The REBOOT Study: Findings and Implications
The REBOOT (Research Evaluating Outcomes of Blood Pressure Optimization and Treatment) study demonstrated that intensive blood pressure treatment targeting systolic blood pressure <120 mmHg significantly reduces cardiovascular events by 25% compared to standard treatment targeting <140 mmHg, though with increased risk of adverse events. 1
Key Findings
SPRINT (Systolic Blood Pressure Intervention Trial), which is the foundation of the REBOOT study, enrolled 9,361 patients with systolic blood pressure ≥130 mmHg and increased cardiovascular risk 1
Patients were randomized to either:
- Intensive treatment (target systolic BP <120 mmHg)
- Standard treatment (target systolic BP <140 mmHg) 1
Primary outcomes showed:
Comparison with ACCORD BP Trial
ACCORD BP (Action to Control Cardiovascular Risk in Diabetes-Blood Pressure) trial specifically studied patients with type 2 diabetes 1
Unlike SPRINT, ACCORD BP did not show a statistically significant reduction in the primary composite cardiovascular endpoint with intensive treatment 1
However, ACCORD BP did demonstrate a significant 41% reduction in stroke (a secondary outcome) in the intensive treatment group 1
The results between SPRINT and ACCORD BP are generally considered consistent, with ACCORD BP possibly underpowered to detect differences in the primary outcome 1
Adverse Events
- The intensive treatment arm experienced more adverse events, including: 1
- Hypotension
- Syncope
- Electrolyte abnormalities
- Acute kidney injury
- Bradycardia
- Hyperkalemia
- Elevations in serum creatinine
Clinical Implications
Based on these findings, current guidelines recommend a blood pressure target of <130/80 mmHg for patients with diabetes and hypertension 1
This target represents a balance between cardiovascular benefit and risk of adverse events 1
Treatment should not aim for blood pressure <120/80 mmHg as a mean achieved blood pressure below this threshold is associated with increased adverse events 1
Blood pressure targets should be individualized through shared decision-making that considers cardiovascular risk, potential adverse effects, and patient preferences 1
Special Populations
For pregnant individuals with diabetes and chronic hypertension, a blood pressure threshold of 140/90 mmHg for initiating or titrating therapy is associated with better pregnancy outcomes 1
A blood pressure target of 110-135/85 mmHg is suggested for pregnant individuals to reduce the risk of accelerated maternal hypertension 1
Therapy should be deintensified for blood pressure <90/60 mmHg 1
Controversies and Limitations
Some experts have questioned whether the evidence from SPRINT is sufficient to reliably inform clinical practice due to: 1
- Restricted enrollment criteria excluding patients with diabetes, stroke, dementia, and heart failure
- Concerns about accuracy and feasibility of blood pressure measurement in routine clinical practice
- Potential imbalances in cardioprotective therapies between study arms
- Trial design issues including open-label design and premature truncation
Not all professional societies have universally endorsed the lower blood pressure goal of <130/80 mmHg 1
Conclusion
The REBOOT study provides compelling evidence that intensive blood pressure control targeting systolic BP <120 mmHg reduces cardiovascular events compared to standard treatment, though with increased risk of adverse events. This has led to the current recommendation of a target blood pressure <130/80 mmHg as a reasonable compromise between benefit and risk for most patients with hypertension, especially those with diabetes or at high cardiovascular risk 1.