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Overview of Cardiac Valvular Disorders

(Heart Valve Disorders)

By

Guy P. Armstrong

, MD, North Shore Hospital, Auckland

Last full review/revision Aug 2021| Content last modified Aug 2021
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Any heart valve can become stenotic or insufficient (also termed regurgitant or incompetent), causing hemodynamic changes long before symptoms. Most often, valvular stenosis or insufficiency occurs in isolation in individual valves, but multiple valvular disorders may coexist, and a single valve may be both stenosed and insufficient.

Heart valve disorders include

Historically, diagnosis of valvular disorders by observation, palpation, and auscultation was a tough test for aspiring clinicians (1 General reference Any heart valve can become stenotic or insufficient (also termed regurgitant or incompetent), causing hemodynamic changes long before symptoms. Most often, valvular stenosis or insufficiency... read more ). Today, with the physical examination supplemented by cardiac ultrasonography Echocardiography This photo shows a patient having echocardiography. This image shows all 4 cardiac chambers and the tricupsid and mitral valves. Echocardiography uses ultrasound waves to produce an image of... read more Echocardiography (including sometimes handheld ultrasonography done by the examining clinician), diagnosis is comparatively straightforward. Standard 2-dimensional studies show the anatomy. Doppler echocardiography Echocardiography This photo shows a patient having echocardiography. This image shows all 4 cardiac chambers and the tricupsid and mitral valves. Echocardiography uses ultrasound waves to produce an image of... read more Echocardiography evaluates pressure gradients and blood flow. Evaluation also includes ECG Electrocardiography The standard electrocardiogram (ECG) provides 12 different vector views of the heart’s electrical activity as reflected by electrical potential differences between positive and negative electrodes... read more (to detect heart rhythm and chamber alterations) and chest x-ray (to detect chamber alterations, pulmonary congestion, and other lung pathology).

General reference

  • 1. Ma I and Tierney LM: Name that murmur—Eponyms for the astute auscultician. N Engl J Med 363:2164–2168, 2010.

Treatment

  • Valvuloplasty or valve replacement

Management of a valvular lesion commonly requires only periodic observation, with no active treatment for many years. In general, neither lifestyle measures nor drugs alter the natural history of valvular lesions. Intervention is usually indicated only when a moderate or severe valvular lesion causes symptoms or cardiac dysfunction. Because patients may not recognize symptoms due to their slow onset, many clinicians use exercise testing Stress Testing In stress testing, the heart is monitored by electrocardiography (ECG) and often imaging studies during an induced episode of increased cardiac demand so that ischemic areas potentially at risk... read more Stress Testing to help monitor patients.

The intervention may involve valvuloplasty (valve repair), or valve replacement, all of which may be done percutaneously or surgically. Valvular disorders are currently subject to intensive research to develop percutaneous valve replacement. In addition, randomized, controlled trials of different valvular interventions are being done. The result for patients is an increasing number of therapeutic options and better evidence on how to choose one. For clinicians, the increase in complexity now requires a multidisciplinary heart valve team composed of surgeons, cardiologists, and other specialists to help decide which intervention is best for a given patient.

If coronary artery bypass surgery is being done, it is usual to surgically treat (during the same operation) any moderate or severe valve lesions, even if asymptomatic.

Choice of cardiac valve prosthesis

Two kinds of cardiac valve prostheses are used:

  • Bioprosthetic (porcine or bovine)

  • Mechanical (manufactured)

Both types have similar survival rates and rates of valve thrombosis. Mechanical prostheses have a higher rate of bleeding complications, and bioprostheses are more likely to require reintervention.

  • Already taking a vitamin K antagonist (eg, for atrial fibrillation) and adhering well to therapy

  • Under age 50 (for aortic valve)

  • Under age 65 (for mitral valve)

A bioprosthetic valve is recommended to replace the aortic valve for patients > 65. For patients aged 50 to 65, the recommendations are guides only because patients' preferences may deviate, particularly depending on how they perceive bleeding complications versus need for reintervention.

Anticoagulation for patients with a prosthetic cardiac valve

Anticoagulation is required to prevent thromboembolism. The duration and drug used differ depending on the type of prosthesis:

  • Mechanical valve: Lifelong anticoagulation with a vitamin K antagonist (VKA) is needed. If a mechanical aortic valve is an On-X model and the patient has no thromboembolic risk factors, then 3 months after implantation the VKA target may be lowered to an international normalized ratio [INR] target of 1.5 to 2.0 with continuation of aspirin lifelong.

  • Bioprosthetic valve: lifelong aspirin is needed (those at low bleeding risk may have 3 to 6 months anticoagulation with a VKA before changing to aspirin).

  • Transcatheter aortic valve: Lifelong aspirin is needed. Addition of either clopidogrel or a VKA (INR target 2.5) may be considered for 3 to 6 months after implantation for patients with increased thrombosis risk.

Target INR for most modern mechanical bileaflet prostheses is 2.5, increasing to 3.0 with any of the following:

  • Atrial fibrillation

  • Left ventricular ejection fraction (LVEF) < 35%

  • Mitral or tricuspid position

  • Previous thromboembolism

Patients who can self-monitor their INR or follow up with dedicated anticoagulation clinics have less variability in their INR and fewer adverse events.

If patients have thromboembolism despite an adequate INR, consider adding low-dose aspirin (75 to 100 mg orally once a day).

When VKA treatment is interrupted, bridging with unfractionated or low molecular weight heparin is indicated, except in patients with a bileaflet (mechanical) aortic valve replacement and no other risk factors for thrombosis (previous thromboembolism, atrial fibrillation, LVEF < 35%, > 1 mechanical valve—1 Treatment reference Any heart valve can become stenotic or insufficient (also termed regurgitant or incompetent), causing hemodynamic changes long before symptoms. Most often, valvular stenosis or insufficiency... read more ).

Pearls & Pitfalls

  • Warfarin is the only appropriate oral anticoagulant for thromboembolism prevention in patients with prosthetic valves. Newer oral anticoagulants are ineffective.

Women of childbearing age who require valve replacement and plan to become pregnant must balance the teratogenic risk due to warfarin when mechanical valves are used against the risk of accelerated valve deterioration when bioprosthetic valves are used. Teratogenic risks can be reduced by use of heparin instead of warfarin in the first 12 weeks and last 2 weeks of the pregnancy, but management is difficult, complications are increased, and careful discussion is required before surgery.

Follow-up of prosthetic valves

Prosthetic valve follow-up is facilitated by obtaining an early postoperative baseline transthoracic echocardiogram (TTE) and by referring to normal echocardiographic parameters (eg, transvalvular gradients) for the patient's prosthesis type and size. If the postoperative baseline study is satisfactory and there has been no interval clinical change, then mechanical valves do not require routine TTE. Patients with bioprosthetic valves should have a follow-up TTE at 5 and 10 years, and then annually. Patients with transcatheter aortic valve prostheses should have annual TTE as the long-term durability of these prostheses is not yet certain.

An increasingly recognised issue is that of thrombus formation on bioprosthetic valves, causing hemodynamic deterioration. This is difficult to diagnose; CT and transesophageal echocardiography (TEE) are often required in addition to TTE. It is important to distinguish thrombus formation from other causes of valve stenosis because vitamin K antagonism usually results in relief of obstruction.

Treatment reference

  • 1. Otto CM, Nishimura RA, Bonow RO, et al: 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation 143(5):e35–e71, 2021. doi: 10.1161/CIR.0000000000000932

Drugs Mentioned In This Article

Drug Name Select Trade
PLAVIX
COUMADIN
PANHEPRIN
No US brand name
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