Symptomatic Pulmonary Arterial Hypertension After Mitral Valve Surgery

Study Summary

Most patients with mitral valve disease are symptomatic with shortness of breath and a limited activity level prior to mitral valve surgery. Despite surgical repair or replacement of the mitral valve, many patients remain symptomatic with an impaired ability to live an active lifestyle. Often after extensive evaluation, no other pulmonary, left ventricular dysfunction, or valvular heart disease is responsible for the continued symptoms, and some of these patients will be limited by persistent pulmonary hypertension (PH) at rest or with exertion that is responsible for limiting their activity level and impacting their quality of their life. It is our goal in the proposed study to systematically characterize symptomatic and asymptomatic patients greater than six months after mitral valve surgery using clinical data, echocardiographic evaluation, laboratory assessment, and in some patients, invasive hemodynamic measurements. The investigators will screen asymptomatic and symptomatic patients with resting echocardiography and also with echocardiography during exercise, as many patients will exhibit exercise-induced PH following mitral valve surgery. Pulmonary artery (PA) pressure will be estimated from echocardiography using Doppler-derived calculations. If elevated PA pressures are observed with echocardiography, then symptomatic patients will undergo right heart catheterization for invasive pressure measurement, which is the gold-standard for the diagnosis of PH. When PH is present and there is a normal wedge pressure (PCWP) during invasive pressure measurement, further assessment to identify potential candidates for PH therapy will be performed. This involves having patients breathe inhaled nitric oxide, a rapid-acting, pulmonary vasodilator with a short half-life. While breathing inhaled nitric oxide, blood pressure, PA pressure, PCWP, and cardiac output will be monitored to characterize individuals who could benefit symptomatically from pharmacotherapy to treat un