Department of Internal Medicine and Systemic Disease, Catheterization Laboratory and Cardiovascular Interventional Unit, Cannizzaro Hospital, University of Catania, Italy.
J Am Coll Cardiol. 2012 Feb 21;59(8):711-8. doi: 10.1016/j.jacc.2011.10.894.
The aim of our study was to assess coronary vasomotion after successful revascularization of chronic total occlusion (CTO).
It is largely unknown whether the recovery of anterograde flow after CTO recanalization with drug-eluting stent implantation affects vascular function in distal coronary segments.
One hundred consecutive CTOs successfully treated with drug-eluting stents underwent coronary diameter measurement after intracoronary nitroglycerin injection 5, 20, and 35 mm distal to the stented coronary segment using 3-dimensional quantitative coronary angiography. In a subgroup of 14 patients, coronary vasomotion was tested in distal segments: incremental atrial pacing for endothelium-dependent cases; and intracoronary nitroglycerin injection for endothelium-independent cases. In another subgroup of 13 patients, distal vessels were assessed by intracoronary ultrasounds.
Vessel diameters significantly increased at follow-up as compared to baseline values (2.0 ± 0.52 mm vs. 2.25 ± 0.50 mm, 1.76 ± 0.49 mm vs. 2.05 ± 0.58 mm, 1.54 ± 0.53 mm vs. 2.04 ± 0.58 mm, at each segment analyzed; p < 0.001). At baseline, distal segments failed to respond to both endothelium-dependent and -independent stimuli. At follow-up, atrial pacing induced vasoconstriction, whereas nitroglycerine administration resulted in significant vasodilation (p < 0.05). Intracoronary ultrasounds failed to show changes of the cross-sectional area of distal segments at follow-up angiography.
Recanalization of CTO is followed by a hibernation of vascular wall at distal coronary segments that fail to respond to endothelium-dependent and -independent stimuli. Distal vessel diameter increases over time in the absence of positive remodeling and in spite of persistent endothelial dysfunction. This severe impairment of vasomotor tone after CTO reopening suggests that intracoronary ultrasound assessment is of paramount importance for the selection of stent size.
本研究旨在评估慢性完全闭塞（CTO）成功血运重建后的冠脉血管舒缩功能。
CTO 血运重建后顺行血流的恢复是否会影响远端冠脉节段的血管功能，目前尚不清楚。
连续 100 例 CTO 患者成功接受药物洗脱支架置入治疗，在支架段远端 5、20、35mm 处注射硝酸甘油后，使用三维定量冠状动脉造影测量冠状动脉直径。在 14 例患者的亚组中，通过递增心房起搏（内皮依赖性）和冠状动脉内注射硝酸甘油（内皮非依赖性）测试远端血管的舒缩功能。在另外 13 例患者的亚组中，通过冠状动脉内超声评估远端血管。
与基线值相比，随访时血管直径显著增加（分别为 2.0±0.52mm 比 2.25±0.50mm，1.76±0.49mm 比 2.05±0.58mm，1.54±0.53mm 比 2.04±0.58mm，每个节段均有差异；p＜0.001）。基线时，远端节段对内皮依赖性和非依赖性刺激均无反应。随访时，心房起搏诱导血管收缩，而硝酸甘油给药导致明显的血管舒张（p＜0.05）。冠状动脉内超声未能显示随访时血管造影远端节段的横截面积变化。
CTO 再通后，远端冠脉节段的血管壁休眠，对内皮依赖性和非依赖性刺激无反应。尽管内皮功能持续障碍，但随着时间的推移，远端血管直径增加。CTO 再通后血管舒缩功能严重受损提示，冠状动脉内超声评估对于支架大小的选择至关重要。
