P213 Severity of pulmonary hypertension correlates with patients' daily physical activity

Abstract

Introduction: The main symptom of pulmonary arterial and chronic thromboembolic pulmonary hypertension (PH, PAH/CTEPH) is impaired exercise tolerance leading to reduced daily activity and quality of life. The aim of this study is to analyze daily physical activity in patients with PAH/CTEPH and to correlate it with pulmonary hemodynamics. Methods: Incident patients with PAH/CTEPH had hemodynamics assessed by right heart catheterization (RHC) and activity monitoring by SenseWear worn at the upper arm for approximately one week. The 6-minute walking distance (6MWD) and New York Heart Association functional were assessed. Pearson Correlations and regression analysis between activity parameters and hemodynamics were calculated. Results: Twenty-one patients (9 females, median (IQR) 57 (40;69) years, mPAP 44 (34;54) mmHg, cardiac output (CO) 5 (4.0;6.3) l/min, 6MWD 397 (271;590) m, steps/day 2373 (1206;8391)) were included. Eleven patients had a sedentary lifestyle (< 5000 steps/day), nine were moderately active (5000-10'000 steps/day) and one very active. Hemodynamic parameters and the 6MWD correlated with activity parameters (Tables).Table 1Pearson correlations between activity parameters and hemodynamics (n=21).Average METsLow (<3METs)Moderate (3 6METs)Steps/dayActive Energy expenditure/day6MWD0.643**-0.545*0.604**0.840**0.457*NYHA0.114-0.2850.192-0.0470.271mPAP-0.1940.255-0.342-0.089-0.340PAWP-0.3030.348-0.411-0.228-0.480*CO0.245-0.3650.544*0.2280.516*Abbreviations: 6MWD: 6 minute walking distance; NYHA: New York Heart Association functional class; mPAP: mean pulmonary arterial pressure; PAWP: pulmonary arterial wedge pressure; PVR: pulmonary vascular resistance; CO: Cardiac output; MET: Metabolic equivalent units (1MET is 3.5ml O2/kg/min); *p<0.05, **p<0.01. Open table in a new tab Table 2Dependent variable = cardiac output, l/minUnivariable analysisMultivariable modelcoefficient95%CIPcoefficient95%CIPSex (female=0, male=1)-0.5-2.3 to 1.20.532Age, years0.04-0.01 to 0.090.103Average METs1.25-1.1 to 3.60.284Low (<3METs)-0.004-0.009 to 0.0010.104Moderate (3-6METs)0.0090.002 to 0.0160.0110.008-0.01 to 0.0250.382Steps/day0.0000.000 to 0.0000.169Active Energy expenditure/day0.0000.000 to 0.0010.0170.000-0.001 to 0.0010.850n=21 patients. Independent variables with p<0.05 in the univariable analysis were included into the multivariable analysis. The multivariable model was adjusted for the two variables listed, R2 was 0.297, P<0.042. CI=confidence interval. MET: Metabolic equivalent units (1MET is 3.5ml O2/kg/min). Open table in a new tab Abbreviations: 6MWD: 6 minute walking distance; NYHA: New York Heart Association functional class; mPAP: mean pulmonary arterial pressure; PAWP: pulmonary arterial wedge pressure; PVR: pulmonary vascular resistance; CO: Cardiac output; MET: Metabolic equivalent units (1MET is 3.5ml O2/kg/min); *p<0.05, **p<0.01. n=21 patients. Independent variables with p<0.05 in the univariable analysis were included into the multivariable analysis. The multivariable model was adjusted for the two variables listed, R2 was 0.297, P<0.042. CI=confidence interval. MET: Metabolic equivalent units (1MET is 3.5ml O2/kg/min). Conclusion: Everyday life activity correlates with hemodynamic disease severity and hospital-based exercise assessments by the 6MWD thus rendering it a promising outcome measure for use in clinical practice and research.