[1] Univ Toronto, Univ Hlth Network, Div Rheumatol, Toronto, ON, Canada
[2] Univ Toronto, Univ Hlth Network, Pulm Hypertens Ctr, Toronto, ON, Canada
[3] London Hlth Sci Ctr, Div Respirol, Lawson Hlth Res Inst, Ctr Crit Illness Res, London, ON, Canada