The present study was performed for characterizing the effect of chronic oral treatment with the
calcium antagonist
gallopamil on regional myocardial perfusion and
free fatty acid utilization in poststenotic human myocardium. Twenty-two patients with angiographically documented
coronary artery disease and
stable angina pectoris underwent consecutive dual-
isotope studies following simultaneous injection of 80 MBq
thallium-201 and 200 MBq
iodine-123 phenylpentadecanoic
acid (
IPPA) during a symptom-limited stress test.
Radionuclide studies were performed after 1 week of placebo treatment (baseline), 4 weeks after oral treatment with 50 mg of
gallopamil t.i.d. and again after 1 week of double-blind treatment with
gallopamil or placebo. As compared to baseline, initial (poststress) uptake of both tracers in poststenotic myocardial segments was significantly improved after 4 weeks of treatment with
gallopamil [
thallium-201, +9.0%; p < 0.001; 95% confidence interval (CI), 4.3-13.6%;
IPPA, +11.8%; p = 0.003; 95% CI, 4.2-19.3%]. Poststenotic
IPPA-clearance was likewise significantly increased (+28.2%; p < 0.001; 95% CI, 12.4-44.0%) indicating a considerably enhanced myocardial
fatty acid oxidation
after treatment. In the final double-blind phase, myocardial uptake of both tracers as well as
IPPA clearance remained enhanced in the subgroup of patients receiving
gallopamil and returned to baseline values in patients receiving placebo. Thus, in poststenotic myocardium, chronic treatment with
gallopamil provokes an improvement of both regional myocardial perfusion (as demonstrated by an increased tracer uptake in poststress scintigrams) and regional myocardial
fatty acid utilization (as demonstrated by an increased uptake and clearance of
IPPA).