EHJ：静息心率升高是心血管疾病的危险标志

流行病学研究显示静息状态心率是全因死亡和心血管死亡率的预测因子。心率升高与预后不良有关。近期哥本哈根大学的一项研究以尚未出现明显心脏病症状的人群为研究对象，结果显示心率升高与死亡率增加、心血管疾病密切相关，其中夜间心率最为重要。该研究发表在《欧洲心脏杂志》上。

本研究受试者为哥本哈根动态心电图研究项目中的653位不同性别的患者，年龄在55岁到75岁之间。研究对象并接受了48小时门诊心电图监控，并在静息至少10分钟后检测静息状态心率。24小时平均心率根据正常的RR间隔的平均时间来计算。夜间心率根据上午2:00至2:15的15分钟计算。随访时间中位数是76个月，评价指标为全因死亡率和心血管疾病死亡、急性心肌梗死和血管重建。即使在调整传统危险因素后，三种心率检测数值与全因死亡率显著相关。三种心率测量值与性别年龄调整后的心血管症状有相关性。然而，当调整心血管危险因素后，静息心率和24小时效率的相关性消失。所有因素纠正后，仅夜间心率有相关性，危害比=1.17（1.05-1.30），P=0.05。

研究者由此得出结论，在尚未出现明显心脏病症状的中年人当中，心率升高与死亡率增加和心血管疾病危险因素有关。其中，夜间心率最为重要，是多变量调整后与病人预后相关的唯一参数。

Resting, night-time, and 24 h heart rate as markers of cardiovascular risk in middle-aged and elderly men and women with no apparent heart disease
Aims
Increased heart rate (HR) is a predictor of all-cause and cardiovascular (CV) mortality. We tested which measure of HR had the strongest prognostic value in a population with no apparent heart disease.
Methods and results
Six hundred and fifty-three men and women between the age of 55 and 75 years were included in the Copenhagen Holter Study and underwent 48 h ambulatory electrocardiographic (ECG) monitoring. Resting HR was measured after at least 10 min of rest. Twenty-four-hour HR was derived from the mean time between normal-to-normal RR intervals (MEANNN). Night-time HR was derived from a 15 min sequence between 2:00 and 2:15 a.m. The median follow-up time was 76 months, and an adverse outcome was defined as all-cause mortality and the combined endpoint of CV death, acute myocardial infarction (AMI), and revascularization. All three measures of HR were significantly associated with all-cause mortality, also after adjustment for conventional risk factors. We found an association between all three measures of HR and CV events in analyses adjusted for sex and age. However, when adjusting for CV risk factors, the association with resting HR and 24 h HR disappeared. In a fully adjusted model, only night-time HR remained in the model, hazard ratio = 1.17 (1.05–1.30), P = 0.005.
Conclusion
In middle-aged subjects with no apparent heart disease, all measures of increased HR were associated with increased mortality and CV risk. However, night-time HR was the only parameter with prognostic importance after multivariable adjustment.