BP and incidence of secondary stroke
We turn now to secondary prevention of stroke, i.e., occurrence of stroke in patients having already had a stroke.
• Evidence is available from 4 randomized trials: Carter1, HSCSG2, TEST3 and Dutch TIA4. All patients had a history of cerebrovascular disease. The mean follow-up was 2.6 years.
The table gives:
-the number of patients in each trial,
-the % of events in the treatment and in the control group,
-the resulting odds ratio of treatment vs. control group, with its 95% confidence interval, &
-the reduction of recurrent stroke in the treatment group compared to the control group.
• Overall, the incidence of stroke was reduced by 19 ±10% (2P=0.07). Although suggesting a trend, this overall result was not statistically significant.
• These 4 studies and their results are somewhat heterogeneous. Only hypertensive patients were recruited into the first 2 trials, whereas the other two included predominantly normotensive patients. The importance of the BP decrease obtained varied, ranging from a SBP/DBP difference of 4/3 to 25/12 mmHg (average 9/5 mm Hg).
• In conclusion, the combined results of these trials in secondary prevention provide promising but not definitive evidence of a reduction of risk of secondary stroke with BP lowering therapy in hypertensive as well as in normotensive individuals. PROGRESS has been set up to fill this gap and provide the information.
