Clinical Trials Logo

Clinical Trial Details — Status: Recruiting

Administrative data

NCT number NCT03636295
Other study ID # 5139
Secondary ID
Status Recruiting
Phase Phase 3
First received
Last updated
Start date September 5, 2019
Est. completion date December 30, 2026

Study information

Verified date May 2024
Source Population Health Research Institute
Contact Emilie Belley-Côté, MD, MSc
Phone 905-527-4322
Email emilie.belley-cote@phri.ca
Is FDA regulated No
Health authority
Study type Interventional

Clinical Trial Summary

This study evaluates the use of a lower INR target (1.5 to 2.5) in patients with a mechanical bileaflet heart valve in the aortic position. This study will inform physicians about whether a lower INR target will decrease the risk of bleeding or increase the risk of blood clot formation and stroke. These results have the potential to reduce the burden of bleeding in patients with a mechanical heart valve who require lifelong warfarin (Coumadin) treatment.


Description:

Warfarin (Coumadin) is a blood thinner used to prevent blood clot formation in patients with mechanical heart valves. Blood clots can block blood flow to the brain, heart, or other parts of the body. Mechanical heart valves increases the risk of clot so patients with a mechanical heart valve must take warfarin to reduce their risk of stroke and other blood clot-related problems. The degree to which warfarin 'works' varies from person to person, and so dosage is determined by measuring each person's response to the drug as an 'international normalized ratio' or INR. A patient with an INR over 1.0 has blood that takes longer to clot than average, and increasing INR values represent increasing time required for blood to clot. While an INR over 1.0 decreases clotting risk, it also increases bleeding risk. It is important to carefully balance these risks. Specific INR targets have been recommended for patients with a mechanical heart valve, but these recommendations differ between scientific groups and are based on low quality evidence. Recent studies suggest that a lower INR target range than is currently recommended can be used safely. A laboratory study showed that warfarin effectively prevents blood clot formation on mechanical heart valves as long as the INR is 1.5 or above. Two moderately-sized clinical studies showed that an INR target range of 1.5-2.5 resulted in less bleeding than the usual higher target range without increasing blood clot formation or stroke in patients with a newer valve model. Whether we could use a lower INR target range for patients with a mechanical aortic valve remains controversial. This study evaluates the use of a lower INR target (1.5 to 2.5) in patients with a mechanical bileaflet heart valve in the aortic position. This study will inform physicians about whether a lower INR target will decrease the risk of bleeding or increase the risk of blood clot formation and stroke. These results have the potential to reduce the burden of bleeding in patients with a mechanical heart valve who require lifelong warfarin (Coumadin) treatment.


Recruitment information / eligibility

Status Recruiting
Enrollment 2625
Est. completion date December 30, 2026
Est. primary completion date March 31, 2025
Accepts healthy volunteers No
Gender All
Age group 18 Years and older
Eligibility Inclusion criteria: - Age is 18 or older at the time of enrolment - Have had a bileaflet mechanical heart valve implant in the aortic position 3 or more months ago - Written informed consent from either the patient or substitute decision maker Exclusion criteria: - Has a second implanted mechanical valve (any position) - Lower boundary of planned INR range is less than 2.0 - Pregnant or expecting to become pregnant during the study follow-up

Study Design


Related Conditions & MeSH terms


Intervention

Drug:
Warfarin
Participants in both arms will be on warfarin therapy post-mechanical valve replacement as is standard, but will have different INR target ranges.

Locations

Country Name City State
Belgium Ziekenhuis Oost-Limburg Genk Limburg
Belgium Universitair Ziekenhuis Leuven Leuven
Brazil Sociedade Hospitalar Angelina Caron Campina Grande Do Sul Parana
Brazil InCor-HCFMUSP Cerqueira César São Paulo
Brazil HEW Cardiologia LTDA Joinville Santa Catarina
Canada Hamilton General Hospital Hamilton Ontario
Canada London Health Sciences Centre Research Inc. London Ontario
Canada Jewish General Hospital Montréal Quebec
Canada The Ottawa Hospital Research Institute Ottawa Ontario
Netherlands Erasmus University Medical Centre Rotterdam
Russian Federation Meshalkin National Medical Research Center Novosibirsk
Spain Hospital de la Santa Creu i Sant Pau Barcelona

Sponsors (2)

Lead Sponsor Collaborator
Population Health Research Institute Hamilton Health Sciences Corporation

Countries where clinical trial is conducted

Belgium,  Brazil,  Canada,  Netherlands,  Russian Federation,  Spain, 

References & Publications (2)

Puskas J, Gerdisch M, Nichols D, Quinn R, Anderson C, Rhenman B, Fermin L, McGrath M, Kong B, Hughes C, Sethi G, Wait M, Martin T, Graeve A; PROACT Investigators. Reduced anticoagulation after mechanical aortic valve replacement: interim results from the prospective randomized on-X valve anticoagulation clinical trial randomized Food and Drug Administration investigational device exemption trial. J Thorac Cardiovasc Surg. 2014 Apr;147(4):1202-1210; discussion 1210-1. doi: 10.1016/j.jtcvs.2014.01.004. Epub 2014 Jan 12. — View Citation

Torella M, Torella D, Chiodini P, Franciulli M, Romano G, De Santo L, De Feo M, Amarelli C, Sasso FC, Salvatore T, Ellison GM, Indolfi C, Cotrufo M, Nappi G. LOWERing the INtensity of oral anticoaGulant Therapy in patients with bileaflet mechanical aortic valve replacement: results from the "LOWERING-IT" Trial. Am Heart J. 2010 Jul;160(1):171-8. doi: 10.1016/j.ahj.2010.05.005. — View Citation

Outcome

Type Measure Description Time frame Safety issue
Primary Thrombosis/thromboembolism Number of patients who have at least one of the following: ischemic stroke, systemic thromboembolism, and valve thrombosis Through study completion, an expected mean of 2-3 years
Primary Major bleeding Number of patients that have bleeding that results in the following:
Death and/or,
Symptomatic bleeding in critical area or organ (e.g. intracranial, intraspinal, intraocular, retroperitoneal, intraarticular, pericardial, in a non-operated joint, or intramuscular with compartment syndrome) and/or,
Bleeding that causes drop of hemoglobin level by 20 g/L or more, or that requires the transfusion of 2 or more units of packed red blood cells or whole blood
Through study completion, an expected mean of 2-3 years
Secondary All cause mortality Selected rather than cardiovascular mortality, as cause-specific mortality is often difficult to ascertain or define in complex cardiovascular patients in whom multi-end-organ dysfunction may accompany cardiovascular decline. Through study completion, an expected mean of 2-3 years
Secondary All clinically important bleeding Number of patients that experience all clinically important bleeding (major and minor) Through study completion, an expected mean of 2-3 years
Secondary Minor bleeding Number of patients that experience a bleed that does not meet major bleeding criteria Through study completion, an expected mean of 2-3 years
Secondary All stroke Number of patients that experience a strokes, including ischemic stroke, ischemic with secondary transformation, stroke of uncertain classification and hemorrhagic stroke Through study completion, an expected mean of 2-3 years
Secondary Ischemic stroke Number of patients that experience an ischemic stroke, defined as focal brain infarction caused by an arterial (or rarely venous) obstruction and as documented by CT/MRI that is normal or shows an infarct in the clinicall expected area Through study completion, an expected mean of 2-3 years
Secondary Hemorrhagic stroke Number of patients that experience a hemorrhagic stroke, defined as requiring neuroimaging or autopsy confirmation, and includes two subcategories: primary intracerebral hemorrhage and primary subarachnoid hemorrhage Through study completion, an expected mean of 2-3 years
Secondary Type 1, 2 or 3 myocardial infarction Number of patients who experience a type 1, 2 or 3 myocardial infarction Through study completion, an expected mean of 2-3 years
Secondary Systemic thromboembolism Number of patients who experience a systemic thromboembolism Through study completion, an expected mean of 2-3 years
Secondary Valve thrombosis Number of patients who experience a valve thrombosis Through study completion, an expected mean of 2-3 years
Secondary Pulmonary embolism Number of patients who experience a pulmonary embolism Through study completion, an expected mean of 2-3 years
Secondary Deep vein thrombosis Number of patients who experience a deep vein thrombosis Through study completion, an expected mean of 2-3 years
Secondary New renal replacement therapy Number of patients requiring new renal replacement therapy Through study completion, an expected mean of 2-3 years
Secondary Time in therapeutic range The percentage of time the patient's INR was within the target range Through study completion, an expected mean of 2-3 years
Secondary Proportion of patients with extreme INR values (>4) The proportion of patients with at least one reported INR value above 4 Through study completion, an expected mean of 2-3 years