Atrial Fibrillation, Peripheral Artery Disease, and Weekly Physical Activity

Pathak RK, Elliott A, Middeldorp ME, Meredith M, Mehta AB, Mahajan R, Hendriks JM, Twomey D, Kalman JM, Abhayaratna WP, Lau DH, Sanders P. Impact of CARDIOrespiratory FITness on arrhythmia recurrence in obese individuals with atrial fibrillation: The CARDIO-FIT Study. J Am Coll Cardiol. 2015;66(9):985–96. doi:10.1016/j.jacc.2015.06.488

Atrial fibrillation, commonly known as Afib, is the one of the most common cardiac arrhythmias. It is an irregular, often very rapid (≥400 atrial b·min⁻¹) heart rhythm originating from the atria which increases the risk of blood clot formation with resultant increased risk of stroke and other heart complications. Two common forms of Afib include paroxysmal and persistent. Paroxysmal is considered short term and often resolves without therapy, while persistent Afib is longer lasting, requiring interventions (medication or cardiac ablation) to resolve. Although obesity is a known risk factor for Afib, both weight loss and physical activity independently have been found to reduce Afib incidence. Despite this knowledge, there is less known about their combined impact. In this study, we sought to implement a graded exercise program to examine Afib outcomes associated with improved cardiorespiratory fitness and weight loss.

Methods: Patients with symptomatic paroxysmal and persistent Afib and a body mass index of 27 kg·m⁻² or greater were enrolled in this study. A face-to-face risk management protocol was implemented for dietary induced weight loss and exercise therapy. A progressive 3-day-per-week combined aerobic and resistance training protocol was implemented after a baseline exercise stress test to determine initial cardiorespiratory fitness (CRF). Patients were categorized by metabolic equivalents (METs) into low, adequate, and high CRF (<85%, 86%–100%, and >100% of predicted METs, respectively). Fitness gains (≥2 or <2 METs) and weight loss (<3% = no weight loss, ≥10% = significant weight loss) was evaluated at follow-up. Patients were also categorized into 4 groups based on the possible combination of interactions between weight loss and fitness gains (Group 1: <10% weight loss and <2 METs gain; Group 2: <10% weight loss and ≥2 METs gain; Group 3: ≥10% weight loss and <2 METs gain; and Group 4: ≥10% weight loss and ≥2 METs gain). Afib symptoms were evaluated via the Atrial Fibrillation Severity Scale (AFSS), and 7-day Holter monitoring was used to determine Afib freedom.

Results: A total of 1,415 patients were screened according to inclusion and exclusion criteria. The study sample consisted of 308 patients who were categorized as low (n = 95), adequate (n = 134), or high (n = 79) CRF after the graded exercise test. Patient follow-up was an average of 49 ± 19 months, after which data were analyzed. Afib freedom was reportedly highest at follow-up in the high CRF group (66%) compared with the adequate (35%) and low (12%) CRF groups (P < 0.001). A higher percentage of patients who gained ≥2 METs (61%) were free from AFib than patients who gained <2 METs (18%). A 9% reduction in AFib recurrence for every MET gain was noted, even after adjustments for weight loss and baseline CRF. Additionally, arrhythmia-free survival rates were significantly (P < 0.001) higher in patients who gained ≥2 METs (89%) than <2 METs gain (40%). Weight loss was more significant (P = 0.001) in patients with ≥2 METs gain (−12 ± 8.8 kg) than <2 METs gain (−3 ± 7.6 kg). AFSS scale scores were similar at baseline and improved for both MET groups at follow-up; however, significantly greater score reductions were seen for ≥2 METs gain than <2 METs gain (P < 0.001). Lastly, when examining the groups by combination of CRF and weight loss, Afib freedom independent of medication or ablation treatment was present at follow-up in 13%, 37%, 45%, and 76% of groups 1–4, respectively (P < 0.001).

Discussion: Obesity is a known risk factor for cardiovascular conditions, including Afib. Weight loss has been previously used as an effective strategy to improve Afib freedom, but less is known about the combined or independent impact of exercise therapy on Afib recurrence with obese populations. In this study, we provide support for the use of prescriptive exercise therapy in the management and treatment of Afib with obese patients, as improved CRF led to reductions in Afib recurrence beyond that of weight loss alone. The authors noted, in addition to weight loss, freedom from Afib was 2 times greater with an increase of ≥2 METs. Thus, using a structured exercise program can potentially serve as an effective tool to reduce the burden of Afib and the need for medications or surgery to improve freedom from Afib in obese populations.

Elliott AD, Verdicchio CV, Mahajan R, Middeldorp ME, Gallagher C, Mishima RS, Hendriks JML, Pathak RK, Thomas G, Lau DH, Sanders P. An exercise and physical activity program in patients with atrial fibrillation: The ACTIVE-AF Randomized Controlled Trial. JACC Clin Electrophysiol. 2023;9(4):455-465. doi:10.1016/j.jacep.2022.12.002

Management of atrial fibrillation (Afib) often includes addressing modifiable risk factors such as obesity and hypertension. Including the above reviewed study by Pathak et al. (2015), there is also compelling literature for the inclusion of exercise to help manage Afib; however, randomized control trials are still lacking. The intent of this study was to evaluate changes in Afib recurrence and symptom severity of patients completing an exercise intervention via a randomized control trial. Additional Afib risk factor variables were evaluated including body weight and blood pressure.

Methods: Afib (symptomatic paroxysmal or persistent) male and female patients 18–80 years of age were randomized into either an exercise or control group. The exercise group completed an individualized exercise plan based on baseline exercise capacity assessed by a clinical exercise physiologist. To optimize feasibility, the exercise intervention included supervised one-on-one sessions consisting of four 4-min aerobic intervals at 85%–90% of heart rate reserve, which were performed weekly for first 3 months and transitioned to biweekly for the final 3 months of the intervention, combined with home-based physical activity (PA). Weekly increases (20 min/week) in PA were encouraged until 210 min/week of moderate to vigorous intensity PA (≥10 min) was achieved. Although the control group did not receive an individualized exercise plan, they were encouraged to achieve 150 min/week of moderate intensity exercise. Afib symptom severity, assessed by the Atrial Fibrillation Severity Scale (AFSS); Afib freedom, determined via 4-day Holter monitoring; weight; and blood pressure were evaluated at baseline and months 6 and 12 postrandomization.

Results: Of the 369 Afib patients screened, 120 (69 males; 51 females) with a mean age of 65 years were eligible and randomized into the control (n = 60) or exercise (n = 60) groups. AFSS scores were significantly lower at 6- and 12-month follow-ups for exercisers than controls. Afib freedom was reported in a higher number of patients the exercise group, 24 (40%) of 60, than the control group, 12 (20%) of 60 (P = 0.002) at 12-month follow-up. Between-groups differences at 6- and 12-month follow-ups were not found for weight, systolic pressure, or diastolic pressure.

Discussion: The current clinical trial offers evidence supporting the efficacy of using customized exercise programs to aid Afib management. The combination of supervised exercise and home-based PA led to improved symptom severity and freedom from Afib, despite a lack of change in Afib risk factor variables such as body weight and blood pressure. This is promising, considering the clinical feasibility of a combined program. It is important, however, to consider the differences in the PA prescribed between the exercise and control groups. The exercise group was prescribed higher PA volume and intensity levels than the control group. Although patients were encouraged to record duration and characteristics of home PA, actual PA data were not reported for comparison. In summary, the integration of customized exercise programs should be strongly considered by practitioners to aid in the clinical management of Afib, as it has been found effective for reducing symptoms and recurrence.

Ney B, Lanzi S, Calanca L, Mazzolai L. Multimodal supervised exercise training is effective in improving long term walking performance in patients with symptomatic lower extremity peripheral artery disease. J Clin Med. 2021;10(10):2057. doi:10.3390/jcm10102057

Restricted blood flow to the muscles of the legs as the result of peripheral arterial disease (PAD) often leads to painful cramping, known as intermittent claudication, diminishing walking capacity and quality of life. Declines in mobility and function are accelerated with PAD, and female patients experience declines at a faster rate than males. The use of supervised exercise training (SET) has been well documented as a first-line intervention for addressing these issues in symptomatic PAD patients; however, less is known regarding the persistent impact of SET on walking performance, which was examined in this study. Additionally, the impact by gender was explored to better address disparities in the literature.

Methods: A retrospective examination was conducted using stage II (Fontaine’s classification) symptomatic PAD patients participating in a 3-month SET program consisting of three 50-min sessions. The indoor SET (1/3 of sessions) included walking, balance, coordination, and resistance training (body weight or resistance bands) exercise, with ratings of perceived exertion (RPEs) maintained between 10 and 14 (6–20 Borg scale), while the outdoor SET (2/3 of sessions) included Nordic walking with RPEs between 12 and 14. Patients were provided education (four 90-min sessions) for PAD which included information about physical activity. At the conclusion of the structured SET program, patients were encouraged to continue to exercise regularly. Vascular and walking variables were assessed at baseline, conclusion of SET, and at 6 and 12 months post-SET. Vascular assessments included ankle brachial index (ABI) and toe brachial index (TBI). Pain-free walking distance (PFWD)—meters walked until onset of lower-limb pain—and maximal walking distance (MWD)—meters walked until maximal pain ceased walking—were assessed using a constant load treadmill test (3.2 kph and 12% slope). Distance obtained during the completion of a 6-min walk test (6MWD) was also recorded.

Results: Data were obtained at baseline and at the completion of SET for 85 patients, but fewer patients completed the 6-month (n = 70) and 12-month (n = 56) follow-ups. Significant (P ≤ 0.001) improvements in PFWD (+145%, +257%, and +272%), MWD (+97%, +132%, and +130%), and 6MWD (+15%, +11%, and +11%) were observed all time points, post-SET, 6 months, and 12 months, respectively, when compared with baseline. Although improvements were not observed from post-SET to 6 or 12 months for either MWD or 6MWD, PFWD was significantly greater at the 6-month (P = 0.006, +45%) and 12-month (P < 0.001, +51%) follow-ups than post-SET. ABI was significantly higher (P = 0.006) at 6 months than post-SET; however, all other time+-point comparisons for ABI were nonsignificant. TBI increased significantly from baseline to post-SET (P = 0.009), 6 months (P ≤ 0.001), and 12 months (P ≤ 0.001) and post-SET to 12 months (P = 0.37). Gender comparisons did not reveal any significant gender differences in walking (PFWD, MWD, and 6MWD) or vascular (ABI and TBI) variables, as all variables increased similarly for males and females.

Discussion: PAD can greatly impact one’s ability to complete daily tasks or activities, directly reducing quality of life. Despite SET being a first-line therapy for PAD, long-term benefits to functional walking are less understood. In the current study, we offer evidence that SET not only improves treadmill tested walking parameters (PFWD and MWD) but also appears to offer long-term benefits to 6MWD, which more closely aligns with daily activity. Unique to treadmill-based SET programs, in the current study, we employed a multimodal training program, which included Nordic walking. The authors speculate this method of training may translate more effectively to continued walking post-SET than treadmill-based programs, supporting the long-term persistence of SET benefits. Vascular data revealed limited changes to ABI, but TBI increased pre-SET to post-SET, which was maintained through the 6- and 12-month follow-ups. Additionally, our findings revealed SET yielded similar improvements in walking performance (PFWD, MWD, and 6MWD) and vascular parameters (ABI and TBI) between men and women. Although these findings contrast with previous studies, they are promising, considering women with PAD tend to experience more rapid functional declines than men. Overall, researchers continue to demonstrate the benefits of SET for PAD, but continued research would aid in determining optimal SET protocols.

Khurshid S, Al-Alusi MA, Churchill TW, Guseh JS, Ellinor PT. Accelerometer-derived “weekend warrior” physical activity and incident cardiovascular disease. JAMA. 2023;330(3):247–52. doi:10.1001/jama.2023.10875

Evidence-based guidelines regarding the amount of weekly accumulated physical activity (PA) to optimize health and reduce the risk of various chronic diseases has been available for decades. Most current recommendations of accumulating a minimum of 150 min of moderate-intensity or 75 min of vigorous-intensity aerobic activity a week have been promoted by numerous health organizations worldwide. Professional organizations, including the American College of Sports Medicine (ACSM), also recommend PA occur on multiple days throughout the week, yet it is less clear if the weekly pattern of PA influences the health benefits obtained. In the current study, we sought to determine if those who accumulate high amounts of PA over a 1–2-day period, often termed “weekend warriors” (WWs), achieve the same cardiovascular health benefits as those who accrue activity minutes over several days per week.

Methods: Axivity AX3 wristband triaxial accelerometry data were used from 103,695 males and females ranging in age from 49 to 69 years old, in association with the UK Biobank from 2006 to 2010. Accelerometry was collected over a 1-week period and used to classify participants according to activity pattern. Using a threshold of ≥150 min of moderate to vigorous PA (MVPA), active WWs were those who accumulated ≥50% of the total MVPA over a 1–2-day period, active regular were those who accumulated the threshold of activity but did not qualify as a WW, and those who did not meet the threshold of MVPA were classified as inactive. Frequency of musculoskeletal conditions and cardiovascular events including atrial fibrillation (AF), myocardial infarction (MI), heart failure (HR), and stroke were self-reported, and analyses examined associations with activity patterns.

Results: Accelerometry data were screened to eliminate data from participants with insufficient wear time, leaving 89,573 participants of which 37,827 were active WWs, 21,473 were active regular, and 30,288 were inactive. Musculoskeletal injuries were similarly reduced for active WWs (13%) and active regular (11%). Risk reduction was similar for active WWs and active regular for AF (22% and 19%, respectively), HF (38% and 36%, respectively), MI (27% and 35%, respectively), stroke (21% and 17%, respectively), and PA patterns.

Discussion: Many barriers limit individuals from engaging in daily PA, leading to more concentrated exercise patterns such as WWs. A plethora of literature demonstrates the positive health benefits of achieving PA guidelines, yet the impact of activity distribution (i.e., days per week and minutes per day) on injury risk and cardiovascular health is less clear. In the current investigation, we examined risk reduction for musculoskeletal conditions, AF, MI, HF, and stroke across 3 activity patterns: active WWs, active regular, and inactive. Regardless of activity pattern, whether obtaining the majority (≥50%) of total PA over 1–2 days or PA spread over several days of the week, those who met the threshold of ≥150 min/week of aerobic activity obtained a similar musculoskeletal injury and cardiovascular incident risk reduction. This is extremely meaningful, considering it may reduce barriers by offering more options while still obtaining the benefits of being active. Continued research is needed to explore the implications of the WW pattern on other health parameters.