Clinical impact of insulin resistance syndrome in cardiovascular diseases and its therapeutic approach

In subjects with coronary artery diseases (obstructive and vasospastic angina pectoris (AP)) who have no diabetes, hypertension, obesity and physical inactivity, insulin sensitivity was significantly reduced with compensated hyperinsulinemia on OGTT. Insulin resistance significantly correlated with coronary atherosclerosis score. In vasospastic AP (VAP), those who fulfilled more than 3 risk factors out of 5 (hyperinsulinemia, obesity, glucose intolerance, hypertension, dyslipidemia) consist of 70 and 40% for smokers and nonsmokers respectively. Insulin resistance syndrome who fulfilled all the criteria was 9-10% for VAP. In atherothrombotic brain infarction (ATTI) with the same exclusion criteria, the similar insulin resistance and hyperinsulinemia have been observed, but not in embolic (cardiac origin) or lacunar infarction. In ATTI, high TG and apo B with low HDL-chol were noted in blood. In essential hypertension without diabetes and obesity, hyperinsulinemia was noted in 25-35% and insulin resistance in 56-88%. Reduction of blood pressure with alpha blocker (bunazosin), ACE inhibitor (cilazapril), long-acting Ca++ blocker (amlodipine) significantly improved lowered insulin sensitivity. Insulin resistance rather than hyperinsulinemia is more closely associated with blood pressure. Cardiovascular diseases (vasospastic and obstructive AP, brain cortical artery diseases) are prone to develop diabetes because of insulin resistance and also promote the generation of cumulative risk factors resulting in a vicious cycle. Efforts to alleviate insulin resistance is crucial for the primary and secondary prevention of cardiovascular diseases.

Influence of antihypertensive therapy with cilazapril and hydrochlorothiazide on the stiffness of the aorta

The purpose of this study was to examine the effects of the angiotensin-converting enzyme (ACE) inhibitor cilazapril on the elastic properties of the aorta. A standard diuretic antihypertensive drug, hydrochlorothiazide, served for comparisons. Increased aortic stiffness leads to a reduction of the buffering windkessel function and is a major component in the pathophysiology of systolic hypertension, inducing an increase in left ventricular afterload and arterial pulsatile stress as well as a decrease in the subendocardial blood supply. Stiffness of arteries increases with age and blood pressure, and depends on the functional elastic structures of the aortic wall. ACE inhibitors have been shown to directly influence elastic properties of peripheral arteries. Seventeen patients with mild to moderate essential hypertension (age 45-67 years) were treated for 3 months double-blind randomized with either cilazapril (C) 5 mg daily (n = 9) or hydrochlorothiazide (HCTZ) 25 mg daily (n = 8). Aortic elastic properties were noninvasively assessed by measurement of pulse wave velocity along the aorta at rest and during isometric handgrip stress. Accelerated pulse wave velocity indicates elevated arterial stiffness and vice versa. A pressure standardized index of aortic cross-sectional distensibility (2 m) was calculated from arterial mean pressure and pulse wave velocity. Compared with pretreatment values, both therapies significantly reduced blood pressure and pulse wave velocity at rest (C: 9.4 +/- 0.9 vs. 7.7 +/- 0.7 m/sec; HcTZ: 8.9 +/- 0.3 vs. 7.8 +/- 0.4 m/sec; means +/- SEM p < 0.05). During isometric stress only C showed a significant decrease in pulse wave velocity (C: 11.3 +/- 0.8 vs. 9.1 +/- 0.8 m/sec; HCTZ: 9.9 +/- 0.5 vs. 9.0 +/- 0.5 m/sec; means +/- SEM p < 0.05). The index 2m at rest and during handgrip increased significantly (p < 0.05) after C but not after HCTZ. With cilazapril we obtained steeper slopes for the treatment-induced reductions in blood pressure and pulse wave velocity for both rest and handgrip stress values. Correlation of the data at rest and during stress revealed a direct relationship between blood pressure and pulse wave velocity. HCTZ linearly extended the relation observed before treatment toward lower values of blood pressure and corresponding pulse wave velocity without changing the relation per se. Cilazapril, in contrast, moved the relation between these variables and decelerated the pulse wave velocities to a greater extent than would have been expected from the corresponding blood pressure reduction (delta approximately 1 m/sec). These results in patients with mild to moderate essential hypertension support the idea that ACE inhibitors, in addition to reducing blood pressure, may exert an additional hemodynamic effect in improving the elastic properties of the aorta.

Effects of cilazapril and amlodipine on kidney function in hypertensive NIDDM patients

Contrasting information has been reported concerning the course of renal function in NIDDM with hypertension alone or in association with renal damage. The aim of the present study was to elucidate the course of the glomerular filtration rate (GFR) in hypertensive NIDDM patients during antihypertensive therapy. Furthermore, we compared the effects of ACE inhibitors (cilazapril, Inibace, Roche, Milan, Italy) and Ca(2+)-channel blockers (amlodipine, Norvasc, Pfizer, Rome, Italy). Of the hypertensive NIDDM patients attending the outpatient's clinic of the internal medicine departments of the University of Padova and Sassari, 44 participated in the present study. Of these patients, 26 were normoalbuminuric and 18 microalbuminuric. They were randomly treated with either cilazapril or amlodipine. The target of antihypertensive treatment was a value < 140 mmHg for systolic and 85 mmHg for diastolic blood pressure (BP). Microalbuminuria was defined as an albumin excretion rate (AER) between 20 and 200 micrograms/min. GFR was measured by plasma clearance of 51Cr-labeled EDTA at baseline and every 6-12 months during a 3-year follow-up interval. A significant decrease was observed in the values of GFR, AER, and systolic and diastolic BP in normoalbuminuric and microalbuminuric patients during antihypertensive therapy. The GFR fall in the overall population of NIDDM patients was significantly and inversely related to the decrease of mean BP (diastolic + 1/3 pulse pressure) (r = -0.80, P < 0.0001) but not to that of HbA1c, triglycerides, and BMI. The GFR decline (mean +/- SE) per year in the normoalbuminuric patient was 2.03 +/- 0.66 ml.min-1 x 1.73 m-2 (95% CI 0.92-3.17) during cilazapril and 2.01 +/- 0.71 ml.min-1 x 1.73 m-2 (95% CI 0.82-3.11) during amlodipine therapy. The GFR decline per year in the microalbuminuric patient was 2.15 +/- 0.69 ml.min-1 x 1.73 m-2 (95% CI 0.86-3.89) during cilazapril and 2.33 +/- 0.83 ml.min-1 x 1.73 m-2 per year (95% CI 1.03-3.67) during amlodipine therapy. Cilazapril and amlodipine lowered AER to a similar extent in normoalbuminuric and microalbuminuric patients. No significant changes were observed concerning other clinical and biochemical features between the two antihypertensive therapies and particularly HbA1c, BMI, triglycerides, and cholesterol plasma values. These results support the tenet that arterial hypertension plays a pivotal role in contributing to renal damage in NIDDM, even when AER is normal. However, the degree of BP control, with both cilazapril and amlodipine, can successfully delay the slope of GFR decline in hypertensive NIDDM patients with or without incipient nephropathy.

Improvement of left ventricular diastolic dysfunction in hypertensive patients 1 month after ACE inhibition therapy: evaluation by ultrasonic automated boundary detection

The purpose of this study was to detect any improvement in left ventricular diastolic dysfunction in hypertensive patients 1 month after cilazapril therapy. Twenty-three patients, 5 men and 18 women (mean age, 53.52 +/- 9.10 years), with mild or moderate hypertension (160 +/- 13/98 +/- 10 mm Hg), and free of other cardiac or systemic diseases, were studied using ultrasonic automated boundary detection (ABD) and pulsed Doppler echocardiography, before and 1 month after a daily dose of 2.5 mg of cilazapril. The following new ABD diastolic indices were determined: the time rate of area change in early diastole (dA/dt)E, that in late diastole (dA/dt)A, and their ratio (dA/dt)E/(dA/dt)A, while Doppler transmitral flow measurements of left ventricular diastolic filling were also simultaneously recorded. The ABD results showed left ventricular diastolic dysfunction (LVDD) in 9 of 23 patients (39%) compared with the ABD values of 12 normal volunteers. Neither method revealed any significant difference before and after treatment in the patient group as a whole. However, in the group of 9 patients with diastolic dysfunction, the ABD ratio (dA/dt)E/(dA/dt)A was significantly improved after cilazapril therapy (1.20 +/- 0.21 versus 1.41 +/- 0.17; P < 0.05). We concluded that a large percentage (39%) of patients with mild or moderate hypertension had reduced diastolic performance of the left ventricle at a stage of the disease when systolic dysfunction and/or hypertrophy were not evident. Significant improvement of diastolic dysfunction in hypertensive patients could be detected by the proposed ABD new diastolic indices 1 month after cilazapril therapy. In conclusion, automatic boundary detection should be a useful non-invasive modality for the early diagnosis of left ventricular diastolic dysfunction, as well as early recognition of its improvement.

Correction of remodeling and function of small arteries in human hypertension by cilazapril, an angiotensin I-converting enzyme inhibitor

Angiotensin II may contribute to the altered structure and function of small arteries. We proposed that angiotensin I-converting enzyme (ACE) inhibitor treatment could induce a regression of vascular remodeling. A double-blind trial was performed comparing effects of the ACE inhibitor cilazapril with the beta-blocker atenolol on small arteries obtained from biopsy specimens of subcutaneous gluteal fat. Nine patients with essential hypertension were randomized to cilazapril and eight to atenolol. Blood pressure was below 140/95 mm Hg under treatment for the duration of the study in all patients. Media-to-lumen ratio of small arteries of the patients, which before treatment was significantly higher than in normotensive subjects, was corrected after 1 year of treatment in the cilazapril group. There was no change in the increased media-to-lumen ratio of small arteries in the atenolol group, even after 2 years of treatment. Attenuated constrictor responses to endothelin-1 returned to normal only in the patients treated with cilazapril. Endothelium-dependent relaxation responses to acetylcholine were slightly depressed in hypertensive patients and improved in the cilazapril-treated group, but remained blunted in the arteries of the atenolol-treated patients. Treatment with cilazapril corrects small artery remodeling and endothelium-related functional abnormalities of gluteal subcutaneous small arteries in hypertensive patients. It remains to be demonstrated whether these apparently beneficial effects translate into reduced morbidity and mortality in hypertension.

Restenosis, reocclusion and adverse cardiovascular events after successful balloon angioplasty of occluded versus nonoccluded coronary arteries. Results from the Multicenter American Research Trial With Cilazapril After Angioplasty to Prevent Transluminal Coronary Obstruction and Restenosis (MARCATOR)

OBJECTIVES

This study sought to compare the frequency of restenosis, reocclusion and adverse cardiovascular events after angioplasty of occluded versus nonoccluded coronary arteries.

BACKGROUND

Angioplasty of chronically occluded coronary arteries is believed to be associated with a higher frequency of restenosis and reocclusion than angioplasty of subtotal stenoses. Whether this leads to adverse cardiovascular events is unknown.

METHODS

The Multicenter American Research Trial With Cilazapril After Angioplasty to Prevent Restenosis (MARCATOR) was a placebo-controlled trial with angiographic follow-up to determine the effect of the angiotensin-converting enzyme inhibitor cilazapril on the frequency of restenosis. In this trial, restenosis was defined as 1) angiographic reduction of minimal lumen diameter > or = 0.72 mm between angioplasty and the follow-up visit; and 2) > 50% diameter stenosis on the follow-up angiogram. We identified 139 patients with successful angioplasty of a coronary occlusion (Group 1) and compared the frequency of restenosis, reocclusion and adverse cardiovascular events with that in 1,295 patients with successful angioplasty of a subtotal stenosis (Group 2).

RESULTS

Restenosis occurred in 36 patients with occluded arteries (29%) versus 264 with nonoccluded arteries (23%, p = 0.177) by definition 1 and in 62 patients with occluded arteries (49%) versus 478 with nonoccluded arteries (42%, p = 0.119) by definition 2. Occlusion was present in 24 Group 1 patients (19%) compared with 74 Group 2 patients (7%) (p < 0.001). During the 6 month follow-up period, two Group 1 patients (1.4%) and six Group 2 patients (0.5%) died; no Group 1 patients and 10 Group 2 patients (0.8%) developed severe congestive heart failure; nonfatal myocardial infarction occurred in 4 Group 1 patients (2.9%) and 31 Group 2 patients (2.4%); repeat coronary angioplasty or bypass surgery was performed in 29 Group 1 patients (21%) and 232 Group 2 patients (18%); and angina was present in 18 Group 1 and 163 Group 2 patients (13% for both). Eighty-six Group 1 patients (62%) and 853 Group 2 patients (66%) remained free of these adverse events during the 6-month follow-up period (p = 0.513).

CONCLUSIONS

The frequency of restenosis was slightly but not significantly greater after successful angioplasty of an occluded artery than after angioplasty of a subtotal stenosis. Although reocclusion was more frequent, occurring in 19% of patients, the net clinical benefit of angioplasty in such patients was similar to that in patients with subtotal stenoses over the 6-month follow-up period.

Tolerability and efficacy of antihypertensive treatment with cilazapril in general practice

Data on the safety, tolerability and efficacy of the new angiotensin-converting enzyme (ACE) inhibitor cilazapril were obtained in a multicenter observational study carried out in a general practice setting. A total of 33,841 hypertensive patients were prescribed cilazapril 2.5-5.0 mg per day and followed for an average of 109 days. 28,792 patients (85.1%) had a baseline diastolic blood pressure (BP) > or = 95 mm Hg. 24,649 patients received cilazapril alone. during the observation period the mean blood pressure of these patients fell from 177/105 to 148/87 mm Hg (an average drop delta of 29/18 mm Hg). The response rate (diastolic BP < or = 90 mm Hg and delta > or = 10 mm Hg) in these patients was 78.9%. Adverse events were reported by 7.3% of all patients. In all, 3.7% of patients discontinued cilazapril treatment because of side effects. The most frequently reported side effect (1.5% of cases) was the dry cough typical of ACE inhibitors. The doctors judged the efficacy of cilazapril as very good or good in 89.8% of cases and its tolerability as very good or good in 94.6%. This reflects the good compliance (regular tablet intake) of more than 90% of patients.

Effect of cilazapril on hyperdipsia in hemodialyzed patients

To investigate whether angiotensin-converting enzyme inhibitor (ACE-I) potentially alleviates hyperdipsia, the effect of cilazapril on dialysis-associated excessive thirst was studied by evaluating various dipsogenic parameters in patients undergoing chronic hemodialysis (HD) who manifest an excessive interdialysis body weight gain of more than 5%, and show simultaneous severe-to-moderate hyperdipsia. An initial single dose of 1 mg of cilazapril given at the end of the HD session produced a marked improvement in the interdialysis thirst scores and a simultaneous reduction in plasma angiotensin II (AII) concentration due to the inhibition of ACE activity. The interdialysis body weight gain in the cilazapril treatment period was significantly smaller than that in the nontreatment period. None of the other parameters including blood pressure, plasma osmolarity, and serum Na and K concentration were different in the treatment vs. the nontreatment period. The present data help to explain the potential pharmacological action of AII in the physiology of thirst and suggest that cilazapril may effectively alleviate dialysis-associated hyperdipsia at least on some occasions. The mechanism by which ACE-I exerts an antidipsogenic action may, in part, be accounted for by the reduction in plasma concentration of AII, as a result of the ACE inhibition.

Cilazapril delays progression of hypertension and uremia in rat polycystic kidney disease

Polycystic kidney disease (PKD) is the fourth most common cause of end-stage renal disease and is a common cause of hypertension and associated vascular morbidity. Activity of the renin angiotensin system has been identified as a major component of hypertension and altered fluid and electrolyte physiology in PKD. Activity of this pathway also has been proposed as a potential modulator of structural change in both tubules and the interstitium of the kidney. Cilazapril is a long-acting angiotensin-converting enzyme inhibitor that has been effective in producing vascular remodelling in hypertensive vascular disease. We undertook a study to determine whether therapy with cilazapril would modify the expression of PKD in the Han:SPRD-cy rat, a model of autosomal dominant PKD that closely resembles human disease. Male rats were treated for 4 months, starting at 1 month of age. Control animals were hypertensive by 3 months of age, whereas treated animals were noted to be hypertensive only at the exit assessment (P < 0.001 at 3 months, P = 0.005 at 5 months). At 5 months of age, cilazapril-treated animals had modest but statistically significant reductions in serum creatinine (mean, 1.77 mg/dL v 1.97 mg/dL; P = 0.0006) and morphometrically assessed cyst volume (mean, 0.32 mL v 0.67 mL; P = 0.036). Cilazapril is an effective treatment for hypertension in this model of progressive renal disease and may have benefits beyond the prevention of cardiovascular morbidity.

Kinin and angiotensin II receptor antagonists in rats with chronic renal failure: chronic effects on cardio- and renoprotection of angiotensin converting enzyme inhibitors

OBJECTIVE

To assess the potential of the kallikrein-kinin and renin-angiotensin systems in mediating the cardio- and renoprotective effects of angiotensin converting enzyme (ACE) inhibitors in rats with chronic renal failure.

MATERIALS AND METHODS

Spontaneously hypertensive rats (SHR) and normotensive control Wistar-Kyoto (WKY) rats subjected to five-sixths nephrectomy were randomly assigned to treatment with vehicle, a kinin antagonist (Hoe 140) or an ACE inhibitor (cilazapril) or both drugs, intraperitoneally via osmotic minipumps for 4 weeks. In addition, the effects of a chronic infusion of a specific angiotensin receptor antagonist (losartan) alone or in combination with an ACE inhibitor (enalapril) were also investigated in nephrectomized SHR for 2 weeks.

RESULTS

In nephrectomized SHR and WKY rats, cilazapril alone significantly reduced systolic blood pressure, urinary protein excretion, heart weight and serum creatinine. In nephrectomized SHR, Hoe 140 alone or cilazapril in combination with Hoe 140 (7 or 70 mu g/kg per day) induced no changes in these parameters, other than those associated with the effects of cilazapril alone. In nephrectomized WKY rats, cilazapril in combination with Hoe 140 (70 mu g/kg per day) slightly, but not significantly, attenuated the antihypertensive effect of cilazapril but did not affect the other parameters. These results were confirmed by morphological analysis of kidneys. All the drug regimens provided effective protection against an increase in focal glomerular sclerosis. Enalapril did not modify the antihypertensive and renoprotective effects of losartan in nephrectomized SHR.

CONCLUSIONS

The present results indicate that the kallikrein-kinin system might not be a major factor in the cardio- and renoprotective effects of ACE inhibitors in rats with chronic renal failure.

Do kinins mediate cardioprotective and renoprotective effects of cilazapril in spontaneously hypertensive rats with renal ablation?

1. We assessed the potential of the kallikrein-kinin system in mediating the cardioprotective and renoprotective effects of an angiotensin-converting enzyme inhibitor (ACEI), cilazapril (CIL) in rats with renal ablation. 2. Eight week old spontaneously hypertensive rats (SHR) were subjected to 5/6 nephrectomy. One week after the operation, the rats were divided into 5 groups: (i) vehicle; (ii) CIL 1 mg/kg per day per os (p.o.); (iii) Hoe140 (HOE) 70 mu g/kg per day given intraperitoneally (i.p.); (iv) CIL 1 mg/kg per day p.o. plus HOE 7 mu g/kg per day i.p.; (v) CIL 1 mg/kg per day p.o. plus HOE 70 mu g/kg per day i.p. The treatment lasted for 4 weeks. 3. CIL alone significantly reduced systolic blood pressure, urinary protein excretion, heart weight and serum creatinine level. HOE alone did not induce any significant changes in these parameters. CIL in combination with HOE (7 or 70 mu g/kg per day) did not induce any changes in these parameters, in addition to those associated with the effects of CIL alone. 4. These results indicate that the kallikrein-kinin system might not play a major role in the cardioprotective and renoprotective effects of ACE inhibitors in the rat remnant kidney model of chronic renal failure.

Effect of cilazapril therapy on glucose and lipid metabolism in patients with hypertension

The effects of long-term monotherapy with cilazapril, an angiotensin-converting enzyme inhibitor, on blood pressure, glucose tolerance, and serum lipid profiles were prospectively investigated in 66 patients with hypertension: 23 with normal glucose tolerance and 43 with glucose intolerance (including 9 patients with non-insulin-dependent diabetes mellitus). The levels of plasma glucose, serum insulin, serum lipids, glycated hemoglobin A(lc) (Hb A(lc)), and fructosamine were determined before and during long-term (mean +/- SD, 26.2 +/- 1.2 weeks) therapy with cilazapril. A 75-g oral glucose tolerance test was performed before and during treatment. Significant reductions in both systolic and diastolic blood pressures in both patient groups were maintained during the study. Neither fasting nor post-glucose load venous plasma glucose levels were altered in either group of patients, and no patient with normal glucose tolerance developed diabetes mellitus during the study. There was no significant change in the insulinogenic index (delta serum insulin/delta venous plasma glucose at 30 minutes post-glucose load) in either group, and glucose intolerance was slightly improved with significant reductions (P < 0.01) in Hb A(lc) and fructosamine in the patient group with impaired glucose tolerance. Serum total cholesterol (TC), low-density lipoprotein cholesterol, and triglyceride levels were significantly (P < 0.01) decreased and high-density lipoprotein cholesterol levels increased in patients with hypercholesterolemia (TC levels > or = 5.69 mmol/L). These results suggest that long-term cilazapril therapy may improve glucose and lipid metabolism in hypertensive patients with impaired glucose tolerance. Cilazapril also appears to be useful as an antihypertensive agent for hypertensive patients with either impaired glucose tolerance or hypercholesterolemia.

[Effect of cilazapril on exercise tolerance and neurohumoral factors in patients with asymptomatic chronic heart failure after myocardial infarction]

The effects of cilazapril on exercise tolerance and neurohumoral factors were investigated in old myocardial infarction (OMI) patients with asymptomatic heart failure and reduced left ventricular ejection fraction. Cilazapril (0.5 mg) was administered once daily to OMI patients (n = 20) [NYHA class I, sinus rhythm, ejection fraction by radionuclide scanning < 50% (36.8 +/- 9.1%, mean +/- SD)]. Two weeks later, five patients were excluded from the study because of cough or hypotension, and 15 patients received 1.0 mg cilazapril once daily for the next 6 weeks. Exercise tolerance, neurohumoral factors and ejection fraction were measured in OMI patients before and after administration of cilazapril. Seven age-matched healthy adults served as the controls. OMI patients had latent heart failure because their exercise tolerance values and aldosterone levels were lower and alpha-atrial natriuretic polypeptide levels were higher than those in healthy subjects. In OMI patients, 8 weeks after cilazapril administration, exercise duration increased from 545 +/- 59 to 590 +/- 74 sec (p < 0.05), anaerobic threshold from 17.5 +/- 3.2 to 20.1 +/- 2.8 ml/min/kg (p < 0.05), peak-VO2 from 23.5 +/- 4.7 to 27.1 +/- 4.4 ml/min/kg (p < 0.05), plasma renin activity from 1.34 +/- 1.13 to 5.82 +/- 5.47 ng/ml/hr (p < 0.01) and alpha-atrial natriuretic polypeptide decreased from 100.7 +/- 44.3 to 80.5 +/- 28.0 pg/ml (p < 0.05). In patients with asymptomatic left ventricular dysfunction after myocardial infarction, 8 week's cilazapril administration improved exercise tolerance and neurohumoral conditions.

Normalization of insulin resistance in non-obese essential hypertension by cilazapril treatment

To determine whether ACE inhibitor other than captopril improves insulin sensitivity in patients with essential hypertension, we measured insulin sensitivity to glucose utilization using SSPG method in 10 lean hypertensive subjects before and after chronic cilazapril treatment (1.5 +/- 0.2 mg/day, 15.6 +/- 2.1 weeks). The results were compared with those obtained in 10 healthy control subjects. SSPG obtained by insulin sensitivity test was significantly higher in hypertensive subjects, indicating a lower insulin sensitivity than in controls. After cilazapril treatment, SSPG reduced significantly to the level which was statistically not different from control subjects. Hyperinsulinemia diminished after treatment, while no significant change of blood glucose was observed during oral glucose tolerance test in hypertensive subjects. Plasma HDL cholesterol increased by cilazapril treatment. Cilazapril treatment has beneficial effect in the reversal of insulin resistance in patients with essential hypertension.

Effects of cilazapril on renal haemodynamics and function in hypertensive patients: a randomised controlled study versus hydrochlorothiazide

In this study the efficacy and safety of short-term cilazapril administration on renal haemodynamics were evaluated in mild to moderate hypertensive subjects. Our final goal was to evaluate whether the reduction in blood pressure achieved by treatment was associated with maintained renal function. After a run-in period with placebo, 40 hypertensive subjects without renal or cardiac diseases were randomly allocated to a double-blind 4 week controlled trial with cilazapril 5 mg once a day (20 patients) or hydrochlorothiazide 25 mg once a day (20 patients). Renal haemodynamics measurements included effective renal plasma flow (ERPF) and glomerular filtration rate (GFR) by radionuclide study using 131I-hippuran and 99mTc, according to the methods described by Schlegel and Gates, respectively. Effective renal blood flow [ERBF = ERPF/(1-Ht)], filtration fraction (FF = GFR/ERPF) and renal vascular resistance (RVR = MBP x 80/ERBF) were calculated. At the end of cilazapril and hydrochlorothiazide administration significant decreases (p < 0.001) in SBP, DBP and MBP vs baseline values were observed. In the cilazapril group a significant decrease (p < 0.001) in RVR and FF and a significant increase (p < 0.001) in ERPF and ERBF were also found. In the hydrochlorothiazide group a significant decrease (p < 0.001) in RVR was found. No important side effects were observed with either treatment. In conclusion our data indicate that both cilazapril and hydrochlorothiazide reduced blood pressure equally well but only cilazapril improved renal blood flow and reduced filtration fraction.

Diuretic effect of cilazapril and dopamine system in the spontaneously hypertensive rat

To assess the role of the kidney dopamine system on the diuretic state induced by angiotensin-converting enzyme (ACE) inhibitors, we examined the changes in urinary excretion and plasma level of dopamine, and kidney dopamine receptors in spontaneously hypertensive rats (SHR) treated with cilazapril, an ACE inhibitor. We administered cilazapril 10 mg/kg orally to 13-week-old SHR daily for 21 days (CILAZA group). Systolic blood pressure was significantly decreased in the CILAZA group on Day 6 compared with that in vehicle-treated SHR (control group). The urine volume was three- to fivefold higher in the CILAZA group, and total urinary dopamine secretion was also increased compared with the control group. There was no significant difference in affinity and number of kidney dopamine receptors between the CILAZA and the control groups. In conclusion, the diuretic effect caused by cilazapril is partly mediated by inhibition of the water reabsorption via the increase of dopamine production in the kidney.

Effect of cilazapril on vascular restenosis after percutaneous transluminal coronary angioplasty

BACKGROUND

In experimental studies using cilazapril, the strongest inhibition of neointima formation was obtained when treatment was initiated 6 days before injury. The MERCATOR trial showed no reduction in restenosis with cilazapril given after percutaneous transluminal coronary angioplasty (PTCA). The purpose of this study is to determine whether previous administration of cilazapril could prevent restenosis.

METHODS

A total of 167 patients were randomly and prospectively assigned to the cilazapril group or the control group. In the cilazapril group, 78 patients received a 2 mg dose of cilazparil daily, starting 7 days before PTCA and continuing for 6 months. Only 128 patients (cilazapril 56, control 72) completed the study because 39 dropped out. Coronary angiograms were evaluated by the quantitative coronary angiogram (QCA) system.

RESULTS

There were no differences between the two groups of patients with regard to baseline clinical and angiographic characteristics. QCA analysis (cilazapril 66 lesions, control 101 lesions): the loss at follow-up in minimal lumen diameter was 0.36 +/- 0.57 mm in the cilazapril group and 0.57 +/- 0.75 mm in the control group (P < 0.05). Restenosis rate: in the cilazapril group, 16 of 56 patients (28.6%) had restenosis in contrast to 36 of 72 patients (50.0%) in the control group (P < 0.02). When vessel restenosis was evaluated, 16 of 63 vessels (25.4%) demonstrated restenosis in the cilazapril group, in contrast to 41 of 82 vessels (50.0%) in the control group (P < 0.01).

CONCLUSIONS

Treatment using cilazapril 7 days before PTCA significantly reduced the rate of restenosis. These data suggest that previous administration of cilazapril might be important for preventing restenosis.

Effects of long-term cilazapril treatment on glucose and lipid metabolism in hypertensive patients with non-insulin-dependent diabetes mellitus

The effects of long-term cilazapril treatment on glucose and lipid metabolism were assessed in 25 hypertensive patients with non-insulin-dependent diabetes mellitus (NIDDM). Patients were treated with 0.5 to 1 mg of cilazapril once daily or a combination of cilazapril and other antihypertensive drugs once daily for 48 weeks. Both systolic and diastolic blood pressures were significantly reduced (P < 0.001) throughout the study with no significant changes in heart rate and no adverse effects such as cough. There were no significant changes in body mass index or serum levels of glycated hemoglobin A1c, fructosamine, total cholesterol, triglycerides, lipoproteins (high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and very-low-density lipoprotein cholesterol), or apolipoproteins (apo A-I, apo C-II, apo C-III, apo B, and apo E). Cilazapril caused a significant increase (P < 0.05) in levels of apo A-II and a significant decrease (P < 0.05) in the apo B:apo A-I ratio, an index of arteriosclerosis. These results suggest that cilazapril has favorable effects on glucose and lipid metabolism and that it may be useful as the first or second choice of antihypertensive drugs in hypertensive patients with NIDDM.

Transforming growth factor-beta 1 expression and phenotypic modulation in the kidney of hypertensive rats

We have previously reported that renal mRNA levels for transforming growth factor-beta 1, fibronectin, and collagens were increased in 32-week-old stroke-prone spontaneously hypertensive rats (SHRSP) with severe nephrosclerosis. To elucidate the mechanism of hypertension-induced nephrosclerosis, we examined gene expression and localization of transforming growth factor-beta 1 and cellular phenotype in the kidney of 25-week-old SHRSP with moderate renal damage. Renal mRNA was measured by Northern blot analysis. The localization of transforming growth factor-beta 1 and cellular phenotype was determined by immunohistochemistry. In the kidney of 25-week-old SHRSP, renal transforming growth factor-beta 1 mRNA was elevated compared with Wistar-Kyoto rats (WKY), whereas renal collagen mRNAs of SHRSP were not increased. Immunoreactive transforming growth factor-beta 1 in SHRSP was mainly localized in glomerular cells. Furthermore, alpha-smooth muscle actin and desmin were significantly expressed in SHRSP glomerular cells, in contrast to negligible expression of these proteins in WKY. alpha-Smooth muscle actin staining was also observed in interstitial cells, and vimentin, another phenotypic marker, was expressed in atrophic tubular cells of SHRSP, despite no staining of these proteins in WKY. Furthermore, all these phenotypic changes in SHRSP were associated with increased cell proliferation, as shown by the increased number of proliferating cell nuclear antigen-positive cells. Treatment of SHRSP with cilazapril and nifedipine (from the age of 13 to 25 weeks) prevented the increase in transforming growth factor-beta 1 expression and the cellular phenotypic modulation and was accompanied by a reduction of urinary albumin excretion and inhibition of cell proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of effects of angiotensin I-converting enzyme inhibition and beta-blockade for 2 years on function of small arteries from hypertensive patients

The effect of treatment with two different antihypertensive agents on the function of small arteries from 17 patients with essential hypertension randomly assigned to receive either the angiotensin I-converting enzyme inhibitor cilazapril or the beta-blocker atenolol was investigated. Subcutaneous small arteries obtained from gluteal fat biopsies were studied on a wire myograph before treatment and at 1 and 2 years of treatment. Blood pressure was mildly elevated in both groups of patients (mean, 150/100 mm Hg) and was well controlled throughout the 2 years of treatment (mean, 130/85 mm Hg). We previously reported, in arteries from patients treated with cilazapril, an improvement at 1 year of treatment of the vasoconstrictor effect of endothelin-1, which had been significantly attenuated in the untreated hypertensive patients compared with normotensive subjects. After 2 years of treatment, this normalization of endothelin-1 response was still present in small arteries of patients treated with the angiotensin I-converting enzyme inhibitor, whereas in patients treated with atenolol, responses were still unchanged after 2 years of treatment. Endothelial function was tested by examining the response of norepinephrine-precontracted arteries to acetylcholine. Untreated hypertensive patients exhibited a slightly but significantly blunted vasorelaxation in response to 10 mumol/L acetylcholine compared with normotensive subjects. After 1 and 2 years of effective antihypertensive treatment, cilazapril-treated patients exhibited responses to acetylcholine that were not different from those of normotensive subjects, whereas atenolol-treated patients still had impaired responses.(ABSTRACT TRUNCATED AT 250 WORDS)

ACE inhibition preserves renal function better than beta-blockade in the treatment of essential hypertension

Antihypertensive treatment can slow down the decline in glomerular filtration rate (GFR) with time. In patients with diabetic nephropathy, angiotensin converting enzyme (ACE) inhibition has been shown to be more effective in this regard than conventional antihypertensive therapy. Whether this applies to the much larger population of patients with essential hypertension is not yet known. In the present study, the effects of two different antihypertensive therapies on the loss of GFR with time, determined with Cr51-EDTA clearance after 6, 12 and 24 months of treatment, were assessed in a prospective, randomised, double-blind trial in 257 patients with essential hypertension. All had normal renal function and none had diabetes mellitus or glucosuria. Proteinuria (dipstick positive or trace) was detected in 7 patients initially. The two therapeutic modalities were the ACE inhibitor cilazapril and the beta-adrenoceptor blocking agent atenolol. Both therapies were equally effective in lowering systolic blood pressure (e.g. from 168 mmHg to 152 mmHg with cilazapril and from 170 mmHg to 155 mmHg with atenolol after 6 months, p < 0.001 for both). However, atenolol was slightly but significantly more effective in lowering the diastolic blood pressure at 6, 12 and 24 months. The decline in GFR with time was significantly smaller with cilazapril than with atenolol. After 6 months the reduction in GFR was 1.0 vs. 4.0 ml/min x 1.73 m2, p = 0.008 (cilazapril vs. atenolol) and after 12 months the corresponding changes were 2.0 vs. 4.5 ml/min x 1.73 m2, p = 0.04 and after 24 months 3.0 vs. 4.0 ml/min x 1.73 m2, respectively (n.s.).(ABSTRACT TRUNCATED AT 250 WORDS)