Aortic stenosis

Valvular heart disease: a primer for the clinical pharmacist

Valvular heart disease is a commonly encountered clinical condition that is not taught in most undergraduate and graduate pharmacy programs, leaving the practicing pharmacist without basic knowledge to expand on and subsequently apply to direct patient care. Unlike other areas of cardiology in which thousands of patients are recruited in many well-designed randomized clinical trials, data assessing treatments for valvular heart disease are limited and often consist of retrospective case series or observations. Our goal is to provide a basic overview of chronic valvular heart disease, with emphasis on describing the common conditions requiring surgery and the available options, as well as common pharmacologic therapies used in this patient population. Anomalies in valves can be broadly classified as stenosis and regurgitation. Depending on the valve and the type of anomaly, the impact on the cardiovascular system will vary. Understanding the hemodynamic consequences of aortic stenosis, aortic regurgitation, mitral stenosis, and mitral regurgitation is imperative to effectively counsel patients surrounding disease progression and self-monitoring, use of vasodilators, and prophylaxis for endocarditis and rheumatic fever. Further, patient characteristics factored into the choice of implanting either a bioprosthetic (tissue) or prosthetic (metal) valve encompass patient choice, life expectancy, and willingness or ability to accept lifelong anticoagulation therapy. The evolution of metal valves has resulted in newer generations under clinical study that have more laminar flow (minimizing interaction with blood products) and improved pyrolytic carbon (minimizing infection and interaction with blood products). Although antithrombotic therapy with warfarin is now mandatory in North America for all patients receiving metal valves, research is ongoing to assess the need with the most recent generation of valves.