Non-Cardiopulmonary Factors Affecting the Six-Minute Walk Distance in Patients with Sickle Cell Disease: Results From the Walk-PHaSST Study

• Published in: Blood 2011-11, Vol.118 (21), p.1074-1074
• Main Authors: Goel, Ruchika, Hassell, Kathryn L., Machado, Roberto F, Barst, Robyn J., Yovetich, Nancy, Kato, Gregory J., Gordeuk, Victor R., Little, Jane A, Gibbs, J Simon R, Schraufnagel, Dean E., Girgis, Reda E., Rosenzweig, Erika Berman, Morris, Claudia R., Badesch, David B., Lanzkron, Sophie, Onyekwere, Onyinye, Nouraie, Mehdi, Castro, Oswaldo L, Sachdev, Vandana, Waclawiw, Myron, Woolson, Robert, Goldsmith, Jonathan C., Gladwin, Mark T, Krishnamurti, Lakshmanan
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V118.21.1074.1074

Abstract 1074▪▪This icon denotes a clinically relevant abstract Non-Cardiopulmonary Factors Affecting the Six-Minute Walk Distance in Patients with Sickle Cell Disease: Results from the Walk-PHaSST Study. The six-minute walk (6MW) test is frequently used to assess exercise capacity. Patients with sickle cell disease (SCD) can have decreased 6MW distance (6MWD) compared to controls. The 6MWD in conjunction with the TR-jet velocity (TRV) and NT-proBNP have recently been proposed to have a greater predictive value for screening SCD patients suspected of having pulmonary hypertension (PH) than TRV alone. (Parent et al, NEJM, 365; 1, 2011 365 (1):44–53). The American Thoracic Society guidelines recommend caution in controlling for sources of variability in the 6MWD (Am J Respir Crit Care Med 166. 111–117, 2002). Age and height are known confounders of the 6MWD. However, non-cardiopulmonary factors including skeletal-mechanics and pain may also impact the 6MWD. This study explores whether non-cardiopulmonary factors affect the 6MWD in SCD patients. We analyzed data from subjects screened for the walk-PHaSST trial. Walk-PHaSST was a multi-center, placebo-controlled, double-blind, 16-week trial evaluating the safety and efficacy of oral sildenafil for the treatment of Doppler-defined PH (TRV ’2.7m/s) in subjects with SCD aged >12 years. The primary endpoint in the trial was change in 6MWD. During screening, subjects were evaluated by self-reported medical history, physical examination, blood sampling, echocardiography and 6MWD. Univariate and multivariable linear regression was performed. A two sided p value