Effect Of Ramipril Research Articles

Sub-Antihypertensive Doses of Ramipril Normalize Sarcoplasmic Reticulum Calcium ATPase Expression and Function following Cardiac Hypertrophy in Rats

We examined the hypothesis that the angiotensin converting enzyme inhibitor ramipril at sub-antihypertensive concentrations could improve sarcoplasmic reticulum (SR) CaATPase expression and function in compensated hypertrophied rat hearts. Five weeks after abdominal aortic constriction, rats received a daily dose (50μg/kg/day) of ramipril or vehicle for 4 weeks. Cardiac angiotensin-converting enzyme (ACE) activity increased with cardiac hypertrophy (CH) but returned to normal following ramipril treatment. SR CaATPase protein levels and activity decreased with CH (P<0.05) and were normalized following ramipril treatment (P<0.05 for protein and activity). No change in phospholamban (PLB) protein levels could be demonstrated between any of the groups. In contrast, ramipril treatment specifically increased control SR CaATPase and PLB mRNA levels by >60% (P<0.01) and >30%, respectively. In the hypertrophied group, SR CaATPase increased by 35% (P<0.05n=6) after ramipril treatment. Calsequestrin mRNA levels were unaffected by ramipril administration. In conclusion, ramipril normalizes SR CaATPase protein expression and function in pressure-overloaded and compensated CH. The effects of ramipril are however multifaceted, affecting RNA and protein expression differentially.

Effect of Ramiprilat or Captopril on Myocardial Infarct Size: Assessment in Canine Models of Ischemia Alone and Ischemia with Reperfusion

Cardioprotective effects of the angiotensin-converting enzyme inhibitors captopril and ramiprilat were studied in two in vivo canine models of myocardial ischemic injury: 90 min of regional ischemia with 18 h reperfusion (protocol I) and 6 h of continuous ischemia without reperfusion (protocol II). In protocol I, neither ramiprilat (50 µg/kg) nor captopril (5 mg/kg + 0.25 mg/kg/h) reduced infarct size after 18 h of reperfusion (vs. controls). In protocol II, drugs were administered directly into both left anterior descending coronary artery and left circumflex branch. Compared to controls, continuous intracoronary administration of ramiprilat (40 ng/kg/min) or captopril (400 ng/kg/min) did not reduce infarct size. Thus neither captopril nor ramiprilat protected the heart from injury under conditions of ischemia with reperfusion or ischemia without reperfusion.

Effect of Ramipril After Acute Myocardial Infarction in Patients With Arterial Hypertension

Effect of Ramipril After Acute Myocardial Infarction in Patients With Arterial Hypertension

Role of Kinins in the Renoprotective Effect of Angiotensin–Converting Enzyme Inhibitors in Experimental Chronic Renal Failure

The aim of this study was to investigate whether the renoprotective effect of angiotensin–converting enzyme inhibitors (ACEIs) following 5/6 renal mass reduction is due in part to the potentiation of kinins. Three groups of rats with 5/6 renal mass reduction were studied during the 14 weeks following surgery. One group received no therapy (control); the second group was treated from the beginning with the ACEI ramipril (1 mg/kg/day) added to the drinking water, and the last group received ramipril plus a β₂–bradykinin antagonist, HOE 140 (500 μg/kg/day) via osmotic minipumps. Plasma creatinine did not change in any group during the study. Urinary protein excretion rose in the controls from 9.18±1.6 to 45.0±5.6 mg/24 h at the end of the study. In ramipril group proteinuria was prevented (initial 7.5±1.0 and final 8.6±0.8 mg/24h). The effect of ramipril was abolished by HOE 140 (initial 11.6±2.0 and final 38.9±11 mg/ 24h). The systolic blood pressure of the controls increased from 106±2 to 144±5mmHg at the 14th week. Ramipril abolished the increase in systolic blood pressure. The effect of ramipril was reverted by HOE 140 (initial 108±2 and final 140±9 mmHg). Control rats had more severe histopathologic changes. Those animals receiving ramipril + HOE 140 displayed less severe glomerular changes, while rats treated only with ramipril had mild alterations. Thus the glomerular injury score was 2.11±0.32 for controls, 1.53±0.52 for rats treated with ramipril + HOE 140, and 0.06±0.04 for rats treated only with ramipril. The glomerular area was 20,886±1,410, 19,693±2,200 and 14,352±3,200 μm², respectively, for the 3 groups. These results suggest that the protective effect of ACEIs in the development of chronic renal failure is partially mediated by kinins.

Nephroprotection by long-term ACE inhibition with ramipril in spontaneously hypertensive stroke prone rats

The effect of life-long treatment with the ACE inhibitor ramipril on hypertension-induced histological changes in the kidney was tested in stroke-prone spontaneously hypertensive rats (SHR-SP). One-month-old pre-hypertensive SHR-SP were randomized into three groups of 45 animals each, and exposed via drinking water for their lifetime to a dose of: 1 mg.kg-1.d-1 ramipril (antihypertensive dose, HRA); 10 micrograms.kg-1.d-1 slight dose of ramipril (non-antihypertensive dose, LRA); or placebo. Histological and biochemical assessments were conducted after 15 months in ten rats each, when about 80% of the placebo group had died. Kidneys from placebo treated SHR-SP showed pronounced arterial wall hypertrophy and sclerosis, arterial fibrinoid necrosis, glomerulopathy and tubular interstitial injury that were, in concert with normalized blood pressure, completely prevented by HRA treatment. LRA treatment did not affect any blood pressure increase, and also attenuated the development of arterial wall hypertrophy, sclerosis and arterial fibrinoid necrosis, though to a minor extent only, but did not change glomerular and tubulointerstitial degeneration. These effects of ramipril were associated with a dose-dependent inhibition of plasma and renal tissue ACE activities as well as lower serum concentrations of creatinine, but there were no changes in serum potassium. Life-long HRA-induced ACE inhibition protects against hypertension-induced renal damages in SHR-SP. This is associated with a doubling of the lifespan in these animals.

The Angiotensin Converting Enzyme Inhibition Post Revascularization Study (APRES): Effects of Ramipril in Patients with Reduced Left Ventricular Function. Rationale, Design, Methods, Baseline Characteristics and First-Year Experience

Invasive revascularization improves prognosis, functional status and quality of life in patients with severe angina pectoris and impaired left ventricular function, and treatment with ACE-I reduces the development of cardiac events and left ventricular dysfunction in patients without or with mild angina pectoris. However, the effects of a combined treatment strategy with invasive revascularization and subsequent long-term ACE-I therapy in patients with limiting angina pectoris and impaired left ventricular function have not previously been investigated. APRES is a long-term, prospective, randomized double-blind study that evaluates the effects of ramipril 10 mg o.d. on the long-term development of cardiac events, left ventricular function, functional status and quality of life following invasive revascularization in patients without recent AMI or clinical heart failure and with preoperative ejection fraction in the range 0.30-0.50. The rationale, design and power of APRES and the choice and relevance of outcome measures are discussed. Based on experience and results from the first year of the study for screening procedure, inclusion rate, patient compliance, reproducibility analyses and the magnitude of outcome measures, we conclude that the study is feasible and safe. The included patients match with the target population, the outcome measures seem appropriate and the power considerations valid for the majority of the outcome measures.

Effect of ramipril after acute myocardial infarction in patients with arterial hypertension

Effect of ramipril after acute myocardial infarction in patients with arterial hypertension

Effect of Ramipril on Mitral Regurgitation Secondary to Mitral Valve Prolapse

Ramipril 10 mg/day reduced regurgitation in chronic mitral regurgitation secondary to mitral valve prolapse in patients with sinus rhythm.

D119 Chronic effects of ramipril and nitrendipine on albuminuria in diabetic hypertensive patients with impaired renal function

D119 Chronic effects of ramipril and nitrendipine on albuminuria in diabetic hypertensive patients with impaired renal function

Effect of neutral endopeptidase 24.11 inhibition on myocardial ischemia/reperfusion injury: the role of kinins.

Angiotensin-converting enzyme inhibitors (ACEi) protect the heart against ischemia/reperfusion injury. Part of this cardioprotective effect may be mediated through kinins. Because kinins are also metabolized by neutral endopeptidase (NEP) 24.11 in vivo, we hypothesized that (a) inhibition of NEP-24.11 would afford cardioprotection similar to that of ACEi and potentiate the effect of ACEi; and (b) these effects are mediated by kinins or atrial natriuretic peptide (ANP) or both. In Lewis inbred rats, the left anterior descending coronary artery (LAD) was occluded for 30 min, followed by 120-min reperfusion. Immediately before reperfusion rats received vehicle, the ACEi ramiprilat, the NEP-24.11 inhibitor (NEPi) CGS24592, or both. To test whether the effect of NEPi could be suppressed by blocking kinins or ANP, the kinin-receptor antagonist icatibant or ANP antagonist HS-142-1 was administered before LAD occlusion. In controls, infarct size/risk area was 69 +/- 4%; NEPi reduced this to 24 +/- 4% (p < 0.001) and ramiprilat to 20 +/- 3% (P < 0.001). NEPi did not potentiate the effect of ramiprilat (infarct size/risk area, 18 +/- 4%). The protective effect of NEPi was blocked by icatibant; infarct size/risk area, 61 +/-4%, significantly larger than NEPi along (p < 0.001) but no different from controls. The effect of NEPi was slightly diminished by the ANP antagonist HS-142-1 (infarct size/risk area, 35 +/- 3%; NS vs. NEPi alone). Thus NEP-24.11 participates in catabolism of kinins in the heart; inhibition of NEP-24.11 may increases cardiac kinins, which are responsible for the cardioprotective effect of NEPi.

Modulation of Myocardial Oxygen Consumption Through ACE Inhibitors

In this issue of Circulation ,1 Zhang and coworkers provide convincing evidence that ACE inhibitors reduce myocardial oxygen consumption by preventing the degradation of bradykinin, which subsequently stimulates the release of nitric oxide (NO). They propose that NO inhibits mitochondrial respiration, thus reducing myocyte oxygen use. This is an exciting observation because it provides a new mechanism whereby ACE inhibitors might benefit ischemia beyond simply inhibiting the formation of angiotensin II, thus reducing the vasoconstrictor effect of this octapeptide. These results are further evidence for a role of bradykinin in the response of tissues to ACE inhibitors. The mechanism enabling these interactions to occur is coming to light on the basis of studies such as the current one from Zhang et al. Interest in bradykinin and related kinins as cardiovascular mediators has grown tremendously in the past several years, largely because it has been recognized that they potently stimulate release of NO and prostacyclin from endothelial cells. Bradykinin and Lys-bradykinin, respectively, are formed when one of a family of enzymes, known as kallikreins, act on either heavy- or low-molecular-weight kininogens.2 This action involves cleavage of amino acids from both the C- and N-terminal ends of the kininogen peptides and takes place both in plasma (for heavy-molecular-weight kininogen) and tissues (for low-molecular-weight kininogen). The kininogens were previously thought to be expressed primarily by hepatocytes; however, it is now clear that many tissues, including vascular cells3 4 and the heart,5 also express kininogens. The kallikreins as well are made by many cell types and are produced by vascular cells in a continuous fashion.6 Thus, many tissues, including the heart and vascular cells, have an intact kallikrein/kininogen system capable of producing bradykinin. The mechanisms whereby bradykinin production is regulated remain unclear; however, there is some evidence that flow …

Early administration of ramipril in acute myocardial infarction: neurohormonal and hemodynamic effects and tolerability.

Although several large studies indicate a beneficial effect of angiotensin-converting enzyme (ACE) inhibitors after myocardial infarction, the optimal timing of therapy in terms of safety and the effects on neurohormones during myocardial infarction are less well known. In order to investigate the effect of ramipril, administered within 24 h after myocardial infarction, on hemodynamics and neurohormones and its safety, 20 patients with a myocardial infarction were studied. Nine patients had an anterior, 10 an inferior, and 1 a non-Q-wave infarction. Fourteen patients received thrombolytic therapy, whereas 6 did not. The initial dose of ramipril was 1.25 mg, but was gradually increased to 5 mg during the next 4 days. Side effects did not occur. The mean arterial pressure decreased 8 h after the first dose from 84 +/- 2 mm Hg (control) to 77 +/- 2 mm Hg (p < 0.05) and remained decreased thereafter. This was accompanied by a reduction in systemic resistance of 8% after 8 h and of 12% on day 2. Heart rate, cardiac and stroke indexes, and pulmonary artery and wedge pressures did not change. The ACE activity decreased within 1 h of ramipril administration with a maximum of 71% at 4 h after the second dose and remained at this level throughout the study. Angiotensin II decreased by 34% (day 2) and by 41% (day 5). The renin activity gradually increased from 33 +/- 7.5 to 75.4 +/- 11.5 microM/ml on day 5, whereas epinephrine was reduced from day 2 onwards, with a maximal reduction of 71% on day 5. Arginine vasopressin was significantly reduced 5 h after ramipril administration until the end of the study, with a maximum of 77% on day 3. Moreover, a late but significant decrease in norepinephrine occurred on day 5. Thus, oral ramipril results in early ACE inhibition, followed by progressive attenuation of the neuroendocrine activation and a reduction in afterload during the acute phase of myocardial infarction. It is well tolerated, also in combination with nitroglycerin and thrombolytic therapy.

Effect of ramipril on morbidity and mode of death among survivors of acute myocardial infarction with clinical evidence of heart failure

The importance of the effects of ACE inhibitors on sudden death, progressive heart failure and recurrent infarction to the reduction in overall mortality in heart failure and after myocardial infarction is disputed. The AIRE study randomized 2006 patients with clinical or radiological evidence of heart failure within 2-9 days of a myocardial infarction to receive ramipiril 5 mg b.d. or matching placebo. Outcomes were assessed independently by members of an end-points committee blinded to treatment allocation. Fewer patients developed severe resistant heart failure as their first validated end-point on rampril, despite the greater number of at-risk survivors, compared to placebo (n = 143 vs 178; risk reduction 23%; CI 5 to 39%; P = 0.017). Ramipril did not alter the rate of reinfarction or stroke. Irrespective of treatment allocation 182 (46%) patients developed resistant heart failure prior to death. A validated acute or remote myocardial reinfarction occurred in 76 (19%) patients prior to death and chest pain occurred in 90 (23%) patients around the time of death suggesting an ischaemic element to these deaths Eighty deaths occurred on the index admission, 167 during re-admission and 145 out-of-hospital. Sudden death accounted for 54% of all deaths and 93% of out-of-hospital deaths. Ramipril reduced the risk of sudden death by 30% (95% CI: 8-47%; P = 0.011). However, overall, 45% of those patients who died suddenly had severe or worsening heart failure prior to their death. Only 39% of sudden deaths were considered to be due to arrhythmias. Ramipril reduced the risk of death from circulatory failure by 18%, but this did not reach statistical significance (95% CI; 41 to -14%; P = 0.237). The magnitude of the effects on sudden death and death due to circulatory failure were not significantly different. However, 38% of the reduction in overall mortality was from the subgroup with sudden death who had developed prior severe resistant heart failure (placebo n = 35, ramipril n = 15), again emphasizing the marked benefit in preventing failure. Ramipril did not selectively alter the proportion of in- to out-of-hospital deaths. Ramipril reduces mortality and progression to resistant heart failure among patients with evidence of heart failure early after myocardial infarction. Retarding the progression of heart failure appears to be a major factor contributing to the reduction in mortality both by reducing circulatory failure and by reducing sudden death.

Effect of ramipril on heart rate variability in digitalis-treated patients with chronic heart failure.

The aim of this study was to evaluate the effect of an angiotensin-converting enzyme (ACE) inhibitor, ramipril, on heart rate variability in patients with heart failure simultaneously treated with digitalis. This study was a multicentric, randomized, double-blind, placebo-controlled study including 50 patients with chronic heart failure (CHF). All patients were in NYHA functional class II and III. The etiology of CHF was mainly idiopathic dilated cardiomyopathy and ischemic heart disease. After a 4-week placebo run-in period with digoxin and diuretics, patients were randomized to receive additional ramipril or placebo. To assess heart rate variability (HRV) and arrhythmias, 24-hour ECGs were recorded at the end of the placebo run-in period, 8 and 24 weeks after randomization. Spectral analysis of HRV was performed during one diurnal and one nocturnal 5-minute time period. No statistically significant differences in HRV within low-, high-, and total-frequency bands were induced by ramipril in either the diurnal or nocturnal periods, both at 8 and 24 weeks after randomization. Ramipril produced a significant decrease in nonsustained ventricular tachycardia at 24 weeks of treatment (p = 0.01). These results run against previous observations showing an increase in parasympathetic tone with ACE inhibitors in heart failure. The present study thus suggests that the effects of ACE inhibitors in CHF are variable and depend on the patient and concomitant treatment that might influence HRV such as digoxin treatment.

A comparison of the effect of ramipril, felodipine and placebo on glomerular filtration rate, albuminuria, blood pressure and vasoactive hormones in chronic glomerulonephritis A randomized, prospective, double-blind, placebo-controlled study over two years

The effects of an ACE-inhibitor (ramipril), a calcium antagonist (felodipine) and placebo on glomerular filtration rate (GFR), urinary albumin/creatinine ratio, blood pressure (BP) and vasoactive hormones were investigated in a randomized, prospective, double-blind, placebo-controlled study of patients with chronic glomerulonephritis and hypertension, with measurements at entrance and after 12 and 24 months. In total, 33 patients were included: 21 completed the study with 7 patients in each group. GFR was measured as 51Cr-EDTA clearance and the vasoactive hormones with radioimmunoassays. The reduction in GFR was significantly more pronounced in the felodipine group (-7 ml/min) than in the ramipril group (0 ml/min) but the same as in the placebo group (-6 ml/min). The urinary albumin/creatinine ratio was significantly more reduced in the ramipril group (-74 mg/mmol) than in the placebo group (-11 mg/mmol), which did not deviate from the felodipine group (-10 mg/mmol). BP was significantly reduced by ramipril and felodipine, but not by placebo. Angiotensin II and aldosterone in plasma increased or tended to increase in the felodipine and placebo groups, but were unchanged in the ramipril group. Endothelin increased only in the placebo group, and vasopressin, atrial natriuretic peptide, and brain natriuretic peptide were not significantly changed in any of the groups. It is concluded that ramipril seems to be superior to felodipine in chronic glomerulonephritis owing to better preservation of GFR.

Meta-analysis of morbidity and mortality in five exercise capacity trials evaluating ramipril in chronic congestive cardiac failure

In 5 separate exercise capacity trials in similar patients with chronic congestive heart failure performed in Europe, the United States, and South Africa, 627 patients were randomized to ramipril and 428 to placebo. The dose of ramipril ranged from 1.25 to 20 mg/day. Follow-up was at 12 or 24 weeks. None of the trials were designed to assess efficacy with regard to clinical out-come. To assess in the combined experience whether there was an effect of ramipril on mortality, hospitalization, functional classification (New York Heart Association class), and exercise capacity, we pooled data from each trial and performed a meta-analysis. Of the patients randomized to ramipril and placebo, respectively, and based on intention to treat, 14 (2.2%) and 18 (3.8%) patients died (odds ratio 0.60, 95% confidence interval 0.28 to 1.29), and 59 (9.4%) and 67 (14.3%) patients died or were hospitalized (odds ratio 0.68, 95% confidence interval 0.46 to 1.00). The New York Heart Association class improved in 29% and 25%, respectively, whereas 8% and 15% deteriorated (p = 0.04, based on intention to treat; death and hospitalization considered as deterioration). In ranked comparisons based on intention to treat and with imputation of exercise time as 0 for patients who were unable to exercise because of death or who were hospitalized, exercise capacity was significantly improved by ramipril. We conclude that ramipril is likely to have an effect on mortality, morbidity, and functional capacity in patients with chronic congestive heart failure similar to that of other angiotensin-converting enzyme inhibitors.

Effect of ramipril, nifedipine, and moxonidine on glomerular morphology and podocyte structure in experimental renal failure

Effect of ramipril, nifedipine, and moxonidine on glomerular morphology and podocyte structure in experimental renal failure

Effect of ramipril, nifedipine, and moxonidine on glomerular morphology and podocyte structure in experimental renal failure

Experimental renal failure causes structural alterations of the kidney. It is still unresolved how these changes are modified by antihypertensive treatment. Purpose of the study. To examine the effects of different antihypertensive agents (ramipril, nifedipine, moxonidine) mainly on glomerular geometry, cell number, cell morphology, and capillarization, in a subtotal nephrectomy model of renal failure. Sham-operated male SD rats and subtotally nephrectomized (SNX) ad libitum-fed rats were examined. Groups of 8-10 SNX rats were left untreated or were treated with ramipril (0.5 mg/kg b.w. per day), nifedipine (20 mg/kg b.w. per day) or moxonidine (10 mg/kg b.w.per day) respectively. After perfusion fixation the kidneys were examined using stereological techniques. Systolic blood pressure (by tail plethysmography) was 110+/-13 mm Hg in sham-op and 119+/-9 in SNX. It was effectively and comparably reduced below normal values by ramipril (89+/-11 mmHg), nifedipine (98+/-23 mmHg) and moxonidine (92+/-11 mmHg). The glomerulosclerosis index (SI) was significantly increased in SNX versus sham-op; it was similarly decreased by ramipril and moxonidine but less so by nifedipine. Vascular damage (preglomerular vessels) was reduced by all treatments whereas tubulointerstitial damage was signficantly reduced only by ramipril and moxonidine. Mean glomerular tuft volume was increased in SNX compared to sham-op. controls and was normalized only by ramipril treatment. Glomerular cells were differentially affected the three antihypertensive agents. After subtotal nephrectomy an increase in podocyte volume and mesangial cell number per glomerulus was noted. Nifedipine, and to a lesser extent ramipril, prevented mesangial cell hyperplasia. In contrast, only the ACE inhibitor ramipril, but not nifedipine or moxonidine prevented podocyte abnormalities, particularly podocyte hypertrophy. (i) Despite comparable reduction in systolic blood pressure, different classes of antihypertensive agents had diverse effects on renal damage in subtotally nephrectomized rat. This observation is consistent with specific, non-hemodynamic actions of anti-hypertensives. (ii) Glomerular and tubulointerstitial damage are prevented by treatment with ACE inhibitors and antisympathotonic agents, but not with the calcium antagonist nifedipine. In contrast, renal vascular changes were also prevented by nifedipine. (iii) Only ACE inhibitors effectively inhibited podocyte hypertrophy and mesangial cell hyperplasia. Whether the superior effect of ACE inhibitors on glomerulosclerosis is related to inhibition of glomerular growth and podocyte hypertrophy as well as preservation of podocyte structure, or whether these findings are merely a passive reflection of greater efficacy, remains unresolved.

Long term effects of ramipril and nitrendipine on albuminuria in diabetic hypertensive patients with impaired renal function.

Long term effects of ramipril and nitrendipine on albuminuria in diabetic hypertensive patients with impaired renal function.

Chronic Kinin Blockade and Effect of Ramipril in Renal Adaptation to Sodium Restriction

The contribution of endogenous kinins to impairment in renal adaptation to a 6-day period of dietary sodium withdrawal associated with treatment with ramipril (5 mg/kg per day) and losartan (30 mg/kg per day) was evaluated by use of concomitant chronic administration of the bradykinin B2-receptor antagonist Hoe 140 (150 or 300 micrograms/kg per day via subcutaneous osmotic pump). A similar level of higher cumulative sodium excretion was observed in ramipril- and losartan-treated rats compared with untreated animals, and the effect of ramipril was not affected by Hoe 140. Similarly, the fall in arterial pressure and the renal vasodilatation associated with ramipril and losartan were not modified by Hoe 140. Glomerular filtration rate (785 +/- 73 microL/min per g KW in untreated sodium-depleted rats) decreased to a larger extent in ramipril-treated rats compared with losartan-treated rats (371 +/- 78 and 550 +/- 55 microL/min per g KW, respectively). Hoe 140 markedly prevented the alteration in glomerular filtration rate associated with ramipril, thus resulting in a final glomerular filtration rate (543 +/- 41 microL/min per g KW) similar to that observed with losartan. These findings demonstrate that despite a lack of influence on arterial pressure and sodium balance, accumulation of kinins markedly contributes to deterioration of the glomerular filtration rate induced by ramipril in sodium-depleted rats.