Department of Internal Medicine, Division of Cardiology, Washington Hospital Center, Washington, DC 20010, USA.
Am Heart J. 2010 Jun;159(6):1139-46. doi: 10.1016/j.ahj.2010.03.011.
The association between obesity and bleeding after percutaneous coronary intervention (PCI) is not well defined. We investigated the impact of body mass index (BMI) on PCI-related bleeding, and whether bivalirudin, compared to heparin, used as PCI anticoagulant modifies this relationship.
From 2000 to 2009, 16,783 patients who underwent PCI were grouped according to 6 BMI groups: underweight (<18.5 kg/m(2)), "normal" weight (18.5-24.9 kg/m(2)), overweight (25-29.9 kg/m(2)), class I (30-34.9 kg/m(2)), class II (35-39.9 kg/m(2)), and class III obesity (> or =40 kg/m(2)). Bivalirudin was used in 11,433 patients and heparin in 5,350. In-hospital major bleeding (hematocrit drop > or =15% or gastrointestinal bleeding) and need for transfusion rates were collected.
The incidence of major bleeding varied significantly throughout the BMI spectrum (5.6% vs 2.5% vs 1.9% vs 1.6% vs 2.1% vs 1.9%, respectively, from underweight to class III obese patients, P < .001). The incidence of transfusion across BMI followed the same reverse J-shape curve (10.9% vs 6.6% vs 3.6% vs 3.4% vs 3.8% vs 5.6%, P < .001). After adjustment for potential confounding factors, underweight patients had neither an increased risk for major bleeding nor an increased risk for transfusion compared with "normal" weight patients. Class I obese patients had a lower risk of major bleeding (odds ratio [OR] 0.68 [95% CI 0.48-0.97]). Overweight, class I, and II obese patients had a lower risk of transfusion (respectively, OR 0.68 [0.55-0.84], 0.68 [0.53-0.87], and 0.66 [0.48-0.92]). The highest BMI patients had neither an increased risk for major bleeding (class II and III obesity) nor an increased risk for transfusion (class III obesity). The same reverse J-shaped relationship to BMI seen in the overall population for the raw incidence of major bleeding was found when the population was divided according to type of anticoagulant used as follows: bivalirudin or heparin. Likewise, the "need for transfusion" relationship to BMI is not altered by bivalirudin use.
The better outcome for bleeding seen in patients in the middle of the BMI spectrum suggests the existence of a "bleeding obesity paradox," which persists after adjustment by confounding factors and exists irrespective of the anticoagulant used.
肥胖与经皮冠状动脉介入治疗（PCI）后的出血之间的关联尚不清楚。我们研究了体重指数（BMI）对 PCI 相关出血的影响，以及与肝素相比，作为 PCI 抗凝剂的比伐卢定是否会改变这种关系。
2000 年至 2009 年，根据 6 个 BMI 组将 16783 例接受 PCI 的患者分组：体重不足（<18.5 kg/m2）、“正常”体重（18.5-24.9 kg/m2）、超重（25-29.9 kg/m2）、I 类（30-34.9 kg/m2）、II 类（35-39.9 kg/m2）和 III 类肥胖（≥40 kg/m2）。11433 例患者使用比伐卢定，5350 例患者使用肝素。收集住院期间主要出血（血细胞比容下降≥15%或胃肠道出血）和输血率。
主要出血的发生率在整个 BMI 谱中差异显著（体重不足至 III 类肥胖患者分别为 5.6%、2.5%、1.9%、1.6%、2.1%和 1.9%，P<.001）。BMI 相关输血的发生率呈相反的 J 形曲线（10.9%、6.6%、3.6%、3.4%、3.8%和 5.6%，P<.001）。调整潜在混杂因素后，与“正常”体重患者相比，体重不足患者既没有更高的大出血风险，也没有更高的输血风险。I 类肥胖患者大出血风险较低（比值比 [OR] 0.68 [95%置信区间 0.48-0.97]）。超重、I 类和 II 类肥胖患者输血风险较低（分别为 OR 0.68 [0.55-0.84]、0.68 [0.53-0.87]和 0.66 [0.48-0.92]）。BMI 最高的患者既没有更高的大出血风险（II 类和 III 类肥胖），也没有更高的输血风险（III 类肥胖）。在根据所用抗凝剂将人群分为比伐卢定或肝素时，在总体人群中观察到的主要出血发生率与 BMI 的反向 J 形关系仍然存在。同样，BMI 与输血的“需要输血”关系不受比伐卢定使用的影响。
BMI 谱中间部分患者的出血结局较好，表明存在“出血肥胖悖论”，在调整混杂因素后仍然存在，并且与所用抗凝剂无关。
