Lack of correlation between clinic and 24 hour ambulatory blood pressure in subjects participating in a therapeutic drug trial.
Although previous studies document that blood pressure measured in the clinic may differ significantly from blood pressure recorded over 24 hours, the impact of these differences on patient selection for therapeutic drug trials is unknown. A placebo controlled double-blind evaluation of an experimental antihypertensive agent was conducted. Of 30 patients entered, 21 were admitted to the active drug phase of the protocol on the basis of a clinic supine diastolic blood pressure greater than or equal to 95 mmHg; 9 subjects with lower levels of diastolic blood pressure were dropped. Noninvasive ambulatory blood pressure monitoring was performed during the placebo period. Comparison of the two subgroups demonstrated similar levels of 24 hour blood pressure (142 +/- 13/86 +/- 7 vs 137 +/- 10/82 +/- 10). Analysis of individual patient data showed that 24 hour mean diastolic blood pressure was apparently normal (less than or equal to 80 mmHg) in 5/21 (24%) "admitted" and 3/9 (33%) "dropped" subjects. Circadian blood pressure pattern were similar in the two subgroups. A statistically large difference was noted between clinic and 24 hour blood pressures in the "admitted" subgroup (20 +/- 18/13 +/- 7 vs 7 +/- 12/4 +/- 6, p less than 0.08/p less than 0.001), suggesting that patients exhibiting a marked blood pressure rise in the clinic setting were preferentially selected.
Gradman
A H
AH
Department of Medicine, Yale University School of Medicine, New Haven, CT.
Pangan
P
P
Germain
M
M
D000959:Antihypertensive Agents; D001794:Blood Pressure / Q000187:drug effects; D002940:Circadian Rhythm; D002986:Clinical Trials as Topic; D003971:Diastole; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010044:Outpatient Clinics, Hospital
D000959:Antihypertensive Agents