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Nifedipine and thallium-201 myocardial perfusion in progressive systemic sclerosis
Insights
Nifedipine improved myocardial perfusion in patients with progressive systemic sclerosis, suggesting reversible coronary vasomotion abnormalities. Further studies are needed to determine long-term therapeutic effects.
Area of Science:
- Cardiology
- Pharmacology
- Radiology
Background:
- Heart disease in progressive systemic sclerosis is linked to coronary microcirculation issues.
- Myocardial ischemia may result from these microcirculation disturbances.
Purpose of the Study:
- To assess if myocardial perfusion abnormalities in systemic sclerosis are reversible.
- To evaluate the effect of nifedipine, a coronary vasodilator, on myocardial perfusion.
Main Methods:
- 20 patients with progressive systemic sclerosis underwent thallium-201 scanning.
- Scans were performed before and after oral administration of 20 mg nifedipine.
- Myocardial perfusion was assessed using single-photon emission computerized tomography (SPECT).
Main Results:
- Nifedipine significantly reduced the number of left ventricular segments with perfusion defects (5.3 to 3.3).
- Perfusion scores improved, with the mean global perfusion score increasing from 11.2 to 12.8.
- Ten patients showed a significant global perfusion score increase, indicating short-term improvement.
Conclusions:
- Nifedipine demonstrates short-term improvement in myocardial perfusion in systemic sclerosis patients.
- Findings suggest a potentially reversible coronary vasomotion abnormality in this condition.
- Long-term therapeutic benefits of nifedipine require further investigation.
Abstract:
Heart disease in patients with progressive systemic sclerosis may be due in part to myocardial ischemia caused by a disturbance of the coronary microcirculation. To determine whether abnormalities of myocardial perfusion in this disorder are potentially reversible, we evaluated the effect of the coronary vasodilator nifedipine on myocardial perfusion assessed by thallium-201 scanning in 20 patients. Thallium-201 single-photon-emission computerized tomography was performed under control conditions and 90 minutes after 20 mg of oral nifedipine. The mean (+/- SD) number of left ventricular segments with perfusion defects decreased from 5.3 +/- 2.0 to 3.3 +/- 2.2 after nifedipine (P = 0.0003). Perfusion abnormalities were quantified by a perfusion score (0 to 2.0) assigned to each left ventricular segment and by a global perfusion score (0 to 18) for the entire left ventricle. The mean perfusion score in segments with resting defects increased from 0.97 +/- 0.24 to 1.26 +/- 0.44 after nifedipine (P less than 0.00001). The mean global perfusion score increased from 11.2 +/- 1.7 to 12.8 +/- 2.4 after nifedipine (P = 0.003). The global perfusion score increased by at least 2.0 in 10 patients and decreased by at least 2.0 in only 1. These observations reveal short-term improvement in thallium-201 myocardial perfusion with nifedipine in patients with progressive systemic sclerosis. The results are consistent with a potentially reversible abnormality of coronary vasomotion in this disorder, but the long-term therapeutic effects of nifedipine remain to be determined.