Effect of home blood pressure monitoring on major adverse cardiovascular events and all-cause mortality: results from the VA HOMESTEAD study

Importance: Home blood pressure monitoring (HBPM) has been shown to lower blood pressure (BP) in randomized trials, however its real-world effect on clinical outcomes is not known. Objective: To determine the association between HBPM and clinical outcomes including cardiovascular events and mortality. Design: Target trial emulation employing matched cohorts with index-date follow-up. Setting: Veterans Health Administration (VHA) telehealth program. Participants: Eligible Veterans had uncontrolled BP (defined as a systolic BP >140 mmHg) at a primary care visit within VHA, with a systolic BP >140 mmHg at the prior primary care visit or average systolic BP >140 mmHg over the year prior. The HBPM (intervention) group included eligible Veterans who were enrolled in a HBPM program for hypertension between January 1, 2013 and December 31, 2019. Individuals in the control group (usual care) were selected from eligible Veterans who were not enrolled in HBPM. Controls were matched with those in the intervention, in part, on demographics, baseline blood pressure and antihypertensive medication use, baseline frailty, mortality risk, and selected comorbidities. Exposure: HBPM in the VHA telehealth program Main Outcomes: All-cause mortality and major adverse cardiovascular events (MACE), defined as the first occurrence during follow-up of acute myocardial infarction, stroke, acute heart failure, or unstable angina. Results: Among 30,203 Veterans enrolled in HBPM and 30,096 non-enrolled controls, with a median duration of 202 days of HBPM and 6.4 years of follow-up, HBPM was associated with 8.3% lower risk of mortality (hazard ratio 0.92; 95% confidence interval 0.89, 0.95) and a 4.1% higher risk of MACE (HR 1.04; 95% CI 1.01, 1.08). In analyses calibrated for negative control outcomes, there was no longer a statistically significant association between HBPM and MACE. Conclusions and Relevance: HBPM as utilized in routine clinical care among a large national cohort of adults with uncontrolled hypertension was associated with reduced risk of mortality. The association between HBPM with increased risk of MACE may have been due to ascertainment differences between those enrolled and not enrolled in HBPM.