Any heart valve can become stenotic or insufficient (also termed regurgitant or incompetent), causing hemodynamic changes long before symptoms occur. Depending on which valve is involved, the most common symptoms include dyspnea, fatigue, and peripheral edema. 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
Aortic regurgitation: Insufficiency of the aortic valve causing backflow of blood from the aorta into the left ventricle during diastole
Aortic stenosis: Narrowing of the aortic valve, obstructing blood flow from the left ventricle to the ascending aorta during systole
Mitral regurgitation: Insufficiency of the mitral valve causing flow of blood from the left ventricle (LV) into the left atrium during ventricular systole.
Mitral stenosis: Narrowing of the mitral orifice that impedes blood flow from the left atrium to the left ventricle
Mitral valve prolapse: Billowing of mitral valve leaflets into the left atrium during systole
Pulmonic regurgitation: Insufficiency of the pulmonic valve causing blood flow from the pulmonary artery into the right ventricle during diastole
Pulmonic stenosis: Narrowing of the pulmonary outflow tract causing obstruction of blood flow from the right ventricle to the pulmonary artery during systole
Tricuspid regurgitation: Insufficiency of the tricuspid valve causing blood flow from the right ventricle to the right atrium during systole
Tricuspid stenosis: Narrowing of the tricuspid orifice that obstructs blood flow from the right atrium to the right ventricle
Historically, diagnosis of valvular disorders by observation, palpation, and auscultation was a tough test for aspiring clinicians (1). Today, with the physical examination supplemented by cardiac ultrasonography (including sometimes handheld ultrasonography done by the examining clinician), diagnosis is comparatively straightforward. Standard 2-dimensional studies show the anatomy. Doppler echocardiography evaluates pressure gradients and blood flow. Evaluation also includes ECG (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 of Valvular Disorders
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 medications 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 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 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.
Endocarditis prophylaxis is indicated when there is a history of endocarditis and for patients with prosthetic heart valves.
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 re-intervention because they deteriorate more rapidly than mechanical valves.
A mechanical valve is usually used (1) in patients who are not contemplating becoming pregnant and who meet one or more of the following criteria:
Already taking a vitamin K antagonist (eg, for atrial fibrillation) and adhering well to therapy
Under age 50 years (for aortic valve)
Under age 65 years (for mitral valve)
A bioprosthetic valve is recommended to replace the aortic valve for patients > 65 years. For patients aged 50 to 65 years, the recommendations are guides only because patients' preferences may deviate, particularly depending on how they perceive bleeding complications versus need for re-intervention.
Anticoagulation for patients with a prosthetic cardiac valve
Anticoagulation is required to prevent thromboembolism. The duration and medication used differ depending on the type of prosthesis.
Mechanical valve: Lifelong anticoagulation with a vitamin K antagonist (VKA) is needed as per the international normalized ratio [INR] targets below
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
Direct oral anticoagulants (DOAC) are ineffective for the above indications and should not be used.
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 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.
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).
Pearls & Pitfalls
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.
Thrombus formation on bioprosthetic valves may cause hemodynamic deterioration. Thrombus formation is difficult to diagnose; CT and transesophageal echocardiography (TEE) are often required in addition to TTE. Thrombus formation should be distinguished from other causes of valve stenosis because vitamin K antagonism usually results in relief of obstruction due to thrombus formation.
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
