Intensive blood pressure lowering harmful for patients with very high blood pressure

ESC 2017 Posthoc SPRINT analysis shows that persons with SBP ≥160 mmHg and low Framingham risk score, have a higher risk of all-cause mortality with intensive treatment.

SPRINT post-hoc analysis: food for thought on defining the ideal blood pressure target

Presented at the ESC congress 2017 by Tzung-Dau WANG (Taipei City, Taiwan)

Background

The SPRINT trial, published two years ago, caused a lot of discussion. In this study, intensive blood pressure lowering (to systolic blood pressure [SBP] <120 mmHg) was associated with better cardiovascular (CV) outcomes and overall survival as compared with standard therapy (target SBP 135-139 mmHg). Although these outcomes were positive, there were hints that aggressive BP-lowering could be associated with both risks and benefits. For instance, a J-curve relation of absolute BP with CV events raises the question how low one can go with BP-lowering. Moreover, it is questioned whether individual BP targets may be better than universal ones. Based on the SPRINT results, risk reduction appears smaller at higher baseline SBP values.

To assess whether individual targets might be better than universal goals, this posthoc analysis of the SPRINT trial (n=9361) studied whether the most optimal SBP targets to lower all-cause mortality and CV events varies between persons with various baseline SBP and CV risk (primary outcome myocardial infarction [MI], non-MI acute coronary syndrome [ACS], acute decompensated heart failure[HF] and CV death).

Main results

• Although no differences were seen in the rates of primary endpoint events at SBP ≥160 mmHg (median Framingham 10-yrs risk score ≤31.3%, n=480) between intensive and standard treatment, intensively treated patients showed a higher frequency of all-cause mortality and non-CV death (HR: 3.12, 95%CI 1.00-9.69, P=0.009 and 2.60, 95%CI 0.81-8.31, P=0.036 respectively).
• This effect was not seen at lower BPs and contradicts the original SPRINT results, in which intensive treatment was associated with a favorable overall survival as compared with standard treatment (HR 0.73, 95% CI 0.60-0.90).

Conclusion

Participants of the SPRINT trial with SBP ≥160 mmHg and a low Framingham risk score showed a 3-fold risk of all-cause mortality when they were treated to SBP target<120 mmHg instead of <140 mmHg.

This magnitude of SBP reduction may be too large for these patients, thus it may be reasonable to propose that SBP targets should be elevated to <140 mmHg in patients with stage 2 hypertension and a 10-years Framingham risk score ≤30%, which reflects a large part of the patient population. This means that it is better to look at the individual levels to set a BP target, considering both baseline BP, follow-up CV risk and extent of BP-lowering.

- Our reporting is based on the information provided at the ESC congress -