Intensive BP reduction beneficial for prevention of acute decompensated HF
Effect of Intensive Blood Pressure Treatment on Heart Failure Events in the Systolic Blood Pressure Reduction Intervention Trial
Hypertension is the most important risk factor for the development and the worsening of heart failure (HF) . However, intensive blood pressure (BP)-lowering in HF patients has been associated with conflicting results, ranging from a 38% risk reduction of acute decompensated HF (ADHF) to significant increases of MACE outcomes, particularly at low diastolic blood pressure (DBP) values [2-4]. This may be due to different effects of intensive BP-lowering on various subgroups of patients, like for example the elderly, women or individuals of black race.
In this analysis of the SPRINT study, which was stopped early because of benefit in the intensive treatment arm on the primary outcome, the relative risk of developing ADHF was evaluated in the pre-specified subgroups. Moreover, the impact of intensive BP-lowering on ADHF and the predictors of incident ADHF were evaluated in these subgroups.
- In the standard treatment arm, there were 103 ADHF events among 4683 (2.2%) patients, and in the intensive treatment arm, there were 65 ADHF events among 4678 (1.4%) patients (HR for ADHF stratified by clinical site 0.63, 95% CI 0.46–0.85, P=0.003).
- The separation between groups in ADHF events was apparent at 6 months.
- The number needed to treat (NNT) to prevent an ADHF event during the median 3.29 years of the trial was 130.
- Irrespective of treatment arm, patients who developed ADHF were older, had a higher prevalence of baseline chronic kidney disease (CKD), increased albuminuria and a lower estimated glomerular filtration rate, as well as clinical cardiovascular disease (CVD) and lower DBP at baseline.
- Race and gender were similar in the ADHF and no ADHF groups in both treatment arms.
- Univariate predictors for the development of ADHF were: randomisation to standard treatment arm (HR intensive treatment arm 0.63, 95% CI 0.46-0.85, P=0.003), age ≥75 years (HR 2.93, 95% CI 2.12—4.10, P<0.001), CKD (HR 2.71, 95% CI 1.97-3.73, P<0.001) and history of CVD (HR 2.37, 95% CI 1.70-3.29, P<0.001).
- In multivariable analyses that included the treatment arm, the baseline covariates that were statistically significant predictors for the development of ADHF included age ≥75 years (HR 2.35, 95% CI 1.59-3.48, P<0.0001), CKD (HR 2.14, 95% CI 1.54-2.99, P<0.0001), history of CVD (HR 2.02, 95% CI 1.43-2.81, P<0.0001), higher baseline systolic blood pressure (HR 1.16, 95% CI 1.04-1.30, P=0.008), higher BMI (HR 1.04, 95% CI 1.02-1.07, P=0.002), smoking status (HR 1.66, 95% CI 1.01-2.65, P=0.038) and lower baseline DBP (HR 0.80, 95% CI 0.68-0.95, P=0.012).
- Patients with incident ADHF had a significantly elevated risk of subsequent cardiovascular events and death, regardless of treatment arm, gender and baseline age, CKD and history of CVD.
- 29% of patients with an initial ADHF event had at least 1 recurrent ADHF event (28% in the standard treatment arm and 29% in the intensive treatment arm; HR 0.93, 95% CI 0.50–1.67, P=0.81).
- Most significant baseline predictors of recurrent ADHF events were black race and CKD.
In all predetermined subgroups of patients at high risk for cardiovascular events in the SPRINT trial, targeting an SBP of <120 mmHg, as compared with <140 mmHg, significantly reduced the risk of developing ADHF by 36%. ADHF patients had a significantly higher risk for death and cardiovascular events. These findings highlight the importance of intensive BP reduction to prevent ADHF.