Reports

This report is based on medical evidence presented at sanctioned medical congress, from peer reviewed literature or opinion provided by a qualified healthcare practitioner. The consumption of the information contained within this report is intended for qualified Canadian healthcare practitioners only.

Canadian Cardiovascular Congress 2006

Vancouver, British Columbia / October 21-25, 2006

The creation process and purpose of the Canadian Cardiovascular Society (CCS) guidelines for the diagnosis and management of heart failure have evolved substantially since the first set (the first national guidelines in the world) was issued in 1994. This year’s document and an update scheduled for publication in January 2007 are aimed at both disseminating current evidence in heart failure to cardiac specialists and translating that knowledge to other health care practitioners.

An early and accurate diagnosis of heart failure is an important element in optimal care, according to Dr. Malcolm Arnold, Professor of Medicine, University of Western Ontario, and program leader for cardiology research, Lawson Health Research Institute, London. “It’s important to have a high index of suspicion in patients who are at increased risk for heart failure. There are a number of clinical presentations and it’s not a single component but the combination and pattern that leads one to make a final diagnosis.” A heart failure diagnosis can be made even in patients without a history or current evidence of volume overload or who have a normal left ventricular ejection fraction, he reminded the audience. In addition, he stressed, elderly patients often present with atypical signs and symptoms such as falls, confusion or delirium.

Proven Strategies

Based on evidence accumulated in numerous landmark clinical trials, the updated algorithm for treatment of chronic heart failure (Can J Cardiol 2006;22(1):23-45) retains the recommendation that in patients with left ventricular ejection fraction <40%, drug therapy should generally begin with the combination of an ACE inhibitor and beta blocker. “We encourage and recommend that as soon as possible patients be on both drugs because they work together better than either alone,” Dr. Arnold indicated. An angiotensin receptor blocker (ARB) may be substituted if one of these agents is not well tolerated by the patient, and may also be considered as additional therapy if the patient’s symptoms persist and the risk of hospitalization remains high. Treatment is similar in patients with preserved systolic function, he observed. Addressing causal factors such as hypertension and arrhythmias is critical.

“The drugs [used] should be the ones that have been proven in large-scale trials to be beneficial. That does not mean that drugs that haven’t been studied in large randomized clinical trials don’t work; [rather] we know that if we use the dose of a drug which was used in a clinical trial and it did show a quantifiable benefit, then we know what we can expect,” Dr. Arnold affirmed.

“It is important for us to acknowledge and recognize that drug therapy has made a major improvement in how we manage and treat heart failure and we’re in a position where we now can give hope to many patients who previously had little hope.”

First-line and Alternative/Additional Therapies

While the bulk of evidence and numerous expert guidelines favour ACE inhibitors/beta blockers as core therapy, numerous clinical trials have documented the efficacy of ARBs as alternative or additional agents. In a debate here, Dr. David Fitchett, Director, Coronary Care Unit, St. Michael’s Hospital, Toronto, Ontario and Dr. Jean-Lucien Rouleau, Dean, Faculty of Medicine, Université de Montréal, Quebec, discussed the relative benefits of these agents in patients with chronic heart failure. Arguing that ACE inhibitors retain an important advantage, Dr. Fitchett pointed out that they have been evaluated in more than 7000 individuals in some 30 placebo-controlled trials. Overall, they have reduced mortality by 23% in patients with heart failure; the figure is 26% in heart failure secondary to myocardial infarction (MI). They also reduce disease progression and decrease the incidence of sudden cardiac death and fatal MI, Dr. Fitchett noted.

When one compares clinical trial data with ARBs and ACE inhibitors, their benefits are broadly similar, Dr. Rouleau countered. In the CHARM (Candesartan in Heart Failure: Assessment of Reduction in Mortality and Morbidity) program, for example, individuals given the ARB candesartan as a substitute for an ACE inhibitor experienced a 23% reduction in the relative risk of cardiovascular (CV) death/heart failure hospitalization. Patients who received the ARB in addition to the ACE inhibitor experienced an additional 15% decrease in the relative risk of CV death/heart failure hospitalization; in this group, there was also a trend toward reduced all-cause mortality, Dr. Rouleau remarked. In the 7000 patients of CHARM, the ARB reduced MI by 23%, he added. Overall, he stated, accumulated evidence indicates that ARBs have a similar effect on CV mortality, heart failure hospitalizations, and MI as ACE inhibitors. They also reduce the incidence of diabetes to a similar extent, he noted.

VALIANT (Valsartan in Acute Myocardial Infarction Trial) findings indicated that in post-MI heart failure, the reduction in composite end points of CV death/MI, CV death/heart failure hospitalizations, and CV death/MI/hospitalizations were similar with valsartan and captopril, Dr. Rouleau observed. He added that the results would have been significantly in favour of the ARB if typical 95% rather than 97.5% confidence intervals had been employed. Similarly, in patients with preserved systolic function, CHARM investigators documented beneficial effects of candesartan on the occurrence of hospitalizations.

Data presented on a poster here by Dr. Subodh Verma, Division of Cardiac Surgery, University of Toronto (Dr. Rouleau was a coauthor), provide corroborative evidence on the effects of ARBs, Dr. Rouleau stated. In a retrospective analysis of 65,493 Ontario residents with heart failure, hospitalizations for an acute coronary syndrome decreased to a similar degree whether individuals had been prescribed an ARB or ACE inhibitor. “Using ACE inhibitors as a reference point, patients taking an ARB have a tendency to have benefit,” he explained. The hazard ratios for acute coronary syndrome in patients receiving an ARB vs. an ACE inhibitor were 0.84 for individuals with heart failure, 0.85 for those with atherosclerotic disease and 0.79 for those with diabetes.

“If you actually compare ACE inhibitors to ARBs, they are dead even,” Dr. Rouleau commented. The trend toward greater benefit with ARBs likely relates to the greater tolerability of these agents, he added. “If you have two equally effective medications, the one that the patient tolerates is the one you want to give, because they will benefit if they take [their medication] and won’t if they don’t.”

Multidisciplinary Disease Management

The 2006 heart failure guidelines emphasize that contemporary treatment requires more than drug therapy, and that many patients with heart failure can benefit from multidisciplinary disease management. Educating patients about nonpharmacologic approaches, and especially fluid and salt restriction, constitutes one of the most challenging aspects of care, commented Dr. Andrew Ignaszewski, Clinical Associate Professor of Cardiology, University of British Columbia, and Head of Cardiology, St. Paul’s Hospital, Vancouver. “Heart failure clinics and disease management programs can go far to help us in this difficult task,” he stated. Collaborative care also ensures patients are reminded about warning signs of decompensation, are screened for depression, and receive appropriate assistance when the time comes for palliative care.

In comments before the congress, Dr. Peter Liu, Heart and Stroke/Polo Chair in Cardiology, University of Toronto, Scientific Director, CIHR Institute of Circulatory and Respiratory Health, stated, “There is little question that because heart failure is a chronic disease [with] periods of stability and deterioration, the best way to manage it is to have a disease management team. There are robust data now that when you use an appropriate multidisciplinary team, you not only have a happier patient, you have better outcomes as well: decreased hospitalizations, decreased utilization of resources, and better use of medications.” Implementation of this care model is an ongoing challenge for the CCS and various other Canadian stakeholders. “The CCS is taking the lead [in this regard]. It is not just publishing guidelines but taking them to the wider medical community so that every practitioner knows the fundamental principles of treating patients with heart failure,” Dr. Liu observed.