Evaluation of renal tubulointerstitial damage as a residual renal risk factor for adverse cardiac events in patients with aortic valve stenosis

Abstract Background Renal dysfunction, defined as a lower eGFR, has been shown to be related to cardiovascular events in patients with aortic stenosis treated with transcatheter aortic valve implantation (TAVI). However, the contribution of renal tubulointerstitial damage to the predictive value for cardiovascular events remains unclear. The aim of this study was to elucidate whether renal tubulointerstitial damage is associated with the occurrence of all death and heart failure patients who have had TAVI. Methods and results In a cohort of 155 patients, urinary beta2-microglobulin (beta2MG) levels were measured. Patients were monitored for less than three years or until experiencing all-cause mortality or hospitalization due to heart failure. The cumulative all-cause mortality was 11.5%, and heart failure admission rate stood at 5.4%. Stratifying outcomes by beta2MG levels revealed significantly lower rates of all-cause mortality and heart failure in patients with beta2MG <0.20 mg/gCre compared to those with beta2MG ≥0.20 mg/gCre (10.2% versus 24.2%, p=0.01). When outcomes were stratified according to the beta2MG levels in combination with eGFR levels, Kaplan-Meier analyses showed that all-cause mortality and heart failure rates increased depending on an increase in the beta2MG levels (p<0.05) even if eGFR is above 60 ml/min. Moreover, multivariate Cox analyses revealed that high levels of beta2MG were an independent predictor of adverse events. Conclusion Renal tubulointerstitial damage is associated with the occurrence of all death and hospitalization for heart failure independent of renal glomerular function.