Heart rate response and functional capacity in patients with chronic heart failure with preserved ejection fraction

Abstract

AimsThe mechanisms of exercise intolerance in heart failure with preserved ejection fraction (HFpEF) are not yet elucidated. Chronotropic incompetence has emerged as a potential mechanism. We aimed to evaluate whether heart rate (HR) response to exercise is associated to functional capacity in patients with symptomatic HFpEF.Methods and resultsWe prospectively studied 74 HFpEF patients [35.1% New York Heart Association Class III, 53% female, age (mean ± standard deviation) 72.5 ± 9.1 years, and 59.5% atrial fibrillation]. Functional performance was assessed by peak oxygen consumption (peak VO2). The mean (standard deviation) peak VO2 was 10 ± 2.8 mL/min/kg. The following chronotropic parameters were calculated: Delta‐HR (HR at peak exercise − HR at rest), chronotropic index (CI) = (HR at peak exercise − resting HR)/[(220 − age) − resting HR], and CI according to the equation developed by Keteyian et al. (CIK) (HR at peak exercise − HR at rest)/[119 + (HR at rest/2) − (age/2) − 5 − HR at rest]. In a bivariate setting, peak VO2 was positively and significantly correlated with Delta‐HR (r = 0.35, P = 0.003), CI (r = 0.27, P = 0.022), CIK (r = 0.28, P = 0.018), and borderline with HR at peak exercise (r = 0.22, P = 0.055). In a multivariable linear regression analysis that included clinical, analytical, echocardiographic, and functional capacity covariates, the chronotropic parameters were positively associated with peak VO2. We found a linear relationship between Delta‐HR and peak VO2 (β coefficient of 0.03; 95% confidence interval: 0.004–0.05; P = 0.030); conversely, the association among CIs and peak VO2 was exponentially shaped.ConclusionsIn patients with chronic HFpEF, the HR response to exercise was positively associated to patient's functional capacity.

Do most patients with obesity or type 2 diabetes, and atrial fibrillation, also have undiagnosed heart failure? A critical conceptual framework for understanding mechanisms and improving diagnosis and treatment

“…However, this guidance has been based on the incorrect premise that HFpEF is characterized by an impairment in LV filling, which would be ameliorated by prolonging diastolic filling. In reality, the LV in patients with HFpEF is overfilled, thus invalidating the traditional rationale for the slowing of heart rate. In fact, patients with HFpEF and AF who have rapid exercise heart rates have greater levels of exercise capacity than those with slower rates; in many patients, effort intolerance is related to chronotropic incompetence .…”

Highlights in heart failure

“…128 It is still controversial to which extent echocardiography can substitute invasive hemodynamic monitoring, above all during exercise, for the diagnosis of HFpEF. 130 Pulmonary mechanisms leading to an increase in the lung dead space have also been shown. They include an impairment of the cardiac output and of the skeletal muscle diffusion of oxygen during exercise with a different contribution in each patient with HFpEF.…”

“…129 Chronotropic incompetence has a major role in the limitation of the cardiac output response, in addition to the impairment of the stroke volume increase. 130 Pulmonary mechanisms leading to an increase in the lung dead space have also been shown. 131 Cardiac and extracardiac comorbidities have a major role in patients with HFpEF.…”

Heightened risk of intensive rate control in patients with atrial fibrillation who are obese or have type 2 diabetes: A critical review and re‐evaluation

“…In reality, the LV in patients with HFpEF is overfilled, thus invalidating the traditional rationale for slowing of heart rate . In fact, patients with HFpEF and AF have greater levels of exercise capacity if they have rapid rather than slower rates, and drugs that slow heart rate can worsen the functional status of patients with HFpEF (Figure ) …”

“…34 In reality, the LV in patients with HFpEF is overfilled, thus invalidating the traditional rationale for slowing of heart rate. 35,36 In fact, patients with HFpEF and AF have greater levels of exercise capacity if they have rapid rather than slower rates, 37,38 and drugs that slow heart rate can worsen the functional status of patients with HFpEF (Figure 1). 39,40 Furthermore, whereas higher heart rates are associated with increased risk of adverse outcomes in patients with HFpEF and sinus rhythm, patients with HFpEF and AF do not fare worse with faster than slower heart rates.…”