Institute of Preventive Pediatrics, Technische Universitaet Muenchen, Munich, Germany; Division of Cardiology, Veterans Affairs Palo Alto Health Care System, California, USA; School of Medicine, Stanford University, Stanford, California, USA.
Institute of Preventive Pediatrics, Technische Universitaet Muenchen, Munich, Germany.
Am J Cardiol. 2020 Sep 1;130:152-156. doi: 10.1016/j.amjcard.2020.06.023. Epub 2020 Jun 16.
Impairments in heart rate (HR) reserve and HR recovery are associated with mortality, and the combination of these two, termed exercise HR gradient (EHRG), is a better predictor than either alone. However, the confounding effect of beta-blockade on chronotropic impairment to exercise has not been fully explored; the aim of the present study was to evaluate the effect of beta blockade on EHRG. Participants were 2769 Veterans (58.7 ± 11.6 years) who underwent a maximal exercise test for clinical reasons. HR reserve and HR recovery were acquired and divided into quintiles and summed to provide an EHRG score. Net reclassification improvement (NRI) was performed to evaluate the impact of HR reserve, HR recovery and EHRG on all-cause mortality for patients with and without beta-blocker use. During a mean follow up of 10.9 ± 4.1 years, 657 patients died. Among patients without beta-blocker therapy, adding EHRG score to an established model including multiple baseline risk factors and exercise capacity resulted in an NRI of 14.3% (p <0.001). Adding HR recovery instead of EHRG score yielded an NRI of 11.5% (p <0.001), whereas HR reserve had no significant NRI among patients without beta-blocker therapy. In contrast, among participants on beta-blocker therapy, the addition of HR reserve, HR recovery, or EHRG score did not result in any significant reclassification. In conclusion, EHRG was superior to both HR reserve and HR recovery in predicting mortality and provides significant reclassification of risk but only among patients not taking beta-blockers.
心率（HR）储备和 HR 恢复受损与死亡率相关，这两者的结合，即运动 HR 梯度（EHRG），比单独任何一个指标预测能力都要强。然而，β受体阻滞剂对运动时变时性功能不全的混杂影响尚未得到充分探讨；本研究旨在评估β受体阻滞剂对 EHRG 的影响。研究对象为 2769 名退伍军人（58.7±11.6 岁），他们因临床原因接受了最大运动测试。获取并将 HR 储备和 HR 恢复分为五分位数并求和，以提供 EHRG 评分。净重新分类改善（NRI）用于评估 HR 储备、HR 恢复和 EHRG 对使用和不使用β受体阻滞剂的患者全因死亡率的影响。在平均 10.9±4.1 年的随访期间，有 657 名患者死亡。在未接受β受体阻滞剂治疗的患者中，将 EHRG 评分添加到包括多个基线风险因素和运动能力的既定模型中，可使 NRI 提高 14.3%（p<0.001）。替代 EHRG 评分添加 HR 恢复可使 NRI 提高 11.5%（p<0.001），而在未接受β受体阻滞剂治疗的患者中，HR 储备没有显著的 NRI。相比之下，在接受β受体阻滞剂治疗的患者中，添加 HR 储备、HR 恢复或 EHRG 评分不会导致任何显著的重新分类。总之，EHRG 在预测死亡率方面优于 HR 储备和 HR 恢复，并且提供了显著的风险重新分类，但仅在未服用β受体阻滞剂的患者中。
