The Norwegian Exercise in Atrial Fibrillation Trial

Atrial fibrillation (AF) patients suffer a high symptom burden and reduced quality of life (QoL), high hospitalization rates and few effective treatment options. They have a high burden of cardiovascular risk factors and events. Lifestyle changes and exercise is a cornerstone of management in most chronic cardiac conditions and holds promise in AF, but the evidence is sparse and specific guidelines for exercise do not exist for AF patients. NEXAF is a large-scale multicenter randomized trial to determine the feasibility and effects of exercise on patient-reported and clinical outcomes. All patients will undergo continuous rhythm monitoring, enabling assessment of duration, frequency and total time of AF episodes. The overall aim of the study is to provide documentation for clinical exercise recommendations in AF. The objectives are to examine the effects of a 1-year exercise intervention in AF patients on (i) QoL and symptom burden, (ii) time-in-AF, and peak oxygen uptake, cardiac structure and function, cardiovascular risk factors and use of healthcare resources.

A pre-planned substudy will examine the immediate (24-h to 7 days) effects of vigorous exercise on AF-burden in a subgroup of participants from each arm. Two main outcomes are prespecified: (i) mean time-in-AF measured by an insertable cardiac monitor (ICM) 24 hours after maximal exercise testing at baseline and follow-up compared to mean of the last week before exercise test. (ii) Normal cardiac biomarker response for Troponin and NT-proBNP to acute exercise (0h, 3h, 24h post exercise). Secondary outcomes are mean time-in-AF the consecutive week and post-exercise heart rate variability and number of atrial and ventricular extra systoles at the same time points. Further, changes in post-exercise responses after the intervention (12 months) and the effect on clinical outcomes will be examined.

Eligibility Criteria:
Inclusion Criteria:

* Signed informed consent
* Diagnosed with paroxysmal or persistent AF in hospital registries
* In sinus rhythm at baseline screening
* Report \<75 minutes per week of vigorous and/or \<150 minutes of moderate intensity exercise the last three months
* Use a smartphone

Exclusion Criteria:

* Permanent AF or persistent AF with at least one continuous episode lasting ≥3 months the last year
* AF as a complication of acute coronary syndromes, cardiothoracic surgery or infections
* Planned ablation procedure next 12 months or ablated last 6 months without known recurrence
* Unstable coronary heart disease
* De-compensated heart failure
* Left ventricular ejection fraction \<40%
* At least moderate to severe mitral or aortic pathology, or aortic aneurysms clinically incompatible with safe exercise
* Moderate to severe chronic obstructive pulmonary disease (GOLD group C+D)
* Ongoing severe cancer or active cancer treatment
* Pacemaker or ICD
* Pregnancy
* Alcohol or drug abuse
* Cognitive or serious psychiatric disease that may impede protocol compliance
* Physical impairments or diseases hindering exercise or making exercise contraindicated
* Resident of nursing home or other institution
* Participation in conflicting research studies (i.e. lifestyle interventions)