Reduced Pulsatility Induces Periarteritis in Kidney: Role of the Local Renin–Angiotensin System

Abstract

The reduced pulsatility produced by a continuous flow LVAD implantation induced severe periarteritis in the kidneys. The local renin-angiotensin system was up-regulated in the inflammatory cells only in the continuous flow LVAD group.

Renal Failure in Patients with Left Ventricular Assist Devices

“…In one study, plasma renin activity increased significantly after LVAD insertion, possibly as an adaptive response to a lack of pulse pressure (39). In another study, there was increased immunohistochemical staining of angiotensin II receptors and angiotensin converting enzyme in the endothelial and inflammatory cells infiltrating the peri-arterial and cortical interstitial areas of the animals (41). The applicability of these findings to LVAD patients is uncertain because animal studies have intact left ventricular function with different flow characteristics than heart failure patients who receive continuous-flow devices.…”

Kidney Dysfunction and Left Ventricular Assist Device Support: A Comprehensive Perioperative Review

“…The effect of LVAD therapy on kidney function and physiology has been studied recently with conflicting results and without a clear pathophysiological understanding [11,12,13,14,15,16,17,18,19]. One current limitation to studying this pathophysiology is that LVAD implantation trends have changed from historically pulsatile to exclusively continuous flow device types.…”

“…Further complicating this issue are animal studies showing that subjects implanted with CF-LVADs with intact LV function experienced negative renal effects, including renal arterial smooth muscle hyperplasia, inflammatory infiltration of the periarterial areas, and development of interstitial nephritis [13,14,15]. Recent studies focusing on homogeneous CF-LVAD populations have shown an initial improvement in kidney function in patients with both baseline normal eGFR and baseline impaired eGFR, followed by a slow decline in renal function over 6-12 months after device implantation [22,32].…”

Implantable Left Ventricular Assist Devices and the Kidney

“…Additional studies indicated upregulation of the local RAAS of the inflammatory cells in periarterial areas of the kidney by continuous-flow LVAD [31]. However, in patients awaiting cardiac transplant, after 86 ± 40 days LVAD support, both plasma renin activity (ng/ml/h) and angiotensin II level (U/l) decreased (57 ± 56 to 3 ± 3, mean change of 92%, p < 0.001; 237 ± 398 to 14 ± 14, mean change of 73%, p < 0.001, respectively) from baseline (before implantation) to at explant/transplantation.…”

“…Ootaki et al [31] showed severe periarteritis with smooth muscle layer hyperplasia in the kidneys of healthy calves with continuous-flow LVAD. The mechanism of this altered morphology was unclear.…”