Intensive Bp Control for the Prevention of Cardiovascular Events Among Individuals With Hypertension at Low Cardiovascular Risk: A Target Trial Emulated Using Observational Data

Objective: There is a lack of evidence on the optimal target blood pressure (BP) for patients with hypertension at low cardiovascular risk. Our population-based study aimed to determine whether following an intensive target BP control plan is associated with a decreased risk of major adverse cardiovascular events (MACE) compared with following a standard BP control plan in this population. Design and method: We conducted a population-based cohort study emulating a target trial. The study was based on electronic medical records from general practices in the United Kingdom. We initially created a base cohort of patients with incident hypertension at low cardiovascular risk (QRISK3-defined risk <10%). All treatment-naïve patients with systolic BP > 150 mmHg entered then the study cohort upon their first prescription for an antihypertensive drug (including combination therapy) between 1998 and 2018. The date of this prescription defined the study cohort entry date. To emulate a target trial of intensive (target BP: 130/80 mmHg), standard (140/90 mmHg), and modest (150/90 mmHg) BP control strategies, we used an active comparator, new-user cohort design with dynamic marginal structural models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for MACE. We also estimated HRs and 95% CIs for serious adverse events (SAEs), a composite endpoint including electrolyte abnormality, acute kidney injury, and antihypertensive drug-related SAEs. Results: Among 77,934 patients included in the study, adjusted incidence rates of MACE were 2.8, 3.2, and 3.3 per 1,000 persons per year in the intensive, standard, and modest strategy groups, respectively. The adjusted HRs (95% CIs) for the intensive versus standard strategy were 0.96 (0.86 to 1.08) for MACE and 0.91 (0.84 to 0.99) for SAEs. The adjusted HRs (95% CIs) for the modest versus standard strategy were 1.06 (0.97 to 1.16) for MACE and 0.99 (0.94 to 1.05) for SAEs. Cumulative hazards for MACE for the three treatment strategies during the first five years of follow-up are shown in Figure Conclusions: Compared with a standard BP control strategy, an intensive strategy was not associated with a decreased risk of MACE among hypertensive patients at low cardiovascular risk.