Staging of Mitral Regurgitation

Mitral regurgitation (MR), a “leaky” mitral valve, is the most common type of heart valve disease. Some people with MR often have no symptoms and can remain stable for many years and often for their whole lives. However, in other people, MR eventually produces decompensation of the heart, and heart failure results. In such cases, heart failure may not be reversible.

The trick to preventing heart failure with MR is to recognize the time when the heart is beginning to decompensate, but before symptoms of heart failure occur.

So if you have MR it is very important that you have regular checkups with your healthcare provider to determine the extent of your MR, and to see whether your condition is stable or whether it is getting worse. This process is called "staging" MR.

Determining the stage of MR can help you and your healthcare provider decide whether you may need surgical therapy, and, very importantly, to determine the optimal time for surgical therapy should you require it.

The Stages of Chronic Mitral Regurgitation

Cardiologists divide chronic MR into three "stages." Determining the stage of your MR helps your cardiologist to decide whether and when mitral valve surgery may be needed.

The Compensated Stage. In the compensated stage of MR, the heart and the cardiovascular system has “adjusted” to the extra volume load placed on the left ventricle by the damaged valve. The heart compensates by enlarging somewhat, but the dilated heart muscle is otherwise functioning normally. People with compensated MR generally report no symptoms, though their exercise capacity generally turns out to be reduced if a stress test is performed. Many people with mild, chronic MR remain in the compensated stage throughout their lives.

The Transitional Stage. For reasons that are not clear, some people with MR will gradually “transition” from a compensated to a decompensated condition. Ideally, valve repair surgery should be performed during this transitional stage, when the risk of surgery is relatively low and the results relatively good.

In the transitional stage the heart begins to enlarge, cardiac pressures rise, and the ejection fraction falls. While people in this stage are more likely to report symptoms of dyspnea and poor exercise tolerance, many don’t notice worsening symptoms until their MR has progressed to the third stage. This is a problem, since delaying surgery until the decompensated stage is likely to yield a poor outcome.

Many experts believe once atrial fibrillation occurs in the presence of MR, especially if it is associated with dilation of the left atrium, that fact alone ought to indicate that the transitional stage has arrived, and therefore, that valve repair surgery ought to be at least considered.

The Decompensated Stage. Those in the decompensated stage almost invariably have very considerable cardiac enlargement, as well as significant symptoms of heart failure. Once the decompensated stage has occurred, cardiomyopathy (damage to the heart muscle ) is present and will remain present even if the mitral valve is repaired. So valve repair surgery becomes quite risky and is not likely to produce an acceptable result.

The Importance of Staging MR

It is critically important to "catch" the transitional stage of MR before it progresses to the decompensated stage. For this reason, if you have MR you need to have close medical monitoring. Among other things, it is important for your healthcare provider to carefully evaluate whether any new symptoms you may be experiencing are due to MR. In addition, periodic echocardiograms are needed to help your healthcare provider to assess the state of your mitral valve and cardiac chambers.

If you have MR, you should make sure your healthcare provider is doing this appropriate monitoring—and you yourself need to pay close attention to any signs of shortness of breath, or a reduced ability to exert yourself.