Predictive ability of perioperative change in GLS , LVOT-VTI and RRI for occurrence of cardiac surgery associated AKI in patients undergoing elective on-pump CABG: An Observational Study

Cardiac surgery–associated acute kidney injury (CSA-AKI) affects nearly one in four patients undergoing cardiopulmonary bypass (CPB) and significantly increases morbidity and mortality. Conventional hemodynamic monitoring often fails to identify early renal hypoperfusion. Echocardiographic indices such as global longitudinal strain (GLS) and left ventricular outflow tract velocity–time integral (LVOT-VTI) assess myocardial performance and forward flow, while renal resistive index (RRI) reflects intrarenal vascular resistance. Integrating these parameters may enable early detection of renal compromise in high-risk patients.

PICOT Framework:

P (Population): Adults (>18 years) undergoing elective on-pump CABG.

I (Intervention/Exposure): Perioperative changes in GLS, LVOT-VTI, and RRI.

C (Comparison): Patients without significant change in these parameters.

O (Outcome): Development of CSA-AKI (KDIGO 2012 criteria).

T (Time): Within 48 hours post-surgery.

Research Question:

Do perioperative changes in GLS, LVOT-VTI, and RRI predict CSA-AKI in patients with reduced ejection fraction undergoing on-pump CABG?

Aims and Objectives:

To evaluate the predictive ability of perioperative changes in GLS, LVOT-VTI, and RRI for CSA-AKI; to determine their inter-relationships; and to assess whether combined indices improve early prediction of AKI and correlate with outcomes such as RRT requirement, mechanical ventilation, and ICU stay.