Dr. Lewen's practice is part of BJC Medical Group of Missouri, a well-established, multi-specialty physician group. His research interests while at St. Louis University Hospital included echocardiography and interventional cardiology. He has published several articles in these areas. He has spoken at numerous programs nationally and has participated in multiple educational symposia in cardiology. He has been active with the American Heart Association's "Get With the Guidelines" and serves as counselor for the Missouri Chapter of the American College of Cardiology. Dr. Lewen is consistently recognized in "The Best Doctors in America" list.