100 QUESTIONS IN CARDIOLOGY

19 Which class of antianginal agent should I

prescribe in stable angina? Does it matter?

Henry Purcell

Nitrates

All patients with angina pectoris should have sublingual glyceryl

trinitrate (GTN) for the rapid relief of acute pain. Long-acting

isosorbide dinitrate (ISDN) and isosorbide mononitrate (ISMN)

preparations are also available but have not been shown to

influence mortality in post-myocardial infarction (MI) patients.

Beta blockers

In the absence of contraindications, beta blockers are preferred as

initial therapy for angina.^1 Evidence for this is strongest for

patients with prior MI. Long term trials show that there is a 23%

reduction in the odds of death among MI survivors randomised to

beta blockers.^2

Calcium antagonists

Calcium antagonists (especially those which reduce heart rate)

are suitable as initial therapy when beta blockers are contra-

indicated or poorly tolerated. Outcome trials are underway but

there is currently little evidence to suggest they improve prog-

nosis post-MI, although diltiazem and verapamil may reduce the

risk of reinfarction in patients without heart failure,^3 and

amlodipine may benefit certain patients with heart failure.

Other agents

Nicorandil, a potassium channel opener with a nitrate moiety,

and the metabolic agent, trimetazidine, may also be useful, but

these have not been tested in outcome studies.

Many patients with exertional symptoms may need a

combination of anti-anginals, but there is little evidence to

support the use of “triple therapy”. Patients requiring this should

be assessed for revascularisation. There are no important differ-

ences in the effectiveness of the principal classes of anti-anginal