Anique Ducharme

Rhythm control versus rate control for atrial fibrillation and heart failure.

BACKGROUND It is common practice to restore and maintain sinus rhythm in patients with atrial fibrillation and heart failure. This approach is based in part on data indicating that atrial fibrillation is a predictor of death in patients with heart failure and suggesting that the suppression of atrial fibrillation may favorably affect the outcome. However, the benefits and risks of this approach have not been adequately studied. METHODS We conducted a multicenter, randomized trial comparing the maintenance of sinus rhythm (rhythm control) with control of the ventricular rate (rate control) in patients with a left ventricular ejection fraction of 35% or less, symptoms of congestive heart failure, and a history of atrial fibrillation. The primary outcome was the time to death from cardiovascular causes. RESULTS A total of 1376 patients were enrolled (682 in the rhythm-control group and 694 in the rate-control group) and were followed for a mean of 37 months. Of these patients, 182 (27%) in the rhythm-control group died from cardiovascular causes, as compared with 175 (25%) in the rate-control group (hazard ratio in the rhythm-control group, 1.06; 95% confidence interval, 0.86 to 1.30; P=0.59 by the log-rank test). Secondary outcomes were similar in the two groups, including death from any cause (32% in the rhythm-control group and 33% in the rate-control group), stroke (3% and 4%, respectively), worsening heart failure (28% and 31%), and the composite of death from cardiovascular causes, stroke, or worsening heart failure (43% and 46%). There were also no significant differences favoring either strategy in any predefined subgroup. CONCLUSIONS In patients with atrial fibrillation and congestive heart failure, a routine strategy of rhythm control does not reduce the rate of death from cardiovascular causes, as compared with a rate-control strategy. (ClinicalTrials.gov number, NCT00597077.)

Enalapril Decreases the Incidence of Atrial Fibrillation in Patients With Left Ventricular Dysfunction Insight From the Studies Of Left Ventricular Dysfunction (SOLVD) Trials

Background Atrial fibrillation (AF) is frequently encountered in patients with heart failure (HF) and is also a predictor of morbidity and mortality in this population. Recent experimental studies have shown electrical and structural atrial remodeling with increased fibrosis in animals with HF and have suggested a preventive effect of ACE inhibitors (ACEi) on the development of AF. To verify the hypothesis that ACEi prevent the development of AF in patients with HF, we conducted a retrospective analysis of the patients from the Montreal Heart Institute (MHI) included in the Studies Of Left Ventricular Dysfunction (SOLVD). Methods and Results Clinical charts were reviewed and serial ECGs interpreted by a single cardiologist blinded to drug allocation. Patients with AF or flutter on the baseline ECG were excluded. Baseline characteristics were obtained from the SOLVD databases. The mean follow‐up was 2.9±1.0 years. Of the 391 patients randomly assigned at MHI, 374 were in sinus rhythm at the time of random assignment, with 186 taking enalapril and 188 taking placebo. Baseline characteristics were similar in the two groups except for a higher incidence of previous myocardial infarction in the enalapril group. Fifty‐five patients had AF during the follow‐up: 10 (5.4%) in the enalapril group and 45 (24%) in the placebo group (P<0.0001). By Cox multivariate analysis, enalapril was the most powerful predictor for risk reduction of AF (hazard ratio, 0.22; 95% CI, 0.11 to 0.44; P<0.0001). Conclusions Treatment with the ACEi enalapril markedly reduces the risk of development of atrial fibrillation in patients with left ventricular dysfunction. (Circulation. 2003;107:2926‐2931.)

Angiotensin Receptor Blockade and Exercise Capacity in Adults With Systemic Right Ventricles A Multicenter, Randomized, Placebo-Controlled Clinical Trial

Background— Pharmacological blockade of the renin-angiotensin system improves exercise tolerance in patients with left ventricular dysfunction, yet its impact on patients with systemic right ventricles (RVs) remains unknown. Methods and Results— A multicenter, randomized, double-blind, placebo-controlled, crossover clinical trial was performed to assess the effects of losartan on exercise capacity and neurohormonal levels in patients with systemic RVs. Of 29 patients studied (age, 30.3±10.9 years), 21 had transposition of the great arteries with a Mustard baffle, and 8 had congenitally corrected transposition of the great arteries. Baseline values were as follows: &OV0312;o2max, 29.8±5.6 mL · kg−1 · min−1 (73.5±12.9% predicted value); RV ejection fraction, 41.6±9.3%; N-terminal pro brain natriuretic peptide (NT-proBNP), 257.7±243.4 pg/mL (normal <125 pg/mL); and angiotensin II, 5.7±4.9 pg/mL (normal <5.0 pg/mL). Comparing losartan to placebo showed no differences in &OV0312;o2max (29.9±5.4 versus 29.4±6.2 mL · kg−1 · min−1; P=0.43), exercise duration (632.3±123.0 versus 629.9±140.7 seconds; P=0.76), and NT-proBNP levels (201.2±267.8 versus 229.7±291.5 pg/mL; P=0.10), despite a trend toward increased angiotensin II levels (15.2±13.8 versus 8.8±12.5 pg/mL; P=0.08). Conclusions— In adults with systemic RVs, losartan did not improve exercise capacity or reduce NT-proBNP levels. Minimal baseline activation of the renin-angiotensin system may explain this lack of benefit and imply an alternative pathophysiological mechanism for the progressive ventricular dysfunction and impaired exercise capacity observed in such patients.

The 2012 Canadian Cardiovascular Society heart failure management guidelines update: focus on acute and chronic heart failure.

The 2012 Canadian Cardiovascular Society Heart Failure (HF) Guidelines Update provides management recommendations for acute and chronic HF. In 2006, the Canadian Cardiovascular Society HF Guidelines committee first published an overview of HF management. Since then, significant additions to and changes in many of these recommendations have become apparent. With this in mind and in response to stakeholder feedback, the Guidelines Committee in 2012 has updated the overview of both acute and chronic heart failure diagnosis and management. The 2012 Update also includes recommendations, values and preferences, and practical tips to assist the medical practitioner manage their patients with HF.

Canadian Cardiovascular Society Consensus Conference recommendations on heart failure update 2007: Prevention, management during intercurrent illness or acute decompensation, and use of biomarkers

Heart failure is common, yet it is difficult to treat. It presents in many different guises and circumstances in which therapy needs to be individualized. The Canadian Cardiovascular Society published a comprehensive set of recommendations in January 2006 on the diagnosis and management of heart failure, and the present update builds on those core recommendations. Based on feedback obtained through a national program of heart failure workshops during 2006, several topics were identified as priorities because of the challenges they pose to health care professionals. New evidence-based recommendations were developed using the structured approach for the review and assessment of evidence adopted and previously described by the Society. Specific recommendations and practical tips were written for the prevention of heart failure, the management of heart failure during intercurrent illness, the treatment of acute heart failure, and the current and future roles of biomarkers in heart failure care. Specific clinical questions that are addressed include: which patients should be identified as being at high risk of developing heart failure and which interventions should be used? What complications can occur in heart failure patients during an intercurrent illness, how should these patients be monitored and which medications may require a dose adjustment or discontinuation? What are the best therapeutic, both drug and nondrug, strategies for patients with acute heart failure? How can new biomarkers help in the treatment of heart failure, and when and how should BNP be measured in heart failure patients? The goals of the present update are to translate best evidence into practice, to apply clinical wisdom where evidence for specific strategies is weaker, and to aid physicians and other health care providers to optimally treat heart failure patients to result in a measurable impact on patient health and clinical outcomes in Canada.

Enalapril Reduces the Incidence of Diabetes in Patients With Chronic Heart Failure

Background—Diabetes mellitus is a predictor of morbidity and mortality in patients with heart failure. The effect of angiotensin-converting enzyme (ACE) inhibitors on the prevention of diabetes in patients with left ventricular dysfunction is unknown. The aim of this retrospective study was to assess the effect of the ACE inhibitor enalapril on the incidence of diabetes in the group of patients from the Montreal Heart Institute enrolled in the Studies of Left Ventricular Dysfunction (SOLVD). Methods and Results—Clinical charts were evaluated for fasting plasma glucose (FPG) levels by blinded reviewers. A diagnosis of diabetes was made when a FPG ≥126 mg/dL (7 mmol/L) was found at 2 visits (follow-up, 2.9±1.0 years). Of the 391 patients enrolled at the Montreal Heart Institute, 291 were not diabetic (FPG <126 mg/dL without a history of diabetes), 153 of these were on enalapril and 138 were on placebo. Baseline characteristics were similar in the 2 groups. Forty patients developed diabetes during follow-up, 9 (5.9%) in the enalapril group and 31 (22.4%) in the placebo group (P <0.0001). By multivariate analysis, enalapril remained the most powerful predictor for risk reduction of developing diabetes (hazard ratio, 0.22; 95% confidence intervals, 0.10 to 0.46;P <0.0001). The effect of enalapril was striking in the subgroup of patients with impaired FPG (110 mg/dL [6.1 mmol/L] ≤FPG <126 mg/dL) at baseline: 1 patient (3.3%) in the enalapril group versus 12 (48.0%) in the placebo group developed diabetes (P <0.0001). Conclusions—Enalapril significantly reduces the incidence of diabetes in patients with left ventricular dysfunction, especially those with impaired FPG.

Impact of care at a multidisciplinary congestive heart failure clinic: a randomized trial

Background: Although multidisciplinary congestive heart failure clinics in the United States appear to be effective in reducing the number of hospital readmissions, it is unclear whether the same benefit is seen in countries such as Canada, where access to both general and specialized medical care is free and unrestricted. We sought to determine the impact of care at a multidisciplinary specialized outpatient congestive heart failure clinic compared with standard care. Methods: We randomly assigned 230 eligible patients who had experienced an acute episode of congestive heart failure to standard care (n = 115) or follow-up at a multidisciplinary specialized heart failure outpatient clinic (n = 115). The intervention consisted of a structured outpatient clinic environment with complete access to cardiologists and allied health professionals. The primary outcomes were all-cause hospital admission rates and total number of days in hospital at 6 months. The secondary outcomes were total number of emergency department visits, quality of life and total mortality. Results: At 6 months, fewer patients in the intervention group had required readmission to hospital than patients in the control group (45 [39%] v. 66 [57%], crude hazard ratio [HR] 0.59, 95% confidence interval [CI] 0.38–0.92. Patients in the intervention group stayed in hospital for 514 days compared with 815 days required by patients in the control group (adjusted HR 0.56, 95% CI 0.35–0.89). The number of patients seen in the emergency department and the total number of emergency department visits were similar in the intervention and control groups. At 6 months, quality of life, which was self-assessed using the Minnesota Living with Heart Failure questionnaire, was unchanged in the control group but improved in the intervention group (p < 0.001). No difference in mortality was observed, with 19 deaths in the control group and 12 in the intervention group (HR 0.61, 95% CI 0.24–1.54). Interpretation: Compared with usual care, care at a multidisciplinary specialized congestive heart failure outpatient clinic reduced the number of hospital readmissions and hospital days and improved quality of life. When our results are integrated with those from other, similar trials, multidisciplinary disease management strategies for congestive heart failure are associated with clinically worthwhile improvements in survival.

Transvenous Catheter Ice Mapping and Cryoablation of the Atrioventricular Node in Dogs

While radiofrequency catheter ablation is very effective, it does not allow for prediction of success prior to full delivery of the energy. We investigated the use of cryoablation using a new catheter on the AV node to determine (1) if a successful site might be identified prior to the ablation itself, and (2) the parameters of cryoablation of the AV node using a new cryocatheter. In eight dogs, the cryoablation catheter was advanced to the AV node to produce transient high degree AV block by lowering the temperature to a minimum of −40°C (ice mapping). Transient high degree AV node block was obtained in seven of eight animals at a mean temperature of −39.9 ± 11.6°C. No significant pathological modification was found in all animals but one and, in all cases, electrophysiological parameters of the A V node measured before, 20 minutes, 60 minutes, and up to 56 days after cryoapplication were not significantly different. In the 12 other dogs, after ice mapping, cryoablation of the A V node was attempted with a single freeze‐thaw cycle in 6 dogs (group 1) and a double freeze‐thaw cycle in the other 6 dogs (group II). Chronic complete AV block was obtained in only one animal in group I compared to all animals in group II. Ablation of the A V node is effective with a double freeze‐thaw cycle using a percutaneous catheter cryoablation system. Ice mapping of the area allows for identification of the targeted site.

The 2011 Canadian Cardiovascular Society heart failure management guidelines update: focus on sleep apnea, renal dysfunction, mechanical circulatory support, and palliative care.

The 2011 Canadian Cardiovascular Society Heart Failure (HF) Guidelines Focused Update reviews the recently published clinical trials that will potentially impact on management. Also reviewed is the less studied but clinically important area of sleep apnea. Finally, patients with advanced HF represent a group of patients who pose major difficulties to clinicians. Advanced HF therefore is examined from the perspectives of HF complicated by renal failure, the role of palliative care, and the role of mechanical circulatory support (MCS). All of these topics are reviewed from a perspective of practical applications. Important new studies have demonstrated in less symptomatic HF patients that cardiac resynchronization therapy will be of benefit. As well, aldosterone receptor antagonists can be used with benefit in less symptomatic HF patients. The important role of palliative care and the need to address end-of-life issues in advanced HF are emphasized. Physicians need to be aware of the possibility of sleep apnea complicating the course of HF and the role of a sleep study for the proper assessment and management of the conditon. Patients with either acute severe or chronic advanced HF with otherwise good life expectancy should be referred to a cardiac centre capable of providing MCS. Furthermore, patients awaiting heart transplantation who deteriorate or are otherwise not likely to survive until a donor organ is found should be referred for MCS.

Canadian Cardiovascular Society Consensus Conference guidelines on heart failure - 2008 update: Best practices for the transition of care of heart failure patients, and the recognition, investigation and treatment of cardiomyopathies

Heart failure is a clinical syndrome that normally requires health care to be provided by both specialists and nonspecialists. This is advantageous because patients benefit from complementary skill sets and experience, but can present challenges in the development of a common, shared treatment plan. The Canadian Cardiovascular Society published a comprehensive set of recommendations on the diagnosis and management of heart failure in January 2006, and on the prevention, management during intercurrent illness or acute decompensation, and use of biomarkers in January 2007. The present update builds on those core recommendations. Based on feedback obtained through a national program of heart failure workshops during 2006 and 2007, several topics were identified as priorities because of the challenges they pose to health care professionals. New evidence-based recommendations were developed using the structured approach for the review and assessment of evidence that was adopted and previously described by the Society. Specific recommendations and practical tips were written for best practices during the transition of care of heart failure patients, and the recognition, investigation and treatment of some specific cardiomyopathies. Specific clinical questions that are addressed include: What information should a referring physician provide for a specialist consultation? What instructions should a consultant provide to the referring physician? What processes should be in place to ensure that the expectations and needs of each physician are met? When a cardiomyopathy is suspected, how can it be recognized, how should it be investigated and diagnosed, how should it be treated, when should the patient be referred, and what special tests are available to assist in the diagnosis and treatment? The goals of the present update are to translate best evidence into practice, apply clinical wisdom where evidence for specific strategies is weaker, and aid physicians and other health care providers to optimally treat heart failure patients, resulting in a measurable impact on patient health and clinical outcomes in Canada.