Abstract 11363: Renal Artery Velocity Time Integral is a Predictor of Improvement in Renal Function After Transcatheter Aortic Valve Implantation

Abstract

Background: It has been reported that renal function (RF) is improved in a certain number of patients who undergo TAVI. However, the mechanisms and predictors of RF improvement remain unclear. We investigated whether preoperative renal hemodynamics assessed by intrarenal doppler ultrasonography (IRD) could predict RF improvement after TAVI. Methods and Results: We enrolled consecutive 84 patients with severe aortic stenosis (AS) who underwent TAVI in our hospital. To assess preoperative intrarenal hemodynamics, we measured renal artery velocity time integral (RA-VTI) as a marker of renal perfusion and renal venous stasis index (RVSI) as a marker of renal congestion using IRD before TAVI (Fig 1). We calculated RVSI as follows: (cardiac cycle time - venous flow time)/cardiac cycle time. RF improvement was defined as an increase >10% of estimated glomerular filtration rate (eGFR) after TAVI. Of the 84 patients, 45 patients (53.5%) showed RF improvement and remaining 39 patients did not. Clinical characteristics including STS score, clinical frailty scale, comorbidities, medications, amount of contrast media and occurrence of procedural complications associated with TAVI were comparable between the two groups. In addition, laboratory data including baseline eGFR and echocardiographic parameters including severity of AS, left ventricular ejection fraction and stroke volume index were also similar between the two groups. RA-VTI determined by IRD was significantly lower in patients with RF improvement compared to those without RF improvement (34.0 ± 12.6 vs. 39.9 ± 12.5 cm, P=0.03). In contrast, there was no difference in RVSI (0.08 ± 0.13 vs. 0.05 ± 0.09, P=0.19). Logistic regression analysis indicated that RA-VTI was a predictor for RF improvement after TAVI (odds ratio 0.96, 95% confidence interval 0.93-0.99, P=0.04). Conclusions: Preoperative RA-VTI, a marker of renal perfusion, is a predictor for RF improvement after TAVI.