Ambulatory blood pressure after 12 weeks of quadruple combination of quarter doses of blood pressure medication vs. standard medication

Background: A combination of four ultra-low-dose blood pressure (BP) medications lowered office BP more effectively than initial monotherapy in the QUARTET trial. The effects on average ambulatory BP changes at 12 weeks have not yet been reported in detail. Methods: Adults with hypertension who were untreated or on monotherapy were eligible for participation. Overall, 591 participants were randomized to either the quadpill (irbesartan 37.5 mg, amlodipine 1.25 mg, indapamide 0.625 mg, and bisoprolol 2.5 mg) or monotherapy control (irbesartan 150 mg). The difference in 24-h, daytime, and night-time systolic and diastolic ambulatory BP at 12 weeks along further metrics were predefined secondary outcomes. Results: Of 576 participants, 289 were randomized to the quadpill group and 287 to the monotherapy group. At 12 weeks, mean 24-h ambulatory SBP and DBP were 7.7 [95% confidence interval (95% CI) 9.6-5.8] and 5.3 (95% CI: 6.5-4.1) mmHg lower in the quadpill vs. monotherapy group (P < 0.001 for both). Similar reductions in the quadpill group were observed for daytime (8.1/5.7 mmHg lower) and night-time (6.3/4.0 mmHg lower) BP at 12 weeks (all P < 0.001) compared to monotherapy. The rate of BP control (24-h average BP < 130/80 mmHg) at 12 weeks was higher in the quadpill group (77 vs. 50%; P < 0.001). The reduction in BP load was also more pronounced with the quadpill. Conclusion: A quadruple quarter-dose combination compared with monotherapy resulted in greater ambulatory BP lowering across the entire 24-h period with higher ambulatory BP control rates and reduced BP variability at 12 weeks. These findings further substantiate the efficacy of an ultra-low-dose quadpill-based BP lowering strategy.