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Journal of Human Hypertension (1998) 12, 473–478 1998 Stockton Press. All rights reserved 0950-9240/98 $12.00 http://www.stockton-press.co.uk/jhh ORIGINAL ARTICLE Effects of losartan titrated to losartan/hydrochlorothiazide and amlodipine on blood pressure and peripheral capillary microcirculation in patients with mild-to-moderate hypertension B Martina, M Weinbacher, J Drewe and P Gasser Medical Outpatient Clinic, University Hospital, Basel, Switzerland Objective: To measure the effects of losartan and amlo- (n = 10) and losartan titrated to losartan-HCT (n = 10) sit- dipine on peripheral capillary microcirculation in hyper- ting BP decreased significantly from 160 ± 7/103 ± 4 tension. mm Hg and 147 ± 7/98 ± 6mmHgto131± 10/86 ± 7 Setting: Medical out-patient clinic, Basel, in a university mm Hg and 134 ± 17/89 ± 9 mm Hg, respectively teaching hospital. (P Ͻ 0.01). After local finger cooling the area under the Methods: After a 4-week placebo run-in period 20 curve (AUC) of capillary blood cell velocities was patients aged 50 ± 8 (range 36–65) years with mild-to- 1.13 ± 0.58 mm (median ± s.d.) at baseline and increased moderate hypertension were randomly allocated to to 1.94 ± 1.15 (P Ͻ 0.05) in losartan/losartan-HCT treated receive active treatment with losartan 50 mg titrated to patients. In amlodipine treated patients the increase in losartan 50 mg/hydrochlorothiazide (HCT) 12.5 mg, or AUC of capillary blood cell velocity did not reach the amlodipine 5 mg titrated to 10 mg for a 12 week period. level of statistical significance (1.59 ± 1.36 to Titration was performed if diastolic blood pressure (BP) 2.14 ± 1.05 mm). у was 90 mm Hg after 6 weeks of treatment. BP Conclusion: This small trial shows that the area under measurements as well as video capillary microscopy of the curve of capillary blood cell velocity increases in the finger nailfold at the end of the placebo period and hypertensive patients treated with both losartan/ after 12 weeks of active treatment were compared. losartan-HCT and amlodipine compared with baseline Capillary blood cell velocity was measured at rest and values. immediately, 1 min and 2 min after local finger cooling. Results: After 3 months of treatment with amlodipine Keywords: losartan; amlodipine; mild-to-moderate hypertension; nailfold capillaroscopy; microcirculation Introduction laries may contribute to the increased peripheral resistance found in essential hypertension.6 Angioten- Essential hypertension is characterised by a rise in sin-converting enzyme (ACE)-inhibitors and calcium- peripheral vascular resistance and by structural antagonists improve structural hypertensive alter- abnormalities of the vasculature and the myocar- 7–9 1,2 ations of the small arteries. Coronary flow reserve dium. Abnormal vasoconstriction and decreased is improved by long-term treatment with enalapril.10 erythrocyte velocity in the finger microcirculation 3,4 In order to achieve sufficient hypertension con- have been found in essential hypertension. More- trol, combination drug therapy is often necessary.11 over, finger microcirculation deteriorates as a func- Both losartan and amlodipine are standard anti- tion of the severity and duration of chronic heart hypertensive drugs. Likewise, both the combination failure, a common condition observed in end-stage of ACE-inhibitor, cilazapril with hydrochlorothia- hypertensive heart disease with activated sympa- 12 5 zide (HCT) and of the angiotensin-II blocker, losar- thoadrenal tone. tan with HCT13 are effective and well tolerated. In Structural changes and reduced density of capil- hypertensive patients treated with cilazapril and HCT, a trend towards increased capillary blood cell velocity in nailfold microscopy was demonstrated.14 Correspondence: Dr B Martina, Medical Outpatient Clinic, Uni- versity Hospital, Petersgraben 4, CH-4031 Basel, Switzerland The angiotensin-II blocker losartan is expected to Received 28 November 1997; revised and accepted 18 March improve cardiovascular hypertrophy in hyperten- 1998 sion. The calcium antagonist, nifedipine, increases Effects of losartan on microcirculation B Martina et al 474 finger nailfold capillary blood cell velocity in clinic were studied. They had untreated mild-to- patients with primary Raynaud Syndrome,15 but moderate essential hypertension. capillary blood cell velocity has not been studied Baseline characteristics are shown in Table 1. in hypertensive patients treated with any calcium There was no significant difference between the los- antagonist. Amlodipine causes smooth blood pres- artan and amlodipine groups concerning age, sex, sure (BP) control and decrease in left ventricular smoking status, body mass index (BMI), pulse rate, mass without activation of sympathetic nervous sys- and BP measured by conventional Riva-Rocci tem.16 However, there are no data on amlodipine method and by ambulatory 24-h registration. Base- and nailfold capillaroscopy. Similarly the effects of line systolic clinical BP was higher in the amlodi- losartan and losartan/losartan-HCT on peripheral pine group (160 mm Hg) than in the microcirculation measured by finger nailfold capil- losartan/losartan-HCT group (147 mm Hg). How- lary microscopy are not known. ever, this difference did not reach a level of statisti- In this double-blind trial we compared the effects cal significance (P = 0.09). In nine patients of the of losartan/losartan-HCT vs amlodipine on BP con- losartan/losartan-HCT group and in six patients of trol and on peripheral microcirculation as assessed the amlodipine group treatment had to be titrated by finger nailfold capillary microscopy. after 6 weeks of active treatment. Sitting clinical BP decreased in both groups after 3 months of active treatment compared to baseline Patients and methods (Table 2 and Figure 1). Systolic and diastolic BP was ± ± ± Twenty patients of the medical out-patient clinic of reduced from 147 7/98 6 mm Hg to 134 17/ ± ± ± the University Hospital Basel were included after 89 9 mm Hg and from 160 7/103 4mmHgto ± ± written informed consent and with permission of 131 10/86 7 mm Hg in the losartan and the amlo- Ͻ the local ethical committee. They had mild-to-mod- dipine group, respectively (P 0.05). Twelve erate hypertension, defined as an average sitting patients had two complete 24-h BP measurements. diastolic BP of 95–115 mm Hg at weeks 2 and 4 of Mean ambulatory 24-h systolic and diastolic BP was the placebo run-in period. Patients with Raynaud’s reduced from 146/98 mm Hg to 128/88 mm Hg in = disease and with previous anti-hypertensive treat- the losartan group (n 6) and from 130/90 mm Hg = ment were excluded. Conventional and 24-h ambu- to 125/85 mm Hg in the amlodipine group (n 6). In latory BP measurements and nailfold video capillary both groups 24-h pressure was reduced at virtually microscopy were performed at baseline after the 4 every hour over the 24-h period (Figures 1 and 2). week placebo period. After the placebo period Treatment effects on capillary microcirculation are patients were randomly assigned to receive either shown in Table 3 and Figures 3 and 4. losartan or amlodipine once daily at 08.00 am for a Finger nailfold capillary cell velocity was meas- duration of 3 months. At the end of the active treat- ured at rest and immediately, 1 min and 2 min after ment period the baseline examinations were local finger cooling at baseline and after 3 months repeated and the results were compared to baseline. of active treatment. All capillary blood cell velo- Losartan 50 mg or amlodipine 5 mg was given, cities as measured at rest and after local cooling titrated to losartan/HCT 50 mg/12.5 mg, or amlodip- increased in the losartan group compared to base- ine 10 mg after 6 weeks of treatment if the BP was line. In the amlodipine group capillary blood cell not controlled (sitting diastolic BP у 90 mm Hg). velocity increased 2 min after local finger cooling, The nailfold capillaries in the digits of both hands but remained unchanged at rest and 1 min after local were studied with the help of an incident light cooling. Baseline capillary blood cell velocity at rest ± microscope coupled to a television monitor. The was 0.85 0.73 mm in the losartan group and ± density of the capillary loops (number of capillary 1.19 1.09 mm in the amlodipine group. However, loops per millimetre in the distal row along the edge this difference was not statistically significant. AUC ± of the fold) and the diameters of the arterioles and of blood cell velocities increased from 1.13 0.58 ± ± Ͻ venules in the two limbs were measured. Capillary mm to 1.94 1.15 mm (median s.d., P 0.05) in blood cell velocity was measured at rest and after the losartan group, and increased from ± ± ± local cold exposure of the nailfold. Area under the 1.59 1.36 mm to 2.14 1.05 mm (median s.d., curve of blood cell velocity was calculated. BP was NS) in the amlodipine group. In 20 normotensive measured by conventional sphygmomanometer after controls capillary blood cell velocity at rest was ± 3 2 min in a sitting position. 0.65 0.27. Arteriolar and venular capillary dia- meter and capillary density did not change in both groups after treatment compared to baseline. Statistics For calculation of changes in BP and for calculation Discussion of the area under the curve for capillary blood cell Hypertensive alterations of peripheral capillaries3,4,6 velocity, paired t-test (two-tailed) was performed and the response of finger nailfold capillaroscopic using SPSS for Windows version 7.01. findings to anti-hypertensive drug treatment14 have rarely been investigated. Results This is the first report on the effects of an angio- tensin-II blocker and a calcium channel blocker on Twenty patients aged 50 ± 8 (range 36–65) years, peripheral capillary microcirculation in patients nine female, 11 male, from our medical out-patient with mild-to-moderate hypertension.