Prevalence and Severity of Pulmonary Hypertension in Patients with Chronic Kidney Disease Stage 4 and 5: A Cross-sectional Study

Introduction: Chronic Kidney Disease (CKD) is a multifaceted medical condition characterised by the gradual loss of kidney function over time, often leading to a myriad of complications affecting various organ systems in the body. Among these complications, Pulmonary Hypertension (PH) has emerged as a significant yet under-recognised co-morbidity, particularly in patients with advanced CKD stages 4 and 5. PH is defined by elevated mean Pulmonary Arterial Pressure (PAP) and increased Pulmonary Vascular Resistance (PVR). Understanding the intricate relationship between CKD and PH is essential for effective management and improved patient outcomes. Aim: To study the prevalence and severity of PH in patients with CKD stages 4 and 5 and to explore the relationship between PH and co-morbidities such as Type 2 Diabetes Mellitus (DM2) and systemic Hypertension (HTN) in these patients. Materials and Methods: This cross-sectional analysis was performed in the Department of General Medicine at Dr. D.Y. Patil Medical College, Hospital and Research Centre, Dr. D. Y. Patil Vidyapeeth (Deemed to be University), Pune, Maharashtra, India on 100 cases from September 2022 to May 2024. The patients were divided into CKD stages 4 and 5 based on the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. PH was diagnosed based on 2D Echocardiography (ECHO) and categorised into mild, moderate and severe. Quantitative variables were compared using an unpaired t-test between CKD stages 4 and 5. Qualitative variables were compared using the Chi-square or Fisher's-exact test. Results: The mean age of the study participants was 56.25 +/- 12.45 years. A total of 66% of the study participants were diagnosed with stage 4 CKD. In this study, a statistically non significant association was seen between the stages of CKD and grades of PH (p-value=0.74). No significant association was found between diabetes and PH (p-value=0.97) in CKD stages 4 and 5. The median Pulmonary Artery Systolic Pressure (PASP) was found to be higher in non diabetics and non hypertensives in CKD stages 4 and 5 and this was statistically significant (p<0.0001). Conclusion: The prevalence of PH among CKD patients was 78%. However, the severity of PH was not found to significantly associated with the severity of CKD. Co-morbidities were present in a substantial number of cases, but no significant correlation was identified.