Nahlawi Maher, Seshadri Niranjan, Boparai Navdeep, Naso Arabi, Jacobsen Donald W, McCarthy Patrick, Young James, Robinson Killian
Department of Cardiology, The Cleveland Clinic Foundation, Cleveland, Ohio, USA.
Am J Cardiol. 2002 Apr 1;89(7):834-7. doi: 10.1016/s0002-9149(02)02194-x.
Atherothrombotic complications are frequently seen in patients undergoing heart transplantation. These patients have high plasma total homocysteine concentrations associated with lower folate and vitamin B(6) levels. The relation between these metabolic abnormalities and the development of vascular complications, however, remains unclear. Fasting plasma total homocysteine, folate, vitamin B(12), vitamin B(6), and creatinine were measured in 160 cardiac transplant recipients who were followed for a mean duration of 28 +/- 9 months after blood draw (mean 59 +/- 28 months after transplant). Cardiovascular events and causes of mortality were determined and Cox proportional-hazards regression analysis was used to identify the independent predictors for cardiovascular events and mortality. Twenty-five patients developed cardiovascular events and 17 died (11 cardiovascular deaths). Mean +/- SD total homocysteine value was 18.4 +/- 8.5 (range 4.3 to 63.5 micromol/L). Hyperhomocysteinemia (> or =15 micromol/L) was seen in 99 patients (62%). Levels were no different in patients with or without cardiovascular complications/death (16.8 +/- 6.2 vs 18.9 +/- 9 micromol/L, p = 0.4). However, vitamin B(6) deficiency was seen in 21% of recipients with and in 9% without cardiovascular complications/death (p = 0.05). The relative risk for cardiovascular events, including cardiovascular death, increased 2.7 times (confidence interval 1.2 to 5.9) for B(6) levels < or =20 nmol/L compared with those with normal B(6) levels (p = 0.02). Thus, hyperhomocysteinemia is common in transplant recipients but may have no causal role in the atherothrombotic vascular complications of transplantation. Deficiency of vitamin B(6), however, may predict adverse outcomes, suggesting a possible role for supplementation with this vitamin.
动脉粥样硬化血栓形成并发症在心脏移植患者中很常见。这些患者血浆总同型半胱氨酸浓度较高，同时伴有较低的叶酸和维生素B6水平。然而，这些代谢异常与血管并发症发生之间的关系仍不明确。对160名心脏移植受者进行了空腹血浆总同型半胱氨酸、叶酸、维生素B12、维生素B6和肌酐的检测，采血后平均随访时间为28±9个月（移植后平均59±28个月）。确定心血管事件和死亡原因，并采用Cox比例风险回归分析来确定心血管事件和死亡的独立预测因素。25名患者发生心血管事件，17人死亡（11例心血管死亡）。平均±标准差总同型半胱氨酸值为18.4±8.5（范围4.3至63.5微摩尔/升）。99名患者（62%）出现高同型半胱氨酸血症（≥15微摩尔/升）。有或无心血管并发症/死亡的患者水平无差异（16.8±6.2对18.9±9微摩尔/升，p = 0.4）。然而，21%有心血管并发症/死亡的受者和9%无心血管并发症/死亡的受者存在维生素B6缺乏（p = 0.05）。与维生素B6水平正常的患者相比，维生素B6水平≤20纳摩尔/升时，包括心血管死亡在内的心血管事件相对风险增加2.7倍（置信区间1.2至5.9）（p = 0.02）。因此，高同型半胱氨酸血症在移植受者中很常见，但可能在移植的动脉粥样硬化血栓形成血管并发症中没有因果作用。然而，维生素B6缺乏可能预示不良结局，提示补充这种维生素可能有作用。
