Ergonovine test in angina with normal coronary arteries. Is it worth doing it?

Patients with angina and normal coronary arteries are often misdiagnosed with having non-cardiac pain. Although vasospasm is a well-known entity, spasm provocation is not routinely done in the majority of hospitals at present.

One hundred and sixty two consecutive patients with thoracic pain and normal coronary arteries were retrospectively studied. The characteristics of pain were analysed. One hundred and sixty one non-invasive tests (with and without imaging) were done to 126 patients before angiography. Increasing doses of ergonovine (from 1 to 30 microg) were injected into the coronary arteries to provoke coronary spasm. The correlation between ergonovine-induced spasm and non-invasive tests was studied.

Oppressive thoracic pain suggestive of angina was present in 144 patients. It occurred at rest in 59 patients, only at night in 14, with effort in 40, and it was mixed in 31. Non-oppressive atypical pain was reported by 18 patients. Non-invasive tests were 94 positive, 60 negative and 7 non-diagnostic. Ergonovine test elicited coronary spasm in 85 patients (52.5%). No significant correlation was found between the positivity of a non-invasive test and ergonovine-induced spasm.

More than half of the patients with angina and normal coronary arteries can be diagnosed with vasospastic angina if ergonovine test is performed. Even patients with a negative non-invasive test maybe sent to coronary angiography when vasospastic angina is suspected, in order to have an accurate diagnosis.