Mullis-Jansson S L, Argenziano M, Corwin S, Homma S, Weinberg A D, Williams M, Rose E A, Smith C R
Departments of Anesthesiology, Surgery,and Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA.
J Thorac Cardiovasc Surg. 1999 Jun;117(6):1128-34. doi: 10.1016/s0022-5223(99)70249-7.
Although triiodothyronine deficiency has been described after cardiopulmonary bypass, data supporting its use have been conflicting. A double-blind, randomized, placebo-controlled study was undertaken to further define the effect of triiodothyronine on hemodynamics and outcome after coronary artery bypass grafting.
A total of 170 patients undergoing elective coronary artery bypass grafting were enrolled and completed the study from November 1996 through March 1998. On removal of the aortic crossclamp, patients were randomized to receive either intravenous triiodothyronine (0.4 microgram/kg bolus plus 0.1 microgram/kg infusion administered over a 6-hour period, n = 81) or placebo (n = 89). Outcome variables included hemodynamic profile and inotropic drug/pressor requirements at several time points (mean +/- standard error of the mean), perioperative morbidity (arrhythmia/ischemia/infarction), and mortality.
Despite similar baseline characteristics, patients randomized to triiodothyronine had a higher cardiac index and lower inotropic requirements after the operation. Subjects receiving triiodothyronine demonstrated a significantly lower incidence of postoperative myocardial ischemia (4% vs 18%, P =.007) and pacemaker dependence (14% vs 25%, P =.013). Seven patients in the placebo group required postoperative mechanical assistance (intra-aortic balloon pump, n = 4; left ventricular assist device, n = 3), compared with none in the triiodothyronine group (P =.01). There were 2 deaths in the placebo group and no deaths in the triiodothyronine group.
Parenteral triiodothyronine given after crossclamp removal during elective coronary artery bypass grafting significantly improved postoperative ventricular function, reduced the need for treatment with inotropic agents and mechanical devices, and decreased the incidence of myocardial ischemia. The incidence of atrial fibrillation was slightly decreased, and the need for postoperative pacemaker support was reduced.
尽管体外循环后已出现三碘甲状腺原氨酸缺乏的描述，但支持其应用的数据一直存在矛盾。为此开展了一项双盲、随机、安慰剂对照研究，以进一步明确三碘甲状腺原氨酸对冠状动脉旁路移植术后血流动力学及预后的影响。
1996年11月至1998年3月，共纳入170例行择期冠状动脉旁路移植术的患者并完成研究。在松开主动脉阻断钳后，患者被随机分为两组，分别接受静脉注射三碘甲状腺原氨酸（0.4微克/千克负荷剂量，随后在6小时内以0.1微克/千克的速度输注，n = 81）或安慰剂（n = 89）。观察指标包括多个时间点的血流动力学参数及对正性肌力药物/升压药的需求（均值±均值标准误差）、围手术期发病率（心律失常/心肌缺血/梗死）及死亡率。
尽管两组患者基线特征相似，但随机接受三碘甲状腺原氨酸治疗的患者术后心脏指数较高，对正性肌力药物的需求较低。接受三碘甲状腺原氨酸治疗的患者术后心肌缺血发生率（4% 对18%，P = 0.007）及起搏器依赖率（14% 对25%，P = 0.013）显著较低。安慰剂组有7例患者术后需要机械辅助（主动脉内球囊反搏，n = 4；左心室辅助装置，n = 3），而三碘甲状腺原氨酸组无患者需要（P = 0.01）。安慰剂组有2例死亡，三碘甲状腺原氨酸组无死亡病例。
在择期冠状动脉旁路移植术中松开主动脉阻断钳后给予静脉注射三碘甲状腺原氨酸可显著改善术后心室功能，减少对正性肌力药物及机械装置的治疗需求，并降低心肌缺血的发生率。房颤发生率略有降低，术后对起搏器支持的需求减少。
