Colchicine for small blood vessel problems in heart failure with preserved ejection fraction
Tests colchicine against placebo for heart blood flow in people with heart failure.
Plain-language title generated from the registry record
Registry title: Reversing Microvascular Dysfunction in Heart Failure With Preserved Ejection Fraction
Key facts
- Where
- Montreal, CanadaSee the site
- Phase
- Phase 2
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults aged 40 or older with long-term heart failure, a left ventricular ejection fraction above 40%, and poor blood flow in the small heart vessels.
- Age
- 40 years or older
- Sex
- All sexes can join
- Disease stage
- Long-term heart failure with symptoms, ejection fraction above 40% within the last 12 months, NYHA class II to IV, taking loop diuretics for at least 30 days. Needs either a hospital stay with IV diuretics in the last 12 months or a raised NTproBNP. Needs small-vessel heart dysfunction (myocardial flow reserve below 2.0 on PET imaging) and hs-CRP above 5mg/L.
- Earlier treatment
- Must have been on loop diuretics for at least 30 days. People currently taking colchicine for other reasons, long-term steroids or regular anti-inflammatory drugs (including NSAIDs) cannot join.
- Biomarker or test result
- NTproBNP above 150pg/ml (sinus rhythm) or above 450pg/ml (chronic atrial fibrillation); hs-CRP above 5mg/L; myocardial flow reserve below 2.0 on dipyridamole-based PET imaging.
Main reasons for not taking part
- Infiltrative cardiomyopathy or primary severe valve disease
- Infection needing antibiotics, acute heart failure, heart attack or heart surgery in the last 3 months
- Significant coronary artery disease that has not been treated by revascularization
- Liver disease, kidney function eGFR below 59 ml/min/1.73 m2, or bowel disease with chronic diarrhea
- Pregnancy, or taking certain interacting drugs such as amiodarone, diltiazem or high-intensity statins
Read by machine on 11 November 2026.
Where in Canada
- Centre de recherche du Centre hospitalier de l'Université de MontréalMontreal, CanadaTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorTrial details
- Who runs it
- Montreal Heart Institute
- Trial code
- NCT06217120
- Record updated
- 10 November 2026
- Original description
This study will evaluate the impact of colchicine on the change in myocardial flow reserve (MFR), a marker for coronary microvascular dysfunction (CMD), compared to a matched placebo in patients with heart failure and ejection fraction above 40% (including patients with improved EF).Read full original descriptionShow less
Reversing Microvascular Dysfunction in Heart Failure With Ejection Fraction > 40% Using Colchicine (The COL-Micro-HF Study)
This study will evaluate the impact of colchicine on the change in myocardial flow reserve (MFR), a marker for coronary microvascular dysfunction (CMD), compared to a matched placebo in patients with heart failure and ejection fraction above 40% (including patients with improved EF).
Inclusion: Subjects ≥ 40 years of age,; Chronic symptomatic HF and left ventricular ejection fraction (LVEF) > 40% within 12 months prior to screening visit (regardless of the imaging modality) and one of the following abnormalities:; 2a. HF requiring hospitalization and IV diuretics within 12 months of study entry, or 2b. NTproBNP > 150pg/ml in sinus rhythm or NTproBNP > 450pg/ml in chronic atrial fibrillation, 3. The presence of coronary microvascular dysfunction (CMD) at baseline assessed using dipyridamole-based PET imaging and defined as myocardial functional reserve (MFR) < 2.0, 4. Symptoms of HF requiring current treatment with loop diuretics for ≥ 30 days, 5. NYHA functional class II to (ambulatory) IV, 6. High-sensitivity C-reactive protein (hs-CRP) > 5mg/L at baseline, 7. Subjects with the capacity to provide informed consent.
Exclusion: Presence of active infection within the 3 months prior to enrollment needing antibiotics,; Acute decompensated HF, acute coronary syndrome (including MI), cardiac surgery, other major cardiovascular surgery, or urgent PCI within the 3 months prior to enrollment,; Patient currently taking colchicine for other indications (Familial Mediterranean Fever, gout or post MI). There is no wash-out period required for patients who have been treated with colchicine and stopped treatment prior to enrolment,; Patients under long-term systemic steroid medication or any chronic use of anti- inflammatory medication (including Non-steroidal Anti-inflammatory Drugs, NSAIDS),; Contra-indications to dipyridamole use (PET-imaging): Patients with bronchospastic lung disease with ongoing wheezing; Acute myocardial infarction or unstable angina in the past 48h; Uncontrolled hypertension (systolic pressure of over 200 mmHg or a diastolic pressure of over 110 mmHg); Symptomatic hypotension; Untreated second- or third-degree atrioventricular block; Known hypersensitivity to dipyridamole; Caffeine intake in the previous 12 hours; Drug-drug interaction (competitive inhibition of CYP3A4 and P-gp): Patients treated with amiodarone, dronedarone, quinidine, propafenone, diltiazem, azithromycin or high-intensity statin therapy; Presence of primary severe valvular heart disease (functional MR/TR are not excluded),; Known or clinically judged significant (i.e., angina with CCS class > 2/4) epicardial coronary artery disease (CAD) that has not been revascularized (revascularized CAD is defined by a history of myocardial infarction, percutaneous intervention, or coronary artery bypass grafting),; History of hypersensitivity to colchicine,; Subject with inflammatory bowel disease (Crohn's disease or ulcerative colitis) or patient with chronic diarrhea,; Patient with pre-existent progressive neuromuscular disease,; Contra-indications to aminophylline use (PET-imaging): epilepsy, peptic ulcer (active) and hypersensitivity to aminophylline, theophylline, ethylenediamine, or any component of the formulation; History or presence of any other disease with a life expectancy of <1 year,; Evidence of hepatic disease as determined by any 1 of the following: SGOT (AST) or SGPT (ALT) values exceeding 3× the upper limit of normal at enrollment; or patient with a history of cirrhosis, chronic active hepatitis or severe hepatic disease,; Patients with at most moderate renal impairment defined as an eGFR < 59 ml/min/1.73 m2 as calculated by the Modification in Diet in Renal Disease (MDRD) formula at enrollment,; Patients with a diagnosis of infiltrative cardiomyopathy,; Positive pregnancy test result at the screening visit, and females of childbearing potential who do not agree to use adequate method of contraception for the duration of the study; acceptable means of birth control include: implantable contraceptives, injectable contraceptives, oral contraceptives, transdermal contraceptives, intrauterine devices, male or female condoms with spermicide, abstinence, or a sterile sexual partner,; Patient considered by the investigator, for any reason, to be an unsuitable candidate for the study,.