Physicians' Academy for Cardiovascular Education

Active BP management is more important than the specific SBP target in stroke patients

Mant et al., BMJ 2016


Different systolic blood pressure targets for people with history of stroke or transient ischaemic attack: PAST-BP (Prevention After Stroke—Blood Pressure) randomised controlled trial

 
Mant J, McManus RJ, Roalfe A, et al.
BMJ 2016;352:i708
 

Background

Approximately 10% of deaths worldwide are caused by stroke, and 20% of strokes are recurrent events [1]. Hypertension is a well-known risk factor for stroke, and lowering high blood pressure (BP) in patients with a history of stroke or transient ischaemic attack (TIA) reduces the risk of recurrent stroke [2]. The appropriate target systolic pressure (SBP) for the optimal prevention of stroke is, however, topic of debate [3]. For example, in the PROFESS trial, SBP < 130 mmHg was associated with a higher risk of vascular events compared with SBP 130-140 mmHg [4]. In the PROGRESS trial, patients with SBP 120-140 mmHg had a reduced risk of stroke [5], while in the SPS3 trial, patients with SBP < 130 mmHg had a non-significantly reduced risk of stroke compared with those with SBP 130-149 mmHg [6].
These conflicting results are also reflected in relevant guidelines that recommend different target SBP levels for the prevention of stroke: the European guidelines recommend a target SBP of 140 mmHg [7], while British guidelines recommend a target SBP of 130 mmHg [8].
This study evaluated whether intensive BP targets lead to lower BP after 1 year, in a primary care cohort of patients with a history of stroke or TIA. Intensive BP targets were defined as SBP < 130 mmHg or a target reduction of 10 mmHg if the baseline SBP was 125-140 mmHg. The target in the standard arm was less than 140 mmHg, irrespective of baseline BP.
 

Main results

  • More consultations with the GP or practice nurse for BP control, more intensification of BP medication and more medication changes due to side effects were observed in the intensive target arm as compared with the standard target arm.
  • The treatment to a more intensive BP target was associated with a significantly greater reduction in SBP at 12 months (mean SBP reduction by 16.1 mmHg to 127.4 mmHg) as compared with treating to the standard target (mean SBP reduction by 12.8 mmHg to 129.4 mmHg)(difference: 2.9; 95% CI: 0.2-5.7 mmHg; P=0.03).
  • Achievement of SPB < 130 mmHg was similar in the two target arms (103/182 (57%) in the intensive arm vs 107/197 (54%) in the standard group; P=0.36).
  • Achievement of SBP < 140 mmHg was similar in the two arms (150/182 (82%) in the intensive arm vs 161/197 (82%) in the standard arm; P=0.59).

Conclusion

In patients with a history of stroke or TIA managed in a primary care setting, the SBP target of less than 130 mmHg rather than 140 mmHg led to a small additional BP reduction. This BP reduction came with an increased workload. The ongoing ESH-CHL SHOT trial will likely shed light on whether intensive BP-lowering beneficially affects CV outcomes in people with stroke.
Over 80% of patients achieved an SBP of < 140 mmHg, irrespectively of the initial target set. Hence, after stroke or TIA, active management of BP is more important than the target itself.
 
Find this article online at BMJ
 

References

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5. Arima H, Chalmers J, Woodward M, et al. PROGRESS Collaborative Group. Lower target blood pressures are safe and effective for the prevention of recurrent stroke: the PROGRESS trial. J Hypertens 2006;24:1201-8
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Management of Arterial Hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). Eur Heart J 2013;34:2159-219
8. Intercollegiate Stroke Working Party. National clinical guidelines for stroke.4th ed. Royal College of Physicians, 2012