Comparative Cardiovascular Outcomes of Fimasartan and Calcium Channel Blockers in Hypertension: A Nationwide 3-Year Follow-Up Cohort Study

Abstract

Background: Fimasartan is an angiotensin II receptor blocker (ARB) that was developed in Korea. Although ARBs and calcium channel blockers (CCBs) are both recommended first-line antihypertensive drug classes, real-world outcome data comparing fimasartan specifically with CCBs remain limited. Methods: We analyzed Korean National Health Insurance Service data for adults aged ≥20 years with hypertension and no prior cardiovascular disease. The primary inferential analysis was treatment-naïve new users of fimasartan or CCB monotherapy using a 30-day landmark design, with outcome follow-up beginning on day 31. The primary endpoint was 3-year major adverse cardiovascular events (MACEs), defined as all-cause death, cardiac death, nonfatal myocardial infarction, or nonfatal stroke. Multivariable Cox models were used for the primary analysis, while broader overall-cohort and propensity-score-matched analyses were considered secondary. Results: In the primary treatment-naïve new-user analysis, fimasartan was associated with a numerically lower MACE risk than CCBs, although the 95% confidence interval included the null value (adjusted HR 0.895, 95% CI 0.796–1.006; p = 0.0628). In secondary analyses of the broader overall cohort, fimasartan was associated with a lower adjusted MACE risk (HR 0.851, 95% CI 0.815–0.890), and the association remained evident after propensity-score matching (HR 0.675, 95% CI 0.653–0.699). Exploratory comparisons showed nearly identical crude MACE rates for fimasartan+CCB and fimasartan+thiazide regimens (3.46% vs. 3.47%). Conclusions: In this nationwide observational cohort, the primary treatment-naïve new-user analysis showed a numerically lower 3-year MACE risk with fimasartan than with CCBs, although the confidence interval included the null value. Stronger associations observed in secondary analyses of the broader cohort should be interpreted cautiously because residual confounding and selection bias cannot be excluded.