Drug-induced changes in ambulatory blood pressure and pulse pressure in patients with or without sustained hypertension.

We retrospectively studied 216 mild to moderate hypertensive patients receiving either an angiotensin converting enzyme inhibitor (ACEI) or a calcium antagonist (CA), as a once-a-day monotherapy; their blood pressure had been measured using both a sphygmomanometer and an ambulatory blood pressure recorder. Numerous discrepancies were found between the two methods of blood pressure measurement with respect to systolic blood pressure (SBP) and diastolic blood pressure (DBP), as well as pulse pressure (PP). Clinic blood pressure measurement did not show any significant differences between the effects of ACEI and those of CA, whereas ambulatory blood pressure measurements (ABPM) showed that in patients with normal ambulatory blood pressure (so-called 'white coat' hypertensive patients), ACEI only (but not CA) significantly lowered SBP, DBP and PP. Accordingly, a threshold of efficacy was sought: it appeared to be lower for ACEI than for CA (120/80 vs 140/85 mmHg). Furthermore, for a given degree of DBP lowering, SBP and PP were more lowered by ACEI than by CA, indicating a greater effect of ACEI on arterial compliance. Likewise, for a given level of mean blood pressure, SBP and PP were lower and DBP slightly higher in patients on ACEI than in those on CA. Our data are consistent with some recent papers, emphasizing a heightened activity of the renin-angiotensin system in 'white coat' hypertensive patients.