Smolis‐Bak 2017.

Methods	Parallel group RCT
Participants	N Randomised: 84 (control group 43; exercise group 41). 12 patients were lost to follow‐up (control group 5, exercise group 7) Profile: SHF and NYHA III with ICD Age: 63.7+/‐9.5 years (exercise group); 61.1 +/‐9.7 (control group) Male: 36 (87.8%) (exercise group); 40 (93.0%) (control group) White: NS Inclusion criteria: SHF of ischaemic or non‐ischaemic etiology Implanted ICD Low LVEF (≤ 35%) Controlled hypertension and diabetes Exclusion criteria: Resynchronisation therapy Possible indications for CRT in the future (left bundle branch block, QRS > 150 ms) Severe musculoskeletal conditions which preclude physical rehabilitation (orthopaedic, neurological) Planned cardiac surgery or percutaneous coronary interventions, cardiac surgery or coronary angioplasty within the last 3 months Acute coronary syndromes, stroke or transient ischaemic attack within the last 6 months Venous thrombosis or pulmonary embolism in the past Significant valvular disease History of malignancy
Interventions	Exercise: Total duration: 6 months Aerobic/resistance/mix: ICD‐exercise patients underwent interval workouts with a cycloergometer and conditioning exercises with elements of resistance exercises Frequency: 3 days pr week Duration: cycloergometer training lasted on average 30 minutes. Resistance training lasted from 5 to 10 minutes Intensity: cycloergometer training with a speed of 55 to 64 revolutions per minute. Resistance training with a load of up to 50% of muscle strength. During the working phase lasting 1 minutes, the patients performed 10–12 repetitions in one cycle. Setting: outpatient setting Other: ns Control: Control group received standard systolic heart failure care
Outcomes	Cardiopulmonary exercise testing Standard echocardiographic examination 6‐minute walk test
Country and setting	Poland. Single‐centre trial, with an outpatient setting
Follow‐up	End of intervention 12 months
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Patients were randomly allocated, but there is no information on how this was done.
Allocation concealment (selection bias)	Unclear risk	No information on concealment
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding because of the nature of exercise‐based cardiac rehabilitation
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Reasons for dropouts and withdrawals were not described. There was no information about any methods being used to handle missing data.
Selective reporting (reporting bias)	Low risk	Outcome described in methods are reported in results.
Performance bias	Low risk	Co‐intervention was delivered equally to both groups
Groups balanced at baseline bias	Low risk	Patients well matched at baseline
Intention‐to‐treat analysis	Low risk	Analyses were conducted according to an intention‐to‐treat analysis
For‐profit bias	Low risk	Reported on their source of funding with conflicts of interest

CHF: systolic heart failure; CRT: cardiac resynchronisation therapy; CRT‐D: cardiac resynchronisation therapy with defibrillator; CRT‐P: cardiac resynchronisation therapy with pacing; ESC: European Society of Cardiology; HF: heart failure; ICD: implantable cardioverter defibrillator; LVEF: left ventricular ejection fraction; NYHA: New York Heart Association; NS: not stated; QoL: quality of life; RCT: randomised controlled trial; SD: standard deviation; SF‐36: Short Form‐36 Health Survey; SHF: systolic heart failure; TIA: transient ischaemic attack; QRS: QRS complex; VF: ventricular fibrillation; VO²: estimated oxygen consumption; VT: ventricular tachycardia.