BRONCHIAL HYPERRESPONSIVENESS TO ACETYLCHOLINE IN PATIENTS WITH VASOSPASTIC ANGINA-PECTORIS

Study objective: To investigate the similarity between coronary vasospasm and bronchial spasm. Design: Nonrandomized, case-control study. Setting: Referral-based clinics for cardiac and pulmonary disease at one secondary care center. Patients: Seventeen patients with vasospastic angina pectoris (VSAP) and 14 patients with chest pain syndrome (CPS). Interventions: Medications prohibited: those with known effects on bronchial responsiveness. Measurement: Induction of coronary vasospasm: ergonovine maleate (10, 20, 40 mu g) injection into coronary arteries during coronary angiography. Bronchial responsiveness to acetylcholine (ACh): acetylcholine chloride (0.08 to 20 mg/ml) inhalation and calculation of the provocative concentration of ACh (PC20-ACh) that revealed 20 percent fall in FEV(1). Results: The median value for PC20-ACh in patients with VSAP, 7.80 mg/ml, was significantly lower than that in patients with CPS, > 20.0 mg/ml (p < 0.01 by Mann-Whitney U test). The PC20-ACh in patients with VSAP, however, was correlated neither with the responsive threshold of ergonovine maleate, which induced coronary vasospasm, nor with the duration from the latest angina attack. Conclusion: These results suggest that bronchial responsiveness was increased in most patients with VSAP, but not with CPS. We therefore speculate that patients with VSAP may also have hypercontractibility to ACh of noncoronary systemic smooth muscles.