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Despite these gains, recent evaluations indicate that the
prevalence of heart disease in most communities is rising steadily,
and that this is reflected in costs of hospitalisation if not in
mortality data.1 This rise suggests that the
strategies directed at reducing risk of ischaemic heart disease
(such as cessation of smoking and lowering of serum cholesterol
level) should be regarded as means of postponing disease onset rather
than as "vaccines" against eventual ischaemia. Therapies such as
thrombolytic agents3 and coronary
angioplasty4 for patients with acute
myocardial infarction, and -adrenoceptor antagonists5 and
angiotensin-converting enzyme (ACE) inhibitors6 for those with
symptomatic heart failure, have led to increased survival rates, and
thus more individuals with chronic heart disease. In addition, in
older people, increasing rates of atrial fibrillation and aortic
stenosis also contribute to cardiac disability.
The Cardiac Awareness Survey and Evaluation (CASE) Study examined
the current contributions of general practitioners to the diagnosis
and management of chronic heart failure (CHF) in patients over the age
of 60 years. The results, published in this issue of the Journal,7 shed considerable light on
the magnitude of this emerging problem in Australia.
One of the most complex questions in cardiology is the diagnosis of
CHF. In the vast majority of controlled clinical trials to date, the
diagnosis of CHF has been predicated on objective evidence of left
ventricular systolic dysfunction, documented by echocardiography
or radionuclide ventriculography. Most intervention studies have
only included patients with severe systolic dysfunction, in order to
maximise the frequency of end-points. Yet, this is just the tip of the
CHF iceberg in the general population. For patients with
predominantly diastolic, or mild degrees of systolic, left
ventricular (LV) dysfunction, estimation of LV ejection fraction
alone provides little diagnostic information, and the diagnosis of
CHF becomes somewhat arbitrary. This was so in some patients in the
CASE study: it is clear that GPs do not use echocardiography widely to
assess patients with possible CHF. This blurring around the edges of
the diagnosis (especially in patients with mild dysfunction) is
regrettable, but there is no easy solution. Conversely, however, it
is impossible to exclude from the CASE study design a number of
patients with LV dysfunction but minimal symptoms, a group which may
benefit from appropriate pharmacotherapy. Overall, one
recommendation from the CASE study, which resulted in new diagnosis
of CHF in 2% of the study population, is that widespread access to
echocardiography by GPs for people older than 60 years is likely to be
cost effective.
The major stimulus to the diagnosis of CHF is the institution of
appropriate therapy. It is here that the CASE study is most revealing.
There have been dramatic advances in the management of CHF in the past
15 years, resulting in considerable improvement in outcomes for this
patient population,8 although there is clearly
scope for further reductions in both morbidity
and mortality.9 ACE inhibitors (preferably
in the largest tolerated dose),6 spironolactone10 and
-adrenoceptor antagonists5 all reduce mortality and
morbidity in patients with LV systolic dysfunction. There is also
evidence for the use of angiotensin-receptor antagonists or
hydralazine/nitrates in patients intolerant of ACE inhibitors.
Digoxin, in patients in sinus rhythm, has no major effect on mortality
but slightly reduces hospitalisation risk.11 Conversely, some agents,
notably calcium antagonists12 and the COX-1 (and
possibly the COX-2)13
inhibitors, should be used with caution in
patients with CHF, and the role of diuretic therapy is probably
limited to the prevention of peripheral and/or pulmonary oedema.
It is therefore an important finding of the CASE study that, even in the
hands of an "interested" cohort of GPs, ACE inhibitors were used in
little more than half of the patients, and usually with low-dose
regimens. In contrast, use of diuretics and digoxin was surprisingly
high. This makes it clear that in Australia, as in other
countries,14 CHF is largely
under-treated, and the price we pay is increased risk of
deterioration, hospitalisation and death. It is possible, although
not specifically examined by the CASE study, that the prescribing
habits of GPs are directed towards agents which are likely to produce
rapid relief of symptoms rather than agents with prognostic
benefits.
The epidemic of CHF in older people has its counterpart in an explosion
of recent relevant clinical trial information. The HOPE study
results suggest that all patients at high risk of ischaemia should be
considered for treatment with ACE inhibitors, irrespective of the
presence or absence of CHF.15 The data on the beneficial
effect of spironolactone are quite recent, as are some of the
-adrenoceptor antagonist data. It is also clear that
community-based outreach services for CHF patients may improve
outcomes.16 Identification of and
optimal therapy for these patients constitutes a major challenge for
the new millennium.
John D Horowitz
Professor of Cardiology University of Adelaide, and Director
Cardiology Unit
North Western Adelaide Health Service, Adelaide, SA
Simon Stewart
Ralph Reader Postdoctoral Fellow Department of Public Health
University of Glasgow, Glasgow, UK
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trends in survival and coronary-event rates to changes in coronary
heart disease mortality: 10-year results from 37 WHO MONICA project
populations. Monitoring trends and determinants in cardiovascular
disease. Lancet 1999; 353: 1547-1557.
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Morrison C, Woodward M, Leslie W, Tunstall-Pedoe H. Effect of
socioeconomic group on the incidence of, management of, and survival
after myocardial infarction and coronary death: analysis of
community coronary event register. BMJ 1997; 314: 541-546.
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Indications for fibrinolytic therapy in suspected acute
myocardial infarction: collaborative overview of early mortality
and major morbidity results from all randomised trials of more than
1000 patients. Fibrinolytic Therapy Trialists' (FTT)
Collaborative Group. Lancet 1994; 343: 311-322.
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A clinical trial comparing primary coronary angioplasty with
tissue plasminogen activator for acute myocardial infarction. The
Global Use of Strategies to Open Occluded Coronary Arteries in Acute
Coronary Syndromes (GUSTO IIb) Angioplasty Substudy
Investigators. N Engl J Med 1997; 336: 1621-1628.
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Effect of metoprolol CR/XL in chronic heart failure: Metoprolol
CR/XL Randomised Intervention Trial in Congestive Heart Failure
(MERIT-HF). Lancet 1999; 353: 2001-2007.
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Packer M, Poole-Wilson PA, Armstrong PW, et al. Comparative
effects of low and high doses of the angiotensin-converting enzyme
inhibitor, lisinopril, on morbidity and mortality in chronic heart
failure. Circulation 1999; 100: 2312-2318.
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Krum H, Tonkin AM, Currie R, et al. Chronic heart failure in
Australian general practice. The Cardiac Awareness Survey and
Evaluation (CASE) Study. Med J Aust 2001; 174: 439-444.
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MacIntyre K, Capewell S, Stewart S, et al. Evidence of improving
prognosis in heart failure: trends in case-fatality in 66,547
patients hospitalised between 1986 and 1995. Circulation
2000; 102: 1126-1131.
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Stewart S, MacIntyre K, MacLeod MM, et al. Trends in
hospitalisation for heart failure in Scotland, 1990-1996. An
epidemic that has reached its peak? Eur Heart J 2001; 22:
209-217.
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Pitt B, Zannad F, Remme WJ, et al. The effect of spironolactone on
morbidity and mortality in patients with severe heart failure.
Randomized Aldactone Evaluation Study Investigators. N Engl J
Med 1999; 341: 709-717.
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The effect of digoxin on mortality and morbidity in patients with
heart failure. The Digitalis Investigation Group. N Engl J
Med 1997; 336: 525-533.
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O'Connor CM, Carson PE, Miller AB, et al. Effect of amlodipine on
mode of death among patients with advanced heart failure in the PRAISE
trial. Prospective Randomized Amlodipine Survival Evaluation.
Am J Cardiol 1998; 82: 881-887.
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Dzau VJ, Packer M, Lilly LS, et al. Prostaglandins in severe
congestive heart failure. Relation to activation of the
renin-angiotensin system and hyponatremia. N Engl J Med
1984; 310: 347-352.
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Edep ME, Shah NB, Tateo IM, Massie BM. Differences between primary
care physicians and cardiologists in management of congestive heart
failure: relation to practice guidelines. J Am Coll
Cardiol 1997; 30: 518-526.
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Yusuf S, Sleight P, Pogue J, et al. Effects of an
angiotensin-converting-enzyme inhibitor, ramipril, on
cardiovascular events in high risk patients. The Heart Outcomes
Prevention Evaluation Study Investigators. N Engl J Med
2000; 342: 145-153.
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Stewart S, Marley JE, Horowitz JD. Effects of a
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Duncan J Campbell. Heart failure: how can we prevent the epidemic? Med J Aust 2003; 179 (8): 422-425. [For Debate] <http://www.mja.com.au/public/issues/179_08_201003/cam10108_fm.html>
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