Cardiology Division, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, 02114, USA.
Circ Heart Fail. 2011 May;4(3):276-85. doi: 10.1161/CIRCHEARTFAILURE.110.959437. Epub 2011 Feb 3.
Elevated resting pulmonary arterial pressure (PAP) in patients with left ventricular systolic dysfunction (LVSD) purports a poor prognosis. However, PAP response patterns to exercise in LVSD and their relationship to functional capacity and outcomes have not been characterized.
Sixty consecutive patients with LVSD (age 60±12 years, left ventricular ejection fraction 0.31±0.07, mean±SD) and 19 controls underwent maximum incremental cardiopulmonary exercise testing with simultaneous hemodynamic monitoring. During low-level exercise (30 W), LVSD subjects, compared with controls, had greater augmentation in mean PAPs (15±1 versus 5±1 mm Hg), transpulmonary gradients (5±1 versus 1±1 mm Hg), and effective pulmonary artery elastance (0.05±0.02 versus -0.03±0.01 mm Hg/mL, P<0.0001 for all). A linear increment in PAP relative to work (0.28±0.12 mm Hg/W) was observed in 65% of LVSD patients, which exceeded that observed in controls (0.07±0.02 mm Hg/W, P<0.0001). Exercise capacity and survival was worse in patients with a PAP/watt slope above the median than in patients with a lower slope. In the remaining 35% of LVSD patients, exercise induced a steep initial increment in PAP (0.41±0.16 mm Hg/W) followed by a plateau. The plateau pattern, compared with a linear pattern, was associated with reduced peak Vo(2) (10.6±2.6 versus 13.1±4.0 mL · kg(-1) · min(-1), P=0.005), lower right ventricular stroke work index augmentation with exercise (5.7±3.8 versus 9.7±5.0 g/m(2), P=0.002), and increased mortality (hazard ratio 8.1, 95% CI 2.7 to 23.8, P<0.001).
A steep increment in PAP during exercise and failure to augment PAP throughout exercise are associated with decreased exercise capacity and survival in patients with LVSD, and may therefore represent therapeutic targets.
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00309790.
患有左心室收缩功能障碍（LVSD）的患者静息肺动脉压（PAP）升高表明预后不良。然而，LVSD 患者运动时的 PAP 反应模式及其与功能能力和结局的关系尚未确定。
连续 60 例 LVSD 患者（年龄 60±12 岁，左心室射血分数 0.31±0.07，均值±标准差）和 19 例对照者接受最大增量心肺运动试验，同时进行血流动力学监测。在低水平运动（30 W）时，与对照组相比，LVSD 患者的平均 PAP 增加幅度更大（15±1 对 5±1 mm Hg）、跨肺梯度更大（5±1 对 1±1 mm Hg）、有效肺动脉弹性更大（0.05±0.02 对-0.03±0.01 mm Hg/mL，均 P<0.0001）。65%的 LVSD 患者 PAP 相对于做功呈线性递增（0.28±0.12 mm Hg/W），高于对照组（0.07±0.02 mm Hg/W，P<0.0001）。PAP/瓦特斜率高于中位数的患者比斜率较低的患者运动能力和生存率更差。在剩余的 35%的 LVSD 患者中，运动引起的 PAP 初始急剧增加（0.41±0.16 mm Hg/W），随后出现平台。与线性模式相比，平台模式与峰值 Vo(2)降低（10.6±2.6 对 13.1±4.0 mL·kg(-1)·min(-1)，P=0.005）、运动时右心室每搏功指数增加减少（5.7±3.8 对 9.7±5.0 g/m(2)，P=0.002）和死亡率增加（风险比 8.1，95%CI 2.7 至 23.8，P<0.001）相关。
LVSD 患者运动时 PAP 急剧增加且运动时 PAP 无法增加与运动能力下降和生存率降低相关，因此可能成为治疗靶点。
