Self-reported functional status predicts post-operative outcomes in non-cardiac surgery patients with pulmonary hypertension

Background Pulmonary hypertension (PHTN) is associated with increased post-procedure morbidity and mortality. Pre-procedure echocardiography (ECHO) is a widely used tool for evaluation of these patients, but its accuracy in predicting post-procedure outcomes is unproven. Selfreported exercise tolerance has not been evaluated for operative risk stratification of PHTN patients. Objective We analyzed whether self-reported exercise tolerance predicts outcomes (hospital length-of-stay [LOS], mortality and morbidity) in PHTN patients (WHO Class I +/- V) undergoing anesthesia and surgery. Methods and findings We reviewed 550 non-cardiac, non-obstetric procedures performed on 370 PHTN patients at a single institution between 2007 and 2013. All patients had cardiac ECHO documented within 1 year prior to the procedure. Pre-procedure comorbidities and ECHO data were collected. Functional status (< or >= 4 metabolic equivalents of task [METs]) was assigned based on responses to standard patient interview questions during the pre-anesthesia clinic visit. Multiple logistic regression was used to develop a risk score model (Pulmonary Hypertension Outcome Risk Score; PHORS) and determine its value in predicting post-procedure outcomes. In an adjusted model, functional status < 4 METs was independently associated with a LOS > 7 days (p <.003), as were higher ASA class (p <.002), open surgical approach (p <.002), procedure duration > 2 hours (p <.001), and the absence of systemic hypertension (p =.012). PHORS Score >= 2 was associated with an increased 30-day major complication rate (28.7% vs. 19.2%; p < 0.001) and ICU admission rate (8.6% s 2.8%; p =.007), but no statistical difference in hospital readmissions rate (17.6% vs. 14.0%; p =.29), or mortality (3.5% vs. 1.4%; p =.75). Similar ECHO findings did not further improve outcome prediction. Conclusions Poor functional status is associated with severe PHTN and predicts increased LOS and post-procedure complications in patients with moderate to severe pulmonary hypertension with different etiologies. A risk assessment model predicts increased LOS with fair accuracy. A thorough evaluation of underlying etiologies of PHTN should be undertaken in every patient.