Tatsuhiko Asano

Effect of balloon inflation time on expansion of sirolimus-eluting stent

There is little information about the relationship between balloon inflation time and sirolimus-eluting stent (SES) expansion. In this randomized intravascular ultrasound (IVUS) study, 92 de novo lesions in native coronary arteries that underwent SES implantation were enrolled. Sirolimus-eluting stent was implanted using an inflation pressure of 14 atm. Stent balloon was gradually inflated until 14 atm in 10 s. In the short inflation group, it was deflated immediately after an image of the balloon inflated at 14 atm was taken. Stent balloon inflation lasted 60 s in the long inflation group. Intravascular ultrasound was then performed. The long balloon inflation resulted in a larger stent cross-sectional area (4.9 ± 1.6 mm2 vs 4.3 ± 1.4 mm2, P < 0.05) and expansion (71% ± 13% vs 60% ± 13%, P < 0.001) compared to the short balloon inflation, although stent expansion was relatively low in both groups. The relatively longer balloon inflation time using an inflation pressure of 14 atm results in better SES expansion. However, in the majority of lesions, adequate stent expansion is not achieved even using long balloon inflation, if it is inflated at 14 atm.

Ubiquitous atherosclerosis in coronary arteries without angiographically significant stenosis

Previous intravascular ultrasound (IVUS) studies have shown coronary artery atherosclerosis even in angiographically normal reference segment. However, IVUS has not been performed in all of the three major coronary arteries. A total of 50 patients with single-vessel disease underwent IVUS evaluation in the proximal two-thirds of the three major coronary arteries. Lumen and external elastic membrane cross-sectional areas were measured at 1-mm intervals. To compensate the difference in pullback length among coronary arteries, normalized total plaque and media volume (TPV) was calculated as TPV/number of slices in pullback × median number of slices in study population. Percent plaque and media volume (PPV) was calculated as TPV/Σ external elastic membrane cross-sectional area × 100. A cross section was defined as atherosclerotic if maximum intimal thickness exceeded 0.5 mm at any point in the vessel circumference. There was no significant difference in normalized TPV, PPV, and the incidence of abnormal intimal thickness between coronary arteries with and without significant stenosis. Frequency distribution of plaque burden was similar. Atherosclerosis is ubiquitous even in coronary arteries without angiographically significant stenosis. The extent of atherosclerosis is similar between coronary arteries with and without significant stenosis.

Multivessel Coronary Artery Spasm Refractory to Intensive Medical Treatment

This case report describes multivessel coronary artery spasm refractory to oral nifedipine, intravenous isosorbide dinitrate, diltiazem and nicorandil, and intracoronary nitroglycerin. Intracoronary administration of nicorandil only transiently relieved coronary artery spasm. Prednisolone was effective in preventing coronary artery spasm.