To the Editor: We were surprised that Campbell’s recent article on heart failure1 made no mention of sleep apnoea. This is despite the fact that about 50% of heart failure patients have sleep apnoea (either central or obstructive) and that quite a large body of literature now supports a causative relationship between obstructive sleep apnoea and congestive heart failure, supported by recent authoritative reviews. 2-4 Canine studies have shown that, in the absence of any other variable, obstructive sleep apnoea results in left ventricular systolic and diastolic dysfunction.

Importantly, the impact of continuous positive airway pressure (CPAP) in acute cardiogenic pulmonary oedema and subacute pulmonary oedema (central sleep apnoea) and heart failure in the setting of obstructive sleep apnoea are not mentioned. Identification and treatment of sleep apnoea in people with heart failure is supported by a trial we have recently conducted in which significant improvements in quality of life and objective markers of cardiac function were seen in patients treated with nasal CPAP.5

In reply: I am grateful to Naughton and colleagues for their contribution to the debate about how we might prevent the epidemic of heart failure.

I agree that both obstructive and central sleep apnoea are frequently associated with heart failure and that treatment of sleep apnoea can improve cardiac function. However, as indicated by its title, my article focused on how we might prevent heart failure. Central sleep apnoea in heart failure is usually the consequence of the heart failure.1 Heart failure may contribute to obstructive sleep apnoea as well,2 and obstructive sleep apnoea may, in turn, be an important contributor to heart failure pathogenesis.

Epidemiological evidence links obesity with hypertension and obstructive sleep apnoea.3 Significant sleep apnoea is present in about 40% of obese people, and about 70% of people with obstructive sleep apnoea are obese.3 Obesity and obstructive sleep apnoea may each contribute to one another, and both may contribute to hypertension. The need to prevent obstructive sleep apnoea is an argument for more effective prevention of obesity. In addition to reducing its metabolic consequences, preventing obesity is likely to reduce the incidence of hypertension and obstructive sleep apnoea, and to thereby decrease the incidence of heart failure.

For people with obstructive sleep apnoea not caused by obesity, alternative strategies will be required to prevent and treat the sleep apnoea and thus prevent its consequences.