More than 5 million Americans are diagnosed with heart valve disease each year. When this condition affects the mitral valve, it disrupts blood flow to the heart, which can lead to catastrophic problems.

"Mitral valve disease is remarkably common, especially among the elderly. The valve tends to weaken with age, so it no longer closes as tightly," explains Dr. Rajendra Makkar, an interventional cardiologist at Cedars-Sinai. The end result: Your heart has to work harder to keep blood flowing in the right direction. 

The heart is a complex piece of human machinery containing four separate valves: mitral, tricuspid, pulmonary and aortic. Each of these valves sports leaflets that open and close with every heartbeat. The mitral valve is charged with regulating blood flow from your lungs into the left ventricle, the heart's primary pumping chamber. 

"If the mitral valve doesn't open completely or if it doesn't close tightly, blood can flow backward into the heart, increasing pressure on the organ and causing fluid to back up into the lungs," explains Dr. Makkar. 

There are two types of mitral valve regurgitation: 

• Primary: Primary mitral valve regurgitation happens when the mitral valve leaflets don't function properly, or when the cord-like tendons that connect the mitral valve to the heart muscle stretch or break away.
• Secondary: Secondary regurgitation occurs as a result of another condition, such as heart failure or atrial fibrillation.

You can have mitral valve disease and not even know it. Signs of the condition can be subtle and hard to detect. 

"Some people live with mitral valve disease for years before they realize there's a problem," says Dr. Joanna Chikwe, chair of Cardiac Surgery at Cedars-Sinai. 

Symptoms include:  

• Rapid or pounding heartbeat
• Cough
• Fatigue
• Shortness of breath, particularly with activity or lying flat

Read: Shortness of Breath: When to See Your Doctor

Until recently, treatment options for mitral valve problems were limited to medication and open-heart surgery. Historically, surgeons corrected mitral valve disease by replacing the faulty valve with an artificial valve (either mechanical or from an animal donor). But that tide is changing. 

"Whenever possible, we repair—rather than replace—the valve," Dr. Chikwe explains. And for good reason: 

• Compared with valve replacement, valve repair is associated with better outcomes and faster recovery times.
• Surgical repair helps restore the natural structure and function of the valve.
• Studies suggest that repaired valves are more likely to be functional 15 years after surgery compared to replaced valves (replacement valves from animal donors often wear out).
• Most patients do not need to take blood thinners like coumadin after repair compared to valve replacement.

Surgical approaches to valve repair range from minimally invasive (through small puncture wounds in the rib or groin) to open-heart surgery requiring a midline incision. With a repair success rate greater than 99%, Cedars-Sinai heart doctors perform almost all surgical repairs minimally invasively with robotic assistance.

"Instead of going through the middle of the chest through the breastbone, we approach the mitral valve between the ribs," Dr. Chikwe says. "For younger patients with a longer life expectancy, this type of surgical repair is still the gold standard. It's also the preferred approach for patients who have other heart issues, such as atrial fibrillation, which we can treat at the same time."

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For patients who are not good surgical candidates, including those who are very elderly and frail, a device called the MitraClip may offer some relief. 

"With this procedure, interventional cardiologists try to accomplish what the surgeons do, but without opening the chest," Dr. Makkar says.

Doctors access the heart by inserting a catheter and connecting the device through a vein in your leg. Once the catheter reaches the leaky part of the valve, the device clips the two edges of the valve together to seal the leak.

The valve continues to open and close on either side of the clip, but it reduces backward blood flow. In fact, studies show the MitraClip device cuts the risk of death in half for patients with mitral valve disease compared to using medication alone. 

"The MitraClip is not a replacement for medication. It's a powerful adjunct," Dr. Makkar says. "The procedure reduces pressure on the organ which allows cardiologists to be more aggressive with heart failure medicines." 

Unfortunately, even in conjunction with high-powered medication, the clip is not a long-term fix. It cannot cure mitral valve regurgitation, and it's not the best approach for all patients.

"In the U.S., about 20% of valves are still leaky after a MitraClip procedure," Dr. Chikwe says. "For patients with severe mitral valve regurgitation, surgical repair is the gold standard."

But the MitraClip isn't the only option for percutaneous mitral valve repair. 

"There has been a huge paradigm shift over the last five years where doctors can offer patients with mitral valve disease a variety of options, including several percutaneous mitral valve replacement systems," Dr. Makkar says. "The MitraClip device is just a preview of what's to come." 

Read: Heart Attack, Cardiac Arrest, Heart Failure—What's the Difference?