An interventional study of HIIT + Strength Training and MICT + Strength Training in Heart Failure Reduced Ejection Fraction, sponsored by Universidad Internacional Isabel I de Castilla. Not yet recruiting at 1 site in Spain. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-09.
Sponsored by Universidad Internacional Isabel I de Castilla · Not applicable, Interventional, and Treatment
Heart failure is associated with impaired health-related quality of life and reduced exercise capacity. Women remain under-represented in cardiac rehabilitation research, and evidence comparing high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) in women with heart failure is limited.
HIIT-WHEF is a prospective, single-centre, randomised pilot feasibility trial involving 36 women aged 18 years or older with heart failure and a left ventricular ejection fraction below 50%. Participants will be randomly allocated in a 1:1 ratio to a 12-week supervised cardiac rehabilitation programme incorporating either HIIT or MICT. Both groups will also undertake individualised resistance training.
The primary objectives are to assess the feasibility and safety of conducting the randomised trial, including recruitment, acceptance, retention, adherence, intervention fidelity, completeness of outcome data and exercise-related adverse events. Health-related quality of life, assessed using the Minnesota Living with Heart Failure Questionnaire (MLHFQ), is the key clinical outcome of interest. Peak oxygen uptake, left ventricular ejection fraction and biomarkers will be assessed as exploratory clinical outcomes.
The study is designed to inform the planning of a future adequately powered confirmatory trial. It is not intended to establish definitive evidence of the superiority of HIIT over MICT.
HIIT-WHEF will be conducted in the cardiac rehabilitation unit of Hospital Universitario Reina Sofía, Córdoba, Spain. Eligible women with clinically stable heart failure, New York Heart Association functional class I-II, a left ventricular ejection fraction below 50%, and stable, guideline-directed medical treatment will be considered for participation following referral for cardiac rehabilitation.
After baseline assessment and written informed consent, 36 participants will be randomly allocated to HIIT or MICT in a 1:1 ratio, with concealed allocation. Outcome assessors and data analysts will remain blinded to treatment allocation where feasible.
Both interventions will be delivered over 12 weeks, three supervised sessions per week. HIIT will comprise repeated high-intensity exercise intervals above the second ventilatory threshold, interspersed with active recovery below the first ventilatory threshold. MICT will comprise continuous aerobic exercise at an individually prescribed moderate intensity, between the first and second ventilatory thresholds. Both groups will receive resistance training, with exercise prescription and progression individualised according to functional capacity, symptoms and clinical response.
Feasibility outcomes will include recruitment rate, acceptance of randomisation, retention, adherence to prescribed sessions, fidelity to the assigned intervention, completeness of MLHFQ and other outcome assessments, and the frequency and nature of adverse events, particularly those related to exercise.
The MLHFQ will be assessed before and after the intervention. Peak oxygen uptake will be measured by cardiopulmonary exercise testing, left ventricular ejection fraction by echocardiography, and relevant blood biomarkers will be collected. Clinical outcomes will be analysed primarily using analysis of covariance, adjusting for baseline values, and reported with estimates and 95% confidence intervals. Given the pilot design and sample size, clinical comparisons will be exploratory and will inform the design of a future confirmatory trial.
Women who decline cardiac rehabilitation may be invited to participate in a separate observational registry, subject to separate informed consent. These women will not form part of the randomised comparison.
230 studies on the registry are indexed under Heart Failure, Systolic; 51 are open to participants now.
This study's planned enrollment of 36 is below the median of 60 across 165 interventional studies indexed under Heart Failure, Systolic.
Browse Heart Failure, Systolic studies →This is the only study on the registry with Universidad Internacional Isabel I de Castilla as lead sponsor.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
LVEF (left ventricular ejection fraction)
The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients assigned to HIIT
Behavioral: HIIT + Strength Training
Patients assigned to MICT
Behavioral: MICT + Strength Training
A 12-week supervised cardiac rehabilitation programme consisting of three individual sessions per week. Aerobic exercise will be performed on a treadmill or cycle ergometer, with intensity individually prescribed according to cardiopulmonary exercise testing and ventilatory thresholds. Sessions will include a 5-minute warm-up below the first ventilatory threshold, at least four high-intensity intervals above the second ventilatory threshold interspersed with active recovery intervals of equal duration below the first ventilatory threshold, and a 5-minute cool-down. Exercise duration and intensity will be progressed according to individual tolerance and clinical response. Both groups will also undertake individualised resistance training targeting the major muscle groups. Total session duration will be approximately 60 minutes. All sessions will be supervised by a physiotherapist, with clinical monitoring and exercise modification or interruption when indicated for safety.
A 12-week supervised cardiac rehabilitation programme consisting of three individual sessions per week. Aerobic exercise will be performed on a treadmill or cycle ergometer at an individually prescribed moderate intensity between the first and second ventilatory thresholds, avoiding significant dyspnoea. Sessions will include a 5-minute warm-up below the first ventilatory threshold and a 5-minute cool-down. Exercise duration will progress according to individual tolerance and clinical response, towards approximately 30 minutes of continuous aerobic exercise. Both groups will also undertake individualised resistance training targeting the major muscle groups, progressing towards approximately 40-60% of one-repetition maximum, with 8-15 repetitions and at least two sets per muscle group when tolerated. Total session duration will be approximately 60 minutes. All sessions will be supervised by a physiotherapist, with clinical monitoring and exercise modification or interruption when indic
Recruitment Rate
Number of participants randomised per month during the first nine months of recruitment. Feasibility will be classified as green if at least 2 participants per month are randomised, amber if 1 to less than 2 participants per month are randomised, and red if fewer than 1 participant per month is randomised.
Time frame: From the start of recruitment to the end of the first 9 months of recruitment.
Acceptance of Randomisation
Proportion of eligible women referred for cardiac rehabilitation who agree to randomisation. Green: at least 50%; amber: 30% to less than 50%; red: less than 30%.
Time frame: From screening and referral throughout the recruitment period.
Participant Retention
Proportion of randomised participants with a post-intervention assessment. Green: at least 85%; amber: 70% to less than 85%; red: less than 70%.
Time frame: At the end of the 12-week intervention.
Adherence to Prescribed Exercise Sessions
Proportion of prescribed exercise sessions attended by participants who complete the programme. Green: at least 80%; amber: 65% to less than 80%; red: less than 65%.
Time frame: Throughout the 12-week intervention.
Fidelity to the Assigned HIIT Intervention
Proportion of HIIT sessions in which at least four intervals are completed above the second ventilatory threshold. Green: at least 75%; amber: 60% to less than 75%; red: less than 60%.
Time frame: Throughout the 12-week intervention.
Completeness of Post-Intervention MLHFQ Data
Proportion of randomised participants with a completed Minnesota Living with Heart Failure Questionnaire (MLHFQ) at post-intervention assessment. Green: at least 90%; amber: 75% to less than 90%; red: less than 75%.
Time frame: At the end of the 12-week intervention.
Exercise-Related Adverse Events
Frequency and nature of adverse events related to exercise, including serious adverse events and events requiring modification of exercise prescription. Feasibility criteria are green if no serious exercise-related adverse event occurs; amber if non-serious events require modification of the prescription in more than 20% of cases; and red if any serious adverse event attributable to exercise occurs.
Time frame: Throughout the 12-week intervention and the study period in which exercise-related adverse events are monitored.
Change in Minnesota Living with Heart Failure Questionnaire (MLHFQ) Total Score
Between-group difference in the post-intervention MLHFQ total score, adjusted for baseline score using analysis of covariance (ANCOVA). The MLHFQ ranges from 0 to 105, with higher scores indicating worse health-related quality of life. The baseline-to-post-intervention change will also be reported. This is an exploratory clinical outcome in the pilot trial and will not be used to establish confirmatory superiority.
Time frame: Baseline and 12 weeks.
Change in Peak Oxygen Consumption (VO2peak)
Between-group difference in peak oxygen uptake measured during cardiopulmonary exercise testing, adjusted for baseline VO2peak. VO2peak will be expressed in mL/kg/min and defined as the highest oxygen uptake achieved during the final 30 seconds of exercise.
Time frame: Baseline and at 12 weeks
Change in Left Ventricular Ejection Fraction (LVEF)
Between-group difference in left ventricular ejection fraction measured by echocardiography, adjusted for baseline LVEF. Results will be expressed as percentage points.
Time frame: Baseline and at 12 weeks
Changes in NT-proBNP, High-Sensitivity C-Reactive Protein and CA125
Changes in circulating NT-proBNP, high-sensitivity C-reactive protein (hs-CRP) and CA125 concentrations from baseline to post-intervention. Between-group comparisons will be exploratory and adjusted for baseline values where appropriate.
Time frame: Baseline and at 12 weeks
Plan to share: Yes — De-identified individual participant data (IPD) that underlie the results reported in future publications (including text, tables, and figures) will be made available to qualified researchers for scientifically sound research proposals. Data sharing will be conducted in strict compliance with the European General Data Protection Regulation (GDPR) and Spanish Organic Law 3/2018. Requests must be evaluated and approved by the competent Research Ethics Committee.
Supporting information: Study protocol, Informed consent form
Time frame: Available beginning 6 months and ending 5 years following article publication.
Access criteria: Data requests should be sent via email to the Principal Investigator (maruor@gmail.com) and the Data Protection Officers (dpo@ui1.es / dpd@imibic.org). Requesters must provide a methodologically sound proposal and obtain prior approval from an authorized Research Ethics Committee. Data will be shared via a secure, encrypted file transfer.
No publications or documents are linked to this record.
Start is estimated for Nov 2026; primary completion for Dec 2027, 13 months later.
Of 52 non-industry interventional studies with no phase under Heart Failure, Systolic, half reached primary completion within 27 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 46. This study's planned 13 months is below that.
Counting every sponsor, half of 56 studies reached it within 30 months; a quarter within 16 and three quarters within 50.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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