CXCL9 and chronic thromboembolic pulmonary hypertension: A similar analysis for time to clinical worsening (TTCW), defined as > 15% decline in 6mwt, admission to the hospital for PH related complications, or the need for increase of PH specific medication or the start of increase of diuretics) only revealed a significant difference for CXCL9 in CTEPH patients (data not shown).