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Therapy of coronary vasoconstriction in patients with coronary artery disease
Insights
Patients with coronary artery disease show abnormal coronary vasoconstriction during cold exposure. Nifedipine, a calcium channel blocker, effectively prevented this response, suggesting it as a potential treatment for angina.
Area of Science:
- Cardiology
- Pharmacology
Background:
- Patients with obstructive coronary artery disease (CAD) and stable exertional angina exhibit an abnormal increase in coronary vascular resistance in response to alpha-adrenergic stimuli, such as the cold pressor test.
- This exaggerated vasoconstriction may contribute to the pathogenesis of ischemic heart disease.
Purpose of the Study:
- To investigate the clinical significance of abnormal coronary vasoconstriction in response to cold pressor test in patients with CAD.
- To evaluate the efficacy of calcium antagonists, specifically nifedipine, in preventing cold-induced coronary vasoconstriction.
Main Methods:
- Utilized the cold pressor test to assess coronary vascular resistance in patients with obstructive coronary artery disease.
- Administered nifedipine (10 mg buccally) or placebo to patients and measured the impact on coronary vascular resistance during the cold pressor test.
- Assessed systemic hemodynamics and myocardial oxygen consumption.
Main Results:
- Patients with obstructive CAD and angina showed an inappropriate increase in coronary vascular resistance during the cold pressor test.
- Buccal nifedipine (10 mg) completely prevented the increase in coronary vascular resistance in all patients tested (10/10).
- Placebo did not alter the abnormal response. Nifedipine did not affect systemic hemodynamics or myocardial oxygen consumption.
Conclusions:
- The abnormal coronary vasoconstrictive response to cold stress in obstructive CAD patients is clinically significant.
- Calcium antagonists, exemplified by nifedipine, demonstrate a selective antivasoconstrictor effect on the coronary vasculature.
- Nifedipine may be an effective therapeutic option for managing coronary vasoconstriction and preventing angina in susceptible patients.
Abstract:
Patients with obstructive coronary artery disease and stable, exertional angina respond to the alpha adrenergic stimulus of the cold pressor test with an inappropriate increase in coronary vascular resistance. The clinical significance of this abnormal response and its possible role in the pathogenesis of ischemic heart disease are discussed. Comparison of the anti-anginal agents currently in use of undergoing investigation suggests that the calcium antagonists may be the most effective therapy for coronary vasoconstriction. Nifedipine, 10 mg buccally, successfully prevented the increase in coronary vascular resistance during the cold pressor test in 10 of 10 patients, whereas the response in placebo-treated patients was unaltered. This dose of nifedipine was without effect on systemic hemodynamics or myocardial oxygen consumption, suggesting a selective antivasoconstrictor effect on the coronary vasculature.