Hollenberg S M, Tamburro P, Klein L W, Burns D, Easington C, Costanzo M R, Parrillo J E, Johnson M R
Section of Cardiology, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Ill 60612, USA.
J Heart Lung Transplant. 1998 May;17(5):487-94.
Cardiac allograft vasculopathy represents the leading cause of death in heart transplant recipients who survive more than 1 year. Functional endothelial abnormalities are sensitive measures of the early development of cardiac allograft vasculopathy, but the relative importance of large and small coronary vessel abnormalities has not been evaluated. The purpose of the study was to distinguish between large and small coronary endothelial dysfunction in patients early after heart transplantation and to test the hypothesis that microvascular endothelial responses can be preserved in the presence of epicardial endothelial dysfunction.
Changes in epicardial lumen area and coronary artery blood flow in response to intracoronary administration of adenosine, acetylcholine, and nitroglycerin were measured simultaneously by use of an intravascular ultrasound catheter positioned over a Doppler flow wire in the left anterior descending coronary artery. The combination of these techniques allowed distinction between large and small coronary vascular responses. In 19 patients studied early after transplantation, adenosine (16 and 32 microg), acetylcholine (5.4 and 54 microg), and nitroglycerin (200 microg) were infused, with continuous intravascular ultrasound imaging and Doppler velocity measurements.
Acetylcholine induced paradoxical epicardial vasoconstriction in 12 of 19 patients (73% +/- 6% of baseline); vasodilation occurred in 7 (108% +/- 3%). In spite of this constriction, coronary artery flow increased in all 19 patients, to the same extent in patients with constriction and those with dilation (239 +/- 26 vs 193 +/- 20, p = 0.38). Adenosine and nitroglycerin increased area (107% +/- 1% and 112% +/- 3%) and flow (258% +/- 17% and 197% +/- 11%) in all patients. None of the area or flow responses correlated with the degree of intimal thickening.
Acetylcholine increased coronary artery flow early after transplantation, indicating preserved microvascular responses in spite of epicardial vasoconstriction. Simultaneous measurement of area and velocity responses, by permitting evaluation of the relative contribution of epicardial and microvascular vessels, may offer unique insights into coronary endothelial function.
心脏移植血管病变是存活超过1年的心脏移植受者的主要死亡原因。功能性内皮异常是心脏移植血管病变早期发展的敏感指标，但大、小冠状动脉异常的相对重要性尚未得到评估。本研究的目的是区分心脏移植术后早期患者的大、小冠状动脉内皮功能障碍，并检验以下假设：在心外膜内皮功能障碍的情况下，微血管内皮反应仍可保留。
使用置于左前降支冠状动脉多普勒血流导丝上的血管内超声导管，同时测量冠状动脉内注射腺苷、乙酰胆碱和硝酸甘油后心外膜管腔面积和冠状动脉血流的变化。这些技术的结合可区分大、小冠状动脉血管反应。在19例移植术后早期接受研究的患者中，分别注入腺苷（16和32微克）、乙酰胆碱（5.4和54微克）和硝酸甘油（200微克），同时进行连续血管内超声成像和多普勒速度测量。
19例患者中有12例（占基线的73%±6%）乙酰胆碱诱发了矛盾的心外膜血管收缩；7例出现血管扩张（占基线的108%±3%）。尽管有这种收缩，但所有19例患者的冠状动脉血流均增加，收缩组和扩张组增加幅度相同（分别为239±26和193±20，p = 0.38）。腺苷和硝酸甘油使所有患者的管腔面积（分别为107%±1%和112%±3%）和血流（分别为258%±17%和197%±11%）增加。管腔面积或血流反应均与内膜增厚程度无关。
移植术后早期乙酰胆碱增加冠状动脉血流，表明尽管有心外膜血管收缩，但微血管反应仍得以保留。通过同时测量管腔面积和速度反应，从而评估心外膜和微血管的相对作用，可能为冠状动脉内皮功能提供独特的见解。
