Heart Valve Replacement Patients With High Risk Recommended Less Invasive Surgery Procedure

The latest guideline update has been published in the American Heart Association journal Circulation and the Journal of the American College of Cardiology.

Suggested Guideline Updates For Aortic Valvular Heart Disease

The guideline update modifies present recommendations for open heart surgical aortic valve replacement and transaortic valve replacement (TAVR) based on the results of clinical studies conducted recently.

Traditionally symptomatic aortic valve disease was treated with open heart surgery to replace the abnormal valve. However in the recently updated guidelines, a set of patients can be managed with a less invasive catheter based approach.

• Surgical aortic valve replacement, for example, is recommended for persons with moderately symptomatic aortic stenosis and are considered low to intermediate risk for surgery i.e. they are deemed fit to undergo open heart surgery and unlikely to suffer any major complications due to the procedure.
• For patients with advanced aortic stenosis who have symptoms, such as shortness of breath (dyspnea) and fatigue, and considered intermediate to high risk for surgery, open heart surgery is more likely to be associated with complications and transaortic valve replacement (TAVR) is recommended as a safer and viable alternative.

The choice to undergo open heart surgery or TAVR should be a shared decision based on the optimal option after taking into consideration the patient’s needs and preferences.

"There have been significant developments in the treatment of patients with valve disease using open heart surgery to repair rather than replace leaky valves," said Rick Nishimura, M.D., a professor of medicine at Mayo Clinic and writing committee co-chair of the new guideline focused update. "For example, we are now able to replace abnormal valves using a catheter based approach, so that patients at higher risk of surgery can be treated less invasively."

Aortic Valvular Disease

The heart valves are 4 in number and normally allow blood flow from one heart chamber to the next only in the forward direction. They include the tricuspid valve, pulmonary valve, mitral or bicuspid valve and the aortic valve. The aortic valve regulates blood flow from the left ventricle into the aorta.

Valvular diseases may be present since birth, be acquired due to infection or damaged following a heart attack. They are diagnosed when these damaged valves cause variations in the blood flow between the various heart chambers resulting in abnormal sounds (murmurs) heard over the chest on auscultation (hearing chest sounds using a stethoscope).

The two major types of valvular disease include ‘stenosis’ and ‘regurgitation’. Stenosis occurs when the valvular orifice is narrowed thus reducing blood flow from one chamber to the next. In an ‘incompetent’ valve, the valve permits backflow of blood into the chamber (in aortic valve incompetence, blood leaks back from aorta into the left ventricle). This phenomenon is also referred to as regurgitation.

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Other Guideline Updates in Addition to Valvular Replacement Outline

• The need for antibiotics prior to a dental procedure in certain patients; and
• Increasing the age range for choosing tissue valve replacement.

Antibiotics before Dental Treatment

Traditionally antibiotics have been given to reduce risk of infective endocarditis, a potentially life-threatening condition that occurs due to infection of the heart valves. The bacteria causing infective endocarditis are released into the bloodstream during dental procedures. As per the latest guidelines, they are recommended in the following situations

• People who have had previous valve replacement surgery 
• People with previous history of infection of the heart valve 
• Patients with certain types of congenital heart disease and were born with abnormal valves

Prophylactic antibiotics are no longer recommended for other congenital heart diseases other than those that have been listed in the guideline updates.

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Increasing the Age-Range for Valve Replacement Surgery

In patients undergoing aortic or mitral valve replacement, the age range was increased from the existing 60 to 70 years of age to 50 to 70 years of age for the choice of either a mechanical or tissue valve.

• Mechanical valves last longer than tissue valves but may require taking blood thinners for life, and were previously recommended for patients younger than 60 years old.
• The availability of newer tissue valves that last longer than the earlier generation of tissue valves, without the need for replacement as often, give patients between the ages of 50 and 60 more options, Nishimura said.

The current update is meant to help medical personnel better manage symptoms and prevent complications due to valvular heart disease (VHD). "A heart murmur often is detected on physical examination many years before symptoms appear and should prompt further evaluation with an echocardiogram. Careful periodic monitoring and medical therapy result in better long term outcomes because patients have valve replacement at the right time; not too soon and not too late," said Catherine M. Otto, M.D., co-chair of the writing committee and professor of Medicine at the University of Washington in Seattle, Washington

Reference:

1. Infective Endocarditis - (http://www.heart.org/HEARTORG/Conditions/CongenitalHeartDefects/TheImpactofCongenitalHeartDefects/Infective-Endocarditis_UCM_307108_Article.jsp#.WMgJW2997IV)

Source-Medindia