Nkomo, Vuyisile, Julius Gardin, Thomas Skelton, John Gottdiener, Christopher Scott, Maurice Enriquez-Sarano. Burden of Valvular Heart Diseases: a population-based study. Lancet. September 2006; 368(9540). http://www.ncbi.nlm.nih.gov/pubmed/16980116
Pulmonary hypertension is a complication in at least 23% of patients with significant mitral regurgitation due to flail leaflet, and approximately doubles the risk of death and heart failure after diagnosis.