Can mild mitral regurgitation get worse? How fast does mitral valve regurgitation progress? Let’s find out about mitral regurgitation symptoms and treatment!
Table of Contents
Mitral Regurgitation Definition
Mitral regurgitation meaning – What is mitral regurgitation? Mitral valve regurgitation is a condition in which your blood doesn’t flow the way it should.
When the mitral valve leaks, it puts more pressure on the heart (increases preload) and less pressure on the heart (reduces afterload). The result is that the LV gets bigger, and the ejection fraction increases (EF). Over time, the stress of the volume overload reduces the myocardium’s ability to contract. When this happens, EF goes down, and the end-systolic volume goes up.
Mitral Regurgitation Causes
What causes mitral regurgitation? What is the most common cause of mitral regurgitation? Most of the time, this happens because of damage to the mitral valve.
Mitral Regurgitation Diagnosis
- It May be asymptomatic for years (or for life).
- When mitral regurgitation is very bad, it can lead to heart failure on the left, pulmonary hypertension, and heart failure on the right.
- Chronic primary mitral regurgitation needs surgery if there are symptoms or if the left ventricle (LV) ejection fraction (LVEF) is less than 60%, or if the LV end-systolic dimension (LV end-systolic dimension on echocardiography) is more than 4.0 cm. Surgery is also recommended for people whose LV size keeps getting bigger or whose LVEF keeps decreasing.
- If the mitral repair can be done successfully with a high degree of certainty, patients with mitral prolapse and severe mitral regurgitation should have surgery as soon as possible.
- If possible, transcatheter edge-to-edge repair can be done in symptomatic patients with a higher risk of surgery who have mitral regurgitation that is either primary or secondary.
- When patients with functional chronic mitral regurgitation are treated and managed according to guidelines, they may feel better.
Mitral Regurgitation Symptoms
Signs and symptoms of mitral regurgitation – What are the symptoms of severe mitral valve regurgitation?
In acute mitral regurgitation, the LA isn’t very big, and the pressure inside the LA rises quickly, which can cause pulmonary edema if it’s bad. The LA gradually gets bigger when it lasts for a long time, but the extra volume can be handled without a big rise in the LA pressure. The pressure in the pulmonary veins and capillaries may only rise when you work hard. As a result, exertional dyspnea and fatigue worsen over a long period.
Mitral regurgitation causes the LA and LV to get bigger over time, which can lead to atrial fibrillation and, in the long run, LV dysfunction. Mitral regurgitation is diagnosed by a pansystolic murmur that is loudest at the top of the heart and spreads to the axilla and sometimes to the bottom. An early beat doesn’t change the LV to LA gradient, so the intensity of the murmur doesn’t change. However, due to the increased volume returning to the LV in early diastole, there may also be a hyperdynamic LV impulse, a quick carotid upstroke, and a loud third heart sound.
Due to the small difference between the LA and LV systolic pressures during ventricular systole, the murmur from acute mitral regurgitation may not be very loud. When the posterior leaflet of the mitral valve prolapses, the mitral regurgitation murmur spreads forward, and when the anterior leaflet prolapses, it spreads backwards. Mitral regurgitation might not happen until after the mitral click in these patients (until late in the disease process, when it becomes progressively more holosystolic).
Mitral Regurgitation Diagnostic Evaluation
Echocardiographic information about the underlying pathological process (rheumatic, calcific, prolapse, flail leaflet, endocarditis, cardiomyopathy), LV size and function, LA size, PA pressure, and RV function can be very helpful when planning treatment and finding associated lesions.
The valvular heart disease guidelines explain how primary and secondary mitral valve regurgitation are grouped and how severe they are. Doppler techniques can estimate the severity of mitral regurgitation in a qualitative and semiquantitative way. TEE can help find out what is causing regurgitation. It is especially helpful for people who have had a mitral valve replaced, may have endocarditis, or are looking for people who could benefit from valvular repair.
When deciding when to do surgery, echocardiographic measurements and tests of systolic function are very important. Patients with severe mitral regurgitation (stage C1) but normal LV size who don’t have any symptoms should get an echocardiogram at least once a year. When the symptoms of mitral regurgitation don’t match the severity of the condition, either Doppler echocardiography or cardiac catheterization may be helpful. In addition, B-type natriuretic peptide (BNP or NT-proBNP) can be used to find early signs of LV dysfunction in patients with mitral regurgitation who don’t have any symptoms. Values that go up over time seem important for predicting the future.
Cardiac MRI is sometimes helpful, especially if specific myocardial causes are being looked for (like amyloid or myocarditis) or if a myocardial viability assessment is needed before deciding whether to add coronary artery bypass grafting to mitral valve surgery.
A cardiac catheterization gives a better look at regurgitation and how it affects the blood flow, LV function, cardiac output at rest, and PA pressure. Before valve surgery, all men over 40 and postmenopausal women with risk factors for coronary artery disease should get a coronary angiography to check for incidental coronary artery disease (CAD).
When it comes to younger people, coronary angiography isn’t needed unless there are signs that they might have coronary disease. Cardiac multidetector coronary CT may be enough to check for asymptomatic CAD in people with valvular heart disease. A normal CT coronary angiogram is a good way to predict that a patient has no disease or a small amount of disease.
Mitral Regurgitation Treatment and Management Guidelines
Treatment of mitral regurgitation – What is the best treatment for mitral regurgitation?
Primary Mitral Regurgitation Treatment
The level of LV enlargement shows how bad and long-lasting regurgitation is. If the LV is overloaded with blood, it could fail and cause the heart to pump less blood. However, the LA can get much bigger in chronic mitral regurgitation, and mitral regurgitation can be tolerated.
So, people with chronic lesions may not have symptoms for a long time. Surgery is needed when symptoms show up, or there is evidence of LV dysfunction because LV function can get worse over time and can’t be fixed. This can happen before symptoms show up. Even if a patient doesn’t have any symptoms, they should have surgery as soon as possible if they have a low EF (less than 60%) or a large LV that isn’t contracting well (end-systolic dimension greater than 4.0 cm).
When the LVEF is more than 60%, the LV end-systolic dimension is less than 4.0 cm. Still, serial imaging shows a progressive increase in the LV end-systolic dimension or a serial decrease in the EF; this is a class Ila indication for mitral valve surgery. Therefore, when pulmonary hypertension happens, mitral regurgitation is bad and should be treated immediately.
Acute mitral regurgitation can happen all of a sudden, like when the papillary muscles don’t work right after a myocardial infarction (MI), when the valve perforates in infective endocarditis, in people with hypertrophic cardiomyopathy (HCM), or when the chordae tendineae in people with mitral valve prolapse tear. So surgery may be needed right away.
Some patients may become hemodynamically unstable and need treatment with vasodilators or intra-aortic balloon counterpulsation, which reduces the amount of retrograde regurgitant flow by lowering systemic vascular resistance and improving forward stroke volume.
There is disagreement about the role of afterload reduction in chronic mitral regurgitation since the lesion reduces afterload. No evidence exists that chronic afterload reduction helps avoid LV dysfunction or surgery. Some experts think betablockade should be used regularly in people with a high sympathetic state, but this is still a guess. When the heart rate slows, mitral regurgitation may improve in people with cardiomyopathy caused by tachycardia.
Secondary Mitral Regurgitation Treatment
When a problem with the heart causes mitral regurgitation, it may go away as the infarct heals or the LV dilation goes down. Most of the time, regurgitation is caused by the movement of the papillary muscles and an enlarged mitral annulus, not by the papillary muscles not getting enough blood. The main issue is that the leaflets don’t close during systole (due to either leaflet prolapse or retraction). In addition, the papillary muscle may tear in an acute MI, which can have terrible effects. Mitral regurgitation can happen during bouts of myocardial ischemia and can be mild or severe. It can also cause flash pulmonary edema.
Patients with dilated cardiomyopathies can have secondary mitral regurgitation if the papillary muscles move or the mitral annulus gets bigger. If the mitral valve is replaced, keeping the chordae to the original valve helps stop the ventricles from getting bigger after surgery. At first, several groups said that fixing the mitral valve in people with LVEF of less than 30% and secondary mitral regurgitation worked well. However, current guidelines say that repair or replacement of the mitral valve can be tried in patients with severe mitral regurgitation who have an EF of less than 30% or an LV end-systolic dimension of more than 5.5 cm, or both, as long as it is possible to repair and keep the chordae. The suggestions for what to do about secondary mitral regurgitation are shown.
When a person has chronic ischemic cardiomyopathy, mitral valve replacement with preservation of the chords is better than mitral valve repair. There may also be a place for cardiac resynchronization therapy with biventricular pacemaker implantation, which has been shown to reduce mitral regurgitation caused by cardiomyopathy in many patients.
Guidelines say that patients with symptoms who have functional mitral regurgitation should get biventricular pacing before surgery if other criteria are met, such as a QRS of more than 150 msec or left bundle branch block, or both.
Several trials of percutaneous ways to reduce mitral regurgitation are still going on. Some of these methods are the use of a mitral clip (MitraClip) to make a mitral valve with two openings, the use of different coronary catheter devices to reduce the mitral annular area, and the use of devices to reduce the size of the septal-lateral ventricles and, as a result, the size of the mitral opening. The edge-to-edge MitraClip has been the most successful of these tools.
The possible benefit of the percutaneous MitraClip has been examined in two large trials. In the COAPT (Clinical Outcomes Assessment of MitraClip) trial, patients with heart failure and moderate-to-severe or severe secondary mitral regurgitation who still had symptoms after getting the maximum doses of guideline-directed medical therapy benefited more from transcatheter mitral-valve repair than medical therapy alone within 24 months of follow-up.
In the COAPT trial, patients who got the MitraClip had a 17% lower risk of dying from any cause. Unfortunately, this meant that 6 people needed to be treated to prevent 1 death over 2 years. This was a very good result, but it was tempered by the MITRA-FR (Percutaneous Repair with MitraClip Device for Severe Functional/Secondary Mitral Regurgitation) study, which looked at a similar group of people and had a neutral result. In this study, the MitraClip therapy did not improve survival over medical therapy during the 1-year follow-up period.
One idea to explain the different results is that the MitraClip doesn’t work if the size of the echocardiographic regurgitant orifice is the same as the size of the dilated LV. Still, it does work if the size of the regurgitant orifice is big compared to the size of the LV. The results of the two tests seemed to show that this was true.
Current guidelines say that people with secondary mitral regurgitation and a high risk of surgery can use MitraClip. Also, vascular plugging and occluder devices are sometimes used to stop leaks around prosthetic mitral valves in certain patients. In addition, a degenerated mitral bioprosthetic valve can be opened in any position with a transcatheter stented valve, which is used as a transcatheter aortic valve replacement (TAVR) device (aortic, mitral, tricuspid, or pulmonary). Transcatheter valve replacement has also been tried, with mixed results, to fix mitral regurgitation after mitral valve repair.
Lastly, the first cases of a stented mitral valve prosthesis to replace the whole mitral valve have been reported. Abbott has started the SUMMIT trial, a key trial in the United States that will use the Tendyne percutaneous mitral valve replacement device. The annulus of the mitral valve and the aortic valve is the same. Some of the first percutaneous valve replacements failed because the aortic outflow was blocked.
When to Refer for Mitral Regurgitation
- All patients with more than mild mitral regurgitation should be sent to a cardiologist for an evaluation.
- Serial exams and echocardiograms should be done, and surgery should be recommended if the LV end-systolic dimensions get bigger, the LVEF drops to less than 60%, there are symptoms, signs of pulmonary hypertension, or atrial fibrillation starts up for the first time.
- There is evidence that mitral valve repair should be done early in the disease process to improve mortality and morbidity.
- Treatment may be helpful for a person with dilated cardiomyopathy who has severe mitral regurgitation.
I hope you understand mitral regurgitation symptoms and treatment guidelines.