Hemodynamic comparison of primary venous or arteriolar dilatation and the subsequent effect of furosemide in left ventricular failure after acute myocardial infarction

Relationship between early drop in systolic blood pressure, worsening renal function, and in-hospital mortality in patients with heart failure: a retrospective, observational study

This study aimed to determine the optimal cut-off value of the early drop in systolic blood pressure (SBP) for worsening renal function (WRF) in hospitalized patients with heart failure (HF) and analyze predictors of WRF and the early drop in SBP at that threshold. We retrospectively enrolled 396 patients with acute decompensated HF. The early drop in SBP was defined as the difference between baseline and SBP measured 24 h after hospitalization. We performed receiver operating characteristic (ROC) analysis to determine the optimal cut-off value of the early drop in SBP for WRF and evaluated the effect of the early drop in SBP on in-hospital mortality by multivariate logistic regression analyses. The mean age of the patients was 73.4 ± 14.7 years, and 61.2% were men. A 14.0% drop in SBP was identified as the optimal cut-off value for WRF from the ROC curve analysis. An early drop in SBP ≥ 14.0% was associated with WRF in multivariate logistic regression analysis (odds ratio 7.84; 95% confidence interval 4.06-15.14; P < 0.0001). The dose of intravenous furosemide within 24 h of admission was one of the predictors of the early drop in SBP ≥ 14.0%, while no early drop in SBP was a predictor of in-hospital mortality in multivariate logistic regression models. In conclusion, the optimal cut-off value for WRF in patients with HF was a 14.0% drop in SBP within 24 h of admission. The early drop in SBP ≥ 14.0% was one of the predictors of WRF in patients with HF. However, no early drop in SBP was associated with in-hospital mortality. This study was registered with the University Hospital Medical Information Network in Japan (UMIN000035989).

Perioperative risk factors for acute kidney injury after off-pump coronary artery bypass grafting: a retrospective study

Background

Acute kidney injury (AKI) after cardiac surgery is associated with increased morbidity and mortality. Although morbidity of AKI after off-pump coronary artery bypass grafting (OPCAB) has been investigated, little is known about risk factors for AKI after OPCAB. To identify risk factors for AKI, we examined the association between perioperative variables and AKI after OPCAB.

Findings

We reviewed the medical records of consecutive adult patients who underwent isolated OPCAB between January 2010 and February 2013 in a single institute, retrospectively. The primary outcome was the incidence of AKI evaluated using Acute Kidney Injury Network classifications during the first 48 h postoperatively. We investigated preoperative and intraoperative variables, including hemodynamic parameters, as potential risk factors for AKI. The relationship between candidates of AKI and incidence of AKI was examined by multivariate logistic regression analysis.A total of 298 patients were enrolled in this study. Acute kidney injury occurred in 47 patients (15.7%). Multivariate logistic regression analysis showed that intraoperative furosemide administration (odds ratio [OR], 5.163; 95% confidence interval, 2.171 to 12.185; P < 0.001] and diabetes mellitus (OR, 1.954; 95% confidence interval, 1.004 to 3.880; P = 0.049) were significantly associated with AKI.

Conclusions

Intraoperative furosemide administration and diabetes mellitus were significantly associated with AKI in patients who had received OPCAB.

Nitrates for the Management of Acute Heart Failure Syndromes, A Systematic Review

Intravenous nitrates are widely used in the management of acute heart failure syndrome (AHFS) yet with lack of robust evidence to support their use. We therefore sought to analyze all randomized studies that evaluated the effects of nitrates on clinical outcomes in patients with AHFS. In total, 15 relevant trials comparing nitrates and alternative interventions in 1824 patients were identified. All but 3 were conducted before 1998. No trials demonstrated a beneficial effect on mortality, apart from 1 trial reporting a reduction in mortality, which was related to the time of treatment. Retrospective review suggests that there is a lack of data to draw any firm conclusions concerning the use of nitrates in patients with AHFS. More studies are needed to evaluate the safety and efficacy of these agents in the modern era of guideline-directed use of heart failure therapy.

Comparison of Hemodynamic and Biochemical Effects of Furosemide by Continuous Infusion and Intermittent Bolus in Critically Ill Patients

Positive fluid balance in critically ill patients is a common problem in the intensive care unit (ICU) often associated with a poor outcome. In addition, clinically important changes in hemodynamic variables have been found to occur after diuretic therapy. This study was conducted to evaluate the safety and relative effectiveness of two diuretic protocols in the ICU. Twenty-two patients in the medical ICU with pulmonary edema or fluid overload and PaO2/FIO2 pressure less than 300, were randomized to diuretic therapy by either continuous infusion or intermittent bolus. Hemodynamic and biochemical measurements were recorded. Protocol-guided diuretic management can be readily and safely implemented in the ICU. Although both continuous and bolus diuretic regimens appear to be equally effective in achieving negative fluid balance, the clinician may consider a continuous infusion of furosemide in the hemodynamically and electrolytically unstable patient to ensure more controlled diuresis with less hemodynamic and electrolyte alteration. From a nursing perspective, a continuous infusion of furosemide is a more efficient means of drug delivery.

Lack of renoprotective effects of dopamine and furosemide during cardiac surgery

Because development of acute renal failure is one of the most potent predictors of outcome in cardiac surgery patients, the prevention of renal dysfunction is of utmost importance in perioperative care. In a double-blind randomized controlled trial, the effectiveness of dopamine or furosemide in prevention of renal impairment after cardiac surgery was evaluated. A total of 126 patients with preoperatively normal renal function undergoing elective cardiac surgery received a continuous infusion of either "renal-dose" dopamine (2 microg/kg per min) (group D), furosemide (0.5 microg/kg per min) (group F), or isotonic sodium chloride as placebo (group P), starting at the beginning of surgery and continuing for 48 h or until discharge from the intensive care unit, whichever came first. Renal function parameters and the maximal increase of serum creatinine above baseline value within 48 h (deltaCrea(max)) were determined. The increase in plasma creatinine was twice as high in group F as in groups D and P (P < 0.01). Acute renal injury (defined as deltaCreamax) >0.5 mg/dl) occurred more frequently in group F (six of 41 patients) than in group D (one of 42) and group P (zero of 40) (P < 0.01). (The difference between group D and group P was not significant.) Creatinine clearance was lower in group F (P < 0.05). Two patients in group F required renal replacement therapy. The mean volume of infused fluids, blood urea nitrogen, serum sodium, serum potassium, and osmolar- and free-water clearance was similar in all groups. It was shown that continuous infusion of dopamine for renal protection was ineffective and was not superior to placebo in preventing postoperative dysfunction after cardiac surgery. In contrast, continuous infusion of furosemide was associated with the highest rate of renal impairment. Thus, renaldose dopamine is ineffective and furosemide is even detrimental in the protection of renal dysfunction after cardiac surgery.

Acute hemodynamic and neurohoromonal effects of furosemide in critically ill pediatrics patients

OBJECTIVES

To study the acute hemodynamic effects of furosemide in critically ill pediatrics patients, the temporal relationship between hemodynamic changes and changes in neuroendocrine axis, and the temporal relationship between hemodynamic changes and urine output.

DESIGN

Prospective study.

SETTING

Pediatric intensive care unit in a tertiary care university center.

PATIENTS

Fourteen critically ill pediatric patients who clinically required diuretic therapy.

INTERVENTIONS

Before and after furosemide administration, hemodynamic and neurohormonal measurements were taken.

MEASUREMENTS AND MAIN RESULTS

Hemodynamic and neurohormonal responses to acute diuretic therapy were measured in 14 pediatric patients treated with furosemide (1 mg/kg/dose). Cardiac index deteriorated by 10 mins after drug administration (-9.4+/-3.9%, p<.05) and was associated with an increase in systemic vascular resistance (17.1+/-4.8%, p<.05). There was a subsequent increase in cardiac index (20+/-4.9%, p<.05) at 30 mins, with a decrease in systemic vascular resistance (-11.5+/-5.2%, p<.05). These hemodynamic changes were associated with marked increases in renin and norepinephrine concentrations and an increase in urinary prostaglandin release. The hemodynamic and neurohormonal effects had their onset before maximum diuresis.

CONCLUSION

Intravenous furosemide administration in acutely ill pediatric patients results in an acute but transient deterioration in cardiac function that appears to parallel the neuroendocrine changes rather than the acute diuresis.

Diuretics in postinfarction heart failure

Severe left ventricular failure, as evidenced by radiographic pulmonary edema or raised left ventricular filling pressure, accompanying acute myocardial infarction, carries a high mortality risk. In this situation, the intravenous loop-diuretic furosemide induces a rapid reduction in the raised left ventricular filling pressure due to an immediate and substantial increase in systemic venous compliance accompanied by increasing diuresis. This diuretic-induced venodilatation is probably due to the release of prostaglandins. The transient systemic arterial constriction and small increase in systemic blood pressure that follows intravenous furosemide probably results from the release of renin and subsequent activation of angiotensin. These diuretic induced hemodynamic changes are accompanied by restoration of the vasodilator reflex, which enables the heart to accommodate an acute volume load. Orally administered loop diuretics achieve slower, but similar, directional hemodynamic changes. There is no information on hemodynamic or neuroendocrine dose-response effects of loop diuretics, and there is no information pertaining to the use of other diuretic groups in this situation. The hemodynamic changes induced by furosemide summate with the changes induced by other anti-heart-failure drugs. In this subset of patients with acute myocardial infarction and severe heart failure, the influence of the diuretics on morbidity incidence and mortality risk remains to be measured.

Sustained cardiac diastolic changes elicited by ultrafiltration in patients with moderate congestive heart failure: pathophysiological correlates

OBJECTIVE

To investigate the pathophysiological (cardiac function and physical performance) significance of clinically silent interstitial lung water accumulation in patients with moderate heart failure; to use isolated ultrafiltration as a means of extravascular fluid reabsorption.

DESIGN

Echocardiographic, Doppler, chest x-ray evaluations, and cardiopulmonary tests at baseline, soon after ultrafiltration (veno venous extracorporeal circuit), and four days, one month, and three months later.

SETTING

University institute of cardiology.

SUBJECTS

24 patients with heart failure due to idiopathic dilated cardiomyopathy or ischaemic myocardial disease with sinus rhythm and ejection fraction less than 35%. Twelve were randomised to ultrafiltration and 12 were taken as controls.

MAIN OUTCOME MEASURES

Left ventricular systolic function (from ultrasonography); Doppler evaluation of mitral, tricuspid, and aortic flow and echo-Doppler determination of cardiac output; radiological score of extravascular lung water; right and left ventricular filling pressures; oxygen consumption at peak exercise and exercise tolerance time in cardiopulmonary tests.

RESULTS

Soon after ultrafiltration (1976 (760) ml of fluid removed) the following was observed: a reduction in radiological score of extravascular lung water (from 15(1) to 9(1)) and of right (from 7.1 (2.3) to 2.3 (1.7) mm Hg) and left (from 17.6 (8.8) to 9.5 (6.4) mm Hg) ventricular filling pressures; an increase in oxygen consumption at peak exercise (from 15.8 (3.3) to 17.6 (2) ml/min/kg) and of tolerance time (from 444 (138) to 508 (134) s); a slight decrease in atrial and ventricular dimensions; no changes in the systolic function of the left ventricle; a reduction of the early to late filling ratio in both ventricles (mitral valve from 2 (2) to 1.1 (1.1)); (tricuspid valve from 1.3 (1.3) to 0.69 (0.18)) and an increase in the deceleration time of mitral and tricuspid flow, reflecting a redistribution of filling to late diastole. Variations in the ventricular filling pattern, lung water content, and functional performance persisted for three months in all cases. None of these changes was detected in the control group.

CONCLUSIONS

Reduction of interstitial lung water was probably the mechanism whereby ultrafiltration modified the pattern of filling of the two ventricles and improved functional performance.

Acute preload effects of furosemide

Acute preload effects (as reflected by the pulmonary capillary wedge pressure [PCWP]) of an intravenous furosemide bolus were studied in 33 patients. In those patients receiving no vasoactive drug and in those receiving predominantly preload reducing agents, there was an initial rise in PCWP up until 15 minutes followed by a diuresis-induced fall in PCWP below baseline levels at 1 h. Patients who were receiving preload and significant afterload reduction showed an immediate drop in PCWP which was sustained. This trend is independent of underlying pathology or dose of furosemide used. It is postulated that furosemide causes an early deleterious release of endogenous vasoconstrictors which may be blocked by combined preload and afterload reduction.

Direct effects of furosemide and amiloride on the perfused and ischaemic rat heart

The present study was undertaken in order to assess direct effects of furosemide and furosemide plus amiloride upon the perfused and ischaemic isolated rat heart. Furosemide in concentrations ranging between 4-400 mg/l in the perfusate increased coronary flow in a concentration dependent manner. There was no evidence for a negative inotropic effect of furosemide. However, very high doses of furosemide (400 mg/l) decreased the post-ischaemic values of left ventricular developed pressure, coronary flow rate, adenosine triphosphate, creatine phosphate and potassium, and increased the myocardial content of calcium and sodium. Furosemide 4 mg/l and 40 mg/l had no effect on post-ischaemic parameters compared to the control group except that furosemide 40 mg/l increased the recovery of coronary flow. Although amiloride 13.3 mg/l alone did not affect post-ischaemic recovery, the addition of this dose to furosemide 400 mg/l improved the post-ischaemic recovery of left ventricular developed pressure, coronary flow rate and adenosine triphosphate. The myocardial content of magnesium and potassium was higher indicating protection of amiloride by its magnesium- and potassium-sparing properties opposing ischaemic losses aggravated by the exposure to furosemide.

Hemodynamic, renal and endocrine effects of atrial natriuretic peptide infusion in severe heart failure

The cardiac release and total body and renal clearances and the hemodynamic, renal and endocrine effects of increasing doses of atrial natriuretic peptide were investigated in 12 patients with severe chronic congestive heart failure. Immunoreactive arterial plasma levels of atrial natriuretic peptide were 10-fold higher than normal and there was no correlation between aortic atrial natriuretic peptide and cardiac filling pressures. The heart released atrial natriuretic peptide into the coronary sinus. The kidney, though a major clearance site, accounted for only 33% of the total body clearance. Administration of 0.3 micrograms/kg per min atrial natriuretic peptide produced significant changes in heart rate (95 +/- 4 to 85 +/- 4 beats/min) and mean arterial (92 +/- 8 to 77 +/- 9 mm Hg), right atrial (13 +/- 3 to 8 +/- 2 mm Hg) and mean pulmonary artery occluded (27 +/- 3 to 14 +/- 3 mm Hg) pressures. Atrial natriuretic peptide increased cardiac index (2.25 +/- 0.18 to 2.83 +/- 0.3 liters/min per m2) and stroke work index (21 +/- 1.5 to 29 +/- 3.4 g/m2), whereas systemic vascular resistance (1,424 +/- 139 to 1,033 +/- 97 dynes.s.cm(-5)) decreased. Infusion of 0.1 microgram/kg per min atrial natriuretic peptide increased urinary flow 128%, fractional excretion of sodium 133% and fractional excretion of potassium 35%. The filtration fraction increased from 29 +/- 2 to 31 +/- 4%. This represented a disproportionate rise in glomerular filtration rate over renal plasma flow. Plasma aldosterone and norepinephrine decreased whereas plasma renin activity remained unchanged. In association with these hemodynamic, excretory and endocrine changes, the urinary excretion of cyclic guanosine monophosphate doubled. Placebo had no effect. These results showed that, despite high circulating levels of atrial natriuretic peptide, administration of this hormone in heart failure is associated with potentially beneficial hemodynamic, renal and endocrine effects.

Hemodynamic effects of intravenous isosorbide dinitrate and nitroglycerine in acute myocardial infarction and elevated pulmonary artery wedge pressure

We compared in a randomized fashion the hemodynamic effects of intravenous (IV) isosorbide dinitrate (ISDN) and nitroglycerine (NTG) in 45 patients with acute myocardial infarction and elevated pulmonary artery wedge pressure (Paw). Titration of ISDN dose to lower Paw greater than or equal to 25 percent resulted in a fall of this parameter from 32 +/- 8 to 24 +/- 5 mm Hg and was associated with a fall in mean blood pressure (96 +/- 15 to 90 +/- 14 mm Hg, p less than 0.05), systemic vascular resistance (1715 +/- 572 to 1548 +/- 414 dynes X s X cm-5, (p less than 0.05), pulmonary vascular resistance (182 +/- 106 to 154 +/- 78 dynes X s X cm-5, p less than 0.05) and mean right atrial pressure (11 +/- 4 to 7 +/- 4 mm Hg, p less than 0.05). In addition, ISDN significantly (p less than 0.05) increased cardiac index from 2.37 +/- 0.54 to 2.54 +/- 0.59 L/min/m2, stroke volume index from 28 +/- 8 to 31 +/- 8 ml/m2, and stroke work index from 28 +/- 11 to 31 +/- 12 g X m/m2. The ISDN dose ranged from 50 to 533 micrograms/min (mean +/- SD 326 +/- 176 micrograms/min) and could not be predicted from baseline hemodynamic values. A comparison between the effect of ISDN and NTG in doses producing comparable reduction in Paw showed similar hemodynamic changes. It was concluded that IV ISDN in patients with elevated mean pulmonary artery wedge pressure due to acute myocardial infarction results in a decrease in right and left ventricular preload and afterload and improvement of cardiac output and cardiac work. The effective dose ranges from 50 to 533 micrograms/min and cannot be predicted from baseline hemodynamic values. In doses producing comparable reduction in Paw, ISDN and NTG had similar hemodynamic effects.

Immediate hemodynamic response to furosemide in patients undergoing chronic hemodialysis

To evaluate the effect of furosemide on cardiovascular hemodynamics in patients with end-stage renal failure, we studied ten patients undergoing hemodialysis three times a week. Arterial pressure, heart rate, and cardiac output (indocyanine green dye) were measured in triplicate; total peripheral resistance and central blood volume were calculated by standard formulas. Hemodynamics were determined at baseline and 5, 10, 15, and 30 minutes after intravenous (IV) bolus injection of furosemide 60 mg. Furosemide produced a decrease in central blood volume of -13% +/- 2.2% from pretreatment values (P less than .01) that was most pronounced five minutes after injection, together with a fall in cardiac output (from 6.76 +/- 0.59 to 6.17 +/- 0.52 L/min, P less than .10). Stroke volume decreased with a maximum fall occurring after 15 minutes (from 84 +/- 7 to 79 +/- 7 mL/min, P less than .05), and total peripheral resistance increased (from 15.8 +/- 2.1 to 17.8 +/- 2.3 units, P less than .05) after furosemide. Arterial pressure and heart rate did not change. The decrease in central blood volume reflects a shift of the total blood volume from the cardiopulmonary circulation to the periphery, suggesting dilation of the peripheral venous bed. Thus, even in patients undergoing hemodialysis, furosemide acutely decreases left ventricular preload by venous dilation and should therefore prove to be beneficial in acute volume overload.

The role of transdermal nitroglycerin in the treatment of coronary heart disease

Nitroglycerin has long been a mainstay of the treatment of ischemic cardiac pain. The introduction of transdermal formulations and in particular the development of controlled methods of delivery have been responsible for the renaissance of clinical interest in this simple and effective treatment. The pathophysiologic abnormality accompanying myocardial ischemia affords a natural theater for the exhibition of the therapeutic utility of these preparations and methods. The means whereby nitrates induce relaxation of vascular smooth muscle are not entirely clear, but their pharmacodynamic activities are perfectly plain. In the doses used in clinical practice, nitrates exert their predominant hemodynamic effects and therapeutic benefits through their peripheral vasodilator activities. This is particularly marked in veins, although in higher doses nitrates also dilate the larger systemic and coronary arteries. Criticisms of the efficacy of transdermal formulations of nitrates in the treatment of angina pectoris have arisen largely from uncritical acceptance of a small number of studies of questionable methodologic validity. Large-scale general practice studies have invariably found that transdermal nitrate delivery systems improve the quality of life in ambulant patients: anginal attacks are reduced with a minimum of side effects. The widespread acceptance of this novel form of drug delivery has stimulated its application in other therapeutic avenues. The efficacy of transdermal nitroglycerin in the suppression of silent ischemic attacks has been demonstrated. The maintenance of benefit initiated by intravenous nitroglycerin in patients with unstable angina also broadens the use of this method of nitrate delivery. In patients with acute myocardial infarction, whether complicated by left ventricular failure or not, the nitrates, and transdermal nitroglycerin in particular, appear to hold considerable promise. Improvement of hemodynamic abnormalities may cause reduction in infarct size and fewer life-threatening arrhythmias. Even survival may be extended. The utility of transdermal nitrates in the treatment of severe chronic heart failure is less certain. But the use of higher doses and an interval regimen of administration may hold promise for such patients. Naturally, more information is required before the overall therapeutic profile of this new method of controlled nitroglycerin delivery across the whole spectrum of coronary heart disease can be fully described. Fortunately, the high level of efficacy and safety of transdermal nitroglycerin demonstrated in the majority of reported studies encourages the pursuit of such an important therapeutic target.

Congestive heart failure

A review of the epidemiology, pathophysiology, and treatment of congestive heart failure is presented, with particular attention given to newer modalities of therapy.

Hemodynamic trial of sequential treatment with diuretic, vasodilator, and positive inotropic drugs in left ventricular failure following acute myocardial infarction

The circulatory effects induced by two sequential intravenous treatment programs with a diuretic, arteriolar or venodilator , and a positive inotropic drug were studied in a randomized between-group trial in 20 male patients with radiographic and hemodynamic evidence of left ventricular (LV) failure following acute myocardial infarction (AMI). Furosemide induced a substantial diuresis in both groups of patients, in association with reductions in LV filling pressure (p less than 0.01) and cardiac output (p less than 0.05), without significant change in heart rate or systemic arterial pressure. The addition of isosorbide dinitrate was followed by reductions in the systemic arterial (p less than 0.01) and LV filling pressures (p less than 0.01) without significant change in the heart rate or cardiac output. Hydralazine after furosemide reduced systemic vascular resistance (p less than 0.01), but the fall in mean blood pressure (p less than 0.01) was limited by the increase in cardiac output (p less than 0.01); heart rate was also increased (p less than 0.01) and LV filling pressure fell (p less than 0.05). The final addition of the beta-1 adrenoceptor agonist, prenalterol, increased systemic arterial systolic pressure (p less than 0.05), cardiac output (p less than 0.05), and heart rate (p less than 0.01), and reduced systemic vascular resistance (p less than 0.01) in both groups; these changes were greatest in those pretreated with furosemide and isosorbide dinitrate. In both treatment pathways compared with control the reductions in systemic vascular resistance and left heart filling pressure were accompanied by increases in heart rate and cardiac output without substantial changes in systemic blood pressure. Which of these hemodynamic pathways offers the optimum prognosis awaits further study.