What are the key factors that determine when to proceed to aortic valve repair, implantation, or replacement for patients with aortic stenosis? What guides decision-making relating to aortic surgery for acute aortic regurgitation?
When should patients with chronic aortic regurgitation undergo surgery?
What are the indications for surgery in patients with mitral stenosis? What are the goals of medical therapy for mitral regurgitation and when should patients be considered for mitral valve repair or replacement?
What are the objectives of treatment of pulmonic stenosis? When should a patient with pulmonic regurgitation be referred for surgery?
What are the factors that determine medical versus surgical treatment of tricuspid stenosis or tricuspid regurgitation?
Valvular heart disease is a common disorder seen by hospitalists. Often a cardiologist and/or cardiac surgeon is consulted to comanage these patients; however, a comprehensive understanding and appropriate screening by an internist is important for both an inpatient and outpatient practice. This chapter provides practical information regarding the pathophysiology, diagnosis, and therapy of the valvular abnormalities that commonly affect each of the four valves.
Aortic stenosis (AS) is a disease of the aortic valve that causes obstruction to the ejection of blood from the left ventricle into the aorta. It is caused by three distinct abnormalities: congenital, rheumatic, and degenerative. Degenerative stenosis (also known as calcific or senile AS) is the leading cause of valvular cardiac surgery in adults. The prevalence is estimated from 2–7% in populations over the age of 65.
Calcific aortic disease represents a spectrum ranging from aortic sclerosis, defined as leaflet thickening without significant obstruction, to severe AS (defined below). Several risk factors have been associated with aortic sclerosis including smoking, hypertension, diabetes, LDL-cholesterol, and C-reactive protein (CRP). Though calcification can occur during the degeneration of all aortic valves, it tends to be more pronounced in patients with congenital abnormalities of the valve (ie, bicuspid valves) than the calcification of the trileaflet valve (the most common anatomy of AS).
Rheumatic heart disease has historically been an important cause of AS, but due to improvements in therapy and diagnosis it is uncommon in industrialized countries. Rheumatic disease remains an important cause of AS in developing nations, and should be considered in immigrant populations. Other uncommon causes of AS include connective tissue diseases, radiation therapy, and hyperlipoproteinemia syndromes. Chronic renal disease is associated with abnormal calcium homeostasis, and has been shown to hasten the progression of AS.
More recent data supports the hypothesis that aortic valve calcification is an active process that may not completely reflect patient age (and “over-use”) of the valve. Abnormalities of blood flow across the valve can lead to damage of the valvular endothelium. Endothelial injury initiates an inflammatory process similar to atherosclerosis and ultimately leads to deposition of calcium on the valve and eventual stenosis. Patients with congenitally bicuspid valves are ...