Faculty Opinions recommendation of Longer-Term All-Cause and Cardiovascular Mortality With Intensive Blood Pressure Control: A Secondary Analysis of a Randomized Clinical Trial.
The Systolic Blood Pressure Intervention Trial (SPRINT) showed that intensive blood pressure control reduced cardiovascular morbidity and mortality {1}. However, the longer-term effect of intensive treatment on cardiovascular and all-cause mortality after the end of trial (i.e. the legacy effect) has not been evaluated. The current study aims to evaluate the longer-term legacy effect of intensive treatment in SPRINT on mortality with passive follow-up using administrative data sources. The patients were randomized to systolic blood pressure (SBP) goal of less than 120mmHg (intensive treatment group; n=4678) vs less than 140mmHg (standard treatment group; n=4683), between 2010 and 2015. Extended observational follow-up for mortality was completed via the US National Death Index from 2016 through 2020. In a subset of 2944 trial participants, outpatient SBP from electronic health records during and after the trial were also examined. The study shows that over a median (IQR) intervention period of 3.3 (2.9-3.9) years, intensive treatment was beneficial for both cardiovascular mortality (hazard ratio [HR], 0.66; 95% CI, 0.49-0.89) and all-cause mortality (HR, 0.83; 95% CI, 0.68-1.01). However, at the median (IQR) total follow-up of 8.8 (8.3-9.3) years, there was no longer evidence of benefit for cardiovascular mortality (HR, 1.02; 95% CI, 0.84-1.24) or all-cause mortality (HR, 1.08; 95% CI, 0.94-1.23). The estimated mean outpatient SBP among participants randomized to intensive treatment increased from 132.8mmHg (95% CI, 132.0-133.7) at 5 years to 140.4mmHg (95% CI, 137.8-143.0) at 10 years following randomization. These results show that the mortality benefits associated with intensive treatment quickly disappear after the trial intervention was discontinued, most likely because the difference in SBP between treatment groups diminished steadily over time, with no detectable difference in SBP approximately 9 years after randomization. They indicate that the beneficial effect of intensive treatment among adults with hypertension appears to diminish quickly if intensive BP control is not sustained. Furthermore, they confirm that the benefits of antihypertensive treatment last as long as blood pressure is kept low and stress the importance of continuous treatment and compliance