several aging-related changes. More research into the biology of aging and more clinical trials in elderly patients are needed to improve morbidity and mortality in elderly HF patients.
Epidemiological studies have demonstrated associations between short-term increases in outdoor air pollution concentrations and adverse cardiovascular effects, including cardiac mortality and hospitalizations. One possible mechanism behind this association is that air pollution exposure increases the risk of developing a cardiac arrhythmia. To investigate this hypothesis, dates of implantable cardioverter defibrillator (ICD) discharges were abstracted from patient records in patients attending the two ICD clinics in Vancouver, BC, for the years 1997-2000. Daily outdoor air pollutant concentrations and daily meteorological data from the Vancouver region were obtained for the same 4-yr period. Generalized estimating equations were used to assess the association between short-term increases in air pollutant concentrations and ICD discharges while controlling for temporal trends, meteorology, and serial correlation in the data. Air pollution concentrations in the Vancouver region were relatively low from 1997 to 2000, as expected. In the 50 patients who resided within the Vancouver region and who experienced at least 1 ICD discharge during the period of follow-up, no significant associations between increased air pollution concentrations and increased ICD discharges were present. When the patient sample was restricted to the 16 patients who had at least 6 months of follow-up and experienced a rate of at least 2 days with ICD discharges per year, there was a statistically significant association between increased sulfur dioxide (SO(2)) concentration and ICD discharge 2 days after the SO(2) increase. When stratified by season, no associations between increased air pollutant concentrations and increased risk of ICD discharge were observed in the summer, although for several pollutants, concentration increases were associated with a decrease in ICD discharges. In the winter, increased SO(2) concentrations again were seen to be associated with increased risk of ICD discharge, at both 2 and 3 days following increases in SO(2) concentrations. These findings provide no compelling evidence that short-term increases in relatively low concentrations of outdoor air pollutants have an adverse effect on individuals at risk of cardiac arrhythmias. The findings regarding SO(2) are difficult to interpret. They may be chance findings. Alternatively, given the very low concentrations of SO(2) that were present in Vancouver, SO(2) may have been serving as a surrogate measure of other environmental or meteorological factors.
Although highly effective in preventing arrhythmic death, patients receiving an implantable cardioverter defibrillator (ICD) may still experience psychological difficulties such as anxiety, depression, and reduced quality of life. The objectives of this study were to describe patient-reported outcomes among ICD patients: (1) compared to a matched healthy population, (2) compared by ICD indication, (3) factors predicting patient-reported outcomes, and (4) if patient-reported outcomes predicted mortality.
The study was a mailed survey to an unselected group of patients 18+ years old receiving ICD between January 1, 2011 and June 30, 2011 (n = 499). The following instruments were used: SF-36, Hospital Anxiety and Depression Scale, HeartQoL, EQ-5D, and the Multidimensional Fatigue Inventory.
The response rate was 72%. Mean age was 65.5 years and 82% patients were males. Fifty-three percent of patients had primary prevention indication ICD. Compared to an age- and gender-matched population without disease, the ICD population had worse mental health (55.0 vs 51.7 points) and physical health (52.6 vs 41.9 points). Patients with primary prevention indication had lower levels of perceived health, quality of life, and fatigue; for example, physical health 39.8 versus 44.3 points, compared to secondary prevention indication. Anxiety, poor perceived health, fatigue, and low quality of life were all predictors of mortality, anxiety being the strongest with an adjusted odds ratio of 4.17 (1.49; 11.66).
Patients with primary prevention ICD had lower levels of perceived health, quality of life, and more fatigue. Anxiety, poor perceived health, fatigue, and low quality of life were all predictors of mortality.
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is characterized by adrenergically induced ventricular tachycardia (VT) associated with syncope and sudden death.
This study sought to characterize arrhythmias associated with CPVT with respect to provocation by exercise and drugs, electrocardiographic characteristics, and association with long-term outcomes; and to explore the relation between age and clinical presentation.
Seventy patients from 16 families were evaluated with exercise and selective adrenaline challenge, and screened for RyR2 mutations. CPVT was diagnosed in probands with symptoms and stress- or adrenaline-provoked VT, or in asymptomatic relatives with provoked VT or RyR2 mutations. Patients were followed up for recurrent syncope, VT, and sudden death.
Twenty-seven patients including 16 probands were identified (median age 35 years, 67% female). Presentation was cardiac arrest in 33% and syncope in 56%, and 11% were asymptomatic. Polymorphic or bidirectional VT was provoked with exercise in 63% and adrenaline in 82%. The initiating beat of VT was late-coupled and wide (coupling interval 418 ± 42 ms; QRSd 131 ± 17 ms), and QRS morphology suggested an outflow tract origin in 59%. During follow-up of 6.2 ± 5.7 years, 2 patients died despite an implantable cardioverter-defibrillator (ICD), 4 patients received ICD therapy for VT, and 5 patients had inappropriate therapy for supraventricular tachycardia. Patients presenting with late-onset CPVT (age > 21; n = 10) were often female (80%) and less likely to have RyR2 (Ryanodine receptor type 2) mutations (33%), and fatal events were not observed during follow-up (4.1 ± 3.6 years).
Ventricular arrhythmia in CPVT is often initiated from the outflow tract region. Despite ß-blocker therapy and selective ICD implantation, breakthrough arrhythmias occur and may be associated with adverse outcomes.
The mortality benefit of implantable cardioverter defibrillator (ICD) therapy in primary and secondary prevention has been shown in various studies in patients with depressed left ventricular systolic function. This study determined the association between the mortality benefit of ICD therapy and the use of beta-blocking medication in randomized ICD trials. Eligible studies were randomized controlled trials of ICD therapy compared with conventional medical treatment reporting mortality as an outcome (Medline from May 1995 to May 2005). Ten randomized trials were included. Included studies were reviewed to determine the number of patients, follow-up, and the mortality of ICD and control groups. The analysis of these trials showed a strong negative association between the use of beta-blocking medication and the 2-year mortality benefit of ICD therapy (r = -0.81, p