Pulmonary Hypertension in Patients with End Stage Renal Disease on Maintenance Hemodialysis-A Cross-sectional Study.

Background: Pulmonary Hypertension (PH) in End Stage Renal Disease (ESRD) on Maintenance Hemodialysis (HD) portends a poor outcome in patients undergoing dialysis.

Methods: 50 patients with ESRD undergoing regular hemodialysis for at least 3 months were included. Biochemical parameters- hemoglobin, urea, creatinine, albumin, calcium, phosphorus and PTH assessed post dialysis. All patients underwent 2D echocardiography one hour after dialysis to avoid overestimation of pulmonary artery pressures. Measurement of various parameters was carried out including right atrial and ventricular dimensions, tricuspid annular plane systolic excursion, flow across tricuspid and pulmonary valves and tissue doppler imaging of the annular plane. PH was defined as mean right ventricular systolic pressure ≥25 mmHg. Variables were compared between two groups- subjects with PH and Non-PH.

Results: Seventeen patients were detected to have PH. All baseline biochemical parameters did not show significant difference between two groups. On ECHO, right atrial and ventricular enlargement and pulmonary vascular resistance were significantly higher in PH group. LA vol index greater than 34ml/m2 was detected in 94.1% patients with PH as opposed to 51.5% in non PH. LVEDP was detected to be significantly higher in PH compared to Non PH (p=0.001; 94.1% vs 39.4%). Mean values of ejection fractions were also significantly different.

Conclusion: This study suggests that up to one third of ESRD patients on HD develop PH. Echocardiography findings reveal a significant association between raised LVEDP and increased pulmonary artery pressures. Thus, volume overload and diastolic dysfunction (heart failure with preserved ejection fraction) appear to be the main contributors to development of PH.