Resting Heart Rate to Assess Patients with Heart Failure: That is All We Need

Keywords Heart Rate; Heart Failure; Electrocardiography

Heart rate (HR) is an important marker of prognosis in cardiovascular diseases.¹ It is present as a predictor of survival in nature itself. For example, animals with a low HR live much longer than animals with a high HR.¹ In the general population, HR has been related to mortality, as demonstrated in the Framingham Study.² Additionally, since the 1980s, it has been known that resting HR is a prognostic factor in patients with coronary artery disease.³,⁴ Data from the Coronary Artery Surgery Study (CASS) showed that it predicts morbidity (hospital readmission rate) as well as total and cardiovascular mortality.⁴

In heart failure (HF) resting HR is a prognostic marker as well, as shown in Figure 1.⁵ The treatment of HF with reduced ejection fraction includes the utilization of beta-blockers.⁶–⁸ Although beta-blockers have many mechanisms through which they may benefit patients with HF, HR reduction probably contributes to the beneficial effects of this class. However, even on maximum tolerated doses of beta-blockers, some patients may remain with HR >70 bpm (recommended range for patients with HF is 50-60 bpm).⁹ For this reason, a new class of drugs was developed. Ivabradine is a selective HR reductor that works by inhibiting the if channels in the sinus node.⁹ Ivabradine was tested against a placebo in the SHIFT study, in patients with symptomatic HF, sinus rhythm, left ventricular ejection fraction ≤35%, and HR ≥70 bpm despite optimized HF treatment.⁹ Ivabradine reduced the composite endpoint of cardiovascular mortality or HF hospitalization.⁹ In a subanalysis, it was observed that the magnitude of HR reduction by beta-blocker plus ivabradine, rather than background beta-blocker dose, primarily determined subsequent effect on outcomes.¹⁰

Figure 1
Resting heart rate has been shown to predict morbidity and mortality in many cardiovascular conditions and even in the general population.

Thus, HR is an important marker in the evaluation of patients with HF, and decisions on the introduction, dose adjustments, and withdrawal of some drugs are based on this parameter. Nevertheless, the medical community has always wondered whether ambulatorial monitoring of HR employing a 24-hour Holter system would provide different information than resting HR. In this issue of Arquivos Brasileiros de Cardiologia, a study by Camazzola et al. compared resting HR with that observed with the 24-hour Holter system in patients with HF with reduced ejection fraction and sinus rhythm.¹¹ The authors conclude that HR obtained from the resting electrocardiogram (ECG) had an excellent correlation with the HR obtained from the 24-hour Holter, except in those with HR <70 bpm on the ECG. The authors state that in the latter group, 24-hour Holter should be considered.

The study is original and has a good methodology and we congratulate the authors for that. It has the merit of reassuring that resting HR is not very different from that observed in the ambulatory monitoring of patients with HF. However, from a practical standpoint, this study does not change our practice, since all data that we have with beta-blockers and ivabradine come from assessment of resting HR. Therefore, according to HF guidelines, the decisions must be made using resting HR as a reference.¹² The authors suggest that in patients with HR<70 bpm 24-hour Holter should be considered but the study lacks information for that recommendation since it was cross-sectional and no events were measured. Resting HR between 50-60 bpm was actually the target in the SHIFT study and no additional procedures were done in the SHIFT study when this range of HR was achieved.⁹

In summary, we congratulate the authors for this elegant study. From a mechanistic point of view, it adds information to our knowledge in the field. Nevertheless, until new longitudinal data from multicentric studies are published, decisions should be made based on resting HR.

References

• ¹ Cook S, Togni M, Schaub MC, Wenaweser P, Hess OM. High Heart Rate: A Cardiovascular Risk Factor? Eur Heart J. 2006;27(20):2387-93. doi: 10.1093/eurheartj/ehl259.
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• ² Kannel WB, Kannel C, Paffenbarger RS Jr, Cupples LA. Heart Rate and Cardiovascular Mortality: The Framingham Study. Am Heart J. 1987;113(6):1489-94. doi: 10.1016/0002-8703(87)90666-1.
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• ³ Dyer AR, Persky V, Stamler J, Paul O, Shekelle RB, Berkson DM, et al. Heart Rate as a Prognostic Factor for Coronary Heart Disease and Mortality: Findings in Three Chicago Epidemiologic Studies. Am J Epidemiol. 1980;112(6):736-49. doi: 10.1093/oxfordjournals.aje.a113046.
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• ⁴ Diaz A, Bourassa MG, Guertin MC, Tardif JC. Long-term Prognostic Value of Resting Heart Rate in Patients with Suspected or Proven Coronary Artery Disease. Eur Heart J. 2005;26(10):967-74. doi: 10.1093/eurheartj/ehi190.
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• ⁵ Vukadinović AN, Vukadinović D, Borer J, Cowie M, Komajda M, Lainscak M, et al. Heart Rate and Its Reduction in Chronic Heart Failure and Beyond. Eur J Heart Fail. 2017;19(10):1230-41. doi: 10.1002/ejhf.902.
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• ⁶ Packer M, Bristow MR, Cohn JN, Colucci WS, Fowler MB, Gilbert EM, et al. The Effect of Carvedilol on Morbidity and Mortality in Patients with Chronic Heart Failure. U.S. Carvedilol Heart Failure Study Group. N Engl J Med. 1996;334(21):1349-55. doi: 10.1056/NEJM199605233342101.
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• ⁷ MERIT-HF Study Group. Effect of Metoprolol CR/XL in Chronic Heart Failure: Metoprolol CR/XL Randomised Intervention Trial in Congestive Heart Failure (MERIT-HF). Lancet. 1999;353(9169):2001-7. doi:10.1016/S0140-6736(99)04440-2.
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• ⁸ CIBIS-II Investigators and Committees. The Cardiac Insufficiency Bisoprolol Study II (CIBIS-II): A Randomised Trial. Lancet. 1999;353(9146):9-13. doi:10.1016/S0140-6736(98)11181-9.
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• ⁹ Swedberg K, Komajda M, Böhm M, Borer JS, Ford I, Dubost-Brama A, et al. Ivabradine and Outcomes in Chronic Heart Failure (SHIFT): A Randomised Placebo-controlled Study. Lancet. 2010;376(9744):875-85. doi: 10.1016/S0140-6736(10)61198-1.
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• ¹⁰ Swedberg K, Komajda M, Böhm M, Borer J, Robertson M, Tavazzi L, et al. Effects on Outcomes of Heart Rate Reduction by Ivabradine in Patients with Congestive Heart Failure: Is there an Influence of Beta-blocker Dose?: Findings from the SHIFT (Systolic Heart Failure Treatment with the I(f) Inhibitor Ivabradine Trial) Study. J Am Coll Cardiol. 2012;59(22):1938-45. doi: 10.1016/j.jacc.2012.01.020.
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• ¹¹ Camazzola FE, Schwartzmann PV, Sabedotti M, Massuti R, Zortea T, Chen V, et al. Análise Comparativa do ECG com o Holter na avaliação da Frequência Cardíaca na Insuficiência Cardíaca com Fração de Ejeção Reduzida e Ritmo Sinusal. Arq Bras Cardiol. 2024; 121(8):e20230771. doi: https://doi.org/10.36660/abc.20230771
  » https://doi.org/10.36660/abc.20230771
• ¹² Marcondes-Braga FG, Moura LAZ, Issa VS, Vieira JL, Rohde LE, Simões MV, et al. Emerging Topics Update of the Brazilian Heart Failure Guideline - 2021. Arq Bras Cardiol. 2021;116(6):1174-212. doi: 10.36660/abc.20210367.
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Publication Dates

• Publication in this collection
  23 Sept 2024
• Date of issue
  2024

History

• Received
  31 July 2024
• Reviewed
  14 Aug 2024
• Accepted
  14 Aug 2024