Blood pressure, change in blood pressure, and cardiovascular event rates in placebo-treated patients in the Medical Research Council Trial.
The relationship between cardiovascular event rate (stroke + coronary events), entry blood pressure (BP), change in BP over 6 months, and other variables was examined in the 8,654 placebo-treated patients in the Medical Research Council (MRC) trial. Entry BP was greater than screening pressures and fell significantly after randomization to placebo. The entry pressure was significantly greater but the fall after entry was less in those who had a cardiovascular event during 5.5 years of follow-up. Thus, patients with high entry pressure that remained elevated during follow-up had the highest event rates. This pattern was marked for stroke but was also found for coronary events. Other variables strongly related to event occurrence were sex, age, and smoking habit. Discriminant analysis based on these variables correctly identified 67% of those who had an event but incorrectly classified 40% of the much larger group who did not. These results suggest that failure of BP to fall after screening examinations is a cardiovascular risk factor. Thus, high-risk patients may be identified by repeated measurements of BP before treatment is started.
Millar
J A
JA
MRC Blood Pressure Research Unit, Western Infirmary, Glasgow, Scotland.
Lever
A F
AF
D000367:Age Factors; D001794:Blood Pressure / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000503:physiopathology*; D002986:Clinical Trials as Topic; D005260:Female; D006801:Humans; D008297:Male; D010919:Placebos; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000503:physiopathology
D010919:Placebos