Effects of the angiotensin II antagonist losartan on endothelin-1 and norepinephrine plasma levels during cold pressor test in patients with chronic heart failure

Investigating the seasonal variation of heart failure hospitalizations and in-hospital mortality risks in Japan using a nationwide database

BACKGROUND

Studies have reported seasonal variations in heart failure (HF) hospitalizations and mortality that are observed to peak in the winter, although many of these studies are from Europe or the USA. However, some studies on non-US patients have reported contrasting results. We aimed to determine whether seasonal variation exists in hospitalizations due to HF, investigate the risk of death during hospitalization, and examine possible contributors to such variability in Japan.

METHODS

This study was an exploratory analysis of our previous report, which included 269,636 hospitalizations due to HF between 2008 and 2018. The monthly hospitalization rate for HF was evaluated using a linear regression model with April as the reference month. The risk factors for in-hospital and monthly mortality were evaluated using the Cox proportional hazards model.

RESULTS

The hospitalizations due to HF were significantly higher in the winter than in the summer. The peak admission rate occurred in January, and the lowest rate occurred in July. Based on April, changes in the number of hospitalizations per month were estimated using linear multiple regression analysis (adjusted R2 = 0.911). The risk of death during hospitalization was lowest in April and gradually increased from August to October (hazard ratio, 1.18-1.21).

CONCLUSIONS

There was a significant seasonal variation in HF hospitalizations in Japan. Peak admission rates occurred in January. However, the risk of death during hospitalization was higher in August, September, and October than that in January.

Heart failure and its treatment from the perspective of sympathetic nerve activity

Heart failure is the end-stage phenotype of several cardiac diseases. The number of heart failure patients is increasing in accordance with an increase in the number of elderly people. The prognosis of heart failure is poor and its 5-year death rate is comparable to that of stage III cancer. It is important to understand the essential mechanism of the worsening prognosis of heart failure and to practice effective treatment from the perspective of improving the prognosis of heart failure based on its essential mechanism. Plasma noradrenaline level is a good predictor of the survival rate of heart failure patients, and sympathetic nerve activity is augmented in patients with heart failure as evidenced by a higher noradrenaline release rate (spillover) from the sympathetic nerve endings especially in the heart and kidney. Noradrenaline release is regulated by presynaptic receptors at the sympathetic nerve endings, and the kidney affects the sympathetic nerve activity. Although the short-term reflex augmentation of sympathetic nerve activity caused by reduced cardiac function may help to improve cardiac function, long-term augmentation of sympathetic nerve activity damages the heart and deteriorates the prognosis of heart failure. Currently, drugs such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, β-blockers, mineralocorticoid antagonists, ivabradine, angiotensin receptor-neprilysin inhibitor, and sodium-glucose transport protein 2 inhibitors, are used for the treatment of heart failure, and had a good prognosis in large randomized, controlled clinical trials. Interestingly, the same characteristics in common of these drugs is the ability to optimize excessively augmented sympathetic nerve activity. This review discusses insights into essential mechanism of heart failure that determines the prognosis of heart failure, focusing on the interaction between sympathetic nerve activity and anti-heart failure drugs currently recommended by the 2021 guidelines of the Japanese Circulation Society and the Japanese Heart Failure Society for heart failure treatment.

Increased hospitalizations for decompensated heart failure and acute myocardial infarction during mild winters: A seven-year experience in the public health system of the largest city in Latin America

BACKGROUND

In high-income temperate countries, the number of hospitalizations for heart failure (HF) and acute myocardial infarction (AMI) increases during the winter. This finding has not been fully investigated in low- and middle-income countries with tropical and subtropical climates. We investigated the seasonality of hospitalizations for HF and AMI in Sao Paulo (Brazil), the largest city in Latin America.

METHODS

This was a retrospective study using data for 76,474 hospitalizations for HF and 54,561 hospitalizations for AMI obtained from public hospitals, from January 2008 to April 2015. The average number of hospitalizations for HF and AMI per month during winter was compared to each of the other seasons. The autoregressive integrated moving average (ARIMA) model was used to test the association between temperature and hospitalization rates.

FINDINGS

The highest average number of hospital admissions for HF and AMI per month occurred during winter, with an increase of up to 30% for HF and 16% for AMI when compared to summer, the season with lowest figures for both diseases (respectively, HF: 996 vs. 767 per month, p<0.001; and AMI: 678 vs. 586 per month, p<0.001). Monthly average temperatures were moderately lower during winter than other seasons and they were not associated with hospitalizations for HF and AMI.

INTERPRETATION

The winter season was associated with a greater number of hospitalizations for both HF and AMI. This increase was not associated with seasonal oscillations in temperature, which were modest. Our study suggests that the prevention of cardiovascular disease decompensation should be emphasized during winter even in low to middle-income countries with tropical and subtropical climates.

Admission-to-discharge temperature reduction in decompensated heart failure is associated with rehospitalization

INTRODUCTION

Decreasing body temperature on first follow-up visit-relative to discharge-predicts early rehospitalization in heart failure (HF). We studied whether admission-to-discharge temperature reduction was associated with increased HF rehospitalization in the ESCAPE trial.

METHODS

We compared patients with or without ≥1 °C decrease in temperature from admission-to-discharge. The study endpoint was rehospitalization due to HF for up to 6 months after discharge.

RESULTS

Among 354 patients (average age 57 years, 73% men) with recorded admission and discharge temperature, 22 (6.2%) had an admission-to-discharge temperature reduction ≥1 ºC. Patients with admission-to-discharge temperature reduction ≥1 ºC had higher frequency of rehospitalization for HF (68.2% vs. 44.3%, estimated odds ratio [OR] 2.697, 95% confidence interval [CI] 1.072-6.787, P = 0.029) despite a significantly higher admission temperature. On multivariate analysis, admission-to-discharge temperature reduction ≥1 ºC predicted rehospitalization for HF (OR 2.02, 95% CI 1.028-3.966, P = 0.041) after adjustment for age, BMI, baseline Na, creatinine, ejection fraction and discharge NYHA class. A standard logistic model treating temperature change as a continuous variable, and a model using a restricted cubic spline, did not demonstrate a statistically significant relationship between temperature reduction and HF rehospitalization. Subsequently, an altered logistic model was fit expressing the log odds of HF rehospitalization as a piecewise linear function of temperature decrease; this model did demonstrate statistical significance (P = 0.013) with an estimated odds ratio of 1.140 per 0.1 ºC beyond 0.5 ºC.

CONCLUSION

Admission-to-discharge temperature reduction ≥1 ºC is an unfavorable prognostic sign associated with future rehospitalization due to HF.

Presentations and outcomes of patients with acute decompensated heart failure admitted in the winter season

BACKGROUND

Seasonal variations in cardiovascular disease is well recognized. However, little is known about the presentations and outcomes of Japanese heart failure (HF) patients in the winter season.

METHODS AND RESULTS

We used a single hospital-based cohort from the Shinken Database 2004-2012, comprising all new patients (n=19,994) who visited the Cardiovascular Institute Hospital. A total of 375 patients who were admitted owing to acute decompensated HF were included in the analysis. Of these patients, 136 (36%) were admitted in winter. Winter was defined as the period between December and February. The HF patients admitted in winter were older, and had a higher prevalence of hypertension and diabetes mellitus than the patients admitted in other seasons. Patients with conditions categorized as clinical scenario 1 tended to be admitted more commonly in winter. HF with preserved left ventricular ejection fraction (LVEF) was more common in HF patients admitted in winter than in those admitted in other seasons. Beta-blocker use at hospital discharge was more common in the patients admitted in other seasons. Kaplan-Meier curves and log-rank test results indicated that the incidences of all-cause death, cardiovascular death, and HF admission were comparable between the patients admitted in winter and those admitted in other seasons.

CONCLUSIONS

HF admission was frequently observed in the winter season and HF patients admitted in the winter season were older, and had higher prevalence of hypertension and diabetes mellitus, and preserved LVEF suggesting that we might need to pay more attention for elderly patients with hypertension, diabetes mellitus, and HF with preserved LVEF to decrease HF admissions in the winter season.

Effect of AT1 Angiotensin II Receptor Antagonists on the Sympathetic Response to a Cold Pressor Test in Healthy Volunteers

The aim of this study was to evaluate the effect of short-term administration of AT(1) angiotensin II receptor antagonists on the sympathetic response to a cold pressor test (CPT) in normotensive healthy volunteers. Eighty-two healthy volunteers were included in this double-blind placebo-controlled study. Blood pressure and heart rate were determined before and 175 minutes after oral administration of placebo, losartan (50 mg), valsartan (80 mg), or eprosartan (600 mg). Immediately, the subjects underwent a CPT and then the same hemodynamic parameters were measured. CPT increased arterial blood pressure (systolic, diastolic, and mean) and heart rate in the placebo-treated group. Pretreatment with a single dose of losartan, valsartan, or eprosartan blunted CPT-induced pressor response but not heart rate increase. Our results demonstrate that endogenous angiotensin II, through stimulation of AT(1) receptor, supports sympathetic-mediated stress response in humans.

The daily incidence of acute heart failure is correlated with low minimal night temperature: cold immersion pulmonary edema revisited?

BACKGROUND

Previous studies suggested a higher incidence of acute heart failure (AHF) during cold months in regions with cold climate. We examined the daily incidence of AHF by same-day trough temperature and humidity in a warmer region.

METHODS AND RESULTS

All admissions for AHF (340 patients) to a city hospital, providing the sole emergency medical care to a geographical region of approximately 500,000 people were recorded. Patients were followed through admission and for 6 months after discharge. Low minimal trough temperature was associated with an increase in the same-day AHF incidence. Lowest tercile trough night temperatures were associated with higher AHF incidence (3.5 +/- 2.1 versus 2.4 +/- 1.6, events/24 hours, P = .012). This association was mainly from increased AHF events in nights with the predetermined trough temperature of <7 degrees C (4 +/- 2.1 versus 2.5 +/- 1.7, events/24 hours, P = .0013). This association persisted even after excluding the coldest consecutive 30 days from the analysis. Humidity was not associated with increased AHF event rate. In a post-hoc analysis we have observed doubling of 6-month mortality in patients admitted with AHF during days with lower trough night temperature, despite no apparent worse baseline characteristics or disease severity at admission.

CONCLUSIONS

AHF rate is increased during days with lower trough night temperature. If confirmed, these results may have implications on issues related to climate control in houses of the elderly or patients susceptible to heart failure.

Effect of eprosartan on the sympathetic response to cold pressor test in healthy volunteers

The aim of this study was to evaluate the effect of short-term administration of the AT1 angiotensin II receptor antagonist, eprosartan, on the sympathetic response to cold pressor test (CPT) in normotensive healthy volunteers. Sixty-nine healthy volunteers were included in this double-blind placebo-controlled study. Blood pressure and heart rate were determined before and 175 min after oral administration of placebo, losartan (50 mg) or eprosartan (600 mg). Immediately, the subjects underwent CPT and then the same hemodynamic variables were measured. CPT increased arterial blood pressure (systolic, diastolic and mean) and HR in placebo-treated group. Pretreatment with a single dose of losartan or eprosartan blunted CPT-induced pressor response, but not the rise in heart rate. Our results demonstrate that endogenous angiotensin II, through stimulation of AT1 receptor, supports sympathetic mediated stress-response in humans.

Add-on and withdrawal effect of pravastatin on proteinuria in hypertensive patients treated with AT1 receptor blockers

BACKGROUND

Although angiotensin receptor antagonists and 3-hydroxy-3-methylgultaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have been shown to attenuate proteinuria individually, it remains unclear whether proteinuria may be additionally improved by statin therapy in well-controlled hypertensive patients treated with angiotensin receptor antagonists-based regimen and whether withdrawal of chronic statin treatment may abrogate this beneficial effect in normolipidemic patients.

METHODS

A total of consecutive 82 proteinuric patients treated with antihypertensive agents, including losartan, were randomized 10 mg of pravastatin or placebo with a 6-month treatment. After completing 6 months of drug treatment, the pravastatin-treated patients were randomly assigned to continue (N= 19) or withdraw (N= 17) pravastatin for a further 6 months.

RESULTS

Subjects treated with pravastatin had significant further improvement of proteinuria at 6 months compared with placebo group (559 +/- 251 mg/24 hours vs. 1262 +/- 557 mg/24 hours) (P < 0.0001). Of 17 patients assigned to withdraw pravastatin, proteinuria returned to the pretreatment levels and was significantly higher than those who continued treatment. Multivariate analysis revealed that proteinuric improvement was significantly correlated with the continuous statin use. Urinary excretion of endothelin-1 (ET-1) is decreased in pravastatin-treated patients, but withdrawal of statin resulted in 27% up-regulation. The linear regression models in the initial statin-treated group showed that changes in urinary ET-1 correlated with urinary protein excretion (r= 0.83, P < 0.0001).

CONCLUSION

We conclude that pravastatin administration is associated with improved proteinuria probably by inhibiting urine ET-1 levels in patients with losartan-based treatment. However, statin withdrawal abrogates this beneficial effect in patients initially responsive to this therapy.

Hypothermia is a bedside predictor of imminent death in patients with congestive heart failure

BACKGROUND

Most studies on predictors of mortality for patients with congestive heart failure (CHF) have described predictors that are either difficult to measure in routine practice or are only modestly sensitive and specific. Having observed 3 patients whose body temperature decreased shortly before death, we hypothesized that hypothermia may predict inhospital mortality.

METHODS

The medical records of 291 patients with a primary discharge diagnosis of CHF were selected from 423 admissions to Memorial Hermann Hospital, Houston, Tex, 1998, after excluding patients with comorbidities that confound body temperature, deaths for causes other than progressive pump failure, and readmissions except the last. Three groups were defined on the basis of admission body temperature (T adm): hypothermia groups T adm (95.5 degrees F-96.5 degrees F) and T adm < 95.5 degrees F, and reference group T adm > or = 96.6 degrees F. Several other known CHF risk factors were studied for confounding, and adjusted hazard ratios were calculated using Cox regression.

RESULTS

Of the 291 patients (mean age 73 years, 47% men), 17 (6%) had hypothermia on admission. Mean hospital stay was 5 days. Of the 17 (6%) patients who died of pump failure, 5 had been hypothermic on admission. Hypothermia was significantly associated with survival, and after adjusting for New York Heart Association functional class, hazard ratio for T adm < 95.5 degrees F was 4.46 (95% confidence interval 1.38-14.3) (P trend = .0283).

CONCLUSIONS

Hypothermia predicted inhospital death in these patients with CHF. If confirmed by future studies, this finding could prove useful, because temperature can be measured continuously, rapidly, and inexpensively, in or out of the hospital.

Seasonal variation in morbidity and mortality related to atrial fibrillation

OBJECTIVE

To determine whether there is seasonal variation in hospitalisations and deaths due to atrial fibrillation (AF) and to examine possible contributors to such variability.

METHODS

We used the linked Scottish Morbidity Record scheme, which provides individualised morbidity and mortality data for the entire Scottish population.

RESULTS

Between 1990 and 1996, there were a total of 33,582 male and 34,463 female hospitalisations related to AF. Significantly more admissions occurred in winter compared to summer (P<0.0001). In women, the peak number of admissions (106 per day) occurred in December (12% more than average) and the lowest number (89) in June (6% less than average). The respective figures for men were 10% more (101), 2% less (90). In both sexes, the greatest variation occurred in those aged >85 years-peak winter rates being 35-39% higher than average. A similar phenomenon was evident in relation to mortality in these patients. The average number of men who died during December was 22% higher, and in August 12% lower, than average, P<0.001. In women, the equivalent figures were 28% higher (December) and 14% lower (August), P<0.001. The winter peak of AF admissions did not, however, coincide with the lowest temperatures, and other factors such as seasonal variation in respiratory infection, may account for the monthly variation observed in hospitalisations for AF.

CONCLUSIONS

There is substantial seasonal variation in AF hospitalisations and deaths, particularly in the elderly.

Seasonal variation in AF-related admissions to a coronary care unit in a "hot" climate: fact or fiction?

BACKGROUND

Seasonal variations in atrial fibrillation (AF)-related morbidity and mortality have been demonstrated in "cold" northern European climates, but there are few data describing such a phenomenon in a "hot" climate.

RESEARCH OBJECTIVE

To examine the pattern of AF-related admissions to a coronary care unit (CCU) in South Australia operating within a Mediterranean climate, and to determine potential differences according to mean daily temperatures. PATIENT COHORT AND METHODS: A total of 144 admissions to the CCU during the 30 hottest and coldest days (60 days in total) during the calendar year 2001 were analyzed in respect to the absolute number of admissions and the profile of those admitted during "hot" and "cold" days.

RESULTS

Overall, there were significantly more admissions to the CCU on "cold" as opposed to "hot" days (90 vs 54 patients in 30 days, P < or = .001). Of the 24 patients found to be in AF on presentation to hospital, 18 (75%) were admitted on cold days (P < .05). Alternatively, during "hot" days, patients were more likely to be diagnosed with unstable angina rather than acute myocardial infarction (46% vs 30%, P = .07) with proportionately fewer patients in AF at the time (11% vs 20%, P = NS).

CONCLUSIONS

These preliminary data suggest that the phenomenon of seasonal variations in AF-related morbidity extend beyond colder climates to hotter climates with sufficiently large relative (as opposed to absolute) changes in ambient temperatures during the year.

Effects of Angiotensin II Type 1 Receptor Antagonist, Losartan, on Ventilatory Response to Exercise and Neurohormonal Profiles in Patients with Chronic Heart Failure

Chronic heart failure (CHF) is associated with abnormal neurohormonal profiles and increased ventilatory response to exercise. This study determined if treatment with angiotensin II type 1 receptor antagonist, losartan, improves ventilatory efficiency and neurohormonal factors in patients with CHF. Symptom-limited cardiopulmonary exercise testing was performed after a 2-week placebo period (baseline) and after 16 weeks of treatment with losartan (40 +/- 4 mg/day) in 10 patients with CHF (age 57.7 +/- 3.7 years). Echocardiogram, daily physical activity (by the specific activity scale), and neurohormones were evaluated. Treatment with losartan increased left ventricular ejection fraction (baseline vs. losartan: 31 +/- 3 vs. 39 +/- 3%, p<0.01) and specific activity scale score (5.3 +/- 0.5 vs. 6.4 +/- 0.4 METS, p<0.05). Losartan decreased the ventilatory response to carbon dioxide production during exercise (VE/VCO2 slope: 34.6 +/- 2.4 vs. 32.0 +/- 2.2, p<0.05). Plasma brain natriuretic peptide concentrations were decreased after therapy (301 +/- 79 vs. 176 +/- 53 pg/ml, p<0.05). In summary, the results of this open-label, uncontrolled study suggest that chronic treatment with losartan may improve ventilatory efficiency and decrease plasma brain natriuretic peptide concentrations with the improvement of physical activity and left ventricular systolic function in patients with CHF.

Heart failure in a cold climate. Seasonal variation in heart failure-related morbidity and mortality

OBJECTIVES

This study was done to determine whether seasonal variation exists in hospitalizations and deaths due to heart failure (HF) and to examine possible contributors to such variability.

BACKGROUND

Although seasonal variation in the incidence of acute myocardial infarction and sudden death is well recognized, it is less well documented in HF.

METHODS

We used the linked Scottish Morbidity Record scheme, which provides individualized morbidity and mortality data for the entire Scottish population.

RESULTS

Between 1990 and 1996, there were a total of 75,452 male and 81,269 female hospitalizations related to HF in Scotland, with an average rate of admissions per 100,000 population of 8.4 and 8.5 per day, respectively. Significantly more admissions occurred in winter compared to summer (p < 0.0001). In women, the peak rate of admission occurred in December (12% more than average) and the lowest rate in July (7% less than average) (odds ratio [OR] 1.14, p < 0.001). The respective figures for men were 6% more, 8% less (OR 1.16, p < 0.001). In both genders, the greatest variation occurred in those aged >75 years---peak winter rates being 15% to 18% higher than average. There was also a winter peak in concomitantly coded respiratory disease; this seasonal excess accounted for approximately one-fifth of the winter increment in HF hospitalizations. Seasonal variation in mortality was also seen in these patients. The number of male deaths in December was 16% higher, and in July 7% lower, than average (OR 1.25, p < 0.001). In women, the equivalent figures were 21% higher (January) and 14% lower (July) (OR 1.21, p < 0.001). Again, the greatest variation occurred in those aged >75 years---peak rates being 23% to 35% higher than average.

CONCLUSIONS

There is substantial seasonal variation in HF hospitalizations and deaths, particularly in the elderly. Approximately one-fifth of the winter excess in admissions is attributable to respiratory disease. Extra vigilance in patients with HF is advisable in winter, as is immunization against pneumococcus and influenza.

Angiotensin type-1 receptor blockers in heart failure

Chronic heart failure is a common condition with a poor prognosis, usually associated with poor exercise tolerance and debilitating symptoms despite optimal modern therapy. Standard therapy includes diuretics, digoxin, angiotensin-converting enzyme inhibitors (ACEIs) and beta-blockers. Despite this, many patients remain symptomatic, and interest is high as to whether the angiotensin receptor blockers (ARBs) would offer further advantage to a patient already receiving quadruple therapy. In addition, some patients are intolerant of ACEIs, and for this group the ARBs seem a logical choice. This article reviews the evidence for the use of ARBs as a class in heart failure concentrating on clinical recommendations and clinical needs and evidence rather than purely on statistical issues of significance in trials. The trials to date have demonstrated clearly similar hemodynamic effects to those seen with ACEIs and variety of ancillary benefits such as improvements in endothelial function, anti-thrombotic effects, and effects on neurohormonal inhibition. There is consistent evidence of a preservation of exercise tolerance when patients with heart failure are crossed over from stable ACEI therapy, and when added to ACEIs exercise tolerance appears to increase with ARBs. In terms of major outcomes, the two largest trials, Elite-II and Val-Heft, demonstrate that angiotensin receptor blockers probably have a clinical role in improving mortality and morbidity as an alternative to ACEIs in those patients unable to tolerate these agents, which remain, however, the first choice in unselected patients with heart failure. There is a worrying suggestion of a negative interaction when ARBs are added to beta-blockers, which is a reason for caution in using the ARBs, not a reason not to use beta-blockers.

Coronary vasodilation and improvement in endothelial dysfunction with endothelin ET(A) receptor blockade

The endothelium-derived peptide endothelin-1 (ET-1) causes vasoconstriction predominantly via smooth muscle ET(A) receptor activation. We hypothesized that ET(A) receptor inhibition would improve human coronary vascular function. We studied unobstructed coronary arteries of 44 patients with atherosclerosis or its risk factors. Epicardial diameter (D) and Doppler flow velocity were measured, and coronary vascular resistance (CVR) was calculated during intracoronary infusions of acetylcholine (ACH) and sodium nitroprusside (SNP), and during cold pressor testing, before and after a 60-minute intracoronary infusion of the ET(A) receptor antagonist BQ-123. BQ-123 dilated the coronary circulation; D increased by 5.6+/-1.0% (P<0.0001), and CVR fell by 12+/-3% (P<0.01). The D response to ACH, corrected for the SNP response, improved in segments that constricted with ACH at baseline (P=0.03), whereas segments that initially dilated with ACH did not change with BQ-123 (P=NS). Improvement in D and CVR responses to ACH with BQ-123 inversely correlated with baseline ACH responses (r=-0.44 [P=0.006] and r=-0.78 [P=0.001], respectively), indicating greater improvement in those with endothelial dysfunction. Similarly, cold pressor testing-mediated epicardial vasoconstriction (-2.0+/-1.1%) was reversed after BQ-123 (+1.0+/-0.7%), especially in dysfunctional segments (from -5.6+/-0.9% to +2.2+/-0.9%, P<0.001). There was no correlation between any risk factor and the response to BQ-123. An arteriovenous difference in ET-1 levels developed after BQ-123, which was consistent with enhanced cardiac clearance of ET-1, probably via ET(B) receptors. Thus, ET-1 acting via the ET(A) receptor contributes to basal human coronary vasoconstrictor tone and endothelial dysfunction. This suggests that ET(A) receptor antagonism may have therapeutic potential in the treatment of endothelial dysfunction and atherosclerosis.

Therapeutic potential of angiotensin II receptor antagonists

The circulating renin-angiotensin system plays an important role in cardiovascular homeostasis. More importantly, the local tissue renin angiotensin plays a pivotal role in cell growth and remodelling of cardiomyocytes and on the peripheral arterial vasculature. In addition, the renin angiotensin system is related to apoptosis, control of baroreflex and autonomic responses, vascular remodelling and regulation of coagulation, inflammation and oxidation. The cardioprotective and vascular protective effects of the angiotensin receptive blockade appears to be related to selective blockade of the angiotensin II (A-II) Type I (AT(1)) receptors. However, there is now growing evidence showing that some of the effects of AT-II receptor blockers (ARBs) are related to the activation of the kinin pathways. This paper will review some of the recent mechanisms related to the cardiovascular effects of angiotensin and more specifically of ARBs. This paper will present the novel data on the role of ARB in the development of atherosclerosis, vascular remodelling, coagulation balance and autonomic regulation. Finally, the role of ARBs, used alone or in combination with ACE inhibitor in patients with heart failure, will be discussed.

Endothelin and renal vascular fibrosis: of mice and men

The present review focuses on recent data regarding the role of endothelin as a mediator of renal vascular fibrosis. Following a brief description of the endothelin system, the question of whether endothelin is involved in hypertensive mechanisms is examined in experimental, genetic and transgenic animal models. Evidence is provided that implicates endothelin as an important factor of the development of tissue fibrosis and end-organ damage associated with hypertension, with particular emphasis on renal vascular fibrosis. Data indicating that endothelin interacts with other vasoconstrictor systems, such as angiotensin II, are also considered. Finally, results from preliminary clinical studies using endothelin receptor antagonists to treat cardiac and renal pathologies are briefly discussed.