1. Pittsburgh Heart, Lung, and Blood Vascular Medicine InstituteUniversity of Pittsburgh School of MedicinePittsburgh, Pennsylvania
2. Department of Cardiovascular MedicineTohoku University Graduate School of MedicineSendai, Japan
3. The Third Xiangya HospitalCentral South UniversityChangsha, Chinaand
4. Division of Pulmonary, Allergy and Critical Care MedicineUniversity of Pittsburgh School of MedicinePittsburgh, Pennsylvania