Abstract 5252: Long-Term Administration of Thiazolidinedione Improves Vasomotion of Coronary Arteries Irrespective of Improvements in Diabetic Status for Patients Receiving an Angiotensin-II Receptor Blocker
Background: Effects of insulin sensitizing agents on coronary artery pathophysiology have marked attention, but the long-term effects remain uncertain. We previously reported clinical effects of thiazolidinedione, and adverse prognostic impacts of vasomotor dysfunction in coronary arteries. This study evaluated long-term effects of thiazolidinedione, an insulin sensitizer, on vasomotion of coronary arteries frequently affected by diabetes mellitus, in patients treated with an angiotensin-II receptor blocker, one of the best possible antiatherosclerotic therapies.
Methods: Twenty-two type-2 diabetic patients treated with an angiotensin-II receptor blocker, were randomized where they received troglitazone (400mg/ day) or pioglitazone (30mg/day) (group-T), or they received therapy without thiazolidinedione for more than 1 year (group-C). We measured reactive changes in coronary blood flow (coronary flow reserve: CFR) or reactive endothelium-dependent dilatation (FMD) of coronary arteries to infusion of ATP (50μg) into the study (normal or minimally diseased) left coronary artery. CFR (maximal hyperemic flow-baseline flow/baseline flow) was quantified by coronary angiography and intracoronary doppler-guidewire. Changes in CFR and FMD were compared between the 2 groups.
Results: All the enrolled patients manifested good compliance to the treatment and there were improvements in some of metabolic variables in group-T (n=11). CFR increased in group-T (p=0.027) but not in group-C (p=0.102). FMD also increased in group-T (p<0.001), while it remained unchanged in group-C (p=0.768). Changes of CFR or FMD did not correlate to those of HbA1c (CFR: r=0.19, p=0.66, FMD: r=0.15, p=0.80).
Conclusion: This study suggests that long-term thiazolidinedione use improves vasomotion of coronary arteries irrespective of glucose metabolic status, which may have beneficial potentials for management of coronary artery disease with type-2 diabetes mellitus.