Effect of Renin-Angiotensin-Aldosterone System Blockade on Long-Term Outcomes in Postacute Kidney Injury Patients With Hypertension*

Objectives: Renal replacement therapy-requiring acute kidney injury frequently occurs in ICUs, which require evidence-based medical attention. However, in the postacute kidney injury patient population, the evidence regarding effective therapies to improve patient outcomes is lacking. Therefore, we aimed to examine whether the renin-angiotensin-aldosterone system blockade is effective in improving renal outcomes in postacute kidney injury patients who experienced temporary renal replacement therapy and have hypertension. Design: A retrospective cohort study. Setting: A nationwide database in Taiwan. Patients: From January 1, 2000, to December 31, 2013, we identified 8,558 acute kidney injury patients with hypertension in the national registry database. All these patients experienced an acute kidney injury episode, which required temporary renal replacement therapy for at least once. Interventions: Users (n = 3,885) and nonusers (n = 4,673) of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers. Measurements and Main Results: We used Cox proportional hazards regression models to analyze hazard ratios for the commencement of end-stage renal disease and all-cause mortality for angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker users (n = 3,885) and nonusers (n = 4,673). In a median follow-up of 4.3 years, 5,880 patients (68.7%) required long-term dialysis, and 4,841 patients (56.6%) died. Compared with postacute kidney injury patients who did not use angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker, angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker users are marginally less likely to progress to end-stage renal disease (adjusted hazard ratio 0.95; 95% CI 0.90-1.01; p = 0.06) and significantly less likely to suffer from all-cause mortality (adjusted hazard ratio 0.93; 95% CI 0.87-0.98; p = 0.011). Conclusions: In patients who experienced renal replacement therapy-requiring acute kidney injury and have hypertension, angiotensin-converting enzyme inhibitor/angiotensin II receptor blocker use is associated with better survival outcomes compared with nonuser.