Purpose: 

Cardiopulmonary exercise testing (CPX) is a well-established assessment with important insight into prognosis and therapeutic efficacy in patients with heart failure (HF). Prior studies have identified several clinical differences between Black or African American (B-AA) and Caucasian patients with HF. Differences in key CPX responses between these two groups require further investigation.

Methods: 

Using a database consisting of subjects with symptomatic HF who had undergone CPX for inclusion in various prospective randomized clinical trials, we identified 198 (n = 94 [47%] B-AA; n = 105 [53%] Caucasian) patients with a qualifying baseline CPX. Significant univariate predictors of peak oxygen uptake (V˙o_2peak) were included in a multivariate linear regression model.

Results: 

When compared with Caucasian patients, B-AA were younger (mean ± SD = 54.8 ± 10.0 vs 57.9 ± 9.6 yr, P = .03), had higher C-reactive protein (CRP) (median [IQR] = 4.9 [2.3, 8.8] vs 1.9 [0.6, 5.5] mg/L, P < .0001), lower hemoglobin (13.0 ± 1.8 vs 13.8 ± 1.6 g/dL, P = .003), and lower left ventricular ejection fraction (LVEF) (40 [32, 51] vs 53 [43, 59]%, P < .00010). During CPX, B-AA patients also had lower V˙o_2peak (14.6 ± 3.9 vs 17.6 ± 4.8 mL·kg⁻¹·min⁻¹, P < .0001). No differences were observed between B-AA and Caucasian in the minute ventilation/carbon dioxide production (V˙e/V˙co₂) slope (P = .14). The difference in V˙o_2peak between B-AA and Caucasian was largely attenuated after adjusting for age, body mass index, CRP, N-terminal pro-brain natriuretic peptide, hemoglobin, LVEF, and peak HR (14.1: 95% CI, 13.2-14.9 vs 15.6: 95% CI, 14.4-16.8 mL·kg⁻¹·min⁻¹, P = .053).

Conclusions: 

Directly measured V˙o_2peak was significantly lower in B-AA than in Caucasians with HF. This is largely explained by differences in clinical characteristics, whereas no significant differences were observed in the V˙e/V˙co₂ slope.

中文翻译：

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黑人或非裔美国人与白人心力衰竭患者心肺健康的比较

目的： 

心肺运动试验（CPX）是一种成熟的评估方法，对于心力衰竭（HF）患者的预后和治疗效果具有重要的洞察力。先前的研究已经确定了黑人或非裔美国人 (B-AA) 与白人心力衰竭患者之间的一些临床差异。这两组之间关键 CPX 反应的差异需要进一步调查。

方法： 

使用由已接受 CPX 纳入各种前瞻性随机临床试验的有症状心力衰竭受试者组成的数据库，我们确定了 198 名符合资格的患者（n = 94 [47%] B-AA；n = 105 [53%] 白种人）基线 CPX。多元线性回归模型中包含峰值摄氧量 (V˙ o _{2peak ) 的显着单变量预测因子。}

结果： 

与白种人患者相比，B-AA 更年轻（平均值 ± SD = 54.8 ± 10.0 vs 57.9 ± 9.6 岁，P = .03），具有更高的 C 反应蛋白 (CRP)（中位数 [IQR] = 4.9 [2.3， 8.8] 对比 1.9 [0.6, 5.5] mg/L，P < .0001)，血红蛋白降低（13.0 ± 1.8 对比 13.8 ± 1.6 g/dL，P = .003），左心室射血分数 (LVEF) 降低 (40 [32, 51] 与 53 [43, 59]%，P < .00010）。CPX 期间，B-AA 患者的 V˙ o _2peak也较低（14.6 ± 3.9 vs 17.6 ± 4.8 mL·kg ⁻¹ ·min ⁻¹，P < .0001）。在 B-AA 和白种人之间，在每分钟通气量/二氧化碳产生量 (V˙ e /V˙ co ₂ ) 斜率方面没有观察到差异 ( P = .14)。在调整年龄、体重指数、CRP、N 端脑钠肽前体、血红蛋白、LVEF 和峰值 HR 后，B-AA 和白种人之间的 V˙ o 2peak 差异大幅减弱（14.1：95 % _CI，13.2-14.9 vs 15.6：95% CI，14.4-16.8 mL·kg ^-1 ·min ^-1，P = .053）。

结论： 

直接测量的 B-AA 中的 V˙ o _2peak明显低于患有 HF 的白种人。这主要是由临床特征的差异来解释的，而 V˙ e /V˙ co ₂斜率没有观察到显着差异。