Klemperer J D, Klein I, Gomez M, Helm R E, Ojamaa K, Thomas S J, Isom O W, Krieger K
Department of Cardiothoracic Surgery, New York Hospital-Cornell University Medical College, New York 10021, USA.
N Engl J Med. 1995 Dec 7;333(23):1522-7. doi: 10.1056/NEJM199512073332302.
Thyroid hormone has many effects on the cardiovascular system. During and after cardiopulmonary bypass, serum triiodothyronine concentrations decline transiently, which may contribute to postoperative hemodynamic dysfunction. We investigated whether the perioperative administration of triiodothyronine (liothyronine sodium) enhances cardiovascular performance in high-risk patients undergoing coronary-artery bypass surgery.
We administered triiodothyronine or placebo to 142 patients with coronary artery disease and depressed left ventricular function. The hormone was administered as an intravenous bolus of 0.8 microgram per kilogram of body weight when the aortic cross-clamp was removed after the completion of bypass surgery and then as an infusion of 0.113 microgram per kilogram per hour for six hours. Clinical and hemodynamic responses were serially recorded, as was any need for inotropic or vasodilator drugs.
The patients' preoperative serum triiodothyronine concentrations were normal (mean [+/- SD] value, 81 +/- 22 ng per deciliter [1.2 +/- 0.3 nmol per liter]), and they decreased by 40 percent (P < 0.001) 30 minutes after the onset of cardiopulmonary bypass. The concentrations in patients given intravenous triiodothyronine became supranormal and were significantly higher than those in patients given placebo (P < 0.001). However, the concentrations were once again similar in the two groups 24 hours after surgery. The mean postoperative cardiac index was higher in the triiodothyronine group (2.97 +/- 0.72 vs. 2.67 +/- 0.61 liters per minute per square meter of body-surface area, P = 0.007), and systemic vascular resistance was lower (1073 +/- 314 vs. 1235 +/- 387 dyn.sec.cm-5, P = 0.003). The two groups did not differ significantly in the incidence of arrhythmia or the need for therapy with inotropic and vasodilator drugs during the 24 hours after surgery, or in perioperative mortality and morbidity.
Raising serum triiodothyronine concentrations in patients undergoing coronary-artery bypass surgery increases cardiac output and lowers systemic vascular resistance, but does not change outcome or alter the need for standard postoperative therapy.
甲状腺激素对心血管系统有多种作用。在体外循环期间及之后，血清三碘甲状腺原氨酸浓度会短暂下降，这可能导致术后血流动力学功能障碍。我们研究了围手术期给予三碘甲状腺原氨酸（碘塞罗宁钠）是否能增强接受冠状动脉搭桥手术的高危患者的心血管功能。
我们对142例患有冠状动脉疾病且左心室功能低下的患者给予三碘甲状腺原氨酸或安慰剂。在体外循环手术完成后移除主动脉阻断钳时，以每千克体重0.8微克的静脉推注方式给予该激素，然后以每千克体重每小时0.113微克的速度输注6小时。连续记录临床和血流动力学反应，以及对强心或血管扩张药物的任何需求。
患者术前血清三碘甲状腺原氨酸浓度正常（平均[±标准差]值为81±22纳克/分升[1.2±0.3纳摩尔/升]），在体外循环开始后30分钟下降了40%（P<0.001）。静脉给予三碘甲状腺原氨酸的患者体内浓度变得高于正常水平，且显著高于给予安慰剂的患者（P<0.001）。然而，术后24小时两组浓度再次相似。三碘甲状腺原氨酸组术后平均心脏指数较高（2.97±0.72对2.67±0.61升/分钟/平方米体表面积，P = 0.007），全身血管阻力较低（1073±314对1235±387达因·秒·厘米⁻⁵，P = 0.003）。两组在术后24小时内心律失常发生率或对强心和血管扩张药物治疗的需求、围手术期死亡率和发病率方面无显著差异。
提高接受冠状动脉搭桥手术患者的血清三碘甲状腺原氨酸浓度可增加心输出量并降低全身血管阻力，但不会改变预后或改变术后标准治疗的需求。
