TRANSDERMAL NITROGLYCERIN PATCH THERAPY REDUCES THE EXTENT OF EXERCISE-INDUCED MYOCARDIAL-ISCHEMIA - RESULTS OF A DOUBLE-BLIND, PLACEBO-CONTROLLED TRIAL USING QUANTITATIVE TL-201 TOMOGRAPHY

Objectives. This study prospectively evaluated whether trans dermal ni troglycerin patches could limit the extent of exercise-induced left ve ntricular ischemia as assessed by quantitative thallium-201 tomography . Background. Although antianginal medications are effective at reduci ng chest pain symptoms in patients with coronary artery disease, there is limited evidence that these agents can also reduce myocardial isch emia. Methods. This was a randomized, double blind, parallel, placebo- controlled trial evaluating nitroglycerin patch therapy in patients in stable condition with angiographic coronary artery disease and no pre vious myocardial infarction. All patients were weaned from antianginal agents and had a baseline symptom-limited treadmill test followed by thallium-201 tomography. Forty patients with perfusion defects involvi ng greater than or equal to 5% of the left ventricle were randomized t o receive either intermittent (12 h on/off) active nitroglycerin patch therapy (0.4 mg/h) or placebo. Exercise tomography was repeated a mea n (+/-SD) of 6.1 +/- 1.8 days after randomization. Results. Patients r andomized to receive active patch therapy had a significant reduction in their total perfusion defect size (-8.9 +/- 11.1%) compared with pl acebo treated patients (-1.8 +/- 6.1%, p = 0.04), which was most appar ent in those with the largest (greater than or equal to 20%) baseline perfusion defects (-11.4 +/- 13.4% vs. 1.0 +/- 3.6%, respectively, p < 0.02). Furthermore, 7 (33%) of 21 patients receiving active therapy h ad a greater than or equal to 10% decrease in their perfusion defects compared with only 1 (5%) of 19 patients randomized to receive placebo (p = 0.002). Nitrate therapy did not significantly reduce heart rate, blood pressure or double product, indicating benefit through enhancem ent of coronary blood dow. Conclusions. Short-term, intermittent nitro glycerin patch therapy significantly reduces myocardial ischemia, part icularly in patients with large ischemic perfusion defects. Thallium-2 01 tomography can be used to assess sequential changes in the extent o f exercise-induced left ventricular ischemia.