Impact of Atrial Fibrillation on Exercise Capacity and Mortality in Heart Failure With Preserved Ejection Fraction: Insights From Cardiopulmonary Stress Testing

Abstract

BackgroundAtrial fibrillation (AF) has been objectively associated with exercise intolerance in patients with heart failure with reduced ejection fraction; however, its impact in patients with heart failure with preserved ejection fraction has not been fully scrutinized.Methods and ResultsWe identified 1744 patients with heart failure and ejection fraction ≥50% referred for cardiopulmonary stress testing at the Cleveland Clinic (Cleveland, OH), 239 of whom had AF. We used inverse probability of treatment weighting to balance clinical characteristics between patients with and without AF. A weighted linear regression model, adjusted for unbalanced variables (age, sex, diagnosis, hypertension, and β‐blocker use), was used to compare metabolic stress parameters and 8‐year total mortality (social security index) between both groups. Weighted mean ejection fraction was 58±5.9% in the entire population. After adjusting for unbalanced weighted variables, patients with AF versus those without AF had lower mean peak oxygen consumption (18.5±6.2 versus 20.3±7.1 mL/kg per minute), oxygen pulse (12.4±4.3 versus 12.9±4.7 mL/beat), and circulatory power (2877±1402 versus 3351±1788 mm Hg·mL/kg per minute) (P<0.001 for all comparisons) but similar submaximal exercise capacity (oxygen consumption at anaerobic threshold, 12.0±5.1 versus 12.4±6.0mL/kg per minute; P =0.3). Both groups had similar peak heart rate, whereas mean peak systolic blood pressure was lower in the AF group (150±35 versus 160±51 mm Hg; P<0.001). Moreover, AF was associated with higher total mortality.ConclusionsIn the largest study of its kind, we demonstrate that AF is associated with peak exercise intolerance, impaired contractile reserve, and increased mortality in patients with heart failure with preserved ejection fraction. Whether AF is the primary offender in these patients or merely a bystander to worse diastolic function requires further investigation.

Evaluation of clinical and psychological parameters in subgroups of people with paroxysmal, persistent, and long- standing persistent atrial fibrillation

“…Differences between individual groups were around 10% and did not gain statistical significance. Similar observations have been described in the literature [18][19]. There were also studies based on the assessment of physical performance in patients with atrial fibrillation before and after effective electrical cardioversion [20][21].…”

“…It was found, among other things, that effective and long-term restoration of the sinus rhythm results in a longer distance covered in the test. The beneficial effects of electrical cardioversion on cardiac performance parameters were also confirmed by other haemodynamic, clinical (NYHA), spirometric parameters and also by quality of life [18][19][20][21][22].…”

Exercise training in the treatment of paroxysmal atrial fibrillation: study protocol of the Cologne ExAfib Trial

“… 28 29 In fact, reduced exercise tolerance has also been associated with increased mortality in patients with AF. 30 Importantly, previous large-scale prospective longitudinal cohort studies observed changes in CRF concomitantly with mortality outcomes, suggesting that improving VO 2peak through exercise may well reduce mortality. 31 In addition, in healthy elderly men (>65 years of age), muscle strength appears to be directly related to all-cause mortality, 32 even irrespective of muscle mass.…”

Exercise Training in Heart Failure Patients With Persistent Atrial Fibrillation: a Practical Approach

“…21 Moreover, AF is associated with lower exercise capacity in both HFrEF and HFpEF. 2,3,22 A landmark study of 1,744 patients diagnosed with HFpEF,of whom 239 showed AF, revealed that peak VO 2 was significantly lower -1.8 ml/ kg/min -when AF was present. 22 The authors observed that AF was associated with exercise intolerance, increased mortality and impaired contractile reserve.…”