Görkem Yıldız, Tolga Kunak
BACKGROUND: Right ventricular (RV) dysfunction in chronic kidney disease (CKD) remains underrecognized. The tricuspid annular plane systolic excursion to systolic pulmonary artery pressure ratio (TAPSE/sPAP) reflects RV-pulmonary arterial coupling, but its relationship with CKD severity is unknown. To evaluate the association between TAPSE/sPAP ratio and CKD stage severity and assess age-related effect modification. METHODS: This cross-sectional study enrolled 120 participants: 40 patients with stage I-II CKD, 40 with stage III-IV CKD, and 40 healthy controls. All underwent echocardiography and nephrologist evaluation. Proportional odds regression models adjusted for cardiovascular risk factors evaluated the TAPSE/sPAP-CKD association. ROC analysis assessed discriminatory performance. Age-stratified analyses (<65 vs. ≥65 years) evaluated effect modification. RESULTS: TAPSE/sPAP ratio declined progressively across CKD stages (controls: 0.67 ± 0.11, stage I-II: 0.61 ± 0.13, stage III-IV: 0.53 ± 0.13 mm/mmHg; p < 0.01). Each 0.10-unit decrease was independently associated with advanced CKD (adjusted OR 2.08, 95% CI 1.49-2.89, p < 0.001). TAPSE/sPAP ratio achieved the highest AUC (0.734, 95% CI 0.625-0.833), outperforming TAPSE alone (AUC 0.615; DeLong p = 0.049), while statistically comparable to sPAP (AUC 0.715; DeLong p = 0.400). Age-stratified analysis revealed excellent performance in patients <65 years (AUC 0.819, sensitivity 78.6%, specificity 86.8%) but limited utility in those ≥65 years (AUC 0.579; p = 0.015). Random forest analysis identified age (35.8%) and TAPSE/sPAP (22.0%) as dominant predictors. CONCLUSIONS: TAPSE/sPAP ratio is an independent marker of CKD severity enabling non-invasive detection of RV-PA uncoupling, with excellent discriminatory performance in younger but limited utility in older patients, suggesting that age-specific interpretation and integration with renal biomarkers are recommended.