Bolon J, McCutcheon K, Klug E, Smith D, Manga P
Division of Cardiology, Department of Internal Medicine, Charlotte Maxeke Johannesburg Academic Hospital and University of the Witwatersrand, Johannesburg, South Africa.
Division of Cardiology, Department of Internal Medicine, Charlotte Maxeke Johannesburg Academic Hospital and University of the Witwatersrand, Johannesburg, South Africa; Department of Cardiovascular Medicine, University Hospitals Leuven, Leuven, Belgium. Email:
Cardiovasc J Afr. 2019;30(2):103-107. doi: 10.5830/CVJA-2019-001. Epub 2019 Feb 11.
Despite the significant clinical benefits of beta-blockers in heart failure with reduced ejection fraction (HFrEF), prescription for and adherence to these agents is reported to be poor. There are few data on the use and tolerance of beta-blocker therapy in patients with HFrEF in South Africa and it is unknown whether these patients would benefit from further heart rate-lowering therapy.
Data from all patients with HFrEF attending the heart failure clinic of Charlotte Maxeke Johannesburg Academic Hospital from January 2000 to December 2014 were retrospectively collected. We first determined the rates of beta-blocker intolerance in this population and then categorised the patients according to their most recent dose of beta-blocker (low, moderate or target dose) in order to identify factors associated with beta-blocker intolerance. Lastly, we used the data to identify patients who would be suitable for further treatment with heart rate-lowering therapy.
Five hundred patients, with a median follow up of 58.7 months, were identified during the study period. Black South Africans constituted the majority (66.4%) and most patients had HFrEF due to hypertension (32.8%). At the last recorded clinic visit at the end of the study period, 489 patients (97.8%) were taking a beta-blocker with 59.8% prescribed a beta-blocker at target dose. Consistent with previous data, bradycardia was the commonest cause for failing to reach target beta-blocker dose. Only 61 (12%) patients were on no (n = 11) or low (n = 50) dose of beta-blocker at final clinic visit. As per current guidelines, only 10.6% (n = 53) of this cohort of patients would qualify for further treatment with heart rate-lowering therapy.
In a dedicated heart failure clinic in South Africa, beta-blockers were well-tolerated in the treatment of HFrEF. The potential role of specific heart rate-lowering therapy in patients treated adequately with heart failure medication and proper up-titration of beta-blockers is relatively small.
尽管β受体阻滞剂对射血分数降低的心力衰竭（HFrEF）具有显著的临床益处，但据报道，这些药物的处方率和依从性较差。关于南非HFrEF患者使用β受体阻滞剂治疗及其耐受性的数据很少，而且尚不清楚这些患者是否会从进一步的心率降低治疗中获益。
回顾性收集了2000年1月至2014年12月在夏洛特·马克西克约翰内斯堡学术医院心力衰竭门诊就诊的所有HFrEF患者的数据。我们首先确定了该人群中β受体阻滞剂不耐受的发生率，然后根据患者最近使用的β受体阻滞剂剂量（低、中或目标剂量）对患者进行分类，以确定与β受体阻滞剂不耐受相关的因素。最后，我们利用这些数据确定适合进一步进行心率降低治疗的患者。
在研究期间共确定了500例患者，中位随访时间为58.7个月。南非黑人占大多数（66.4%），大多数患者因高血压导致HFrEF（32.8%）。在研究期结束时的最后一次记录的门诊就诊时，489例患者（97.8%）正在服用β受体阻滞剂，其中59.8%的患者被处方了目标剂量的β受体阻滞剂。与先前的数据一致，心动过缓是未能达到目标β受体阻滞剂剂量的最常见原因。在最后一次门诊就诊时，只有61例（12%）患者未服用（n = 11）或低剂量（n = 50）的β受体阻滞剂。根据当前指南，该队列中只有10.6%（n = 53）的患者有资格接受进一步的心率降低治疗。
在南非一家专门的心力衰竭门诊，β受体阻滞剂在治疗HFrEF时耐受性良好。对于已接受充分心力衰竭药物治疗且β受体阻滞剂适当滴定的患者，特定的心率降低治疗的潜在作用相对较小。
