Telmisartan, an angiotensin II type 1 receptor blocker, improves coronary microcirculation and insulin resistance among essential hypertensive patients without left ventricular hypertrophy.

Hypertension and insulin resistance are associated with reduced coronary vasodilatory capacity, possibly caused by structural changes in the coronary resistance vessels. The goal of this study was to compare the effect of an angiotensin receptor blocker (ARB) with that of a calcium channel blocker (CCB) on coronary flow reserve and insulin resistance among essential hypertensive patients without left ventricular hypertrophy. A total of 40 consecutive essential hypertensive patients were randomized to daily 40 mg telmisartan or 20 mg nifedipine coat-core treatment. Coronary flow velocity reserve (CFVR) measurement using transthoracic Doppler echocardiography and blood tests were performed before and after 12 weeks of treatment. At baseline, blood pressure, CFVR, and homeostasis model assessment of insulin resistance (HOMA-IR) were not significantly different between the two groups. At the end of the treatment period, the telmisartan and nifedipine groups exhibited similar declines in blood pressure. CFVR was improved in the telmisartan group (2.4+/-0.4 to 2.9+/-0.4; p<0.01), but there was no difference in the nifedipine group (2.5+/-0.3 to 2.5+/-0.3; n.s.). HOMA-IR was improved in the telmisartan group (3.1+/-1.1 to 1.6+/-0.7; p<0.01), but there was no difference in the nifedipine group (2.8+/-1.1 to 2.4+/-0.7; n.s.). In conclusion, this study demonstrates that antihypertensive therapy with telmisartan, but not nifedipine, has a beneficial effect on coronary microcirculation and insulin resistance among essential hypertensive patients.

Noninvasive assessment of coronary stents in patients by 16-slice computed tomography.

BACKGROUND: The usefulness of thin-slice multi-detector computed tomography (MDCT) has been highly expected to assess the lumens of coronary artery stents. We evaluated the usefulness of 16-slice MDCT to assess the in-stent lumen after coronary artery stenting. METHODS: In 42 consecutive patients after coronary artery stenting, retrospective ECG-gated CT-angiography using 16-slice MDCT (0.5-s rotation time, 16x0.625-mm detector collimation) was performed. The qualitative assessability of the lumens of 61 coronary stents (14 different types) by MDCT and the reasons for non-assessability were investigated. Furthermore, the evaluation of in-stent restenosis in 21 assessable stents of 16 patients, including quantitative density analysis by MDCT, was performed and the results were compared with those of conventional coronary angiography (CAG). RESULTS: Of 61 stents, 42 (68.9%) were assessable. The assessability of diameter > or =3.5-mm stents made of stainless steel or cobalt was high (88.6%, 31/35), that of 3.0-mm stents was low (57.9%, 11/19) and all 2.5-mm stents were non-assessable due to partial volume effects and metal artifacts of stents. The lumens of stents made of tantalum were totally obscured and the metal artifacts of Bestent2 (gold markers) and S670 were severer than others. All non-assessable stents due to banding artifact and calcification were implanted in segment #1-3 and #6, respectively. In comparison to CAG, MDCT correctly detected the 5 in-stent restenoses and identified absence of restenoses was influenced strongly by the stent strut. CONCLUSION: Despite some limitations, 16-slice MSCT is sufficiently useful for assessment of various coronary stents in patients and can detect in-stent restenoses of assessable stents with high accuracy in comparison to CAG.

Ability for visualization, reasons for nonassessable image, and diagnostic accuracy of 16-slice multidetector row helical computed tomography for the assessment of the entire coronary arteries.

It was demonstrated that 16-slice multidetector row helical computed tomography may permit more accurate assessment of entire coronary arteries, with a low rate of arteries unable to be evaluated. The detection of coronary artery stenoses with this modality was applicable to assessable segments.