Comparing Cardiovascular Outcomes and Costs of Perindopril-, Enalapril- or Losartan-Based Antihypertensive Regimens in South Africa: Real-World Medical Claims Database Analysis

Abstract

Introduction: Differences in class or molecule-specific effects between renin–angiotensin–aldosterone system (RAAS) inhibitors have not been conclusively demonstrated. This study used South African data to assess clinical and cost outcomes of antihypertensive therapy with the three most common RAAS inhibitors: perindopril, losartan and enalapril. Methods: Using a large, South African private health insurance claims database, we identified patients with a hypertension diagnosis in January 2015 receiving standard doses of perindopril, enalapril or losartan, alone or in combination with other agents. From claims over the subsequent 5 years, we calculated the risk-adjusted rate of the composite primary outcome of myocardial infarction, ischaemic heart disease, heart failure or stroke; rate of all-cause mortality; and costs per life per month (PLPM), with adjustments based on demographic characteristics, healthcare plan and comorbidity. Results: Overall, 32,857 individuals received perindopril, 16,693 losartan and 13,939 enalapril. Perindopril-based regimens were associated with a significantly lower primary outcome rate (205 per 1000 patients over 5 years) versus losartan (221; P < 0.0001) or enalapril (223; P < 0.0001). The risk-adjusted all-cause mortality rate was lower with perindopril than enalapril (100 vs. 139 deaths per 1000 patients over 5 years; P = 0.007), but not losartan (100 vs. 94; P = 0.650). Mean (95% confidence interval) overall risk-adjusted cost PLPM was Rands (ZAR) 1342 (87–8973) for perindopril, ZAR 1466 (104–9365) for losartan (P = 0.0044) and ZAR 1540 (77–10,546) for enalapril (P = 0.0003). Conclusion: In South African individuals with private health insurance, a perindopril-based antihypertensive regimen provided better clinical and cost outcomes compared with other regimens.