[Comparative effects of angiotensin converting enzyme inhibitors and calcium inhibitors related to baseline ambulatory blood pressure. A French multicenter study]

This multicenter study was aimed at determining whether the baseline ambulatory blood pressure (BP) level does influence the efficacy of angiotensin-converting enzyme inhibitors (CEI) and that of calcium antagonists (CA) to the same degree.The BP recordings of 236 patients with mild to moderate hypertension were reviewed: these subjects previously entered clinical trials comprising a mean 2-week placebo period and a mean 6-week active treatment phase (CEI = 115, CA = 121). The 24-hour baseline ambulatory BP was considered as high when greater than 139/87 mmHg, according to Staessen's meta-analysis.In the patients with an high baseline ambulatory BP, CEI and CA have had roughly a similar effect (reduction in systolic = 9.5 +/- 7.8% vs 7.7 +/- 6.3%, NS; reduction in diastolic = 9.8 +/- 8.6% vs 8.3 +/- 5.8%, NS). Conversely, the patients with a baseline ambulatory BP level lower than or equal to 139/87 mmHg experienced a greater reduction in ambulatory BP with CEI than with CA (systolic = 7.9 +/- 7.0% vs 0.6 +/- 6.7%, p = 0.0001; diastolic: 5.0 +/- 7.4% vs 1.9 +/- 7.6%, p = 0.040). Finally, further analysis found the threshold of drug efficacy to be 120/80 and 135/85 mmHg in CEI and CA patients respectively.1) CEI are more effective than CA in patients with a low ambulatory BP only. 2) The risk of a visceral hypoperfusion seems however to be limited, since CEI do not reduce diastolic ambulatory BP further, when its baseline level is lower than 80 mmHg.