A new indicator of contrast-induced nephropathy in patients undergoing elective coronary angiography: tissue doppler-derived E/(EA x SA) index

OBJECTIVE: Hemodynamic insta-bility plays an important role in the development of contrast-induced nephropathy (CIN), which is an important complication of coronary angiogra-phy. Left ventricular (LV) end-diastolic pressure (LVEDP) accurately reflects hemodynamic chang-es. In clinical practice, measuring LVEDP invasive-ly presents some challenges and is not always ac-cessible. This study aimed to investigate the rela-tionship between tissue Doppler-derived early di-astolic conduction velocity (E)/[early mitral annu-lar diastolic velocity (Ea), x peak systolic annu-lar velocity (Sa)] index, an important surrogate for LVEDP, and CIN in patients undergoing elective coronary angiography (ECA).PATIENTS AND METHODS: This retrospec-tive study included 388 consecutive patients un-dergoing ECA. CIN was defined as a 25% or 0.5 mg/dL increase in serum creatinine compared to baseline values within 72 hours after ECA. Meh-ran score was calculated in all patients and sys-tolic and diastolic functions were evaluated with Doppler echocardiography.RESULTS: The incidence of CIN was 9.7%. There was a positive correlation between LV EDP levels and LV E/(Ea x Sa) index (r = 0.691, p < 0.001). Higher LV E/(Ea x Sa) index (OR = 1.03, p < 0.001) and Mehran score (OR = 1.41, p < 0.001) were independent predictors of CIN. The threshold value of LV E/(Ea x Sa) index in pre-dicting CIN was > 1.71 with 75.7% sensitivity and 84.3% specificity (AUC = 0.825). CONCLUSIONS: In patients undergoing ECA, the non-invasively measured E/(Ea x Sa) index can be used as a risk indicator for CIN.