Correlation between Exercise Stress Test and Echocardiographic Parameters in Elderly Individuals

Abstract Background: Maximum oxygen consumption (VO2 max) in healthy individuals decreases approximately 10% per decade of life, and such decrease is more pronounced after the seventh decade. Objectives: To assess functional capacity of individuals aged 75 years or older, submitted to ergometric test and transthoracic echocardiogram exam, by means of metabolic equivalent (MET) and VO2 max measurements. Methods: A total of 381 patients (205 women; 79 ± 3.7 years) were evaluated. Exclusion criteria were: presence of left ventricular (LV) systolic dysfunction, LV diastolic dysfunction grade II and III, significant valve disease, or coronary artery disease with systolic LV dysfunction or dilatation. Associations between quantitative variables were analyzed by Pearson and Spearman correlation coefficients, and comparisons of quantitative data by Student's t-test for independent samples. Results: Increasing age was associated with a progressive decrease in the distance covered (p = 0.021), in the expected increase in HR (p < 0.001), in VO2 max (p < 0.001), and METs (p < 0.001) in both genders. There was no correlation of exercise test parameters with the echocardiographic parameters. Conclusions: Relatively healthy older individuals, with global systolic and diastolic functions of the left ventricle preserved, presented a progressive decrease in their functional capacity due to their natural aging process, comorbidities related to their age range and physical deconditioning.

背景：健康个体的最大摄氧量（Maximum Oxygen Consumption, VO2 max）每十年约下降10%，且70岁后该下降趋势更为显著。
研究目的：通过代谢当量（MET）与最大摄氧量测量，评估接受运动负荷试验（ergometric test）及经胸超声心动图检查的75岁及以上人群的功能能力。
研究方法：共纳入381例受试者（女性205例；年龄79±3.7岁）。排除标准包括：左心室（left ventricular, LV）收缩功能障碍、Ⅱ级及Ⅲ级左心室舒张功能障碍、显著瓣膜病变，或合并左心室收缩功能障碍或扩张的冠状动脉粥样硬化性心脏病。定量变量间的关联采用Pearson相关系数与Spearman相关系数分析，定量资料的组间比较采用独立样本Student t检验。
研究结果：在两性人群中，年龄增长与运动距离（p=0.021）、预期心率增幅（p<0.001）、最大摄氧量（p<0.001）及代谢当量（METs，p<0.001）的进行性下降显著相关。运动试验参数与超声心动图参数未发现相关性。
研究结论：左心室整体收缩及舒张功能保留的相对健康老年人群，其功能能力会因自然衰老过程、年龄相关共病及体力活动减退而呈进行性下降。