Elevated AT1R Antibody and Morbidity in Patients Bridged to Heart Transplant using Continuous Flow Left Ventricular Assist Devices.

Abstract Background We studied longitudinal levels of angiotensin-II type 1 receptor antibody (AT1R-Ab) and their effects on adverse events (death, treated rejection and cardiac allograft vasculopathy) in patients who were bridged to heart transplant (BTT) using a continuous flow left ventricular assist device (LVAD). Methods and Results Sera of 77 BTT patients (2009 to 2017) were tested for AT1R-Ab and CRP before and after LVAD. Elevated AT1R-Ab was defined as >10.0U/mL. Median follow-up after transplant was 3.6 years (IQR 2.2-5.6 years). Post-LVAD, AT1R-Ab levels increased from baseline and remained elevated until transplant. Freedom from adverse events at five years was lower in those with elevated AT1R-Ab levels at time of transplant. In an adjusted, multivariable Cox analysis, an AT1R-Ab level >10U/mL was associated with developing the primary endpoint (adjusted hazard ratio [95%CI]: 3.4 [1.2-9.2], P=0.017). Though CRP levels were high before and after LVAD placement, CRP did not correlate with AT1R-Ab. Conclusions In BTT LVAD patients, an increased AT1R-Ab level at time of transplant was associated with poor outcomes after heart transplant. Post-LVAD AT1R-Ab elevations were not correlated with serum markers of systemic inflammation. Larger studies are needed to examine the pathological role of AT1R-Ab in heart transplant.