Paciocco G, Martinez F J, Bossone E, Pielsticker E, Gillespie B, Rubenfire M
Dept of Internal Medicine, University of Michigan, Ann Arbor, USA.
Eur Respir J. 2001 Apr;17(4):647-52. doi: 10.1183/09031936.01.17406470.
There are no reliable predictors of mortality in primary pulmonary hypertension (PPH). This study assessed whether exercise oxygen desaturation and distance achieved during a six-minute walk are associated with mortality in moderately symptomatic patients with PPH. Thirty-four patients with PPH underwent a pretreatment six-minute walk test, and an invasive haemodynamic assessment of pulmonary vasodilator reserve, to select the best treatment option (epoprostenol in 27 and nifedipine in 7). Median follow-up was 26 months (12 months for the nonsurvivors was 26%), and median survival, >46 months by Kaplan-Maier estimate. The mean+/-SD distance walked was 275+/-155 m and reduction in arterial oxygen saturation (Sa,O2) at maximal distance (deltaSa,O2) was 8.4+/-4.5%). A distance < or =300 m increased mortality risk by 2.4, and a deltaSa,O2 of > or = 10% increased mortality risk by 2.9. Only Sa,O2 at peak distance, deltaSa,O2 and pulmonary vascular resistance (PVR) were related to mortality. After adjusting for PVR, there remained a 27% increase in risk of death for each per cent decrease in Sa,O2. The six-minute walk distance and exercise oxygen saturation may be helpful in selecting patients with primary pulmonary hypertension for whom transplant listing is appropriate.
原发性肺动脉高压（PPH）尚无可靠的死亡率预测指标。本研究评估了中度症状性PPH患者六分钟步行期间的运动性氧饱和度下降及步行距离是否与死亡率相关。34例PPH患者接受了预处理六分钟步行试验及肺血管扩张储备的有创血流动力学评估，以选择最佳治疗方案（27例使用依前列醇，7例使用硝苯地平）。中位随访时间为26个月（非存活者的12个月为26%），根据Kaplan-Meier估计，中位生存期>46个月。平均步行距离为275±155米，最大步行距离时动脉血氧饱和度（SaO₂）的下降幅度（ΔSaO₂）为8.4±4.5%。步行距离≤300米使死亡风险增加2.4倍，ΔSaO₂≥10%使死亡风险增加2.9倍。仅峰值距离时的SaO₂、ΔSaO₂及肺血管阻力（PVR）与死亡率相关。校正PVR后，SaO₂每降低1%，死亡风险仍增加27%。六分钟步行距离及运动性氧饱和度可能有助于选择适合列入移植名单的原发性肺动脉高压患者。
