University College London Hospital NHS Trust, London, UK.
Eur J Heart Fail. 2015 Jan;17(1):35-43. doi: 10.1002/ejhf.193. Epub 2014 Dec 3.
Plasma volume (PV) expansion hallmarks worsening chronic heart failure (CHF) but no non-invasive means of quantifying volume status exists. Because weight and haematocrit are related to PV, they can be used to calculate relative PV status (PVS). We tested the validity and prognostic utility of calculated PVS in CHF patients.
First, we evaluated the agreement between calculated actual PV (aPV) and aPV levels measured using (125)Iodine-human serum albumin. Second, we derived PVS as: [(calculated aPV - ideal PV)/ideal PV] × 100%. Third, we assessed the prognostic implications of PVS in 5002 patients from the Valsartan in Heart Failure Trial (Val-HeFT), and validated this in another 246 routine CHF outpatients. On analysis, calculated and measured aPV values correlated significantly in 119 normal subjects and 30 CHF patients. In the Val-HeFT cohort, mean (+SD) PVS was -9 ± 8% and related to volume biomarkers such as brain natriuretic peptide (BNP). Over 2 years, 977 (20%) patients died. Plasma volume status was associated with death and first morbid events in a 'J-shaped' fashion with the highest risk seen with a PVS > -4%. Stratification into PVS quartiles confirmed that a PVS > -4% was associated with increased mortality (unadjusted hazard ratio 1.65, 95% confidence interval 1.44-1.88, χ(2) = 54, P < 0.001) even after adjusting for 22 variables, including brain natriuretic peptide. These results were mirrored in the validation cohort.
Relative PVS calculated from simple clinical indices reflects the degree to which patients have deviated from their ideal PV and independently relates to outcomes. The utility of PVS-driven CHF management needs further evaluation.
血浆容量（PV）扩张是慢性心力衰竭（CHF）恶化的标志，但目前尚无无创量化容量状态的方法。由于体重和红细胞压积与 PV 相关，因此可以用来计算相对 PV 状态（PVS）。我们测试了在 CHF 患者中计算出的 PVS 的有效性和预后价值。
首先，我们评估了计算实际 PV（aPV）与使用（125）Iodine-human serum albumin 测量的 aPV 之间的一致性。其次，我们将 PVS 定义为：[(计算出的 aPV - 理想 PV)/理想 PV] × 100%。第三，我们评估了 PVS 在来自缬沙坦心力衰竭试验（Val-HeFT）的 5002 例患者中的预后意义，并在另外 246 例常规 CHF 门诊患者中进行了验证。分析表明，在 119 名正常受试者和 30 例 CHF 患者中，计算出的和测量出的 aPV 值呈显著相关。在 Val-HeFT 队列中，平均（+SD）PVS 为-9 ± 8%，与脑利钠肽（BNP）等容量生物标志物相关。在 2 年期间，977（20%）例患者死亡。血浆容量状态与死亡和首次发病事件呈“J 形”相关，PVS >-4%的风险最高。将患者分层为 PVS 四分位数组证实，PVS >-4%与死亡率增加相关（未经调整的危险比 1.65，95%置信区间 1.44-1.88，χ²=54，P<0.001），即使在调整了 22 个变量（包括脑利钠肽）后也是如此。验证队列中也出现了这些结果。
从简单的临床指标计算得出的相对 PVS 反映了患者偏离其理想 PV 的程度，并与结果独立相关。需要进一步评估基于 PVS 的 CHF 管理的效用。
