Kidney Outcomes Following Angiotensin Receptor-Neprilysin Inhibitor vs Angiotensin-Converting Enzyme Inhibitor/Angiotensin Receptor Blocker Therapy for Thrombotic Microangiopathy

Importance Thrombotic microangiopathy (TMA) on kidney biopsy is a pattern of endothelial injury commonly seen in malignant hypertension (mHTN), but treatment strategies are not well established. Objective To evaluate the kidney outcomes of angiotensin receptor-neprilysin inhibitor (ARNI), specifically sacubitril/valsartan, vs angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) therapy for patients with mHTN-associated TMA. Design, Setting, and Participants This single-center cohort study enrolled consecutive patients in China diagnosed with mHTN-associated TMA through kidney biopsy from January 2008 to June 2023. Follow-up was conducted until the conclusion of the study period. Data were analyzed in September 2023. Exposures Treatment with sacubitril/valsartan or ACEI/ARBs during hospitalization and after discharge. Main Outcomes and Measures The primary outcome was a composite of kidney recovery: a 50% decrease in serum creatinine level, decrease in serum creatinine levels to the reference range, or kidney survival free from dialysis for more than 1 month. The secondary and tertiary outcomes were a 15% increase in the estimated glomerular filtration rate (eGFR) relative to baseline and kidney survival free from dialysis, respectively. Propensity score matching (PSM) and Cox proportional hazards regression analysis were used to evaluate the association between sacubitril/valsartan and ACEI/ARB therapy with kidney recovery outcomes. Results Among the 217 patients (mean SD age, 35.9 8.8 years; 188 men 86.6%) included in the study, 66 (30.4%) received sacubitril/valsartan and 151 (69.6%) received ACEI/ARBs at baseline. Sacubitril/valsartan treatment was associated with shorter time to the primary outcome compared with ACEI/ARB treatment (20 of 63 31.7% vs 38 of 117 32.5%; adjusted hazard ratio aHR, 1.85; 95% CI, 1.05-3.23). Sacubitril/valsartan treatment was independently associated with shorter time to a 15% increase in eGFR (15 of 46 32.6% vs 46 of 83 55.4%; aHR, 2.13; 95% CI, 1.09-4.17) and kidney survival free from dialysis (11 of 23 47.8% vs 16 of 57 28.1%; aHR, 2.63; 95% CI, 1.15-5.88) compared with ACEI/ARB treatment. These differences remained significant in the PSM comparison. Conclusions and Relevance In this cohort study, sacubitril/valsartan treatment was associated with a potential kidney function benefit in patients with mHTN-associated TMA compared with ACEI/ARB treatment. The findings suggested that sacubitril/valsartan could be a superior therapeutic approach for managing this serious condition in terms of kidney recovery.