Improved detection of myocardial perfusion reversibility by rest-nitroglycerin Tc-99m-MIBI: comparison with TI-201 reinjection.

BACKGROUND: The role of nitroglycerin (NTG) in Tc-99m-methoxyisobutil isonitrile (MIBI) studies to improve the assessment of myocardial viability in patients with coronary artery disease and its comparison with TI-201 reinjection has not yet been clarified. This study aimed to test whether sublingual administration of NTG could improve the capability of Tc-99m-MIBI to detect reversibility in exercise-induced perfusion defects and to compare it with the TI-201 stress-redistribution-reinjection protocol. METHODS AND RESULTS: Thirty-eight patients (33 men, 5 women; mean age 49.3 +/- 8.2 years with previous myocardial infarction [mean evolution 7.1 +/- 3.9 months]) underwent exercise, redistribution, and reinjection TI-201 imaging, as well as exercise, rest, and NTG MIBI myocardial scintigraphy (3-day protocol). A total of 494 myocardial segments were assessed by quantitative analysis. Of the 136 myocardial segments with fixed defects on exercise-rest sestamibi imaging, 109 (80%) did not change after NTG MIBI study, and 27 (20%) demonstrated enhanced uptake. In the 140 myocardial segments with fixed defects on exercise-redistribution thallium imaging, 112 (80%) did not improve after TI-201 reinjection study, and 28 (20%) showed increased activity. The observed agreement on reversibility detection between NTG MIBI and TI-201 reinjection, with the 210 segments with perfusion defects used for this analysis on both studies, was 78%, with a significant kappa = .56 +/- .07 SE. CONCLUSION: Our data suggest that the use of an NTG MIBI protocol results in an incremental improvement for detecting exercise-induced perfusion defect reversibility and achieves results similar to those from a TI-201 reinjection protocol.

Long-term therapy with policosanol improves treadmill exercise-ECG testing performance of coronary heart disease patients.

This study examined the effects of long-term lipid-lowering therapy with policosanol on the clinical evolution, and exercise-ECG testing responses of 45 coronary heart disease (CHD) patients with myocardial ischemia, documented by exercise 201T1-myocardial perfusion scintigraphy, in an overall randomized, double-blind, placebo-controlled trial, made for different test endpoints. Fifteen patients were treated with 5 mg of policosanol twice daily; another 15 patients were administered the same drug dose plus 125 mg aspirin; and the other 15 patients received placebo plus equal aspirin dose. They were followed for 20 months, previous baseline observations, with treadmill exercise-ECG, besides serum lipid test. Beneficial changes on proportions among the 2 policosanol groups and the placebo group, showed an increment on functional capacity class, a decrement on rest and exercise angina, and a significant decrease in cardiac events, and in ischemic ST segment response, especially in the policosanol plus aspirin group (p = 0.05, X2(2df) = 5.8; p = 0.04, p = 0.02; Fisher). After treatment, sets of mean changes revealed an increase on maximum oxygen uptake, and a decline on double product simultaneously in both policosanol groups (p < or = 0.02, p < or = 0.002; Pillais, Hotellings' T2), while the placebo group was impaired. Aerobic functional capacity percent showed an increment in policosanol groups (p < or = 0.05, paired T). Lipid levels improved as other endpoints already reported. A supposed ergogenic effect of octacosanol, policosanol's main active compound, was not detected with this design. These results show that policosanol-treated CHD patients improved clinical evolution, and exercise-ECG responses, owing to the amelioration of myocardial ischemia, even more when administered with aspirin.