Researchers say that a drug frequently used to treat gout can also relieve angina.
The Lancet reports that allopurinol is cheap compared with some other angina drugs, and seems to work by reducing the energy needs of the heart.
Scientists from Dundee University studied 65 angina patients, and found those on allopurinol could exercise for longer periods without chest pain.
Angina is the most common symptom of heart disease, and affects around two million people in the UK.
Some treatments already exist, but for many patients they may not work and for others they can prove too costly.
Professor Allan Struthers and his team believe allopurinol could fill this void.
He told The Lancet, "On the basis of our results, allopurinol is a useful anti-ischaemic treatment option in patients with angina that has the advantage of being inexpensive, well tolerated and safe in the long term.
"The precise place of allopurinol in the management of angina pectoris now needs to be explored further, but this drug might be especially appealing for use in developing countries where coronary artery disease is rapidly increasing in frequency and where access to expensive drugs or invasive treatments (angioplasty and bypass surgery) is often restricted."