Kosiborod Mikhail, Curtis Jeptha P, Wang Yongfei, Smith Grace L, Masoudi Frederick A, Foody JoAnne M, Havranek Edward P, Krumholz Harlan M
Section of Cardiovascular Medicine, Yale University School of Medicine, New Haven, Conn 06520, USA.
Arch Intern Med. 2005 Oct 24;165(19):2237-44. doi: 10.1001/archinte.165.19.2237.
Recent reports have suggested that anemia is associated with adverse outcomes in patients with heart failure (HF), but were unable to adjust for a broad range of comorbid conditions. As a result, whether anemia is a truly independent predictor of risk or a marker of comorbid illness in these patients is unknown.
We analyzed medical records from the Centers for Medicare & Medicaid Services' National Heart Care Project, a national sample of 50,405 patients 65 years and older admitted to acute care hospitals with a principal discharge diagnosis of HF between April 1, 1998, and March 31, 1999, or between July 1, 2000, and June 30, 2001. Multivariable logistic regression analyses were conducted to test whether hematocrit level was an independent predictor of all-cause mortality and HF-related readmission at 1 year.
In unadjusted analysis, lower hematocrit levels were associated with increased 1-year mortality and readmission for HF. Compared with patients with a hematocrit greater than 40% to 44%, those with a hematocrit of 24% or less had a 51% higher risk of death (relative risk [RR], 1.51; 95% confidence interval [CI], 1.35-1.68; P<.001) and a 17% higher risk of HF-related readmission (RR, 1.17; 95% CI, 1.01-1.34; P = .04). However, after adjustment for multiple comorbidities and other clinical factors, the association between lower hematocrit levels and increased 1-year mortality was markedly attenuated, even in those patients with the most severe anemia (hematocrit, < or = 24% vs > 40%-44%: RR, 1.02; 95% CI, 0.86-1.19; P = .85). The association between lower hematocrit values and HF-related readmission persisted after multivariable adjustment (hematocrit, < or = 24% vs > 40%-44%: RR, 1.21; 95% CI, 1.04-1.38; P = .01).
Although anemia is an independent predictor of hospital readmission, its relationship with increased mortality in HF patients is largely explained by the severity of comorbid illness. These findings suggest that anemia may be predominantly a marker rather than a mediator of increased mortality risk in older patients with HF.
最近的报告表明，贫血与心力衰竭（HF）患者的不良预后相关，但未能对广泛的合并症进行调整。因此，贫血在这些患者中是真正的独立风险预测因素还是合并疾病的标志物尚不清楚。
我们分析了医疗保险和医疗补助服务中心国家心脏护理项目的医疗记录，该项目是一个全国性样本，包含1998年4月1日至1999年3月31日或2000年7月1日至2001年6月30日期间因主要出院诊断为HF而入住急性护理医院的50405名65岁及以上患者。进行多变量逻辑回归分析，以检验血细胞比容水平是否是1年全因死亡率和HF相关再入院的独立预测因素。
在未调整分析中，较低的血细胞比容水平与1年死亡率增加和HF再入院相关。与血细胞比容大于40%至44%的患者相比，血细胞比容为24%或更低的患者死亡风险高51%（相对风险[RR]，1.51；95%置信区间[CI]，1.35 - 1.68；P <.001），HF相关再入院风险高17%（RR，1.17；95% CI，1.01 - 1.34；P =.04）。然而，在对多种合并症和其他临床因素进行调整后，即使是那些患有最严重贫血的患者（血细胞比容，≤24% 对比 > 40% - 44%：RR，1.02；95% CI，0.86 - 1.19；P =.85），较低的血细胞比容水平与1年死亡率增加之间的关联也明显减弱。多变量调整后，较低的血细胞比容值与HF相关再入院之间的关联仍然存在（血细胞比容，≤24% 对比 > 40% - 44%：RR，1.21；95% CI，1.04 - 1.38；P =.01）。
虽然贫血是医院再入院的独立预测因素，但其与HF患者死亡率增加的关系在很大程度上由合并疾病的严重程度所解释。这些发现表明，在老年HF患者中，贫血可能主要是死亡率增加风险的一个标志物而非介导因素。
