Effect of high dose angiotensin-converting enzyme inhibition on restenosis: final results of the MARCATOR Study, a multicenter, double-blind, placebo-controlled trial of cilazapril. The Multicenter American Research Trial With Cilazapril After Angioplasty to Prevent Transluminal Coronary Obstruction and Restenosis (MARCATOR) Study Group

OBJECTIVES

We conducted a randomized, double-blind, placebo-controlled trial to assess the effect of low and high dose angiotensin-converting enzyme inhibition with cilazapril on angiographic restenosis prevention after percutaneous transluminal coronary angioplasty.

BACKGROUND

Angiotensin-converting enzyme inhibitors possess antiproliferative effects in animal models of vascular injury. However, a recent clinical trial using low dose cilazapril, a long-acting angiotensin-converting enzyme inhibitor, failed to prevent restenosis.

METHODS

Patients received either cilazapril (1 or 2.5 mg in the evening after successful coronary angioplasty, then 1, 5 or 10 mg twice daily for 6 months) or matched placebo. All patients received aspirin for 6 months. Coronary angiograms before and after angioplasty and at 6-month follow-up were quantitatively analyzed. In addition, the clinical, procedural and angiographic factors associated with restenosis were determined with the use of stepwise logistic analysis.

RESULTS

A total of 1,436 patients with a successful coronary angioplasty were recruited. As assessed by an intention-to-treat analysis, the mean difference in minimal coronary lumen diameter (mean +/- 1 SD) between the postangioplasty and follow-up angiogram at 6 months (primary end point) was -0.35 +/- 0.51 for the placebo group and -0.37 +/- 0.52, -0.45 +/- 0.52 and -0.412 +/- 0.53, respectively, for the 1-, 5- and 10-mg twice daily cilazapril groups (p = NS). Clinical events during follow-up did not differ among the four study groups. Multivariate analysis revealed only six variables as independent predictors of the loss of minimal lumen diameter: duration of angina < 6 months, history of myocardial infarction, minimal lumen diameter before and after angioplasty as well as a proximal lesion location and reference diameters. Traditional risk factors for atherosclerosis did not relate to restenosis.

CONCLUSIONS

Long-term angiotensin-converting enzyme inhibition with cilazapril in high as well as low dosages does not prevent restenosis and does not favorably influence the overall clinical and angiographic outcome after coronary angioplasty. Few factors are predictive of restenosis.

An adaptive method for establishing a dose-response relationship

A multistage sampling method is proposed in dose-response trials, where dose adaptions can be performed in the preplanned adaptive interim analyses. The overall test for proving a dose-response relationship is performed by Fisher's product criterion for the p-values from the separate tests of a dose effect in the disjoint samples at the different stages. Based on these p-values decision boundaries for early stopping with the rejection of the global null hypothesis of no existing dose-response relationship are introduced. The power of the adaptive two-stage procedure using a particular adaptation rule is compared with the power of the test for a linear trend under analysis of variance assumptions in extensive simulations. The bias in estimation is also quantified. This procedure could be used for establishing a dose-response relationship without including a placebo treatment.

Effects of cilazapril on vascular structure and function in essential hypertension

Hypertension is associated with an altered design of resistance vessels and decreased endothelium-dependent vasodilator response to acetylcholine. A role of angiotensin II in both defects is suggested by animal experiments in which angiotensin-converting enzyme inhibition reverted structural and functional changes. We investigated the effects of 20 weeks of therapy with the angiotensin-converting enzyme inhibitor cilazapril (5 mg twice daily) on the endothelium-dependent response to brachial artery infusions of acetylcholine and the endothelium-independent vascular relaxation after sodium nitroprusside in 22 subjects with mild to moderate essential hypertension. In addition, we measured minimal forearm vascular resistance (ratio of mean arterial pressure and forearm blood flow after heating, ischemia, and ischemic exercise) as an indirect estimate of vascular structure. Cilazapril decreased blood pressure (151 +/- 14/99 +/- 7 mm Hg during placebo to 138 +/- 17/89 +/- 8 mm Hg after cilazapril treatment, P<.01) and baseline (42.2 +/- 12.6 to 37.1 +/- 10.6 U, P<.05) and minimal (3.0 +/- 1.1 to 2.4 +/- 0.7 U, 15.9 +/- 20.2%; P<.05) forearm vascular resistances. The change in minimal forearm vascular resistance was unrelated to age, duration of hypertension, or changes in blood pressure. Sodium nitroprusside increased forearm blood flow from 2.6 +/- 1.0 to 11.4 +/- 5.9 mL/min per 100 mL and acetylcholine to 21.5 +/- 17.8. Both responses did not change after cilazapril. The data provide indirect evidence that cilazapril therapy may improve vascular structure in human hypertension. The lack of relationship between vascular and blood pressure changes would be compatible with experimental evidence supporting a role for angiotensin II in the development and regression of vascular changes, but this needs further study. Therapy with cilazapril for 20 weeks, like other antihypertensive therapy, does not seem to influence endothelial vasodilator function in humans to a significant degree.

Rosiglitazone improves, while Glibenclamide worsens blood pressure control in treated hypertensive diabetic and dyslipidemic subjects via modulation of insulin resistance and sympathetic activity

BACKGROUND

Type II diabetes is often associated with high blood pressure, elevated sympathetic activity, and high plasma insulin levels. Hypoglycemic agents may negatively interfere with blood pressure control, sympathetic activity, and plasma insulin level; therefore the choice of treatment in type II diabetes may be crucial. We aimed to compare the effects of two hypoglycemic drugs on blood glucose, blood pressure, sympathetic activity, and insulin levels in type II diabetic and hypertensive patients.

METHODS

Forty-eight (24M, 24F) type II diabetic, hypertensive, and hyperlipidemic subjects were enrolled and treated for 4 weeks with an ACE inhibitor (Cilazapril) and a statin (Simvastatin). They were then randomized into two groups to receive a thiazolidinedione (Rosiglitazone; ROS) or a sulfonylurea (Glibenclamide; GLB) for 8 weeks. Blood biochemistry, blood pressure, plasma insulin, endothelial function, and sympathetic skin activity were measured before and after treatment.

RESULTS

A significant drop in systolic and diastolic blood pressure by 6.1 +/- 4.1 mm Hg and 4.2 +/- 1.9 mm Hg respectively; a reduction in plasma insulin concentration by 4.3 +/- 1.9 mU/L and a decline in skin sympathetic activity were observed in the group receiving ROS. The GLB group showed an increase in systolic blood pressure by 3.1 +/- 2.5 mm Hg, no change in diastolic blood pressure, significant elevation in plasma insulin concentration by 2.3 +/- 1.4 mu/L, and augmentation of sympathetic activity. No significant changes in endothelial function were observed in either group.

CONCLUSIONS

Rosiglitazone improved both plasma glucose and blood pressure levels, probably by attenuation of hyperinsulinemia and sympathetic activity, while Glibenclamide worsened blood pressure control possibly by elevation of insulin levels and activation of the sympathetic system.

Effects of Cilazapril on atrial electrical, structural and functional remodeling in atrial fibrillation dogs

BACKGROUND AND PURPOSE

The effects of angiotensin-converting enzyme inhibitor on long-term atrial electrophysiologic and structural remodeling are still unclear. The purpose of this study is to investigate the effects of Cilazapril on atrial electrical, structural, and functional remodeling in atrial fibrillation (AF) dogs induced by chronic rapid atrial pacing.

METHODS

Twenty dogs were randomly divided into sham-operated group (n = 6), control group (n = 7), and Cilazapril group (n = 7). One thin silicon plaque containing 4 pairs of electrodes was sutured to each atrium. A pacemaker was implanted in a subcutaneous pocket and attached to a screw-in epicardial lead in the right atrial appendage. The dogs in control group and Cilazapril group were paced at 400 beats per minute for 6 weeks. The dogs in Cilazapril group received Cilazapril (0.5 mg x kg(-1) x d(-1)) 1 week before rapid atrial pacing until pacing stop. Before and after 6-week rapid atrial pacing, atrial effective refractory period (AERP) at 8 sites, AERP dispersion, intraatrium conduction time, inducibility, and duration of AF were measured. Transthoracic and transesophageal echocardiographic examinations included left atrium (LA) maximal volume, LA minimal volume, LA ejection fraction, left atrial appendage (LAA) maximal volume, LAA minimal volume, LAA ejection fraction, LAA maximal forward flow velocity, and LAA minimal backward flow velocity were performed. Atrial collagen volume fraction was analyzed by Masson staining.

RESULTS

After 6-week rapid atrial pacing, although there was no significant difference in AERP shortening and AERP rate adaptation reduction between the control group and the Cilazapril group, the inducibility and duration of AF were found to be dramatically lower in the Cilazapril group than those in the control group (AF inducibility, 65.7% vs 95.7%, P < .05; AF duration, 531.5 +/- 301.2 vs 1432.2 +/- 526.5 s, P < .01). The post-tachycardia intraatrium conduction times after 6 weeks with Cilazapril were significantly shorter than those in the control group. Cliazapril could partially prevent AERP dispersion increase induced by chronic rapid atrial pacing. Compared with the control group, the LA and LAA volumes were significantly smaller; LA ejection fraction, LAA ejection fraction, LAA maximal forward flow velocity, and LAA minimal backward flow velocity were dramatically higher in the Cilazapril group. The Cilazapril group had a significantly lower percentage of interstitial fibrosis than the control group.

CONCLUSIONS

Cilazapril can suppress structural and functional remodeling and prevent the induction and promotion of AF in chronic rapid atrial pacing dogs.

Comparative effects of three different potent renin inhibitors in primates

The goal of the present study was to compare the effects of three potent reference renin inhibitors (remikiren, CGP 38560A, and enalkiren) in sodium-depleted normotensive squirrel monkeys. In these monkeys, arterial pressure was measured in the conscious state with a telemetry system. Oral and intravenous maximal effective doses of the three renin inhibitors were compared in parallel groups of monkeys. In additional experiments, remikiren was given on top of either CGP 38560A or enalkiren in the same animals. Finally, the three drugs were compared with the angiotensin converting enzyme inhibitor cilazapril. The effects of the three drugs on the plasma components of the renin-angiotensin system (plasma renin activity, immunoreactive renin, and immunoreactive angiotensin II concentrations) were also measured. Our results show that remikiren was as effective as cilazapril and markedly more effective than CGP 38560A or enalkiren in reducing arterial pressure in our monkey model. Interestingly, these differences in arterial pressure could not be explained by differences of in vitro potency or different biochemical changes of the plasma components of the renin-angiotensin system, because the inhibitors all reduced immunoreactive angiotensin II to similarly low levels. One possible explanation is that, in our model, remikiren in contrast to CGP 38560A and enalkiren is able to inhibit renin in a functionally important extraplasmatic compartment.

Altered cerebrovascular response to a potassium channel opener in hypertensive rats

We examined whether the effect of Y-26763, an ATP-sensitive potassium channel opener, on cerebral blood flow is altered in stroke-prone spontaneously hypertensive rats (SHRSP) and, if altered, whether long-term antihypertensive treatment with cilazapril, an angiotensin-converting enzyme inhibitor, is capable of preventing the change. Cerebral blood flow during intracarotid infusion of Y-26763 was measured in anesthetized SHRSP and normotensive Wistar-Kyoto rats (WKY) as control. Y-26763 increased cerebral blood flow in a dose-dependent manner in WKY, and glibenclamide, a selective inhibitor of ATP-sensitive potassium channels, inhibited the Y-26763-induced increase in cerebral blood flow. In contrast, the response to Y-26763 in SHRSP was significantly impaired compared with that in WKY. Antihypertensive treatment with cilazapril lowered blood pressure toward normal and prevented the impaired response in cerebral blood flow to Y-26763 in SHRSP. These findings suggest that (1) ATP-sensitive potassium channels contribute to the regulation of cerebral blood flow in rats, (2) the response to an ATP-sensitive potassium channel opener is markedly diminished in hypertensive rats, and (3) the altered response to an ATP-sensitive potassium channel opener during chronic hypertension can be prevented by long-term antihypertensive treatment.

Inhibition of angiotensin-converting enzyme increases the nitric oxide levels in canine ischemic myocardium

Since angiotensin-converting enzyme (ACE) produces angiotensin II in the heart, ACE inhibitors may prevent coronary vasoconstriction and increase coronary blood flow. On the other hand, since ACE inhibitors also inhibit kininase II which results in reduced degradation of bradykinin, ACE inhibitors may increase cardiac nitric oxide (NO) levels via stimulation of bradykinin receptors. This study was undertaken to test whether ACE inhibitors increase the cardiac NO levels and coronary blood flow in the ischemic myocardium. In 34 open-chest dogs, the left anterior descending coronary artery was perfused through an extracorporeal bypass tube from the left carotid artery. When either imidaprilat or cilazaprilat of 3 microg/kg/min was infused into the bypass tube for 10 min after reduction of coronary blood flow due to partial occlusion of the bypass tube, coronary blood flow increased from 31 +/- 1 to either 45 +/- 5 or 43 +/- 4 ml/100 g/min despite no changes in coronary perfusion pressure (43 +/- 2 mmHg). During an infusion of either imidaprilat or cilazaprilat, bradykinin and the end-products of NO (nitrate + nitrite) concentrations of coronary venous blood were markedly increased, which were attenuated by either HOE-140 (an inhibitor of bradykinin receptors) or by N(omega)-nitro-L-arginine methyl ester (an inhibitor of NO synthase). We also observed increases in cardiac bradykinin and NO levels due to either imidaprilat or cilazaprilat in the low constant coronary blood flow condition. It is concluded that ACE inhibitors can increase cardiac NO levels via the accumulation of bradykinin in the ischemic myocardium.

Effects of angiotensin converting enzyme inhibitor cilazapril and angiotensin II antagonist saralasin in ovarian hyperstimulation syndrome in the rabbit

We investigated the possible effects of the angiotensin converting enzyme (ACE) inhibitor cilazapril and angiotensin II antagonist saralasin on ovulation, ovarian steroidogenesis and ascites formation in the ovarian hyperstimulation syndrome (OHSS) in the rabbit model. OHSS was induced in rabbits by human menopausal gonadotropin (hMG) and intermittent human chorionic gonadotropin (hCG). In the cilazapril group (n = 10), animals also received cilazapril 2 mg/kg intraperitoneally daily for 7 days. In the saralasin group (n = 8), animals received saralasin intraperitoneally 1 h before or 1 h after hCG administration. Control animals (n = 8), received intraperitoneal saline solution. Serial blood samples were drawn on days 1, 5, 7 and 9 to measure serum estradiol and progesterone levels. On day 9, all rabbits underwent surgical exploration. Peritoneal and pleural fluid formation, ovarian weights and number of ovulations were determined. The volume of the ascitic and pleural fluids after hyperstimulation were not statistically different between the control, cilazapril and saralasin groups. The weight gains and ovarian weights of animals were similar between treatment and control groups. Saralasin significantly (p < 0.05) inhibited ovulation, but cilazapril did not. Cilazapril and saralasin did not affect progesterone production. Only cilazapril significantly decreased estradiol production (p < 0.05). In conclusion, the ACE inhibitor cilazapril and angiotensin II antagonist saralasin did not prevent ascites formation in OHSS. The ovarian renin-angiotensin system may not be the only factor acting in ascites formation in the OHSS.

Combination treatment with a calcium channel blocker and an angiotensin blocker in a rat systolic heart failure model with hypertension

The mechanism and treatment of hypertensive systolic heart failure are not well defined. We compared the effect of an angiotensin-converting enzyme inhibitor (cilazapril, 10 mg/kg), an angiotensin receptor blocker (candesartan, 3 mg/kg), a calcium channel blocker (benidipine, 1, 3 or 6 mg/kg), and the same calcium channel blocker combined with renin-angiotensin blockers on systolic heart failure in Dahl salt-sensitive (DS) rats. DS rats were fed an 8% Na diet from 6 weeks of age and then subjected to the above drug treatments. Benidipine (1 mg/kg), cilazapril, and candesartan had compatible hypotensive effects and similar beneficial effects on cardiac hypertrophy, gene expression, and survival rate. The combination of benidipine with cilazapril or candesartan was found to have no additional beneficial effects on the above parameters, with the exception of a reduction in atrial natriuretic polypeptide gene expression. On the other hand, candesartan normalized serum creatinine, but serum creatinine was unaffected by either benidipine at 1 or 3 mg/kg or cilazapril. Further, the combined use of benidipine and either candesartan or cilazapril resulted in an additional reduction of urinary albumin excretion in DS rats. Thus systolic heart failure in DS rats is mainly mediated by hypertension, while renal dysfunction of DS rats is due to both hypertension and the AT1 receptor itself. These findings suggest that the combination of a calcium channel blocker with an AT1 receptor blocker or ACE inhibitor may be more effective in treating the renal dysfunction associated with systolic heart failure than monotherapy with either agent alone. However, further studies will be needed before reaching any definitive conclusion on the efficacy of this combination therapy in patients with heart failure.

Disparate results of ACE inhibitor dosage on exercise capacity in heart failure: a reappraisal of vasodilator therapy and study design

Despite manifest benefits of angiotensin converting enzyme (ACE) inhibitors on the prognosis of patients with heart failure, there is a lack of consistency in the results of trials investigating the effects of ACE inhibitors on exercise capacity. The inconsistencies cannot be readily explained by variations in effects on known neurohumoral or conventional haemodynamic factors. Drawing on insights from physiology of pump-load interactions, in a normal circulation there is an optimal extent of systemic vasodilation at which the delivery of hydraulic energy from the cardiac pump is maximal (the 'impedance matchpoint'). In heart failure, the vasoconstrictive effects shift the operating point towards mismatch at higher resistances, and optimal vasodilatory therapy would reshift the operating point to the matchpoint. Excessive dosage, however, would cause overvasodilatation leading to a reduction in cardiac power output and consequently compromising exercise ability. High levels of ACE inhibitors may not therefore improve exercise ability. Another potential reason for the observed inconsistencies is that the often used parallel-group study design (ideal for mortality studies) may not be suitable for investigating drug effects on exercise capacity because dropouts from such studies would introduce occult selection biases, thereby confounding treatment effects. In conclusion, this reappraisal of the conflicting observations reported on ACE inhibitor effects on exercise capacity has highlighted a proposition that there is an optimal dosage of ACE inhibitors which will most enhance exercise capacity, and this will require further well designed cross-over studies to elucidate.

Combined therapy of cilazapril and losartan has no additive effects in ameliorating adriamycin-induced glomerulopathy

AIMS

Effects of the blockade of renin-angiotensin system (RAS), by angiotensin-converting enzyme inhibitor (ACEi), type 1 angiotensin II receptor blocker (ARB), or a combination of both, were evaluated in Adriamycin (ADR)-induced glomerulopathy.

METHODS

Male Sprague-Dawley rats (180-250 g) were induced of glomerulopathy by treatment with ADR (2 mg/kg, i.v.). Six weeks later, they were treated with cilazapril (1 mg/kg/day) and/or losartan (10 mg/kg/day) for an additional 6 weeks.

RESULTS

The urinary excretion of protein progressively increased following the treatment with ADR, which was prevented by ACEi, ARB, and a combination of both. Similarly, the glomerulopathy assessed by glomerulosclerosis index was also ameliorated by ACEi or ARB. However, combined therapy of both ACEi and ARB was without an additional effect (Control 1.4 +/- 0.4%, ADR 10.7 +/- 2.7%**, ACEi 0.8 +/- 0.4%, ARB 2.6 +/- 1.0%, ACEi+ARB 1.7 +/- 1.5%, ** p < 0.01 vs. Control). The expression of transforming growth factor-beta(1) was increased following the treatment with ADR (1.4 +/- 0.07-fold, p < 0.05 vs. Control), however, the degree of which was similarly blunted by either ACEi, ARB, or the combination of both. The expression of type 1 angiotensin II receptor mRNA increased following the treatment with ADR, the degree of which was further upregulated by ACEi and decreased by ARB to the control level (ADR 1.3 +/- 0.06-fold*, ACEi 1.8 +/- 0.05-fold***, ARB 1.0 +/- 0.04-fold, * p < 0.05 and *** p < 0.001 vs. Control). The combined therapy of ACEi and ARB still showed an upregulation of type 1 angiotensin II receptor mRNA, however, of which degree was mitigated compared with that induced by ACEi alone (ACEi+ARB 1.5 +/- 0.04-fold, ** p < 0.01 vs. Control). On the contrary, the expression of type 2 angiotensin II receptor mRNA was downregulated following the treatment with ADR, which was similarly restored to the control level by ACEi, ARB, and a combination of both (ADR 0.5 +/- 0.08-fold**, ACEi 1.0 +/- 0.06-fold, ARB 1.0 +/- 0.05-fold, ACEi+ARB 1.0 +/- 0.05-fold, ** p < 0.01 vs. Control).

CONCLUSION

It is suggested that combined therapy of ACEi and ARB with relatively high or maximal doses of each drug has no additive or synergistic benefits on the progression of ADR-induced glomerulopathy. Effects of RAS blockade may in part be related to differential regulation of type 1 and type 2 angiotensin II receptors.

Changes in left ventricular mass during treatment with minoxidil and cilazapril in hypertensive patients with left ventricular hypertrophy

Attainment of the regression of hypertension-associated left ventricular hypertrophy (LVH) seems to be a desirable goal of blood pressure (BP)-reducing therapy. Since antihypertensive drugs of differing types may exhibit markedly different abilities to modulate LVH, we examined the effects of the angiotensin-converting enzyme inhibitor cilazapril, and the potassium channel activator minoxidil, alone or in combination with each other, on the left ventricular mass (LVM) in patients with severe essential hypertension who had LVH detected by echocardiography. All patients received the same base therapy of bopindolol and guanfacine. After a run-in period, they were treated with: (1) cilazapril (n = 10); (2) minoxidil, combined with a diuretic (n = 10); or (3) both cilazapril and monoxidil (n = 6) for 12 months. The LVM index (LVMI; LVM per body surface area) was estimated every 3 months by means of echocardiography. Each kind of therapy decreased the arterial pressures to a similar degree. The 1-year treatment with the cilazapril-based regimen resulted in a significantly diminished LVMI (from a mean +/- s.d. of 173 +/- 38 to 152 +/- 22 g/m2; P < 0.05). On the other hand, the minoxidil-based therapy led to a significant increase in LVMI (from 148 +/- 19 to 170 +/- 35 g/m2; P < 0.05). There were no significant LVMI changes in patients receiving the combined, cilazapril + minoxidil-based treatment (172 +/- 34 vs the pretreatment 183 +/- 54 g/m2). The results confirm that long-term treatment with cilazapril is effective both in reducing BP and in reducing LVM. In spite of yielding a satisfactory reduction of BP, minoxidil therapy, even in combination with a diuretic and a beta-blocker, may lead to an aggravation of pre-existing LVH; this effect of minoxidil could be prevented by the simultaneous administration of cilazapril.

Cilazapril reverses endothelium-dependent vasodilator response to acetylcholine in mesenteric artery from spontaneously hypertensive rats

This study was designed to evaluate the effect of chronic treatment with cilazapril on vascular reactivity of aorta and mesenteric artery from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). Cilazapril (5 mg/kg), an angiotensin converting enzyme inhibitor, was injected intraperitoneally twice a day for 4 weeks. Results demonstrated that acetylcholine (ACh)-induced relaxation in aorta and mesenteric artery from SHR was significantly less than that from WKY, cilazapril-treated WKY, and SHR. The impairment of ACh-induced relaxation in SHR was significantly reversed after cilazapril treatment and there were no significant differences among WKY, cilazapril-treated WKY, and SHR. Meanwhile, both N omega-nitro-L-arginine (LNNA; 10(-4) mol/L) and methylene blue (MB; 10(-5) mol/L) completely blocked the vasodilator response to ACh in aorta but only partly inhibited in mesenteric artery from WKY, cilazapril-treated WKY, and SHR. These LNNA- and MB-resistant vasodilator responses to ACh in mesenteric artery were only slightly inhibited by TEA (10(-3) mol/L) but not by indomethacin (5 x 10(-6) mol/L). These findings suggest that there may be an unidentified endothelium-dependent relaxing factor(s) (EDRF), which exists in the endothelium and may participate in the modulation of blood pressure in SHR. Results further demonstrate that the antihypertensive effect of cilazapril may be partly mediated by the reversing function of endothelium to release EDRF and LNNA-resistant, unidentified relaxing factor(s).

Adaptive changes in the acute haemodynamic effects of cilazapril during chronic treatment. Comparison with long-term clinical effect

OBJECTIVE

To study the adaptive changes in the acute haemodynamic response to ACE inhibition during chronic treatment in CHF.

METHODS

The acute and chronic effects of oral cilazapril (CLZ) treatment, an ACE-inhibitor with prolonged duration on haemodynamic measures (PCWP, PAP, RAP, CI and SVR) and clinical parameters (Quality-of-Life and NYHA class) were investigated in a double-blind, randomised, placebo-controlled trial in CHF. One hundred and thirty five patients (112 completing) in NYHA Classes II-III, on digitalis and diuretic treatment, were randomised after 2 weeks of placebo run-in, to receive either placebo or CLZ 0.5 mg, 1.0 mg or 2.5 mg daily for 12 weeks, followed by 2 week placebo wash-out. Haemodynamic studies, including exercise tests before and 3 h after medication, were performed on the first and last days of treatment. Measurements were performed at rest and at the maximum exercise level.

RESULTS

In ACEI-naive patients oral CLZ 0.5 and 1 mg/d caused a dose dependent decrease in PCWP and diastolic PAP, and a significant reduction of SVR mg. A slight increase in CI was observed in all groups. The maximum effect was observed 3-5 h post dose. After 12 weeks of oral treatment, the acute response was similar but was attenuated relative to the first dose. Exercise tolerance improved in a dose dependent manner. The NYHA classification remained unchanged or improved in the majority of patients. Entry into the 2.5 mg group had to be terminated at an early stage due to severe adverse events observed after the first dose.

CONCLUSION

During chronic treatment, the haemodynamic response to oral cilazapril was attenuated, indicating that continued clinical improvement in patients with CHF on CLZ is independent of to its acute haemodynamic effects.

Effect of renin-angiotensin inhibition on glomerular injuries in DOCA-salt hypertensive rats

To determine whether growth factors in the glomerulus are induced in the renin suppressed hypertensive model, we examined the mRNA expressions of platelet-derived growth factor (PDGF) B-chain, transforming growth factor (TGF)-beta 1 and angiotensin II type 1 (AT1) receptors in the glomeruli of deoxycorticosterone acetate (DOCA)-salt-treated hypertensive rats (DOCA-treated rats). We also examined the effects of treatment with cilazapril, an angiotensin I-converting enzyme inhibitor (ACEI), and L-158,809, an AT1 receptor antagonist, on these expressions in DOCA-treated rats. We administered oral 10 mg/kg of cilazapril (CILAZA group) and 1 mg/kg of L-158,809 (L158 group) to DOCA-treated rats daily. Systolic blood pressure in the two groups was not decreased compared with that in DOCA-treated rats given saline. The mRNA expressions were examined using reverse transcriptase polymerase chain reaction (RT-PCR) methods. The mRNA expressions of these genes were higher in DOCA-treated rats than in age-matched control rats. After treatment with these agents for 4 weeks, the mRNA expressions of growth factors were suppressed in both the CILAZA and L158 groups. Mesangial expansion and cell proliferation observed in DOCA-treated rats were suppressed in both the CILAZA and L158 groups. Decreases in the size of the glomerulus were observed only in the CILAZA group. These findings suggested that suppression of growth factors and glomerular proliferative changes of these agents are mediated by blocking tissue renin-angiotensin system (RAS) in the renin-suppressed model.

Limitations of angiotensin-converting enzyme inhibitor in restenosis of a deep arterial injury model

Cilazapril (CLZ) has been reported to reduce intimal hyperplasia in a rat carotid model of restenosis. The purpose of this study was to determine whether CLZ inhibits restenosis after deep arterial injury in lathyritic rats. The lathyritic rat was used as a model of deep arterial injury; in this model the internal elastic lamina is easily broken by balloon injury because of the fragility of the connective tissue. Deep arterial injury is defined as rupture of the internal elastic lamina with damage to both the intima and the media. The rats were divided into 4 groups (n = 40): mild injury (intimal damage with intact internal elastic lamina), mild injury +CLZ, deep injury, and deep injury +CLZ. In the CLZ-treated groups, the drug was administered orally (10 mg/day) from 7 days before balloon injury until the time of sacrifice 21 days after balloon injury. The intimal hyperplasia was determined histologically using a computerized morphometry program. At sacrifice, blood pressure was lower in the CLZ-treated groups than in the untreated (control) rats (p < 0.05). In the mild injury model, CLZ decreased intimal hyperplasia markedly. In contrast, CLZ failed to reduce intimal hyperplasia in the rats with deep injury. CLZ markedly decreased neointimal hyperplasia in mild injury. In contrast, CLZ failed to reduce intimal area in deep injury. The type of arterial injury seems to determine the effectiveness of CLZ.

Hemodynamic and biochemical changes after chronic administration of cilazapril to hypertensive patients

The study describes the changes in basic hemodynamic parameters after long-term antihypertensive therapy with cilazapril--a new ACE inhibitor lacking a sulfhydryl group--in hypertensive patients and the drug effects on renal function, glucose tolerance and lipid metabolism. 30 patients (18 males, 12 females, mean age: 53.3 +/- 18 years) with mild to moderate essential hypertension were studied. The following determinations were performed in patients, before and after 4.5 months of cilazapril monotherapy at a dose of 5 mg/24 h: (a) antihypertensive action of the drug (arterial pressure at rest and during a 24-hour recording); drug effects on left ventricular (LV) mass index; its contractility indexes (%FS, EF) and the left atrial emptying index were studied by means of echocardiography; (b) plasma insulin concentration during oral glucose tolerance tests, in the fasting state, after the administration of 75 g glucose per os, as well as the changes in the insulinogenic index and the 6-keto-PGF1 alpha/TXB2 ratio, and (c) drug effect on renal function (urea, creatinine, uric acid, plasma electrolytes), blood lipid profile (total cholesterol, triglycerides, HDL-CH) and serum transaminases. Long-term drug administration exhibits an effective antihypertensive action, without causing reflex tachycardia and also reduces the LV mass index without affecting its EF, while improving its diastolic function. It does not significantly affect the various biochemical parameters, and achieves glucose regulation, both in the fasting state and after glucose loading, with a decrease in the insulinogenic index, and simultaneously increases the 6-keto-PGF1 alpha/TXB2 ratio. The existence of a direct cause-effect relationship between the changes in the above hormone systems is possible.

A comparison of the efficacy of cilazapril versus cilazapril plus hydrochlorothiazide in patients with mild to moderate essential hypertension. Inhibace General Practice Study Group

The efficacy of cilazapril monotherapy and in combination with hydrochlorothiazide 12.5 mg was compared in a multicentre, double blind, randomised parallel group study in 87 patients with mild to moderate essential hypertension over 8 weeks. After a 2 week single blind placebo run-in period, patients received either 2.5 mg cilazapril or 2.5 mg cilazapril plus 12.5 mg hydrochlorothiazide once daily. At Week 4 the cilazapril dose was increased from 2.5 mg to 5.0 mg if the mean sitting diastolic blood pressure was greater than 90 mmHg or had not decreased by more than 10 mmHg. After 8 weeks treatment 72% of patients responded to 2.5 mg cilazapril increasing to 88% with cilazapril 5.0 mg. For cilazapril plus hydrochlorothiazide, 83% responded to 2.5 mg cilazapril increasing to 96% on 5.0 mg cilazapril. The high response rate to low dose cilazapril monotherapy and hydrochlorothiazide combination therapy has important implications for minimising the cost of therapy with ACE inhibitors.

Blockade of renin-angiotensin system reduces QT dispersion and improves intracellular Ca/Mg status in hemodialysis patients

BACKGROUND

Electrolyte impairments are common in hemodialysis (HD) patients. Consequently, QT dispersion (QTd) is prolonged, correlating with high intracellular magnesium. In patients with cardiac disorders, renin-angiotensin system (RAS) inhibition reduces QTd.

AIM

To compare the effects of ACE inhibition or AT-1 blockade on QTd duration and intracellular magnesium (Mg)/calcium (Ca) in peripheral blood mononuclear cells (PBMC) from chronic HD patients.

METHODS

24 HD patients received cilazapril for 8 weeks and, following a 2-week withdrawal, were switched to valsartan for additional 8 weeks. QTd measurements and PBMC isolation were performed at the beginning and the end of each period. Total intracellular Ca and Mg were assessed by atomic spectrometer, and cytosolic free Ca2+ by fluorocytometer.

RESULTS

Both treatments significantly decreased QTd, demonstrating similar reduction magnitudes. In both groups, PBMC exhibited basally low cytosolic Ca2+ and undisturbed high transmembrane Ca2+ influx following phytohemagglutinin stimulation. Total intracellular Ca was increased, while Mg was reduced, following either treatment. The total intracellular Ca/Mg ratio inversely correlated with QTd duration.

CONCLUSIONS

(1) RAS inhibition reduces prolonged QTd in HD patients. (2) In PBMC from ordinarily Ca-depleted HD patients, RAS suppression brings about elevation of total intracellular Ca. (3) RAS blockade decreases high intracellular Mg in PBMC from HD patients. Consequently, the Ca/Mg ratio increases, inversely correlating with QTd reduction.

Outcome survey in unselected hypertensive patients with type 2 diabetes mellitus: effects of ACE inhibition

Although the benefit of angiotensin converting enzyme (ACE) inhibitors in diabetic nephropathy is well documented in double-blind randomized, controlled clinical trials, it is uncertain whether the benefit extends to unselected patients with diabetes mellitus and arterial hypertension in general practice. In 2504 unselected patients with type 2 diabetes mellitus (mean age 63+/-10 years) blood pressure, cardiovascular, renal, and metabolic parameters were assessed at baseline and during a treatment period of 1 year with the ACE inhibitor cilazapril by primary care physicians. The average dose of cilazapril was 2.5 mg/day. Outcome measures were blood pressure, serum creatinine, proteinuria (dip stick), HbA1c levels, evaluation of edema, and exertional dyspnea. In the study cohort, systolic blood pressure decreased by 24+/-17 mm Hg and diastolic blood pressure by 12+/-11 mm Hg. An increase in serum creatinine (> 0.2 mg/dL) occurred more frequently in patients with than in those without renal involvement (19% v 7%; P < .05). Serum creatinine decreased more frequently in patients with renal involvement than in those without (26%+/-4% v 12%+/-3.8%; P < .05). Overall renal function in patients with diabetic nephropathy (n = 318) improved (2.1+/-1.6 mg/dL v 1.7+/-1.4 mg/dL; P < .05). The frequency of proteinuria was lower after 1 year than at baseline (62%+/-9% v 82%+/-8%; P < .05). Metabolic control of diabetes mellitus improved in parallel (median HbA1c 8.0% v 7.0%; P < .01). Scores for edema formation and exertional dyspnea improved as well (P < .01). In this outcome survey of unselected patients with type 2 diabetes mellitus and arterial hypertension, the ACE inhibitor cilazapril effectively lowered blood pressure, which was associated with an improvement in glucose metabolism, cardiac function, and renal function.

The effects of monotherapy or combined therapy with an angiotensin converting enzyme inhibitor following initial treatment with calcium channel blockers on residual cardiovascular abnormalities

The effects of sequential therapy with angiotensin-converting enzyme inhibitor (cilazapril) on left ventricular (LV) mass, LV diastolic function, and carotid artery distensibility were evaluated in 90 hypertensive patients whose blood pressure controlled below 140/90 mmHg with a calcium channel blocker monotherapy. The possibility of predicting the efficacy of cilazapril based on evaluation of biochemical and genetic markers of the renin-angiotensin system was examined. Before cilazapril therapy, LV diastolic function and carotid artery distensibility were significantly impaired in 32 patients with residual LV hypertrophy compared with patients without LV hypertrophy. Cilazapril improved the LV mass in these patients with LV hypertrophy and improved LV diastolic function in a subset of 20 patients with elevated plasma renin activity. Patients with residual LV hypertrophy accompanied by cardiovascular functional abnormalities. Subsequent treatment with cilazapril significantly improved LV morphology and function in those with residual LV hypertrophy or elevated plasma renin activity.