Clinical Characteristics and Progression in Patients with Malignant Hypertension and Thrombotic Microangiopathy Kidney Damage

Background: Malignant hypertension (MHT) is a group of syndromes characterized by severe hypertension and acute microvascular injury, often accompanied by thrombotic microangiopathy (TMA). This study aimed to establish a high-quality and standardized historical prospective study cohort to preliminarily investigate the possible mechanism of renal injury in MHT with TMA. Methods: The MHT patients with TMA confirmed by renal biopsy were enrolled from July 2015 to December 2023. General information, clinical data, and renal pathology were collected. Patients were divided into two subgroups: the ESRD group (eGFR<15ml/min/1.73m2) and the non-ESRD group (eGFR≥ml/min/1.73m2). Results: A total of 47 patients were enrolled with an age of 39.4±4.83 years, of which 43 (71.4%) were male. 17 (36.1%) of patients had a family history of hypertension. The highest systolic blood pressure was 204.8±15.0 mmHg and the highest diastolic blood pressure was 140.0±18.7 mmHg. Serum creatinine was 286.0 (158.0, 427.5) μmmol/L and eGFR was 23.6 (14.2, 49.6) ml/min/1.73m2 at baseline. Renin, angiotensinogen II, and aldosterone were 130.0 (81.9, 301.0) IU/μl, 64.8 (46.6, 85.5) pg/μl and 530.0 (326.0, 1831.3) pg/μl respectively, all higher than normal. ACEI/ARB treatment was given to 30 patients (63.8%). During the follow-up period, 20 (42.6%) patients progressed to ESRD with a median time of 113 (4.5, 332.8) days. 1 patient (2.1%) died of heart failure.The level of baseline hemoglobin (t=5.151, P<0.001), eGFR (z=-4.769, P=0.005), immunoglobulin G (t=2.641, P=0.011), the proportion of ACEI/AERB use (χ2=8.560, P=0.003) were lower in the ESRD group compared to the non-ESRD group. While the serum creatinine (Z=-4.688, P=0.005) and lactate dehydrogenase levels (z=-2.872, P=0.004) were higher in the ESRD group. Multivariate logistic regression analysis showed that lower hemoglobin level (OR=0.937, 95% CI 0.904-0.972, P<0.001) was associated with earlier progression to ESRD in MHT with TMA patients. Conclusion: The renal prognosis for patients with MHT and TMA renal injury is poor. Patients with MHT and TMA kidney injury had secondary hyperaldosteronism. Baseline plasma hemoglobin level is an independent risk factor for progression to ESRD in patients with MHT and TMA kidney injury.