Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.
Stroke Unit, Department of Internal Medicine, St. Olav's University Hospital, Trondheim, Norway.
PLoS One. 2021 Aug 2;16(8):e0255308. doi: 10.1371/journal.pone.0255308. eCollection 2021.
Cardiorespiratory fitness is often impaired following stroke, and peak oxygen consumption (VO2peak) is an important prognostic value of all-cause mortality. The primary objective was to investigate whether functional walk tests assessed in the subacute phase after stroke added value in predicting VO2peak in chronic stroke, in addition to age, sex and functional dependency. Secondary objectives were to investigate associations between daily physical activity and functional walk tests, and with VO2peak in chronic stroke.
This prospective cohort study included eligible participants originally included in the randomized controlled trial Life After Stroke. Functional walk tests, i.e., six-minute walk test (6MWT) and maximal gait speed, were assessed at inclusion and 18 months later. VO2peak [ml/kg/min] was assessed by a cardiopulmonary exercise test on a treadmill 20 months after inclusion. Daily physical activity was measured by a uniaxial accelerometer (activPAL) at 18-month follow-up.
Ninety-two community-dwelling individuals, with a mean (SD) age of 69.2 (10.6) years and 33 (35.9%) women, were included 3 months after stroke onset. Eighty-three (90.2%) participants had a modified Rankin Scale (mRS) score of 1 or 2, indicating functional independence. An overall assessment of four prediction models indicated the combination of age, sex, mRS and 6MWT as predictors to be the best fitted model in predicting VO2peak (adjusted R2 = 0.612). Secondary results showed statistically significant, but not clinically significant, associations between daily physical activity and functional walk tests, and with VO2peak.
6MWT add significant value to the prediction of mean VO2peak in the chronic phase in mild strokes, in combination with age, sex and functional dependency. This prediction model may facilitate clinical decisions and rehabilitation strategies for mildly affected stroke survivors in risk of low levels of VO2peak. Future studies should validate the model in various stages after stroke and in patients moderately and severely affected.
心肺功能通常会在中风后受损，而最大摄氧量（VO2peak）是全因死亡率的重要预后指标。主要目的是探究中风后亚急性期的功能步行测试能否除年龄、性别和功能依赖外，还能增加对慢性中风 VO2peak 的预测价值。次要目标是探究慢性中风中日常体力活动与功能步行测试之间的关联，以及与 VO2peak 的关联。
这项前瞻性队列研究纳入了最初纳入随机对照试验 Life After Stroke 的符合条件的参与者。在纳入时和 18 个月后评估了功能步行测试，即 6 分钟步行测试（6MWT）和最大步行速度。在纳入后 20 个月通过跑步机心肺运动试验评估 VO2peak [ml/kg/min]。在 18 个月随访时，通过单轴加速度计（activPAL）测量日常体力活动。
92 名居住在社区的个体，平均（SD）年龄为 69.2（10.6）岁，33 名（35.9%）为女性，在中风发作后 3 个月纳入。83 名（90.2%）参与者的改良 Rankin 量表（mRS）评分为 1 或 2，表明功能独立性。四项预测模型的综合评估表明，年龄、性别、mRS 和 6MWT 作为预测因子的组合是预测 VO2peak 的最佳拟合模型（调整 R2=0.612）。次要结果显示，日常体力活动与功能步行测试以及与 VO2peak 之间存在统计学显著但临床意义不显著的关联。
6MWT 与年龄、性别和功能依赖性相结合，对轻度中风慢性期平均 VO2peak 的预测具有重要价值。该预测模型可能有助于对 VO2peak 水平较低的轻度中风幸存者的临床决策和康复策略。未来的研究应在中风后各个阶段以及中度和重度中风患者中验证该模型。
