Significance of pulmonary hypertension probability in predicting six-minute walking distance in uncorrected acyanotic grown-up congenital heart disease at Sanglah General Hospital, Bali

Abstract

Background: Pulmonary hypertension may cause impairment of functional capacity, which is a predictor of survival and quality of life in a patient with uncorrected acyanotic grown-up congenital heart disease. A six-minute walking test (6MWT) is a submaximal exercise test to measure these patients' functional capacity. This study aims to determine the significance of echocardiography parameters, such as Pulmonary Hypertension (PH) probability and Mean Pulmonary Artery Pressure (MPAP), as a predictor of functional capacity by 6MWT measurement.Methods: Analytic observational study was used to determined walking distance as a measurement of functional capacity in acyanotic CHD patients. The probability of (PH) and MPAP was obtained from echocardiography and divided into three categories (low, intermediate, and high probability) based on guidelines defined by PH 2015. MPAP measured the d using the pulmonary valve acceleration time formula (90 – 0.62*PVAT). The relationship between 6MWT distance with MPAP and probability of PH was measured using pearson correlation and one-way ANOVA. We included 43 patients from the Grown-Up Congenital Heart Disease (GUCH) registry who fulfills the inclusion criteria (age more than 18 years whom defect correction has not been done). All participants were given informed consent. Data were analyzed using SPSS version 20 for Windows.Results: Forty-three patients were included in this study, with 35 females (81.4%) and 8 males with age range 18-75 years old. The most prevalent GUCH was an atrial septal defect (69.8%). Twenty-one (48%) patient was classified as high PH probability. There was a significant difference between the mild probability of PH with intermediate (MD=94.3 meters; p < 0.001) and high probability (MD=141.9 meters; p<0.001). MPAP shows a strong correlation with walking distance (r=-0.68; p<0.001).Conclusion: GUCH patients with high and intermediate PH probabilities from echocardiography had a shorter walking distance and lowered functional capacity. MPAP is a reliable measurement to predict 6MWT in these patients.