100 QUESTIONS IN CARDIOLOGY

54 What is the role of vasodilators in chronic

heart failure? Who should receive them?

Lionel H Opie

There are three main groups of vasodilator therapies used in the

treatment of chronic heart failure.

Nitrates alone

Nitrates on their own can be used intermittently for relief of

dyspnoea – not well documented, but logical to try. For example,

intermittent sublingual or oral nitrates may benefit a patient

already on high doses of loop diuretics and an ACE inhibitor, but

who still has severe exertional or nocturnal dyspnoea, and needs

relief. The continuous use of nitrates does, however, run the risk

of nitrate tolerance, which in turn may be lessened by

combination with hydralazine.^1

Nitrates plus hydralazine

Nitrates plus hydralazine are better than placebo in chronic heart

failure, although inferior to ACE inhibitors. They therefore

represent treatment options when the patient experiences ACE

intolerance, although the drugs of choice for this situation would

be the angiotensin receptor blockers.

The long-acting dihydropyridines (DHPs, e.g. amlodipine and

felodipine)

Regarding the calcium blockers, the non-DHPs are contra-

indicated whereas the long acting DHP amlodipine has

suggestive benefit on mortality in non-ischemic cardiomyopathy,

as shown in the PRAISE study.^2 In the ischaemic patients, the

drug was safe yet without any suggestion of mortality benefit.

Hypothetically, part of the benefit in dilated cardiomyopathy

could be by inhibition of cytokine production,^3 and not by

vasodilatation. PRAISE 2 is focusing on non-ischaemic cardiomy-

opathy patients. In the meantime, long acting DHPs such as

amlodipine or felodipine may be cautiously added when heart

failure patients still have angina that persists after nitrates and