[Prognostic value of coronary spasm threshold determined by the ergometrine test]

The prognosis of spastic angina is difficult to determine. The object of this study was to try to evaluate the prognosis of coronary spasm on the results of provocative, ergometrine testing. Out of 708 patients with angiographically normal or near-normal coronary arteries undergoing the ergometrine test for assessment of chest pain, 78 patients with positive results were retained for study. The threshold of spasm was established in every case: this was defined as the quantity of ergometrine per kilogramme body weight required to provoke spasm. The values ranged from 1 to 12.5 micrograms/kg (average 7.58 micrograms/kg +/- 3.84). The reproducibility of the ergometrine test appeared to be very satisfactory. In the short term, only 4 out of 32 tests became negative. The test remained positive in 28 cases and the mean value of the threshold of spasm did not change significantly (5.64 +/- 3.27 to 5.52 +/- 3.18 micrograms/kg). In the long term only 2 out of 18 tests became negative. The test remained positive in 16 cases and the mean value of the threshold of spasm did not change significantly (5.68 +/- 2.96 to 6.58 +/- 3.11 micrograms/kg). The ergometrine test with a reference threshold of positivity of 5 micrograms/kg is doubly useful: this threshold value helps predict a good response to calcium inhibitor drugs: the threshold of spasm was less than this value in 6 of the 41 patients whose tests became negative after diltiazem therapy, and in 12 of 14 patients in whom the test remained positive (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)