A Cross-sectional Study on Pulmonary Hypertension in Patients with Stage 5 Chronic Kidney Disease

Abstract

It is well known that chronic kidney disease (CKD) is associated with significant morbidity and mortality, predominantly due to cardiovascular complications. Recent literature report pulmonary hypertension (PH) as a common accompaniment of CKD and in majority of these cases, secondary causes of PH are not evident. In this study, we looked at the prevalence and possible risk factors of PH in stage 5 CKD patients with a special focus on unexplained PH. In this cross-sectional study, 100 stage 5 CKD patients [50 each on maintenance hemodialysis (HD) and conservative management] were included. After baseline investigations participants underwent two-dimensional transthoracic echocardiogram. The routine method of PH diagnosis based on modified Bernoulli’s formula was complemented with an alternate method based on pulmonary artery acceleration time (PAAT). Detailed workup for secondary causes was carried out in patients with PH. The prevalence of PH in the study population was 89% (56% mild, 35% moderate, and 9% severe). Asymptomatic left ventricular diastolic and systolic dysfunction were noted in 54% and 20%, respectively. Significant association with PH was found with the duration of CKD, systolic and diastolic Blood pressure, hemoglobin, transferrin saturation, maintenance HD, and dialysis vintage. In sharp contrast to the existing data this study showed a very high prevalence of PH though severe PH was present only in 9%. The inclusion of PAAT-based method enabled the detection of more cases of PH. Further evaluation carried out for common secondary causes did not show significant abnormalities except for a sizeable proportion with asymptomatic left ventricular dysfunction.