Exercise capacity and prognosis in patients with chronic atrial fibrillation

Impacts of sinus rhythm maintenance with catheter ablation on exercise tolerance in patients with paroxysmal atrial fibrillation

BACKGROUND

It has been recently reported that sinus rhythm (SR) maintenance with catheter ablation therapy improves exercise tolerance (ET) in patients with persistent atrial fibrillation (AF). However, it remains to be elucidated whether this is also the case for patients with paroxysmal AF (PAF).

METHODS

We enrolled consecutive 54 patients with PAF (age; 63 ± 10 [SD] years old, male/female 46/8) and 26 patients with persistent AF (non-PAF) (age; 57 ± 12 [SD] years old, male/female 23/3) who underwent AF ablation without recurrence. ET and cardiac function were evaluated by cardio-pulmonary exercise test and ultrasound echocardiography before and 6 months after ablation.

RESULTS

The parameters of cardiopulmonary exercise test were comparable between the 2 groups. When PAF group was divided into 2 groups according to the time since diagnosis, peak oxygen uptake (peak VO₂) before ablation was significantly lower in patients with PAF duration of more than 1 year (n = 26), compared with those with less than 1 year (n = 28) (18.1 ± 3.7 vs 21.3 ± 5.8 ml/kg/min, P = 0.022). At 6 months after SR maintenance without AF burden, peak VO₂ significantly improved in both PAF (19.8 ± 5.1 to 22.0 ± 4.8 ml/kg/min, P = 0.0001) and non-PAF (20.6 ± 3.9 to 23.4 ± 5.0 ml/kg/min, P < 0.01). Furthermore, the improvement rate of peak VO₂ after successful ablation had a highly significant inverse relationship with peak VO₂ at baseline in patients with PAF (r = - 0.48, P = 0.0003).

CONCLUSIONS

These results indicate that SR maintenance with ablation improves ET in patients with PAF, especially in those with reduced ET.

Role of Geriatric Syndromes in the Management of Atrial Fibrillation in Older Adults: A Narrative Review

OBJECTIVES

Atrial fibrillation (AF) is common in older adults and associated with increased risk of cardiovascular events including thromboembolism. However, less is known about its association with noncardiovascular events, especially geriatric syndromes and conditions such as dementia, depression, impaired physical function, polypharmacy, falls, and poor quality of life. This review aims to help healthcare professionals integrate the special needs of older adults into their management of AF.

DESIGN

Nonsystematic review. A literature search on published articles on AF and geriatric syndromes and conditions was performed using the electronic databases MEDLINE, EMBASE and SCOPUS, and DARE until December 2017. Non-English articles were excluded.

SETTINGS AND PARTICIPANTS

Older adults with and without AF from different settings.

MEASURES

Various cognitive, mood, and functional measurements were used in these studies. In studies regarding polypharmacy, the Beers or PRISCUS criteria were used to identify inappropriate medications. In quality of life measurements studies, instruments like Medical Outcomes Study Short Form 36 and Atrial Fibrillation Quality of Life questionnaire were used.

RESULTS

This literature review finds that AF has a substantial association with geriatric syndromes and conditions and that AF is a risk factor for the development of geriatric syndromes and conditions. Evidence is limited regarding the potential benefit of long-term treatment of AF in lowering the risk of developing geriatric syndromes and conditions.

CONCLUSIONS/IMPLICATIONS

Considering the impact of AF on cardiovascular outcomes and geriatric syndromes and conditions in older adults, healthcare professionals need to consider these complex dynamics while managing AF in older adults. An individual approach to AF management is needed in older adults with multiple comorbidity and polypharmacy that may help lower the risk of disease-disease, disease-drug, and drug-drug interactions. Special consideration needs to be given to patients' cognitive and functional impairment and ability to adhere to therapy.

Atrial Fibrillation and Declining Physical Performance in Older Adults: The Health, Aging, and Body Composition Study

BACKGROUND

Age is the foremost risk factor for atrial fibrillation (AF), and AF has a rising prevalence in older adults. How AF may contribute to decline in physical performance in older adults has had limited investigation. We examined the associations of incident AF and 4-year interval declines in physical performance at ages 70, 74, 78, and 82 years in the Health, Aging, and Body Composition (Health ABC) Study.

METHODS AND RESULTS

Health ABC is a prospective cohort of community-dwelling older adults (n=3075). The study conducted serial assessments of physical performance with the Health ABC physical performance battery (scored 0-4), grip strength, 2-minute walk distance, and 400-m walking time. Incident AF was identified from the Center for Medicare and Medicaid Services and related to 4-year interval decline in physical performance. After exclusions, the analysis included 2753 Health ABC participants (52% women, 41% black race). Participants with AF had a significantly greater 4-year physical performance battery decline than those without AF at age 70, 74, 78, and 82, with mean estimated decline ranging from -0.08 to -0.10 U (95% confidence interval, -0.18 to -0.01; P<0.05 for all estimates) after multivariable adjustment. Grip strength, walk distance, and walk time similarly showed significantly greater declines at each 4-year age interval in participants with AF.

CONCLUSIONS

In community-based cohort older adults, incident AF was associated with increased risk of decline in physical performance. Further research is essential to identify mechanisms and preventive strategies for how AF may contribute toward declining physical performance in older adults.

Clinical significance of left atrial volume in clinical outcomes of heart transplant recipients

Background

Left atrial volume (LAV) is surgically kept enlarged in heart transplant (HT) recipients. On the other hand, LAV has been known an independent predictor of various cardiovascular diseases and is associated with exercise capacity of HT recipients. Thus, we evaluated the hypothesis that LAV is still associated with clinical outcomes in HT recipients whose left atria are artificially enlarged.

Methods

Clinical outcomes over 5 years after HT were retrospectively evaluated in 35 HT recipients who had a LAV measurement with echocardiography at 1 year after HT at the University of Cincinnati Medical Center. The LAV was derived from a stacked disc method using apical 4 and 2 chamber views.

Results

The average LAV normalized to body surface area was 38.3 ± 9.9 ml/m² (mean ± SD) at 1 year after HT. Two deaths and one drop-out occurred during 5-year follow up. A total of 552 cardiac symptom-related hospitalizations occurred in the recipients. The average time to first hospitalization was 166 ± 279 days and average number of hospitalizations of each recipient was 15 ± 16. The indexed LAV failed to correlate with the time to first hospitalization and number of hospitalizations of each recipient (Spearman’s p-value; 0.141 and 0.519 respectively). When the patients were divided to groups of large LAV (n = 17) and small LAV (n = 18) using the cut off value of the mean LAV, no significant difference was noted in mortality, hospitalization, and new onset of atrial fibrillation between the groups.

Conclusions

Although our study is limited by a retrospective study design and relatively small number of patients, our results implicate that LAV is not significantly associated with clinical outcomes in HT recipients over 5 years after HT.

Short-term ECG recordings for heart rate assessment in patients with chronic atrial fibrillation

INTRODUCTION

There is no consensus on the length of ECG tracing that should be recorded to represent adequate rate control in patients with atrial fibrillation (AFib). The purpose of the study was to examine whether heart rate measurements based on short-term ECGs recorded at different periods of the day may correspond to the mean heart rate and rate irregularity analyzed from standard 24-hour Holter monitoring.

MATERIAL AND METHODS

The study enrolled 50 consecutive patients with chronic AFib who underwent 24-hour Holter monitoring. Mean heart rate (mHR) and the coefficient of irregularity (CI) were assessed from 5- and 60-minute intervals of Holter recordings in different periods of the day.

RESULTS

The highest correlation in mean heart rate interval within 24 h was found during a 6-hour sample and in the periods 11.00 AM-12.00 PM, 12 PM-1.00 PM, and 1.00 PM-2.00 PM. With respect to irregularity, only the CI measurements based on a 6-hour interval (7.00 AM-1.00 AM) show a correlation > 0.08 compared to data from the 24-hour recording.

CONCLUSIONS

Only long-term (6-hour) recordings provide a high correlation within 24 h in mean heart rate interval and coefficient of irregularity. It seems that the mean heart rate interval in 1-hour periods between 11 AM and 2 PM might be predictive for 24-hour data. Short time recordings of the coefficient of irregularity of heart rate in AFib patients at this moment are not useful in clinical practice for long-term prognosis of ventricular irregularity.

Exercise performance and training in cardiac patients with atrial fibrillation

PURPOSE

Exercise training in cardiac patients with chronic atrial fibrillation (AF) has received little attention in the literature. Therefore, this study compared exercise performance and the effect of an exercise training program over a period of 3 months in patients with and without AF.

METHODS

Data in patients with AF (n = 19) were compared with a control group of patients in sinus rhythm (n = 44), drawn from a database of 2,116 patients. Patients performed a maximal exercise test on the bicycle until exhaustion before and after an ambulatory exercise training program where exercise training was offered 3 times a week for 3 months.

RESULTS

Before training, peak oxygen uptake (VO2) was significantly lower in patients with AF compared with the control group (1271 +/- 368 versus 1496 +/- 414 mL/min, P < 0.05). Exercise training significantly increased peak VO2 in both groups (+31%, P < 0.001 in AF and +25%, P < 0.001 in the control group). The gain in peak VO2 did not significantly differ between both groups. A significant decrease in resting heart rate was achieved in both groups after exercise training. AF was also a significant and independent determinant of peak VO2 in the total database, but not of the change in peak VO2.

CONCLUSIONS

Exercise training significantly improves exercise performance in cardiac patients with AF. AF affects exercise performance but does not impair the beneficial effects of training. Patients with chronic AF should therefore not be dissuaded from participating in exercise training after a cardiac event.

Does the 6-minute walk test predict the prognosis in patients with NYHA class II or III chronic heart failure?

BACKGROUND

We prospectively evaluated the potential of the 6-minute walk test compared with peak VO2 in predicting outcome of patients with New York Heart Association (NYHA) class II or III heart failure.

METHODS AND RESULTS

Patients with a history of heart failure caused by systolic dysfunction were included. The combined final outcome (death or hospitalization for heart failure) was used as the judgment criterion. One hundred twenty-one patients (age 59+/-11 years; left ventricular ejection fraction 29.6%+/-13%) were included and followed for 1.53+/-0.98 years. Patients were separated into two groups according to outcome: group 1 (G1, 74 patients), without events, and group 2 (G2, 47 patients), who reached the combined end point. Peak VO2 was clearly different between G1 and G2 (18.5+/-4 vs. 13.9+/-4 ml/kg/min, p=0.0001) but not the distance walked (448+/-92 vs 410+/-126 m; p=0.084, not significant). Survival analysis showed that unlike peak VO2, the distance covered was barely distinguishable between the groups (p < 0.08). However, receiver operating characteristic curves revealed that the best performances for the 6-minute walk test were obtained for subjects walking < or =300 m. These patients had a worse prognosis than those walking farther (p=0.013). In this subset of patients, there was a significant correlation between distance covered and peak VO2 (r=0.65, p=0.011). Thus it appears that the more severely affected patients have a daily activity level relatively close to their maximal exercise capacity. Nevertheless, the 300 m threshold suggested by this study needs to be validated in an independent population.

CONCLUSIONS

A distance walked in 6 minutes < or =300 m can predict outcome. Moreover, in these cases there is a significant correlation between the 6-minute walk test and peak VO2 demonstrating the potential of this simple procedure as a first-line screening test for this subset of patients.