[High prognostic significance of blood pressure variability in consecutive checks]

In a series of papers in the Lancet and Lancet Neurology, comprising 3 post-hoc studies and one meta-analysis of hypertension and TIA trials, Peter Rothwell and coworkers showed that the within-person visit-to-visit blood pressure variability - changes in office blood pressure between visits spaced 3 months apart - is a strong risk predictor for stroke and coronary events. There was also a strong association between the so defined blood pressure variability and the classes of antihypertensive drugs that were used: beta-blockers and then diuretics increased variability most and reduced stroke risk least, calcium-antagonists increased variability least and reduced stroke risk most, in spite of comparable effects on mean blood pressure. ACE- inhibitors and AII receptor-antagonists had intermediate positions. The 'Rothwell' variability seems to be driven by different mechanisms than the short-term variability in blood pressure: it is likely that individual pharmacokinetic and dynamic properties drive the former, and that vessel wall characteristics and autonomic function drive the latter. Rothwell et al. do not argue the importance of mean or usual blood pressure as the most important risk predictor, but make a strong case for looking at the visit-to-visit blood pressure as well. In practice these findings most easily translate in to choosing drugs that provide stable blood pressures over time, such as calcium-antagonists for the elderly patients that took part in the Rothwell analyses.