Hung Rupert K, Al-Mallah Mouaz H, Whelton Seamus P, Michos Erin D, Blumenthal Roger S, Ehrman Jonathan K, Brawner Clinton A, Keteyian Steven J, Blaha Michael J
Department of Cardiology, Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, Maryland.
Department of Cardiology, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, King Abdulaziz Cardiac Center, Ministry of National Guard, Health Affairs, Riyadh, Saudi Arabia; Department of Cardiology, Henry Ford Hospital, Detroit, Michigan.
Am J Cardiol. 2016 Dec 1;118(11):1751-1757. doi: 10.1016/j.amjcard.2016.08.060. Epub 2016 Aug 31.
Whether lower heart rate thresholds (defined as the percentage of age-predicted maximal heart rate achieved, or ppMHR) should be used to determine chronotropic incompetence in patients on beta-blocker therapy (BBT) remains unclear. In this retrospective cohort study, we analyzed 64,549 adults without congestive heart failure or atrial fibrillation (54 ± 13 years old, 46% women, 29% black) who underwent clinician-referred exercise stress testing at a single health care system in Detroit, Michigan from 1991 to 2009, with median follow-up of 10.6 years for all-cause mortality (interquartile range 7.7 to 14.7 years). Using Cox regression models, we assessed the effect of BBT, ppMHR, and estimated exercise capacity on mortality, with adjustment for demographic data, medical history, pertinent medications, and propensity to be on BBT. There were 9,259 deaths during follow-up. BBT was associated with an 8% lower adjusted achieved ppMHR (91% in no BBT vs 83% in BBT). ppMHR was inversely associated with all-cause mortality but with significant attenuation by BBT (per 10% ppMHR HR: no BBT: 0.80 [0.78 to 0.82] vs BBT: 0.89 [0.87 to 0.92]). Patients on BBT who achieved 65% ppMHR had a similar adjusted mortality rate as those not on BBT who achieved 85% ppMHR (p >0.05). Estimated exercise capacity further attenuated the prognostic value of ppMHR (per-10%-ppMHR HR: no BBT: 0.88 [0.86 to 0.90] vs BBT: 0.95 [0.93 to 0.98]). In conclusion, the prognostic value of ppMHR was significantly attenuated by BBT. For patients on BBT, a lower threshold of 65% ppMHR may be considered for determining worsened prognosis. Estimated exercise capacity further diminished the prognostic value of ppMHR particularly in patients on BBT.
对于正在接受β受体阻滞剂治疗（BBT）的患者，是否应使用较低的心率阈值（定义为达到年龄预测最大心率的百分比，即ppMHR）来判定变时性功能不全仍不明确。在这项回顾性队列研究中，我们分析了64549名无充血性心力衰竭或心房颤动的成年人（年龄54±13岁，46%为女性，29%为黑人），他们于1991年至2009年在密歇根州底特律的一个医疗系统接受了临床转诊的运动应激试验，全因死亡率的中位随访时间为10.6年（四分位间距7.7至14.7年）。我们使用Cox回归模型评估了BBT、ppMHR和估计的运动能力对死亡率的影响，并对人口统计学数据、病史、相关药物以及接受BBT的倾向进行了校正。随访期间有9259人死亡。BBT与调整后的ppMHR降低8%相关（未接受BBT者为91%，接受BBT者为83%）。ppMHR与全因死亡率呈负相关，但BBT使其显著减弱（每10% ppMHR的风险比：未接受BBT者：0.80 [0.78至0.82]，接受BBT者：0.89 [0.87至0.92]）。达到65% ppMHR的接受BBT的患者与未接受BBT但达到85% ppMHR的患者调整后的死亡率相似（p>0.05）。估计的运动能力进一步减弱了ppMHR的预后价值（每10% ppMHR的风险比：未接受BBT者：0.88 [0.86至0.90]，接受BBT者：0.95 [0.93至0.98]）。总之，BBT显著减弱了ppMHR的预后价值。对于接受BBT的患者，判定预后恶化时可考虑较低的阈值65% ppMHR。估计的运动能力进一步降低了ppMHR的预后价值，尤其是在接受BBT的患者中。
