Background: Recently, both international and Chinese guidelines have mentioned for the first time that blood pressure (BP) target range is more reasonable and workable than BP target in clinical practice, and time in target range (TTR) could become a potential evaluation indicator for long-term blood pressure management. Until now, there was no research on the long-term effects of antihypertensive treatment on systolic BP (SBP) TTR. The objective, therefore, is to observe the impact of long-acting calcium channel blockers (CCBs) on BP TTR in Chinese patients with hypertension (HTN).
Methods: A retrospective observational study was conducted using data from the China Cardiovascular Association Hypertension Centre, including 36,153 adult patients diagnosed with primary HTN and treated with amlodipine-based antihypertensive therapy between 1 January 2018 and 31 December 2022. The primary endpoint was the SBP TTR. Other endpoints included the annual trend of SBP TTR, factors influencing SBP TTR, etc.
Results: Results showed an overall SBP TTR was 80.42 ± 21.97%. The SBP TTR at 1, 2 and 3 years of follow-up was 79.49 ± 26.16%, 81.86 ± 25.10% and 82.79 ± 25.77%, respectively, showing a significant difference (p < 0.001). Seven factors were positively correlated with SBP TTR, while three factors were negatively correlated with SBP TTR including heart failure, high baseline SBP level, and high LDL-C level.
Conclusion: Long-term and continuous use of amlodipine-based antihypertensive therapy could improve SBP TTR. This finding may relate to the characteristic of amlodipine which is a long-acting drug due to pharmacokinetic properties.
Trial registration: Chinese Clinical Trial Registry Identifier: ChiCTR2400090150.
Keywords: Amlodipine; primary hypertension; systolic blood pressure; time in target range.
What is the context?Hypertension (HTN) is a major health problem worldwide. Physicians usually measure blood pressure (BP) during clinic visits, but this only provides a single snapshot of BP control. Time in target range (TTR) is considered a new approach to evaluate long-term BP management by international and domestic guidelines. TTR reflects the prevailing BP during the follow-up period and the magnitude of BP variability (BPV). In China, amlodipine—a long-acting antihypertensive therapy—is widely used, but its long-term effects on TTR have not well studied.What is new?This study analysed more than 3 years of data from 36, 153 Chinese adults with primary HTN who continuous prescribe amlodipine-based antihypertensive therapy.The key findings included:Overall SBP TTR was over 80% and the annual trend of SBP TTR was increasing.Follow-up frequency and target range significantly influence the value of TTR.Figure out seven positive factors and three negative factors which were correlated with SBP TTR.What is the impact?These findings provide strong evidence that continuous long-acting antihypertensive therapy, such as amlodipine, can effectively improve long-term BP management.In clinical practice, reasonable follow-up frequency and target range should be accurately defined based on more evidence.Factors influencing SBP TTR underscore the importance of early detection, timely and standardised treatment, long-term regular follow-up, and improved medication compliance once more.