SPRINT trial: It's not just the blood pressure!
Gijs Fn Berkelmans1, Frank Lj Visseren1, Nicole Em Jaspers1
11 Department of Vascular Medicine, University Medical Center Utrecht, The Netherlands.
Insights
Lowering systolic blood pressure (SBP) reduces cardiovascular risk. While SPRINT trial data suggest this benefit, the exact contribution of SBP reduction versus medication differences requires further investigation.
Area of Science:
- Cardiology
- Clinical Trials
- Hypertension Management
Background:
- The Systolic Blood Pressure Intervention Trial (SPRINT) demonstrated cardiovascular benefits of a 120 mmHg systolic blood pressure (SBP) target versus 140 mmHg.
- Medication differences, particularly diuretics, have been proposed as an alternative explanation for SPRINT's findings.
Purpose of the Study:
- To investigate whether the reduced event rate in the SPRINT trial is attributable to changes in systolic blood pressure (ΔSBP).
Main Methods:
- Post-hoc analysis of 9361 SPRINT participants.
- ΔSBP defined as change from baseline to 6-month follow-up.
- Cox regression used to assess the relationship between ΔSBP and major cardiovascular events (myocardial infarction, acute coronary syndromes, stroke, heart failure, cardiovascular death).
- Analyses stratified by baseline SBP tertiles.
Main Results:
- A 10 mmHg decrease in SBP was associated with a hazard ratio of 0.93 (95% CI 0.89-0.98) for major cardiovascular events.
- Similar associations were observed in the lowest baseline SBP tertile (HR per 10 mmHg decrease: 0.91; 95% CI 0.82-1.01).
- Not all observed benefits could be explained by ΔSBP alone.
Conclusions:
- Lowering blood pressure is confirmed as a strategy to prevent cardiovascular disease.
- The SPRINT trial's full benefits may not be solely explained by systolic blood pressure changes.
- Alternative factors, including medication use, warrant consideration in interpreting the SPRINT trial's positive outcomes.
Abstract:
Background The SPRINT trial showed a beneficial effect of systolic blood pressure treatment targets of 120 mmHg on cardiovascular risk compared to targets of 140 mmHg. However, differences in medication use, most importantly diuretics, are suggested as an alternative explanation. This post-hoc analysis aimed to determine whether the reduced event rate can be attributed to changes in systolic blood pressure (ΔSBP) . Methods Analyses were based on all 9361 participants of the SPRINT trial. ΔSBP was defined as the change between baseline and 6-month follow-up systolic blood pressure. Major cardiovascular events were myocardial infarction, other acute coronary syndromes, stroke, heart failure, or cardiovascular death. Cox regression was used to describe the relation between ΔSBP and major cardiovascular events. Analyses were performed separately for patients in the lowest tertile of baseline systolic blood pressure, as the SPRINT trial reported the highest treatment effect in this subgroup. Results The relation between ΔSBP and major cardiovascular events was a hazard ratio per 10 mmHg decrease of 0.93 (95% confidence interval 0.89-0.98). Similar results were found within the lowest tertile of baseline systolic blood pressure: hazard ratio per 10 mmHg decrease 0.91 (95% confidence interval 0.82-1.01). Conclusion Our results show that lowering blood pressure prevents cardiovascular disease. However, not all the positive effects in the SPRINT trial could be explained by ΔSBP. Alternative explanations, such as differences in medication use, should be considered for the positive findings of the SPRINT trial.
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