Hemodynamic effects of diuresis at rest and during intense upright exercise in patients with impaired cardiac function

The role of kidney injury molecule-1 in predicting cardiorenal syndrome type 1 after diuretic treatment

Introduction

Cardiorenal syndrome (CRS) is defined as acute or chronic dysfunction in the heart and kidney due to important interactions between the heart and kidney disease. The aim of this study was to evaluate prediction of CRS type 1 by measuring kidney injury molecule-1 (KIM-1) and to establish early diagnosis of acute kidney injury (AKI).

Material and methods

During 2015–2016, 146 patients who were admitted to the emergency service with acute decompensated HF were included in the study. We investigated urinary KIM-1 levels in 146 consecutive patients with decompensated heart failure before and after diuretic treatment. Statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS – version 21.0)/Windows Statistical Software. P-values less than < 0.05 were considered significant.

Results

There was a moderate negative correlation between the percentage change of creatinine values and the percentage change of KIM-1 values (r = –0.357, p = 0.016). There was no statistically significant relationship between KIM-1 and the development of CRS type 1 (p = 0.011).

Conclusions

No statistically significant relationship was observed between KIM-1 levels and the development of CRS type 1. In addition, there was no correlation between mortality in patients and KIM-1 values. It is thought that KIM-1 is not a potential prognostic indicator because renal tubular damage is only one of many factors in the pathophysiology of CRS type 1 and heart failure.

KSHF Guidelines for the Management of Acute Heart Failure: Part III. Specific Management of Acute Heart Failure According to the Etiology and Co-morbidity

The prevalence of heart failure (HF) is on the rise due to the aging of society. Furthermore, the continuous progress and widespread adoption of screening and diagnostic strategies have led to an increase in the detection rate of HF, effectively increasing the number of patients requiring monitoring and treatment. Because HF is associated with substantial rates of mortality and morbidity, as well as high socioeconomic burden, there is an increasing need for developing specific guidelines for HF management. The Korean guidelines for the diagnosis and management of chronic heart failure (CHF) were introduced in March 2016. However, CHF and acute heart failure (AHF) represent distinct disease entities. Here, we introduce the Korean guidelines for the management of AHF with reduced or preserved ejection fraction. Part III of this guideline covers management strategies optimized according to the etiology of AHF and the presence of co-morbidities.

Pathogenesis and treatment of the cardiorenal syndrome: Implications of L-arginine-nitric oxide pathway impairment

A highly complex interplay exists between the heart and kidney in the setting of both normal and abnormal physiology. In the context of heart failure, a pathophysiological condition termed the cardiorenal syndrome (CRS) exists whereby dysfunction in the heart or kidney can accelerate pathology in the other organ. The mechanisms that underpin CRS are complex, and include neuro-hormonal activation, oxidative stress and endothelial dysfunction. The endothelium plays a central role in the regulation of both cardiac and renal function, and as such impairments in endothelial function can lead to dysfunction of both these organs. In particular, reduced bioavailability of nitric oxide (NO) is a key pathophysiologic component of endothelial dysfunction. The synthesis of NO by the endothelium is critically dependent on the plasmalemmal transport of its substrate, L-arginine, via the cationic amino acid transporter-1 (CAT1). Impaired L-arginine-NO pathway activity has been demonstrated individually in heart and renal failure. Recent findings suggest abnormalities of the L-arginine-NO pathway also play a role in the pathogenesis of CRS and thus this pathway may represent a potential new target for the treatment of heart and renal failure.

Right ventricular function in dilated cardiomyopathy and ischemic heart disease: assessment with non-invasive imaging

Background

Dilated cardiomyopathy and ischaemic heart disease can both lead to right ventricular (RV) dysfunction. Direct comparisons of the two entities regarding RV size and function using state-of-the-art imaging techniques have not yet been performed. We aimed to determine RV function and volume in dilated cardiomyopathy and ischaemic heart disease in relation to left ventricular (LV) systolic and diastolic function and systolic pulmonary artery pressure.

Methods and results

A well-characterised group (cardiac magnetic resonance imaging, echocardiography, coronary angiography and endomyocardial biopsy) of 46 patients with dilated cardiomyopathy was compared with LV ejection fraction (EF)-matched patients (n = 23) with ischaemic heart disease. Volumes and EF were determined with magnetic resonance imaging, diastolic LV function and pulmonary artery pressure with echocardiography.

After multivariable linear regression, four factors independently influenced RVEF (R² = 0.51, p < 0.001): LVEF (r = 0.54, p < 0.001), ratio of peak early and peak atrial transmitral Doppler flow velocity as measure of LV filling pressure (r = − 0.52, p < 0.001) and tricuspid regurgitation flow velocity as measure of pulmonary artery pressure (r = − 0.38, p = 0.001). RVEF was significantly worse in patients with dilated cardiomyopathy compared with ischaemic heart disease: median 48 % (interquartile range (IQR) 37–55 %) versus 56 % (IQR 48–63 %), p < 0.05.

Conclusions

In patients with dilated cardiomyopathy and ischaemic heart disease, RV function is determined by LV systolic and diastolic function, the underlying cause of LV dysfunction, and pulmonary artery pressure. It was demonstrated that RV function is more impaired in dilated cardiomyopathy.

Diastolic heart failure: a confusing concept

Descriptions of the pathophysiology of heart failure have gone through a substantial evolution in the last 50 years. It is now recognised that heart failure can occur in the presence and also in the absence of a reduction in left ventricular function. In the former situation, this classically has been described to lead to hypotension and secondary salt and volume retention by the kidneys, further aggravating cardiac function. In the latter, this has been described to lead to pulmonary congestion because of impaired cardiac diastolic filling. These concepts have further evolved in the discrimination of 'acute vascular' versus 'acute congestive' heart failure. The current paper builds the argument from numerous smaller observational studies that irrespective of the clinical presentation of heart failure, fluid congestion is the key. If left ventricular function is preserved, fluid retention is probably due to the inability of damaged kidneys to excrete the large amounts of salt ingested with modern diet. In the extreme of end-stage renal disease requiring haemodialysis, heart failure is frequent, but can be prevented almost entirely by strict volume control. Unfortunately, the absence of systematic studies describing fluid volumes and renal haemodynamic and reabsorptive function in patients with acute heart failure precludes the final proof of our concept. This paper therefore is a strong call for mechanistic research in this area.

Narrative review: the management of acute decompensated heart failure

Acute decompensated heart failure (ADHF) is the most common reason for hospitalization in Western nations. The prognosis of patients admitted to hospital with ADHF is poor, with up to 64% being readmitted within the first 90 days after discharge and with a 1-year mortality approximating 20%. Epidemiological studies suggest that the majority of patients hospitalized with ADHF receive treatment that is inadequate and which is not based on scientific evidence. Furthermore, emerging data suggest that the "conventional" therapeutic interventions for ADHF including morphine, high-dose diuretics, and inotropic agents may be harmful. The goal of this review is to provide evidence-based recommendations for the diagnosis and management of ADHF.

Prognostic Implications of Diuretic Dose in Chronic Heart Failure

Background: Prognostic implications of diuretics dose are not completely understood. We aim to study the association between diuretic doses and long-term prognosis in patients with chronic stable heart failure (HF). Methods and Results: We conducted a retrospective cohort study of 244 patients followed at an outpatient HF clinic. Admission criteria were clinical stability in the previous 3 months and optimized medical therapy. Demographic characteristics, clinical, and laboratory parameters were recorded. Patients were followed for 2 years and the outcome was defined as all-cause death or hospital admission due to HF worsening. Patients on ≤80 mg furosemide were compared with those on higher doses. Patients were grouped according to furosemide dose (≤80 mg and >80 mg/d) and according to volemia as assessed by the sodium retention score: <3 (euvolemia) versus ≥3 (hypervolemia). Patients on higher diuretic doses (n = 79) were older, more hypervolemic, and more symptomatic. Patients on >80 mg furosemide had a higher risk of death or hospital admission (hazard ratio [HR]: 2.07, 95% confidence interval [CI]: 1.37-3.1). For each 40-mg furosemide tablet, there was a 67% increase in risk of an adverse outcome within 2 years. The increase in risk was independent of other variables crudely associated with prognosis. Among euvolemic patients, those on ≤80 mg/d furosemide performed better than those on higher doses. Among hypervolemic patients, the diuretic dose had no prognostic implications. Conclusions: Higher diuretic doses associated strongly and independently with adverse long-term outcome in chronic HF. Possibly, in euvolemic patients, efforts should be made to reduce diuretic dose.

Haemodynamics and renal function following injection of bumetanide

Haemodynamics and renal function have been investigated in 12 patients with valvular heart disease before and after injection of 2 mg bumetanide in the right heart catheter. There were no significant changes in oxygen consumption, arteriovenous oxygen difference, cardiac index, heart beats per minute, stroke volume or right and left ventricular stroke work 35 min after the injection, whereas pulmonary and systemic arteriolar resistance showed a slight but insignificant reduction. Mean pulmonary capillary venous pressure, left ventricular end-diatolic pressure, mean pulmonary arterial pressure and mean pressure in the right atrium were highly significantly reduced after injection, systolic left ventricular pressure showing a significant but slight decrease. The creatinine and urea clearances increased considerably during the first 50 min after injection of bumetanide, but diminished during the second period to levels somewhat lower than the initial values. There was also a marked increase in the clearance of sodium potassium, calcium, magnisium and phosphate. It is concluded that bumetanide is a very potent diuretic which changes haemodynamic parameters towards normal values.

Evaluation of prehospital use of furosemide in patients with respiratory distress

OBJECTIVE

To evaluate the appropriateness of prehospital use of furosemide.

METHODS

All patients over 18 years old receiving prehopsital furosemide were retrospectively identified, and cases were matched to subsequent hospital records. Data collected included ED and hospital primary and secondary diagnoses, brain-type natriuretic peptide (BNP) levels and final disposition. Furosemide was considered appropriate when the primary or secondary ED or hospital diagnoses included congestive heart failure (CHF) or pulmonary edema, or the BNP was > 400. Furosemide was considered inappropriate when none of the diagnoses included CHF, when the BNP was < 200, or when an order for IV fluid hydration was given. Furosemide was considered potentially harmful when the diagnoses included sepsis, dehydration or pneumonia, without a diagnosis of CHF or BNP > 400.

RESULTS

Of the 144 included patients, a primary or secondary diagnosis of CHF was reported in 42% and 17% patients, respectively. The initial BNP was > 400 in 44% of the 120 patients in which this lab test was obtained. Sixty patients (42%) did not receive a diagnosis of CHF, 30 (25%) patients had a BNP < 200, and 33 (23%) had an order for IV fluid hydration. A diagnosis of sepsis, dehydration or pneumonia without a diagnosis of CHF or a BNP > 400 occurred in 17% of patients. Seven of the 9 deaths did not receive a diagnosis of CHF. Furosemide was considered appropriate in 58%, inappropriate in 42% and potentially harmful in 17% of patients.

CONCLUSIONS

In this EMS system, prehospital furosemide was frequently administered to patients in whom its use was considered inappropriate, and not uncommonly to patients when it was considered potentially harmful. EMS systems should reconsider the appropriateness of prehospital diuretic use.

Relation of loop diuretic dose to mortality in advanced heart failure

Although loop diuretics are widely used in heart failure (HF), their effect on outcomes has not been evaluated in large clinical trials. This study sought to determine the dose-dependent relation between loop diuretic use and HF prognosis. A cohort of 1,354 patients with advanced systolic HF referred to a single center was studied. Patients were divided into quartiles of equivalent total daily loop diuretic dose: 0 to 40, 41 to 80, 81 to 160, and >160 mg. The cohort was 76% male, with a mean age of 53+/-13 years and a mean ejection fraction of 24+/-7%. The mean diuretic dose equivalence was 107+/-87 mg. The diuretic quartile groups were similar in terms of gender, body mass index, ischemic cause of HF, history of hypertension, and spironolactone use, but the highest quartile was associated with a smaller ejection fraction and lower serum sodium and hemoglobin levels but higher serum blood urea nitrogen and creatinine levels. There was a decrease in survival with increasing diuretic dose (83%, 81%, 68%, and 53% for quartiles 1, 2, 3, and 4, respectively). Even after extensive co-variate adjustment (age, gender, ischemic cause of HF, the ejection fraction, body mass index, pulmonary capillary wedge pressure, peak oxygen consumption, beta-blocker use, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, digoxin use, statin use, serum sodium, blood urea nitrogen, creatinine, hemoglobin, cholesterol, systolic blood pressure, and smoking history), diuretic quartile remained an independent predictor of mortality (quartile 4 vs quartile 1 hazard ratio 4.0, 95% confidence interval 1.9 to 8.4). In conclusion, in this cohort of patients with advanced HF, there was an independent, dose-dependent association between loop diuretic use and impaired survival. Higher loop diuretic dosages identify patients with HF at particularly high risk for mortality.

Six minute corridor walk test as an outcome measure for the assessment of treatment in randomized, blinded intervention trials of chronic heart failure: a systematic review

AIMS

The 6 min walk test (6MWT) is commonly used in clinical trials to assess treatments for heart failure, but its ability to distinguish between effective and ineffective treatments is questionable. The aim of this study is to investigate, using a systematic literature review, the utility of the 6MWT as a measure of the effectiveness of treatment in randomized controlled trials of heart failure.

METHODS AND RESULTS

A literature search was performed using Medline, EMBASE, CINAHL, and Biological abstracts for randomized controlled trials that measured 6MWT between 1988 and 31 May 2004. A significant increase in 6MWT distance was observed in only 9 of 47 randomized controlled trials of pharmacological therapy; 2 of 6 trials of ACE-inhibitors; 3 of 17 trials of beta-blockers; 1 of 4 trials of digoxin; one trial of ibopamine; one trial of l-arginine; one trial of beriberine; and one trial showed superiority of captopril over flosequinan. A significant increase in 6MWT was observed in four out of six placebo-controlled trials of cardiac resynchronization. Smaller pharmacological trials with fewer centres were more likely to be positive; six out of nine positive pharmacological trials had four or less participating centres, raising the possibility of publication bias. Pharmacological trials including patients with more severe heart failure were more likely to show a significant improvement with therapy than trials of milder heart failure. Five out of seven pharmacological trials that reported an improvement in symptoms also reported an improvement in 6MWT distance. Of 30 pharmacological trials, 29 that reported no improvement in symptoms also reported no improvement in 6MWT. Using mean values in these trials, the age of patients appeared a more important determinant of 6MWT distance than New York Heart Association classification.

CONCLUSION

The 6MWT has not yet been proven to be a robust test for the identification of effective pharmacological interventions although it appears useful for the assessment of cardiac resynchronization therapy. The results of the 6MWT were concordant with changes in symptoms, suggesting that it may be used as supportive evidence for symptom benefit. The test may be of greater value in patients with more advanced heart failure, where it may function as a maximal exercise test.

Treatment of edematous disorders with diuretics

Generalized edema results from alterations in renal sodium homeostasis that ultimately result in an expansion of extracellular fluid volume and accumulation of interstitial fluid. The common edematous disorders include congestive heart failure, cirrhosis, nephrotic syndrome, and renal insufficiency. The abnormalities of sodium homeostasis contributing to edema formation in each condition are discussed. Management of volume homeostasis, with an emphasis on the role of diuretic therapy, is reviewed.

Comparison of the short-term effects of candoxatril, an orally active neutral endopeptidase inhibitor, and frusemide in the treatment of patients with chronic heart failure

BACKGROUND

Candoxatril is a novel neutral endopeptidase inhibitor that increases plasma concentrations of atrial natriuretic factor and thereby produces natriuresis, diuresis, and vasorelaxation. This profile of action offers theoretical advantages over standard diuretic therapy in the treatment of patients with heart failure. The aims of the study were to compare the effects of candoxatril with those of frusemide in the treatment of patients with mild heart failure.

METHODS

Male patients with mild heart failure were randomly assigned to 9 days of therapy with 20 mg frusemide twice a day, 200 mg candoxatril twice a day, or 400 mg candoxatril twice a day (n = 10 per group) after a 14-day placebo washout phase. Systemic hemodynamic measurements, exercise tolerance, and urinary and plasma hormone concentrations were assessed during the placebo run-in and at the beginning and end of the double-blind therapy.

RESULTS

Frusemide and candoxatril caused similar diuresis and natriuresis. Candoxatril caused a slight decrease in systolic blood pressure and a dose-dependent increase in plasma and urinary concentrations of atrial natriuretic factor without elevating plasma renin activity. Frusemide reduced plasma concentrations of atrial natriuretic factor and increased plasma renin activity. Treadmill exercise capacity decreased 30 +/- 26 seconds after use of frusemide, compared with increases of 12 +/- 35 seconds after use of 200 mg candoxatril twice a day and 35 +/- 31 seconds after use of 400 mg candoxatril twice a day (P =.13; frusemide versus 400 mg candoxatril twice a day).

CONCLUSIONS

In the treatment of patients with mild heart failure, candoxatril has diuretic effects equivalent to those of 20 mg frusemide twice a day without the associated and potentially detrimental activation of the renin-angiotensin-aldosterone system. The trend for improved exercise capacity with candoxatril warrants further investigation.

Effects of spironolactone on exercise capacity and neurohormonal factors in patients with heart failure treated with loop diuretics and angiotensin-converting enzyme inhibitor

1. Treatment with spironolactone is reported to be useful when combined with loop diuretics and an angiotensin-converting enzyme (ACE) inhibitor in severe congestive heart failure (CHF). However, the effects of the addition of spironolactone on exercise capacity and neurohormonal variables have not been demonstrated. This study determined the effects of additive spironolactone on exercise capacity and neurohormonal factors in patients with mild CHF. 2. Oxygen uptake (VO2), plasma norepinephrine (NE), renin activity (PRA), angiotensin II (AII), aldosterone (ALD), and atrial natriuretic peptide (ANP) were measured at rest and after peak exercise in nine patients with CHF (six idiopathic and three ischemic cardiomyopathy; New York Heart Association (NYHA) classes II and III) who were already taking furosemide (mean 29 +/- 5 mg/day) and enalapril (mean 4.7 +/- 0.8 mg/day). Studies were repeated after 16 weeks of treatment with additive single daily dose of 25 mg of spironolactone. In four of nine patients, the exercise test was repeated after a 4-weeks washout of spironolactone. 3. Treatment with spironolactone caused natriuresis, decreased cardiothoracic ratio in chest X-ray (before vs. after treatment: 53.7 +/- 1.2 vs. 50.7 +/- 1.4%, P < 0.01), and improved NYHA functional class. Peak VO2 (17.1 +/- 1.6 vs. 17.5 +/- 2.2 ml/min/kg, NS) and heart rate and blood pressure responses to exercise were not altered. Resting NE (215 +/- 41 vs. 492 +/- 85 pg/ml, P < 0.01) and resting PRA (8.2 +/- 2.3 vs. 16.2 +/- 4.1 ng/ml/hr, P < 0.01) as well as peak NE (1618 +/- 313 vs. 2712 +/- 374 pg/ml, P < 0.01) and peak PRA (12.8 +/- 3.2 vs. 28.1 +/- 11.8 ng/ml/hr, P = 0.17) were augmented after additive spironolactone. ALD and AII were insignificantly increased, and ANP was insignificantly decreased at peak exercise after spironolactone treatment. Spironolactone washout was associated with a trend of the neurohormones to return toward pretreatment values. 4. In conclusion, chronic additive treatment with spironolactone was associated with neurohormonal activation both at rest and during exercise without changing the exercise capacity of patients with mild CHF who were already on loop diuretics and ACE inhibitor therapy.

Review of furosemide in horse racing: its effects and regulation

Furosemide has been used empirically and has been legally approved for many years by the US racing industry for the control of exercise-induced pulmonary haemorrhage (EIPH) or bleeding. Its use in horses for this purpose is highly controversial and has been criticized by organizations outside and inside of the racing industry. This review concentrates on its renal and extra-renal actions and the possible relationship of these actions to the modification of EIPH and changes in performance of horses. The existing literature references suggest that furosemide has the potential of increasing performance in horses without significantly changing the bleeding status. The pulmonary capillary transmural pressure in the exercising horse is estimated to be over 100 mmHg. The pressure reduction produced by the administration of furosemide is not of sufficient magnitude to reduce transmural pressures within the capillaries to a level where pressures resulting in rupture of the capillaries, and thus haemorrhage, would be completely prevented. This is substantiated by clinical observations that the administration of furosemide to horses with EIPH may reduce haemorrhage but does not completely stop it. The unanswered question is whether the improvement of racing times which have been shown in a number of studies are due to the reduction in bleeding or to other actions of furosemide. This review also discusses the difficulties encountered in furosemide regulation, in view of its diuretic actions and potential for the reduction in the ability of forensic laboratories to detect drugs and medications administered to a horse within days or hours before a race. Interactions between nonsteroidal anti-inflammatory drugs (NSAIDs) and furosemide have also been examined, and the results suggest that the effects of prior administration of NSAID may partially mitigate the renal and extra-renal effects which may contribute to the effects of furosemide on EIPH.

Sustained improvement in functional capacity after removal of body fluid with isolated ultrafiltration in chronic cardiac insufficiency: failure of furosemide to provide the same result

OBJECTIVES

This study was designed to investigate whether a subclinical accumulation of fluid in the lung interstitium associated with moderate congestive heart failure interferes with the patient's functional capacity, and whether furosemide treatment can promote reabsorption of the excessive fluid.

BACKGROUND

In patients with moderate congestive heart failure, pulmonary overhydration may be detected by chest roentgenography even if therapy is optimized to keep the urinary output normal and to prevent weight gain and dependent edema formation. Removal of the overhydration may help define its significance.

METHODS

Patients, whose regimens of digoxin, oral furosemide, and angiotensin-converting enzyme (ACE) inhibitor therapy were kept constant, were randomly allocated to receive ultrafiltration (8 cases) or an intravenous bolus of supplemental furosemide (mean dose: 248 mg; 8 cases). The amount of body fluid removed with each method approximated 1600 mL. Functional performance was assessed with cardiopulmonary exercise tests.

RESULTS

Soon after fluid withdrawal by either method, the filling pressures of the two ventricles and body weight were reduced and plasma renin activity, norepinephrine, and aldosterone were augmented. After furosemide administration, hormone levels remained elevated for the next 4 days, and during this period, patients had positive water metabolism, recovery of the elevated ventricular filling pressures, and re-occurrence of lung congestion with no improvement in functional capacity. After ultrafiltration, levels of renin, norepinephrine, and aldosterone fell to below control values within the first 48 hours and water metabolism was equilibrated at a new set point (less fluid intake and diuresis without weight gain). The favorable circulatory and ventilatory adjustments consequent to the reabsorption of lung water improved the functional capacity of these patients. That may also have restored the lung's ability to clear norepinephrine, thus restraining its facilitation of renin release. The improvement continued 3 months after the procedure.

CONCLUSIONS

In patients with congestive heart failure the set point of fluid balance is altered in spite of oral furosemide therapy; supplemental intravenous furosemide does not shift the set point, at least not when combined with ACE inhibition. Excessive, although asymptomatic, lung water limits the functional capacity of the patient.

Postinfarct heart failure: role of diuretic therapy

There can be no doubt that ACE inhibitors prolong survival in patients with a low ejection fraction. There is no evidence whether or not diuretics have the same effect. The pathophysiology of asymptomatic patients with poor left ventricular function differs from that of patients with the clinical syndrome of heart failure, and different treatments may well be needed. Diuretics still have a crucial role in the relief of symptoms.

The effect of venous occlusion with tourniquets on peripheral blood pooling and ventricular function

Rotating tourniquets were once part of the traditional treatment of acute pulmonary edema. Their effectiveness has been questioned and vasodilator therapy has replaced them, but early favorable results suggested that they may play a beneficial role. A radioisotope technique was used to evaluate blood volume increments in the leg after venous occlusion at 60 mm Hg in 26 patients with left ventricular dysfunction following myocardial infarction. Mean radionuclide counts (reflecting the blood volume distal to the occlusion) increased from the preocclusion value. Thus, satisfactory trapping of blood is achieved. However, mean left ventricular ejection fraction (EF) decreased slightly but significantly and this decrease in EF was observed in 18 of 26 patients. Left ventricular end-diastolic and end-systolic volume equivalents tended to decrease slightly but not in all patients. Mean stroke volume and cardiac output equivalents were reduced by 14 percent while peripheral resistance increased significantly. The present study thus fails to support the hypothesis that preload reduction by tourniquets improves left ventricular function; the exact opposite effect may occur because of increased afterload.

Acute and chronic effects of a diuretic monotherapy with piretanide in congestive heart failure--a placebo-controlled trial

To evaluate the acute and chronic effects of diuretic monotherapy with 3 mg piretanide bid, 46 patients (pts) with congestive heart failure (NYHA II-III) secondary to coronary artery disease were studied. Within 3 weeks of therapy, the patients lost 1.6 kg body weight. Forty-four patients reported a subjective feeling of improvement. Echocardiographically, a highly significant (p less than 0.001) reduction of diastolic and systolic diameters was found, as well as an increase of fraction shortening. Chest x-ray indicated a reduction of heart volume from 1012 +/- 263 ml to 936 +/- 233 ml (p less than 0.001). The serum potassium level remained unchanged. A subgroup of 26 pts underwent invasive hemodynamic examinations. IV injection of 6 mg piretanide resulted in an acute reduction of pulmonary wedge pressure (pc) from 20.2 +/- 5.3 mmHg to 11.9 +/- 5.0 mmHg (p less than 0.001); simultaneously a slight decrease of cardiac index from 3.2 +/- 0.6 l/min/m2 to 3.0 +/- 0.4 l/min/m2 was observed. Invasive control after 3 weeks of oral therapy showed no decline of the piretanide effect. The exercise tolerance increased clearly from 135 +/- 161 Wmin to 249 +/- 268 Wmin (p less than 0.05). A control group of further 14 pts was treated with placebo only and did not show any significant changes of pc (20.0 +/- 6.4 mmHg vs. 22.8 +/- 19.2 mmHg), exercise tolerance, or other clinical parameters. Thus, the diuretic monotherapy of congestive heart failure with piretanide is highly effective and shows a significant improvement in all clinical and hemodynamic parameters in the absence of any remarkable side effects.

Dependence of enhanced maximal exercise performance on increased peak skeletal muscle perfusion during long-term captopril therapy in heart failure

Maximal oxygen uptake (VO2), skeletal muscle blood flow by xenon-133 washout technique and femoral vein arteriovenous oxygen difference and lactate were measured at rest and during maximal bicycle exercise in eight patients with severe congestive heart failure before and after 8 weeks of therapy with captopril. During therapy, skeletal muscle blood flow at rest increased significantly from 1.5 +/- 0.6 to 2.6 +/- 1.0 ml/100 g per min (p less than 0.05), with a concomitant decrease in the femoral arteriovenous oxygen difference from 10.0 +/- 1.7 to 8.3 +/- 1.9 ml/100 ml (p less than 0.05). Maximal VO2 increased significantly from 13.4 +/- 3.0 to 15.5 +/- 4.1 ml/kg per min (p less than 0.05). In four patients, the increase in maximal VO2 averaged 3.7 ml/kg per min (range 2.7 to 4.9), whereas in the remaining four patients, it was less than 1 ml/kg per min. Overall, peak skeletal muscle blood flow attained during exercise did not change significantly during long-term therapy with captopril (19.6 +/- 6.2 versus 27.6 +/- 14.3 ml/100 g per min, p = NS). However, the four patients with a significant increase in maximal VO2 experienced substantial increases in peak skeletal muscle blood flow and the latter changes were linearly correlated with changes in maximal VO2 (r = 0.95, p less than 0.001). Femoral arteriovenous oxygen difference at peak exercise was unchanged (12.6 +/- 2.6 versus 12.6 +/- 2.4 ml/100 ml). Thus, improvement in maximal VO2 produced by long-term therapy with captopril is associated with an increased peripheral vasodilatory response to exercise, and this improvement only occurs when the peak blood flow is augmented.(ABSTRACT TRUNCATED AT 250 WORDS)

Enhanced metabolic vasodilation secondary to diuretic therapy in decompensated congestive heart failure secondary to coronary artery disease

Since sodium and water retention have been implicated as major factors limiting maximal metabolic vasodilation in congestive heart failure (CHF), the effect of rigorous diuresis on maximal vasodilatory capacity was studied systematically in 9 subjects hospitalized with decompensated CHF. Peak reactive hyperemic blood flow, measured by strain-gauge plethysmography, was used as an index of maximal vasodilatory capacity. After 24 hours of diuresis and a 2.2-kg weight loss, maximal flow increased from 19.9 to 26.1 ml/min X 100 ml (p less than 0.05). Despite a further 1.4-kg weight loss between 24 and 48 hours, maximal blood flow increased no more (26.1 to 25.8 ml/min X 100 ml). Since blood pressure did not change significantly, minimal forearm resistance and maximal conductance showed similar improvements. It is unlikely that vasoconstrictor hormone changes could account for this effect since a marked decrease in plasma norepinephrine occurred in only 2 of 8 subjects and plasma renin activity decreased in only 1 subject. As a group there was no significant change in norepinephrine level, which remained substantially above normal (1,525 to 1,148 pg/ml), or in plasma renin activity (12.3 to 18.9 ng/ml/hour). Because the improvement in vasodilator capacity reached a plateau by 24 hours despite continued diuresis, and because peak reactive hyperemic blood flow was still 32% below normal, it is suggested that a second mechanism besides sodium and water retention is responsible for a significant portion of the impaired peripheral vasodilation in CHF.

Untreated heart failure: clinical and neuroendocrine effects of introducing diuretics

The clinical and neuroendocrine response to diuretic treatment was assessed at rest and on exercise in 12 patients with heart failure. Before treatment all patients were limited by breathlessness on exercise; one was oedematous. Plasma renin activity and aldosterone were normal but plasma noradrenaline was raised both at rest and on exercise. After one month's treatment with frusemide (40 mg) and amiloride (5 mg) weight was significantly reduced by a mean of 3.5 kg and exercise capacity had doubled. Plasma noradrenaline fell to normal at rest but remained abnormally raised on exercise. Plasma renin activity and aldosterone increased significantly both at rest and on exercise. Diuretics bring about a considerable clinical improvement in patients with chronic heart failure but they stimulate the renin-angiotensin system. Activation of the renin-angiotensin system in moderate heart failure occurs as a response to diuretic treatment rather than as a result of the disease process itself.

Central and peripheral components of cardiac failure

Chronic heart failure results from two processes, i.e., myocardial and congestive failure. Myocardial failure is clinically silent, most often progresses slowly, and is documented by a depressed left ventricular ejection fraction. Multiple etiologic factors include systolic and diastolic overloads, myocardial necrosis and/or ischemia, and, perhaps, microvascular spasm. Myocardial failure ultimately leads to exaggerated neurohumoral compensatory mechanisms and derangements of the peripheral circulation, which are the hallmarks of congestive heart failure. At that stage of the syndrome, patients have symptoms, initially, with exercise and, later, at rest. Objective assessment of severity is afforded by determination of maximal oxygen uptake during maximal exercise testing. When congestive heart failure supervenes, the prognosis is poor. Current medical therapy is aimed at improving the derangements of the peripheral circulation, which relieves the symptoms but leaves the primary myocardial process unaffected. The goal of future therapy is to intervene at an earlier stage of the syndrome to halt or even partially reverse the myocardial failure.

Aortic valve stenosis: comparison of patients with to those without chronic congestive heart failure

Eighty-four patients with aortic valve stenosis (AS) and without other valvular or coronary artery disease were studied to investigate the pathophysiologic importance of hemodynamic and functional factors in the development of congestive heart failure (CHF). Thirty had clinical and radiographic signs of CHF. There was no significant difference between patients with and those without CHF in aortic valve index (0.26 +/- 0.09 vs 0.34 +/- 0.16 cm2/m2), mean aortic valve gradient (64 +/- 19 vs 59 +/- 25 mm Hg), left ventricular (LV) systolic pressure (201 +/- 31 vs 201 +/- 35 mm Hg), LV end-diastolic diameter (4.8 +/- 1.0 vs 4.4 +/- 0.7 cm) or posterior LV wall thickness (14.0 +/- 4.7 vs 15.0 +/- 30.0 mm). Patients with CHF had higher LV end-diastolic pressure (22 +/- 10 vs 16 +/- 7 mm Hg, p less than 0.005) and LV wall stress (370 +/- 138 vs 300 +/- 69 g/cm2, p less than 0.005) and lower cardiac index (2.0 +/- 0.5 vs 2.4 +/- 0.6 liters/min/m2, p less than 0.005) and LV ejection fraction (55 +/- 18 vs 68 +/- 13%, p less than 0.0005). An inverse linear relation (r = -0.59, p less than 0.01) was present between LV wall stress and LV ejection fraction such that as stress increased, LV ejection fraction fell. Values for both LV wall stress and LV ejection fraction overlapped considerably between the groups and, more important, only 40% of patients with CHF had a depressed LV ejection fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of diuresis on the performance of the failing left ventricle in man

To determine the effect of diuresis on the performance of the failing left ventricle, we measured cardiac output, pulmonary wedge pressure and M-mode echo left ventricular diastolic dimension before and after diuresis in 13 patients with heart failure. Diuresis increased stroke volume (43 +/- 23 ml to 50 +/- 18 ml (p less than 0.05)) and decreased pulmonary wedge pressure (28 +/- 3 mm Hg to 19 +/- 5 mm Hg (p less than 0.01)), mean blood pressure (100 +/- 14 mm Hg to 88 +/- 10 mm Hg (p less than 0.01)) and systemic vascular resistance (2,059 +/- 622 dynes-sec-cm-5 to 1,783 +/- 556 dynes-sec-cm-5 (p less than 0.05)). Echo left ventricular diastolic dimension was not changed by diuresis (6.0 +/- 0.8 cm to 6.0 +/- 0.8 cm). Percent change in stroke volume correlated with systemic vascular resistance (r = 0.60, p less than 0.05) and with left ventricular diastolic dimension (r = 0.62, p less than 0.05) but not with pulmonary wedge pressure (r = 0.12) or right atrial pressure (r = 0.04). Thus, diuresis improved the performance of the failing ventricle and reduced afterload, but it did not alter left ventricular diastolic dimension, an index of preload. These data suggest that diuresis improves ventricular function by decreasing afterload.

Relation of plasma aldosterone concentration to diuretic treatment in patients with severe heart disease

To assess the relation of hyperaldosteronism and potassium depletion to the intensity of diuretic therapy we have measured plasma aldosterone by radioimmunoassay and total exchangeable potassium by radioisotope dilution in 24 patients when they were stable at the end of their preparation for cardiac operation. Some patients required intensive frusemide therapy to reach an optimal state for operation and many showed hyperaldosteronism. Plasma aldosterone was significantly related to daily dose of frusemide (r=0.77). Depletion of total exchangeable potassium expressed in terms of predicted weight was significantly related to plasma aldosterone (r= -0.64). The reduction in total exchangeable potassium is interpreted as chiefly related to loss of lean tissue mass from the wasting that leads to cardiac cachexia, but evidence is presented on the basis of measurements of extracellular fluid volume as sulphate space (20 patients) of entry of sodium into the cells which may indicate a true cellular potassium loss. Although plasma potassium is usually easily maintained with oral potassium supplements or aldosterone antagonists, we postulate that intensive diuretic therapy in severe heart disease may provoke hyperaldosteronism which accentuates potassium loss and may contribute to wasting and to intracellular potassium depletion in critical tissue, such as myocardium.

Paradox of improved exercise but not resting hemodynamics with short-term prazosin in chronic heart failure

In patients with chronic heart failure exercise allows the simultaneous observation of the cardiovascular pathophysiology and the symptoms of these patients. We administered short-term, oral prazosin to 10 patients with severe chronic heart failure. Prazosin increased cardiac output and stroke volume significantly during exercise (both P less than 0.05) but not at rest (both P greater than 0.10). Prazosin decreased the arteriovenous oxygen difference and left ventricular filling pressure significantly during exercise (both P less than 0.05) but not at rest (both P greater than 0.10). There was no significant correlation between prazosin-induced changes at rest and during exercise in cardiac output (r = 0.12), stroke volume (r = 0.02), arteriovenous oxygen difference (r = 0.33) or left ventricular filling pressure (r = 0.43). Prazosin predominantly affects hemodynamics during exercise because its pharmacologic activity as an alpha-adrenergic blocking agent is most prominent during exercise. The full evaluation of prazosin-induced changes in the hemodynamics of patients of patients with chronic heart failure requires evaluation during exercise.

Direct assessment of cardiac function

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Acute effects of furosemide on blood electrolytes and hemodynamics in dogs

The effects of furosemide on the hemodynamics, blood electrolytes, and urinary output in 5 anesthetized dogs were studied. There were no significant changes in blood Na+ or Ca++ levels, but K+ decreased significantly after 15 minutes of furosemide treatment. There were no significant changes in the blood pressure, heart rate, left ventricular systolic pressure, index of left ventricular contractility [(dp/dt)/IIP], or systemic vascular resistance. Left ventricular dp/dt decreased for 30 to 60 minutes. Later the dp/dt and (dp/dt)/IIP of left ventricular pressure exceeded control values, although increases were not significant. Left ventricular work index and stroke volume decreased significantly between 30 and 90 minutes. The cardiac output and cardiac index also decreased. Left ventricular end-diastolic pressure decreased significantly only at 30 minutes. Cardiac function remained unchanged and consistent with the electrolytes changes. Although there was a marked diuresis, which normally must have significantly decreased the effective blood volume and hence the myocardial contractility, the cardiac function remained unchanged. These results suggests that furosemide might have a direct effect on the myocardium. Clinical improvement in patients might be the result of a direct effect on the myocardium aside from its effect due to diuresis.

Diuretics: mechanism of action and clinical application

Despite the bewildering number of diuretics available to the physician, these drugs can be divided into 4 main groups, characterised by their site of action on sodium reabsorption in the kidney. Drugs acting on the ascending limb of the loop of Henle have a powerful but short acting diuretic effect; they include frusemide, ethacrynic acid and bumetanide. The benzothiadiazines and related compounds have a moderate diuretic action spread over a longer period, whilst the potassium-sparing diuretics, triamterene, amiloride and spironolactone, have only a weak diuretic effect but a marked ability to diminish urinary potassium excretion. The fourth group is made up of miscellaneous substances which function as vasodilator or osmotic agents. The pathogenesis of oedema formation in heart failure is outlined and a logical approach to treatment suggested. Duiretics are being increasingly used in the treatment of non-oedematous states, in particular hypertension, diabetes insipidus and hypercalciuria; their exact role in pregnancy and acute renal failure remains controversial. Side-effects can be related to their effect on electrolyte excretion and include hypokalaemia, hyponatraemia, hyperkalaemia and hyperuricaemia. The incidence of disturbed carbohydrate tolerance in previously normal individuals is low. Other less common side-effects are also discussed.