Small heart opening added during leaky mitral valve surgery
Tests a small opening between heart upper chambers during mitral valve repair in adults.
Plain-language title generated from the registry record
Registry title: LEFT ATRIAL MONITORING IN PATIENTS BEFORE AND AFTER MITRAL SURGERY - LAMBDA STUDY
Key facts
- Where
- Ottawa, CanadaSee the site
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 with severe mitral valve leakage caused by valve disease who are planned for mitral valve repair surgery. It tests whether making a small opening between the heart's two upper chambers during surgery helps.
- Age
- 18 years or older
- Sex
- All sexes can join
- Disease stage
- Severe (4+) mitral regurgitation with symptoms, Carpentier Type II, caused by degenerative disease
- Earlier treatment
- Must be planned for mitral valve repair surgery. Cannot have had any earlier mitral valve procedure.
- Biomarker or test result
- Pressure difference between the right and left upper heart chambers of 5 mmHg or more at baseline. Pulmonary vascular resistance of 4 Wood units or less.
Main reasons for not taking part
- Mitral valve leakage from other causes, or mixed mitral valve disease
- Heart valve infection (infective endocarditis) within 30 days
- Any earlier mitral valve procedure
- Need for emergency procedure or surgery
Read by machine on 9 November 2026.
Where in Canada
- University of Ottawa Heart InstituteOttawa, 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
- Ottawa Heart Institute Research Corporation
- Trial code
- NCT06547788
- Record updated
- 5 November 2026
- Original description
Mitral valve leakage, or mitral regurgitation (MR), is associated with heart failure symptoms including shortness of breath, fatigue, irregular heart rate. When left untreated, it may cause death. Patients with MR can be divided in two broad groups: those with primary MR, caused by disease of the mitral valve structures, and those with secondary MR, due to dilation of the heart chambers. Our study focuses on patients with primary MR.Read full original descriptionShow less
LEFT ATRIAL MONITORING IN PATIENTS BEFORE AND AFTER MITRAL SURGERY - LAMBDA STUDY
Mitral valve leakage, or mitral regurgitation (MR), is associated with heart failure symptoms including shortness of breath, fatigue, irregular heart rate. When left untreated, it may cause death. Patients with MR can be divided in two broad groups: those with primary MR, caused by disease of the mitral valve structures, and those with secondary MR, due to dilation of the heart chambers. Our study focuses on patients with primary MR.
The standard treatment for severe symptomatic primary MR is mitral valve surgery, a type of open-heart surgery. The outcomes following this procedure are excellent, however, a subset of patients continue to experience heart failure symptoms after surgery due to very high pressures in the heart, more specifically in the left atrium, which is one of the four heart chambers. This is called functional mitral stenosis (FMS).
Previous studies have shown that creating a small opening between the left and right atria can help relieve the pressure inside the left atrium. We would like to determine whether creating this opening between the two atria at the time of mitral valve surgery can help prevent FMS. To answer this question, we will study two groups of patients who need mitral valve surgery for primary MR. The first group will undergo mitral valve surgery, along with the creation of the opening between the two atria. The second group will undergo mitral valve surgery alone. We will then compare the outcomes between both groups, namely with regards to their heart failure symptoms after open-heart surgery.
Inclusion: Patients ≥18 years of age; Severe (4+) symptomatic Carpentier Type II MR due to degenerative disease; Planned surgical mitral valve repair; Right-to-left atrial pressure gradient ≥ 5 mmHg at baseline; Pulmonary vascular resistance ≤ 4 Wood units.
Exclusion: Any prior mitral valve intervention; Need for emergency intervention or surgery; Secondary causes of MR and mixed mitral valve disease; Left ventricular ejection fraction 2+; Infective endocarditis within 30-days.