1169Interim analysis of data from a long-term, extension trial of tafamidis meglumine in patients with transthyretin amyloid cardiomyopathy

Background

Transthyretin amyloid cardiomyopathy (ATTR-CM), is an underdiagnosed, fatal disease caused by the deposition of transthyretin amyloid fibrils in the heart leading to heart failure. The Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT), an international, multi-center, double-blind, placebo-controlled, randomized study, demonstrated the efficacy and safety of tafamidis treatment for patients with ATTR-CM due to variant (ATTRm) or wild-type (ATTRwt) TTR.

Purpose

This is a pooled analysis of data from ATTR-ACT and interim data from the ongoing, long-term, extension study to evaluate longer term data on the efficacy of tafamidis in patients with ATTR-CM.

Methods

Patients who completed ATTR-ACT (which had a duration of 30 months) were eligible to be enrolled in a long-term, extension study in which patients either continued to receive tafamidis meglumine at the same dose (the tafamidis/tafamidis [T/T] group) or, for patients previously treated with placebo, were randomised (in a 1:2 ratio) to tafamidis meglumine 20 mg or 80 mg (the placebo/tafamidis [P/T] group) for up to 60 months. The primary efficacy outcome was all-cause mortality. This analysis combined data from the completed ATTR-ACT with interim data from the extension study (cut-off date: 15 Feb, 2018), and included patients treated with tafamidis meglumine across the two studies with a median follow up of 36 months.

Results

All-cause mortality was significantly lower in the T/T group (n=264; 88 events, 33.3%) compared with the P/T group (n=177; 88 events, 50.3%); hazard ratio (95% CI), 0.64 (0.47, 0.85); P=0.001. In the subgroup of ATTRwt patients, all-cause mortality was significantly reduced in the T/T group (55/201; 27.4%) compared with the P/T group (60/134; 44.8%); 0.64 (0.44, 0.92); P=0.002. In the 106 (24.0%) ATTRm patients, there was a trend towards a reduction in all-cause mortality in the T/T group (33/63; 52.4%) compared with the P/T group (29/43; 67.4%); 0.66 (0.39, 1.09); P=0.17. In patients who were NYHA Class I or II at baseline, all-cause mortality was significantly reduced in the T/T group (38/186; 20.4%) compared with the P/T group (45/114; 39.5%); 0.49 (0.32, 0.75); P=0.001. In those patients with more severe symptoms at baseline (NYHA Class III), there were fewer deaths in the T/T group (50/78; 64.1%) compared with the P/T group (44/63; 69.8%); 0.80 (0.53, 1.21), but this difference was not statistically significant (P=0.50).

Conclusions

In ATTR-ACT, tafamidis was shown to significantly improve survival, functional capacity, and quality of life in patients with ATTR-CM. This pooled analysis with data from the ongoing extension study further supports the efficacy of tafamidis in patients over a longer period of time and the importance of early diagnosis and treatment.

Acknowledgement/Funding

This study was sponsored by Pfizer.

Effect of nesiritide in patients with acute decompensated heart failure

BACKGROUND

Nesiritide is approved in the United States for early relief of dyspnea in patients with acute heart failure. Previous meta-analyses have raised questions regarding renal toxicity and the mortality associated with this agent.

METHODS

We randomly assigned 7141 patients who were hospitalized with acute heart failure to receive either nesiritide or placebo for 24 to 168 hours in addition to standard care. Coprimary end points were the change in dyspnea at 6 and 24 hours, as measured on a 7-point Likert scale, and the composite end point of rehospitalization for heart failure or death within 30 days.

RESULTS

Patients randomly assigned to nesiritide, as compared with those assigned to placebo, more frequently reported markedly or moderately improved dyspnea at 6 hours (44.5% vs. 42.1%, P=0.03) and 24 hours (68.2% vs. 66.1%, P=0.007), but the prespecified level for significance (P≤0.005 for both assessments or P≤0.0025 for either) was not met. The rate of rehospitalization for heart failure or death from any cause within 30 days was 9.4% in the nesiritide group versus 10.1% in the placebo group (absolute difference, -0.7 percentage points; 95% confidence interval [CI], -2.1 to 0.7; P=0.31). There were no significant differences in rates of death from any cause at 30 days (3.6% with nesiritide vs. 4.0% with placebo; absolute difference, -0.4 percentage points; 95% CI, -1.3 to 0.5) or rates of worsening renal function, defined by more than a 25% decrease in the estimated glomerular filtration rate (31.4% vs. 29.5%; odds ratio, 1.09; 95% CI, 0.98 to 1.21; P=0.11).

CONCLUSIONS

Nesiritide was not associated with an increase or a decrease in the rate of death and rehospitalization and had a small, nonsignificant effect on dyspnea when used in combination with other therapies. It was not associated with a worsening of renal function, but it was associated with an increase in rates of hypotension. On the basis of these results, nesiritide cannot be recommended for routine use in the broad population of patients with acute heart failure. (Funded by Scios; ClinicalTrials.gov number, NCT00475852.).

Quality of life and psychological status of patients with implantable cardioverter defibrillators

INTRODUCTION

Implantable cardioverter defibrillators (ICDs) are effective at reducing mortality in patients at high risk for sudden cardiac death (SCD) but can cause psychological distress and reduce quality of life (QOL). The full benefits of ICDs can only be achieved when the patient's QOL and psychological status are maintained. We examined psychological status and QOL post ICD implantation; the relationship of psychological status to QOL; the relationship of time since implantation to psychological status and QOL; and the relationship of time since ICD implantation and age of patient to these variables.

METHODS AND RESULTS

A cross-sectional self-administered assessment of QOL, depression, anxiety, demographic characteristics and cardiovascular health history of patients (n = 48) who had received ICDs within the past 10 years at an urban hospital. Patients who had ICDs for longer experienced worse depression and QOL. Patients who were younger had worse depression, anxiety, and QOL. The combination of anxiety, depression, age, and time since ICD implant significantly predicted overall QOL and the psychosocial and physical dimensions of QOL explaining 55.5, 54, and 34.9% of the variance, respectively.

CONCLUSION

Younger ICD patients are at highest risk for psychological distress and poor QOL. Longitudinal research would facilitate determination of the trajectory of changes in psychological status and QOL over the duration of the ICD experience.

Renal effects of adenosine A1-receptor antagonists in congestive heart failure

Renal function is a very important prognostic indicator in patients with congestive heart failure. While some of the prognostic importance of poor renal function is related to the worse physiology associated with it, there are suggestions that the dysfunction itself is detrimental. Recently, it has been shown that adenosine may mediate much kidney activity. In addition to vasoconstrictive and vasodilatory effects, adenosine is intrinsic to the tubuloglomerular feedback which occurs when an acute increase in sodium levels in the proximal tubule feeds back to decrease glomerular filtration. Adenosine works via both adenosine A1 and A2 receptors. A1-receptor antagonists decrease afferent arteriolar pressure, and increase urine flow and sodium excretion. Studies suggest that A1-receptor antagonists cause a diuretic effect not by a change in the renal haemodynamics, but by the inhibition of water and sodium reabsorption in tubular sites secondary to direct tubuloglomerular feedback. Less consistent has been the occasional finding of increased glomerular filtration rate despite the lack of improved renal plasma flow. Clinically important questions are: what role adenosine plays in causing the poor renal function associated with heart failure and what A1-receptor antagonists do in such situations? If an A1-receptor antagonist could cause diuresis while maintaining or improving glomerular filtration, it would be a useful adjunct in the treatment of severe heart failure. We evaluated the effects of the A1-receptor antagonist CVT-124 (BG-9719) in heart failure patients. CVT-124 increased sodium excretion without decreasing glomerular filtration rate. These data suggest that adenosine might be an important determinant of renal function in patients with heart failure.

Exercise in the geriatric patient with congestive heart failure

The benefits of exercise in the elderly patient with heart failure have been well documented, but the studies have been limited by restrictive inclusion criteria. Most studies have involved patients who are younger and healthier than those normally seen in clinical practice. Improvements in neurohormonal, metabolic, and vascular status have been well documented in the relatively young patients who have been evaluated. Consequently, peak exercise time, oxygen consumption, submaximal exercise, and quality of life have also improved. Studies suggest that older, more severely limited patients may also benefit from exercise. However, they are less likely to tolerate an exercise program and may not improve their quality of life if the exercise is excessive. Caution is warranted when exercise is prescribed to elderly patients with heart failure.

Comparative effects of three beta blockers (atenolol, metoprolol, and propranolol) on survival after acute myocardial infarction

The beneficial impact of beta blockade after an acute myocardial infarction (AMI) is clear, but beta-adrenergic blockers differ in multiple characteristics, including lipophilicity and selectivity. The impact of these factors on the effects of beta blockade is unknown. We therefore compared the effects of different beta blockers on mortality after AMI. Charts of 201,752 patients with AMI were abstracted by the Cooperative Cardiovascular Project, a quality assurance program sponsored by the Health Care Financing Administration. Of the 69,338 patients prescribed beta blockers, we compared mortality of patients receiving different beta-adrenergic blockers using the Cox proportional-hazards model accounting for multiple factors that might influence survival. The mortality rates of the 2 selective agents, metoprolol and atenolol, were virtually identical (13.5% and 13.4% 2-year mortality, respectively). Compared with metoprolol, patients discharged on propranolol had a slightly increased mortality (15.9% 2-year mortality), which may be related to undetected differences at baseline. Survival with all of the drugs was superior to the 23.9% 2-year mortality seen in patients not receiving beta blockers. Beta blockade overall was associated with a 40% improvement in survival. Although the use of beta blockade after AMI has major prognostic importance, the present study suggests that the specific beta blocker chosen will have little influence on mortality.

Are all beta-blockers the same for chronic heart failure?

beta-Adrenergic receptor blockade has been conclusively proven to increase survival and morbidity in patients with heart failure. Hospitalization rate decreases and patients feel better after receiving beta-blockers. Furthermore, this benefit is observed in a wide range of patients. The beta-blockers bisoprolol, metoprolol, and carvedilol have been extensively evaluated in heart failure patients. These drugs all show marked benefit. Bucindolol, an investigational beta-blocker, showed only mild improvement in survival in patients with heart failure. The beta-blockers differ regarding beta-selectivity, vasodilation properties, and perhaps other ancillary properties. At present, the importance and consequences of these differences are unknown.

Depression is common and precludes accurate assessment of functional status in elderly patients with congestive heart failure

BACKGROUND

Congestive heart failure (CHF) and depression are independently known to result in physical decline and diminished functional capacity in the general population. The prevalence and relationship of depressive symptoms in CHF to physical limitations has not been objectively examined.

METHODS AND RESULTS

The Center for Epidemiological Studies Depression Scale (CES-D) was used to ascertain depressive symptoms in 33 elderly ambulatory individuals with CHF. Self-report assessment of functional status, cardiopulmonary exercise testing (CPX), and measurement of energy expenditure by doubly labeled water and Caltrac Accelerometer (Muscle Dynamics, Torrance, CA) were performed. Depressed and nondepressed groups were compared. Forty-two percent of the patients scored in the depressed range (CES-D score of 16 or greater). There were no differences in demographic variables or severity of illness between the depressed and nondepressed patients. Energy expenditure was comparable across groups. Although obtaining similar maximal heart rate and maximal oxygen consumption (VO2max) on CPX, the depressed group showed less exertion on exercise testing with a significantly lower respiratory quotient (P = .017).

CONCLUSION

Depressive symptoms were common and unrelated to the severity of CHF. Although depressed individuals tended to report worse physical functioning than nondepressed individuals, objective assessment of energy expenditure was comparable. Depressed patients appear to underestimate their functional ability. Subsequently, inaccurate assessment of functional status may occur.

Acute hemodynamic and clinical effects of levosimendan in patients with severe heart failure. Study Investigators

BACKGROUND

We determined the short-term hemodynamic and clinical effects of levosimendan, a novel calcium-sensitizing agent, in patients with decompensated heart failure.

METHODS AND RESULTS

One hundred forty-six patients with New York Heart Association functional class III or IV heart failure (mean left ventricular ejection fraction 21+/-1%) who had a pulmonary capillary wedge pressure >/=15 mm Hg and a cardiac index </=2.5 L x min(-1) x m(-2) were enrolled in a multicenter, double-blind, placebo-controlled study and randomized 2:1 to intravenous infusion of levosimendan or placebo. Drug infusions were uptitrated over 4 hours from an initial infusion rate of 0.1 microg x kg(-1) x min(-1) to a maximum rate of 0.4 microg x kg(-1) x min(-1) and maintained at the maximal tolerated infusion rate for an additional 2 hours. Levosimendan caused dose-dependent increases in stroke volume and cardiac index beginning with the lowest infusion rate and achieving maximal increases in stroke volume and cardiac index of 28% and 39%, respectively. Heart rate increased modestly (8%) at the maximal infusion rate and was not increased at the 2 lowest infusion rates. Levosimendan caused dose-dependent decreases in pulmonary capillary wedge, right atrial, pulmonary arterial, and mean arterial pressures. Levosimendan appeared to improve dyspnea and fatigue, as assessed by the patient and physician, and was not associated with a significant increase in adverse events.

CONCLUSIONS

Levosimendan caused rapid dose-dependent improvement in hemodynamic function in patients with decompensated heart failure. These hemodynamic effects appeared to be accompanied by symptom improvement and were not associated with a significant increase in the number of adverse events. Levosimendan may be of value in the short-term management of patients with decompensated heart failure.

Acute endothelin A receptor blockade causes selective pulmonary vasodilation in patients with chronic heart failure

BACKGROUND

Elevated plasma endothelin-1 (ET-1) levels in patients with chronic heart failure correlate with pulmonary artery pressures and pulmonary vascular resistance. ET(A) receptors on vascular smooth muscle cells mediate pulmonary vascular contraction and hypertrophy. We determined the acute hemodynamic effects of sitaxsentan, a selective ET(A) receptor antagonist, in patients with chronic stable heart failure receiving conventional therapy.

METHODS AND RESULTS

This multicenter, double-blind, placebo-controlled trial enrolled 48 patients with chronic New York Heart Association functional class III or IV heart failure (mean left ventricular ejection fraction 21+/-1%) treated with ACE inhibitors and diuretics. Patients with a baseline pulmonary capillary wedge pressure >/=15 mm Hg and a cardiac index </=2.5 L. min(-1). m(-2) were randomized to 1 of 3 doses (1.5, 3.0, or 6.0 mg/kg) of sitaxsentan or placebo as an intravenous infusion over 15 minutes. Hemodynamic responses were assessed by catheterization of the right side of the heart for 6 hours. Sitaxsentan decreased pulmonary artery systolic pressure, pulmonary vascular resistance, mean pulmonary artery pressure, and right atrial pressure (P</=0.001, 0.003, 0.017, and 0.031, respectively) but had no effect on heart rate, mean arterial pressure, pulmonary capillary wedge pressure, cardiac index, or systemic vascular resistance. Plasma ET-1 levels were elevated at baseline and decreased with sitaxsentan.

CONCLUSIONS

In patients with moderate to severe heart failure receiving conventional therapy, acute ET(A) receptor blockade caused selective pulmonary vasodilation associated with a reduction in plasma ET-1. Sitaxsentan may be of value in the treatment of patients with pulmonary hypertension secondary to chronic heart failure.

The impact of beta-blockade on mortality rates in patients with congestive heart failure

The beneficial effects of beta-adrenergic blockade on mortality rates in patients after a myocardial infarction have been clear for decades. The efficacy data are now just as apparent for patients with heart failure. Although there are many subgroups of patients in whom the mortality effects of beta-blockers are not proven, knowledge about these specific populations continues to increase. Nevertheless, more information is needed so that we can properly tailor our therapy for individual patients.

The effect of coenzyme Q10 in patients with congestive heart failure

BACKGROUND

Coenzyme Q10 is commonly used to treat congestive heart failure on the basis of data from several unblinded, subjective studies. Few randomized, blinded, controlled studies have evaluated objective measures of cardiac performance.

OBJECTIVE

To determine the effect of coenzyme Q10 on peak oxygen consumption, exercise duration, and ejection fraction.

DESIGN

Randomized, double-blind, controlled trial.

SETTING

University and Veterans Affairs hospitals.

PATIENTS

55 patients who had congestive heart failure with New York Heart Association class III and IV symptoms, ejection fraction less than 40%, and peak oxygen consumption less than 17.0 mL/kg per minute (or <50% of predicted) during standard therapy were randomly assigned. Forty-six patients completed the study.

INTERVENTION

Coenzyme Q10, 200 mg/d, or placebo.

MEASUREMENTS

Left ventricular ejection fraction (measured by radionuclide ventriculography) and peak oxygen consumption and exercise duration (measured by a graded exercise evaluation using the Naughton protocol) with continuous metabolic monitoring.

RESULTS

Although the mean (+/-SD) serum concentration of coenzyme Q10 increased from 0.95+/-0.62 microg/mL to 2.2+/-1.2 microg/mL in patients who received active treatment, ejection fraction, peak oxygen consumption, and exercise duration remained unchanged in both the coenzyme Q10 and placebo groups.

CONCLUSION

Coenzyme Q10 does not affect ejection fraction, peak oxygen consumption, or exercise duration in patients with congestive heart failure receiving standard medical therapy.

Effects of BG9719 (CVT-124), an A1-adenosine receptor antagonist, and furosemide on glomerular filtration rate and natriuresis in patients with congestive heart failure

OBJECTIVES

To determine the effects of furosemide and the selective A1 adenosine receptor BG9719 on renal function in patients with congestive heart failure (CHF).

BACKGROUND

Studies suggest that adenosine may affect renal function by various mechanisms, but the effects of blockade of this system in humans is unknown. In addition, the effects of a therapeutic dose of furosemide on glomerular filtration rate (GFR) and renal plasma flow (RPF) in heart failure patients are controversial.

METHODS

On different days, 12 patients received placebo, BG9719 and furosemide. Glomerular filtration rate, RPF and sodium and water excretion were assessed immediately following drug administration.

RESULTS

Glomerular filtration rate was 84 +/- 23 ml/min/1.73m2 after receiving placebo, 82 +/- 24 following BG9719 administration and a decreased (p < 0.005) 63 +/- 18 following furosemide. Renal plasma flow was unchanged at 293 +/- 124 ml/min/1.73m2 on placebo, 334 +/- 155 after receiving BG9719 and 374 +/- 231 after receiving furosemide. Sodium excretion increased from 8 +/- 8 mEq following placebo administration to 37 +/- 26 mEq following BG9719 administration. In the six patients in whom it was measured, sodium excretion was 104 +/- 78 mEq following furosemide administration.

CONCLUSIONS

Natriuresis is effectively induced by both furosemide and the adenosine A1 antagonist BG9719 in patients with CHF. Doses of the two drugs used in this study did not cause equivalent sodium and water excretion but only furosemide decreased GFR. These data suggest that adenosine is an important determinant of renal function in patients with heart failure.

A four-part regimen for clinical heart failure

Combination therapy with a diuretic, digoxin, ACE inhibitor, and beta-blocker can help patients with heart failure caused by severe systolic dysfunction feel better and live longer. Especially with ACE inhibitors and beta-blockers, the key to success is starting at low doses and titrating carefully to proven target doses. The demanding complexity of the four-drug regimen is well worth the results.

Effects of exercise training on peak performance and quality of life in congestive heart failure patients

BACKGROUND

Exercise programs for patients with heart failure have often enrolled and evaluated relatively healthy, young patients. They also have not measured the impact of exercise performance on daily activities and quality of life.

METHODS AND RESULTS

We investigated the impact of a 6-month supervised and graded exercise program in 33 elderly patients with moderate to severe heart failure randomized to usual care or an exercise program. Six of 17 patients did not tolerate the exercise program. Of those who did, peak oxygen consumption increased by 2.4 +/- 2.8 mL/kg/min (P < .05) and 6-minute walk increased by 194 ft (P < .05). However, outpatient energy expenditure did not increase, as measured by either the doubly labeled water technique or Caltrac accelerometer. Perceived quality of life also did not improve, as measured by the Medical Outcomes Study, Functional Status Assessment, or Minnesota Living With Heart Failure questionnaires.

CONCLUSION

Elderly patients with severe heart failure can safely exercise, with an improvement in peak exercise tolerance. However, not all patients will benefit, and daily energy expenditure and quality of life do not improve to the same extent as peak exercise.

Effect of beta-blockade on mortality among high-risk and low-risk patients after myocardial infarction

BACKGROUND

Long-term administration of beta-adrenergic blockers to patients after myocardial infarction improves survival. However, physicians are reluctant to administer beta-blockers to many patients, such as older patients and those with chronic pulmonary disease, left ventricular dysfunction, or non-Q-wave myocardial infarction.

METHODS

The medical records of 201,752 patients with myocardial infarction were abstracted by the Cooperative Cardiovascular Project, which was sponsored by the Health Care Financing Administration. Using a Cox proportional-hazards model that accounted for multiple factors that might influence survival, we compared mortality among patients treated with beta-blockers with mortality among untreated patients during the two years after myocardial infarction.

RESULTS

A total of 34 percent of the patients received beta-blockers. The percentage was lower among the very elderly, blacks, and patients with the lowest ejection fractions, heart failure, chronic obstructive pulmonary disease, elevated serum creatinine concentrations, or type 1 diabetes mellitus. Nevertheless, mortality was lower in every subgroup of patients treated with beta-blockade than in untreated patients. In patients with myocardial infarction and no other complications, treatment with beta-blockers was associated with a 40 percent reduction in mortality. Mortality was also reduced by 40 percent in patients with non-Q-wave infarction and those with chronic obstructive pulmonary disease. Blacks, patients 80 years old or older, and those with a left ventricular ejection fraction below 20 percent, serum creatinine concentration greater than 1.4 mg per deciliter (124 micromol per liter), or diabetes mellitus had a lower percentage reduction in mortality. Given, however, the higher mortality rates in these subgroups, the absolute reduction in mortality was similar to or greater than that among patients with no specific risk factors.

CONCLUSIONS

After myocardial infarction, patients with conditions that are often considered contraindications to beta-blockade (such as heart failure, pulmonary disease, and older age) and those with nontransmural infarction benefit from beta-blocker therapy.

The effects of diuresis on the pharmacokinetics of the loop diuretics furosemide and torsemide in patients with heart failure

PURPOSE

To evaluate the pharmacokinetics of furosemide and torsemide before and after diuresis in patients presenting with marked fluid overload.

SUBJECTS AND METHODS

We studied 44 patients with New York Heart Association class III or IV heart failure, ejection fraction < or =40%, and an estimated excess fluid body weight > or =6.8 kg. Oral furosemide or torsemide was administered before and after diuresis. Pharmacokinetic parameters were assessed before and after diuresis.

RESULTS

Following diuresis, maximum plasma concentration increased from 11.0+/-5.0 microg/mL to 13.9+/-6.8 with torsemide (P <0.05) and from 3.1< or =1.5 to 3.9+/-1.9 with furosemide (P=0.16). Maximum concentration increased by more than 30% in only one third of the patients. Total absorption (by area under the curve method) increased 6% among patients on torsemide (P=0.38) and 7% among patients on furosemide (P=0.63) and increased >30% in only 1 torsemide and 2 furosemide patients. The time to maximum concentration decreased from 1.40+/-.82 h to 0.81+/-0.36 with torsemide (P <0.01). There were no differences between furosemide and torsemide in the effects of edema on absorption.

CONCLUSION

Marked diuresis altered the pharmacokinetics of both furosemide and torsemide in only a small percentage of patients. The use of adequate doses of oral diuretics in edematous patients may be successful, thereby permitting home treatment with oral diuretics and avoiding the cost of hospitalizations or home intravenous administration services.

Daily energy requirements in heart failure patients

Diminished body cell mass in heart failure patients contributes to poor prognosis and decreased quality of life. The level of daily energy intake needed to maintain body cell mass and optimal physiological function in heart failure patients is unknown. Thus, we examined daily energy expenditure in free-living heart failure patients to estimate daily energy requirements. Daily energy expenditure (doubly labeled water) and its components (resting and physical activity energy expenditures) were measured in 26 heart failure patients (25 men and one woman aged 69 +/- 7 years) and 50 healthy controls (48 men and two women aged 69 +/- 6 years). Resting energy expenditure was measured by indirect calorimetry; physical activity energy expenditure from the difference between daily and resting energy expenditure; body composition by dual-energy x-ray absorptiometry; leisure time physical activity from a questionnaire; and peak oxygen consumption ([peak VO2] n = 16 heart failure patients) from a treadmill test to exhaustion. Plasma markers of nutritional status were also considered. Daily energy expenditure was 17% lower (2,110 +/- 500 v 2,543 +/- 449 kcal/d) and physical activity energy expenditure 54% lower (333 +/- 345 v 728 +/- 374 kcal/d) in heart failure patients compared with healthy controls. Daily energy expenditure was related to physical activity energy expenditure (r = .79, P < .01), resting energy expenditure (r = .63, P < .01), leisure time physical activity (r = .63, P < .01), and peak VO2 (r = .58, P < .01) in heart failure patients. Stepwise regression analysis showed that daily energy requirements in heart failure patients were best estimated by a combination of resting energy expenditure and reported leisure time physical activity (total R2 = 61%; standard error of the estimate, +/- 333 kcal/d). Daily energy requirements predicted from equations derived in healthy elderly were inaccurate when applied to heart failure patients, deviating -10% to +30% from measured daily energy expenditure. We conclude that despite low levels of activity, markers of physical activity predicted daily energy needs in heart failure patients. We provide a new equation to estimate energy needs in free-living heart failure patients based on measurements of daily energy expenditure.

Torsades de pointes with administration of high-dose intravenous d-sotalol to a patient with congestive heart failure

A patient with heart failure was administered d-sotalol 3.0 mg/kg infused over 2 minutes. The patient had normal electrolytes and baseline QT. Six minutes after drug administration the QT prolonged to 600 msec, and the patient developed torsades de pointes and required electrical cardioversion. This emphasizes the need to consider both rate of administration and the dosage when evaluating the safety and efficacy of a new class III antiarrhythmic drug.

Skeletal muscle atrophy and peak oxygen consumption in heart failure

We measured skeletal muscle mass and peak oxygen consumption (VO2) in 13 cachectic heart failure patients, 14 noncachectic patients, and in 52 healthy controls to examine skeletal muscle atrophy and its relation to low peak VO2 in heart failure patients. Our results show that skeletal muscle atrophy is associated with prior weight loss and is related to low peak VO2 in heart failure patients.

Plasma leptin concentrations and energy expenditure in heart failure patients

Leptin, the protein encoded by the obese gene, is a newly described hormone implicated in the regulation of energy balance. To examine the possible role of leptin in the energy dysregulation that frequently accompanies chronic heart failure, we examined plasma leptin concentrations and energy expenditure in 18 heart failure patients (aged 71 +/- 6 years) and 46 healthy elderly controls (66 +/- 6 years). Plasma leptin concentrations were measured by radioimmunoassay, daily energy expenditure by doubly labeled water, and body composition by dual-energy x-ray absorptiometry. Fat mass was lower (P < .01) in heart failure patients compared with healthy controls, whereas fat-free mass did not differ between groups. Plasma leptin concentrations were not different between heart failure patients and healthy controls (5.1 +/- 4.2 v 6.8 +/- 4.4 pg/mL) and remained similar after statistical control for fat mass (6.0 +/- 3.1 v 7.1 +/- 3.2 pg/mL). Plasma leptin was related to fat mass in heart failure patients (r = .92, P < .01) and healthy controls (r = .69, P < .01). Free-living daily and physical-activity energy expenditures were lower (P < .01) in heart failure patients compared with healthy controls. Plasma leptin concentrations were related to both daily (r = .67, P < .01) and resting (r = .67, P < .01) energy expenditure in heart failure patients, but not in healthy controls (r = .09 and r = .33, respectively). In conclusion, we found an association between plasma leptin concentrations and energy expenditure in heart failure patients, but not in healthy controls. Thus, leptin may participate in the regulation of energy expenditure and body energy stores in heart failure patients.

Daily energy expenditure in free-living heart failure patients

We examined the hypothesis that weight loss in heart failure patients is associated with elevated daily energy expenditure. Twelve cachectic patients [age = 73 +/- 6 yr; weight loss = 15 +/- 6 kg; body mass index (BMI) = 21 +/- 5 kg/m2], 13 noncachectic patients (age = 67 +/- 5 yr; BMI = 27 +/- 5 kg/m2), and 50 healthy elderly controls (age = 69 +/- 6 yr; BMI = 26 +/- 4 kg/m2) were studied. Daily energy expenditure and it components were measured using doubly labeled water and indirect calorimetry and body composition by dual-energy X-ray absorptiometry. Fat mass and fat-free mass were lower (P < 0.05) in cachectic patients compared with noncachectic patients and healthy controls. Daily energy expenditure was lower (P < 0.05) in cachectic patients (1,870 +/- 347 kcal/day) compared with noncachectic patients (2,349 +/- 545 kcal/day) and healthy controls (2,543 +/- 449 kcal/day). Differences in daily energy expenditure were primarily due to lower (P < 0.05) physical activity energy expenditure in cachectic (269 +/- 307 kcal/day) and noncachectic patients (416 +/- 361 kcal/day) compared with healthy controls (728 +/- 374 kcal/day). A lower (P < 0.05) resting energy expenditure was also noted in cachectic patients (1,414 +/- 210 kcal/day) compared with noncachectic patients (1,698 +/- 252 kcal/day) and healthy controls (1,561 +/- 223 kcal/day). These findings show that daily energy expenditure is not higher, but significantly lower, in cachectic heart failure patients due to lower physical activity and resting energy expenditure. These results argue against the hypothesis that an abnormally elevated daily energy expenditure is associated with weight loss in heart failure.

The acute hemodynamic effects of right ventricular septal pacing in patients with congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy

To assess the hemodynamic effects of right ventricular septal pacing in patients with severe chronic heart failure, we studied 13 patients during intrinsic rhythm and with pacing in the VDD mode at atrioventricular delays of 100 to 200 ms. There was no improvement of any hemodynamic parameter measured with pacing, even in the subgroup of patients with prolonged PR intervals.

Ventricular dysfunction and the risk of stroke after myocardial infarction

BACKGROUND

In patients who have had a myocardial infarction, the long-term risk of stroke and its relation to the extent of left ventricular dysfunction have not been determined. We studied whether a reduced left ventricular ejection fraction is associated with an increased risk of stroke after myocardial infarction and whether other factors such as older age and therapy with anticoagulants, thrombolytic agents, or captopril affect long-term rates of stroke.

METHODS

We performed an observational analysis of prospectively collected data on 2231 patients who had left ventricular dysfunction after acute myocardial infarction who were enrolled in the Survival and Ventricular Enlargement trial. The mean follow-up was 42 months. Risk factors for stroke were assessed by both univariate and multivariate Cox proportional-hazards analysis.

RESULTS

Among these patients, 103 (4.6 percent) had fatal or nonfatal strokes during the study (rate of stroke per year of follow-up, 1.5 percent). The estimated five-year rate of stroke in all the patients was 8.1 percent. As compared with patients without stroke, patients with stroke were older (mean [+/-SD] age, 63+/-9 years vs. 59+/-11 years; P<0.001) and had lower ejection fractions (29+/-7 percent vs. 31+/-7 percent, P=0.01). Independent risk factors for stroke included a lower ejection fraction (for every decrease of 5 percentage points in the ejection fraction there was an 18 percent increase in the risk of stroke), older age, and the absence of aspirin or anticoagulant therapy. Patients with ejection fractions of < or = 28 percent after myocardial infarction had a relative risk of stroke of 1.86, as compared with patients with ejection fractions of more than 35 percent (P=0.01). The use of thrombolytic agents and captopril had no significant effect on the risk of stroke.

CONCLUSIONS

During the five years after myocardial infarction, patients have a substantial risk of stroke. A decreased ejection fraction and older age are both independent predictors of an increased risk of stroke. Anticoagulant therapy appears to have a protective effect against stroke after myocardial infarction.

Hemodynamic effects of the class III antiarrhythmic drug, d-sotalol, in patients with congestive heart failure

In contrast to Vaughan Williams class I drugs, class III drugs, such as d-sotalol, may not be negative inotropic. These drugs block potassium ion channels and prolong repolarization, theoretically leading to improved contractility. We investigated the hemodynamic actions of acute intravenous administration of 1.5 mg/kg of d-sotalol in 28 patients with congestive heart failure randomized to receive placebo (n = 10) or active drug (n = 18) in a double-blind study. A Swan-Ganz catheter was placed in all patients > or = 16 hours before drug administration. All hemodynamic variables were assessed at baseline and 30 minutes and 1, 2, 4, 8, and 12 hours after administration of the drug. Electrocardiograms were obtained before and 1, 2, 4, and 12 hours after drug administration. The QT interval increased from 370 +/- 9 to 426 +/- 14 ms at 1 hour, whereas the QTc increased from 433 +/- 5 to 470 +/- 12 ms (both p < 0.001). The increase was still statistically significant at 12 hours. There was no change in the placebo group. Although heart rate decreased in the d-sotalol group (84 +/- 2 to 76 +/- 2 at 1 hour, p < 0.001), there were no changes in blood pressure or right atrial pressure. Cardiac index decreased slightly (2.0 +/- 0.2 to 1.9 +/- 0.1 mm Hg), consistent with the lower heart rate. Pulmonary capillary wedge pressure decreased from 18.9 +/- 2.4 to 17.9 +/- 1.9 mm Hg at 1 hour despite reduced cardiac index. We conclude that in contrast to class I, II, and IV antiarrhythmic drugs, d-sotalol exerts no clinically important acute hemodynamic actions at doses that produce electrophysiologic effects.

Double-blind, placebo-controlled study of the effects of carvedilol in patients with moderate to severe heart failure. The PRECISE Trial. Prospective Randomized Evaluation of Carvedilol on Symptoms and Exercise

BACKGROUND

Carvedilol has improved the symptomatic status of patients with moderate to severe heart failure in single-center studies, but its clinical effects have not been evaluated in large, multicenter trials.

METHODS AND RESULTS

We enrolled 278 patients with moderate to severe heart failure (6-minute walk distance, 150 to 450 m) and a left ventricular ejection fraction < or = 0.35 at 31 centers. After an open-label, run-in period, each patient was randomly assigned (double-blind) to either placebo (n = 145) or carvedilol (n = 133; target dose, 25 to 50 mg BID) for 6 months, while background therapy with digoxin, diuretics, and an ACE inhibitor remained constant. Compared with placebo, patients in the carvedilol group had a greater frequency of symptomatic improvement and lower risk of clinical deterioration, as evaluated by changes in the NYHA functional class (P = .014) or by a global assessment of progress judged either by the patient (P = .002) or by the physician (P < .001). In addition, treatment with carvedilol was associated with a significant increase in ejection fraction (P < .001) and a significant decrease in the combined risk of morbidity and mortality (P = .029). In contrast, carvedilol therapy had little effect on indirect measures of patient benefit, including changes in exercise tolerance or quality-of-life scores. The effects of the drug were similar in patients with ischemic heart disease or idiopathic dilated cardiomyopathy as the cause of heart failure.

CONCLUSIONS

These findings indicate that, in addition to its favorable effects on survival, carvedilol produces important clinical benefits in patients with moderate to severe heart failure treated with digoxin, diuretics, and an ACE inhibitor.

Energy expenditure and symptom severity in men with heart failure

Our results demonstrate a graded increase in resting metabolic rate based on symptom severity as reflected in the New York Heart Association classification. This finding supports the hypothesis that clinical severity of illness corresponds to the magnitude of the increase in resting energy demands.

Hemodynamic effects of intravenous sematilide in patients with congestive heart failure: a class III antiarrhythmic agent without cardiodepressant effects

OBJECTIVES

This study sought to evaluate the hemodynamic effects of intravenous sematilide hydrochloride, a selective class III antiarrhythmic agent, in patients with heart failure and left ventricular systolic dysfunction.

BACKGROUND

Class I antiarrhythmic agents, which primarily slow conduction, can depress ventricular function, particularly in patients with heart failure. In contrast, pure class III agents, which selectively prolong repolarization, do not adversely affect hemodynamic variables in animal models, but there are no data evaluating their hemodynamic effects in humans.

METHODS

In 39 patients with congestive heart failure and a left ventricular ejection fraction < 40%, hemodynamic and electrocardiographic measurements were obtained at baseline, after a loading dose and during a maintenance infusion of intravenous sematilide using either a low (0.75 then 0.3 mg/min) or high dose (1.5 then 0.6 mg/min) regimen. The study had an 80% power to detect clinically meaningful differences in hemodynamic variables.

RESULTS

Both low (n = 20) and high (n = 19) dose sematilide infusions produced dose-dependent increases in QT interval (5 +/- 8% [mean +/- SD] and 18 +/- 10%, respectively) and corrected QT interval (4 +/- 8% and 14 +/- 10%), and high dose sematilide decreased heart rate by 7 +/- 10% (all p < 0.025 vs. baseline). Neither dose regimen had a statistically significant effect on any other hemodynamic variable, including mean arterial, right atrial, pulmonary artery and pulmonary capillary wedge pressures; cardiac index, stroke volume, systemic and pulmonary vascular resistances; and left ventricular stroke work index. Sematilide showed no adverse hemodynamic effects in patients with left ventricular ejection fraction < or = 25% or > 25% and in patients with cardiac index < 2 or > or = 2 liters/min per m2. Sustained polymorphic ventricular tachycardia (n = 1) and excessive QT prolongation (n = 4) were seen during the high dose.

CONCLUSIONS

Sematilide, in the doses administered, prolonged repolarization but did not alter hemodynamic variables in patients with heart failure. These data suggest that class III antiarrhythmic agents, which selectively prolong repolarization, are not cardiodepressant but may be proarrhythmic in humans, especially at high doses.

Sarcopenia in aging humans: the impact of menopause and disease

We examine the association of the menopause transition, congestive heart failure, and Parkinson's disease on body composition and energy expenditure. We present evidence suggesting that the normal menopausal transition is associated with accelerated loss of fat-free mass, a decline in resting metabolic rate, and increased central body fatness. Second, we show that the cardiac cachexia associated with heart failure is partially due to an elevated level of energy expenditure. Despite having a lower quantity of fat-free mass, congestive heart failure patients have a higher resting metabolic rate (approximately 283 kcal/d) for their metabolic size than healthy elderly. The elevated level of resting energy expenditure probably contributes to their unexplained weight loss. Parkinson's patients experience muscular rigidity and tremor which could contribute to inappropriately high levels of energy expenditure and difficulty in maintaining body weight and composition. We examined resting metabolic rate and body composition in eight Parkinson's patients and 34 healthy age-matched controls. Parkinson's patients showed lower levels of fat-free mass (approximately 6 kg), but similar resting metabolic rates (1601 +/- 250 kcal/d) versus healthy controls (1671 +/- 212 kcal/d), suggesting a hypermetabolic state. A re-examination of daily energy needs and the metabolic factors contributing to periods of energy imbalance during the menopausal transition and in several disease states may be a prerequisite to offsetting accelerated sarcopenia.

Dual-chamber pacing with a short atrioventricular delay in congestive heart failure: a randomized study

OBJECTIVES

This prospective study assessed the initial hemodynamic effects and long-term clinical benefits of dual-chamber pacing with a short atrioventricular (AV) delay in patients with chronic heart failure who had no traditional indication for pacemaker implantation.

BACKGROUND

Dual-chamber pacing with a short AV delay has been proposed as a nonpharmacologic treatment for drug-refractory heart failure. Both initial and long-term hemodynamic as well as functional benefits have been reported. All previous studies have used an AV delay of 100 ms. Despite encouraging results, these previous studies have been anecdotal and uncontrolled.

METHODS

This double-blind, randomized, crossover trial included 12 subjects with chronic congestive heart failure despite optimal medical therapy. Patients were required to be in sinus rhythm with no evidence of significant bradyarrhythmias. On the day after implantation of a dual-chamber pacemaker, invasive hemodynamic measurements were made at varying AV delays between 100 and 200 ms. Patients were then randomized to either dual-chamber pacing with a 100-ms AV delay or backup mode (VVI at 40 beats/min). After 4 to 6 weeks, crossover to the other pacing mode was programmed.

RESULTS

Hemodynamic measurements on the day after pacemaker implantation demonstrated no benefit of pacing with any AV delay compared with intrinsic conduction. At the optimal AV interval for each patient, neither cardiac output (4.5 +/- 1.5 vs 4.7 +/- 1.6 liters/min [mean +/- SD]) nor wedge pressure (16 +/- 10 vs 17 +/- 8 mm Hg) improved significantly from baseline measurements during intrinsic conduction. The long-term pacing protocol was completed in nine patients. Ejection fraction was 16 +/- 6% with dual-chamber (VDD mode) pacing and 18 +/- 4% in backup mode (p = NS). No patient had an increase in ejection fraction by > or = 5% with VDD pacing, nor did any patient improve in New York Heart Association functional class with short AV delay dual-chamber pacing. Also, there were no significant reductions in body weight or diuretic requirements during this pacing period.

CONCLUSIONS

Dual-chamber pacing with a short AV delay does not improve hemodynamic and clinical status or ejection fraction measured on the day after pacemaker implantation in patients with chronic congestive heart failure. Routine use of pacemaker therapy with a short AV delay aas a primary treatment of heart failure in patients without standard arrhythmic indications is unwarranted.

Prognostic importance of the length of ventricular tachycardia in patients with nonischemic congestive heart failure

In patients with congestive heart failure the frequency of ventricular arrhythmias poorly predicts mortality. It is unknown whether the length of ventricular tachycardia is a better predictor of mortality in these patients. We therefore investigated the prognostic importance of the length of the longest run of ventricular tachycardia, the frequency of ventricular tachycardia, and the frequency of ventricular premature depolarizations with 24-hour ambulatory electrocardiographic recordings in 122 patients with heart failure. We also determined whether the cause of heart failure affects the prognostic importance of these parameters. Each ambulatory electrocardiographic recording was evaluated for the frequency of ventricular premature depolarizations and ventricular tachycardia and for the length of the longest run of ventricular tachycardia. For each electrocardiographic parameter patients were divided into groups based on the median value of that parameter. Mortality among groups was compared in all patients and then separately for nonischemic and ischemic patients. Neither the frequency of ventricular premature depolarizations nor the frequency of ventricular tachycardia predicted mortality whether or not cause was considered. When all patients were examined, the length of ventricular tachycardia did predict an increased risk of death. However, when cause was considered, length of ventricular tachycardia predicted mortality only in the nonischemic patients and not in the ischemic patients. We conclude that the length of ventricular tachycardia may be the best electrocardiographic predictor of mortality in patients with nonischemic heart failure.

Acute electrophysiologic effects of amiodarone in patients with congestive heart failure

Patients with severe congestive heart failure (CHF) are at increased risk for atrial and ventricular arrhythmias and sudden cardiac death. Amiodarone is generally well tolerated by this population and has a low proarrhythmic potential. Because of its peculiar kinetics, amiodarone requires a prolonged loading period, necessitating lengthy hospitalizations in a monitored setting. This study was planned prospectively to assess the electrophysiologic effects of an abbreviated high-dose oral load of amiodarone in patients with severe CHF and known or suspected life-threatening ventricular arrhythmias. Fifteen patients with stable CHF and known or suspected life-threatening ventricular arrhythmias underwent baseline electrophysiologic study. The study was repeated after administration of oral amiodarone, 50 mg/kg/day for 2 days in 8 divided doses (mean dose 6.9 +/- 0.4 g). After amiodarone administration, there was prolongation in virtually all conduction times and refractory periods. The prolongation of refractoriness was most pronounced in the atrium. Ventricular effective refractory periods demonstrated reverse frequency dependence. We conclude that a brief high-dose oral load of amiodarone is well tolerated by patients with CHF. It has marked and diffuse electrophysiologic actions suggestive of class I and III effects in addition to antiadrenergic and calcium blocking action. These effects are especially pronounced in the atrium.

New approaches to managing congestive heart failure

The appreciation that congestive heart failure is not merely a disorder of myocardium has led to a substantial alteration in the treatment of this disease. The use of angiotensin-converting enzyme inhibitors is increasing as their well-demonstrated mortality and symptomatic benefits become better publicized and known. Although diuretics and digoxin continue to remain standard additions to angiotensin-converting enzyme inhibitors for the therapy of congestive heart failure, investigations of these and other agents continue. For example, acceptance of beta-blockade as a potentially beneficial therapeutic intervention increased in the past year with the publication of the Cardiac Insufficiency Bisoprolol Study (CIBIS), the largest controlled trial to date. Similarly, survival studies of vasodilators and positive inotropic agents such as vesnarinone are ongoing. Even the effects of exercise in severely ill patients (who were previously advised to be sedentary) are being studied. With the understanding that heart failure is a systemic disease and that controlled trials are needed because many of our assumptions prove to be incorrect, we can expect continued improvement in the management of heart failure.

Prognostic value of the signal-averaged electrocardiogram and a prolonged QRS in ischemic and nonischemic cardiomyopathy

Studies of electrocardiographic predictors of mortality in patients with chronic heart failure have reached varying conclusions. Differences in the characteristics of the patients studied may explain the conflicting results regarding both a prolonged QRS and an abnormal signal-averaged electrocardiogram (SAE). We therefore investigated the impact of the etiology of heart failure on the prognostic importance of a prolonged QRS and an abnormal SAE in 200 patients with heart failure. Patients were categorized according to etiology of heart failure and electrocardiographic parameters. The mortality of patients with a prolonged QRS was compared with mortality in those with both abnormal and normal SAEs. This was done for the entire group, and separately for those with ischemic and those with nonischemic cardiomyopathy. The mean follow-up was 18.8 months. Nonischemic patients with a prolonged QRS had significantly worse survival than other patients. However, nonischemic patients with an abnormal SAE did not have a worse prognosis than patients with a normal SAE. One-year survival of patients with a prolonged QRS was 71%, compared with 98% in patients with a normal and 87% in patients with an abnormal SAE (p < 0.05). In contrast, a prolonged QRS was not a predictor of poor prognosis in patients with ischemic cardiomyopathy (81% one year mortality). Patients with ischemic cardiomyopathy and an abnormal SAE tended to have a poorer survival than patients with a normal SAE (73% and 81% one year mortality, respectively). Thus, the etiology of heart failure affects the prognostic importance of both a prolonged QRS and an abnormal SAE.

Increased resting metabolic rate in patients with congestive heart failure

OBJECTIVE

To examine resting metabolic rate in patients with congestive heart failure as a cause of cardiac cachexia and associated weight loss.

DESIGN

Cross-sectional study.

SETTING

Baltimore Veterans Affairs Medical Center.

PATIENTS

20 men with heart failure (mean age +/- SD, 69 +/- 7 years) and reduced ejection fraction (mean, 0.24 +/- 0.10) and 40 healthy men (mean age, 69 +/- 7 years).

RESULTS

Patients with heart failure had smaller fat-free mass than did controls (53 +/- 8 kg compared with 56 +/- 6 kg; P < 0.09), but no difference in fat mass existed (21 +/- 8 kg compared with 19 +/- 8 kg). Measured resting metabolic rate was 18% higher in patients with heart failure than in controls (1828 +/- 275 kcal/d compared with 1543 +/- 219 kcal/d; P < 0.01); no difference in caloric intake existed (2144 +/- 479 kcal/d compared with 2174 +/- 826 kcal/d). The difference in resting metabolic rate between the two groups was even more striking when indexed per kilogram of fat-free mass.

CONCLUSIONS

Higher resting metabolic rate in patients with heart failure at least partially accounts for otherwise unexplained weight loss. Present caloric guidelines, which were established in healthy elderly persons, substantially underestimate the resting caloric needs of elderly persons with heart failure.

First-dose effects of enalapril 2.5 mg and captopril 6.25 mg in patients with heart failure: a double-blind, randomized, multicenter study. The Enalapril-Captopril Investigators

Significant decreases in blood pressure (BP) may occur when administration of angiotensin-converting enzyme (ACE) inhibitors is initiated for the treatment of heart failure. The purpose of this study was to compare the safety and tolerability of recommended initial doses of the longer-acting ACE inhibitor enalapril (ENAL) with those of the shorter-acting captopril (CAP) in patients with heart failure who were treated concomitantly with digitalis and diuretic agents. We evaluated BP, serum ACE activity, and clinical status when a low, first dose of ENAL (2.5 mg, n = 59) or CAP (6.25 mg, n = 58) was administered in a double-blind, randomized, and parallel fashion to 117 patients with mild to moderate heart failure. BP and serum ACE activity were measured at 30 min and hourly for 8 hours after drug administration. BP decreases were similar for both groups (mean supine BP -6.2/-4.8 mm Hg for ENAL vs -8.3/-6.4 mm Hg for CAP; mean standing BP -9.2/-5.6 mm Hg for ENAL vs -10.0/-4.7 mm Hg for CAP). Although the maximum mean decrease in BP occurred at hours 4 and 5 in the ENAL group and hours 1 and 2 in the CAP group, considerable between-group overlap was observed for individual patients. Decreases in mean serum ACE activity occurred earlier and were of shorter duration in the CAP group. ENAL significantly inhibited serum ACE activity to a greater extent than did CAP at all time points except the 1st hour. Administration of a first dose of ENAL, 2.5 mg or CAP, 6.25 mg to patients with heart failure was well tolerated.

The hemodynamic actions of the antiarrhythmic agent ipazilide fumarate in patients with congestive heart failure

Ipazilide fumarate is an investigational antiarrhythmic agent with Vaughan Williams class I and III actions, including prolongation of both ventricular refractoriness and action potential duration. Because of the frequent use of antiarrhythmic agents in patients with heart failure, we investigated the hemodynamic effects of oral administration of 400, 200, and 100 mg of ipazilide fumarate in 15 patients with congestive heart failure. There was a marked hemodynamic response to ipazilide, with the peak effect noted 2 hours after drug administration. In patients who received 400 mg ipazilide, the mean cardiac index was decreased by 0.5 L/min/m2 at 2 hours (p < 0.05). After 200 and 100 mg ipazilide, the decreases were a more modest 0.3 and 0.1 L/min/m2, respectively. The mean arterial pressure also decreased in a dose- and time-dependent manner, although this did not reach statistical significance for any of the doses. Left ventricular filling pressure, right atrial pressure, and heart rate were not altered by ipazilide. Plasma concentrations of ipazilide peaked 90 minutes after administration of 100 or 200 of the drug, but peak concentrations were noted 3 hours after administration of 400 mg. The hemodynamic response correlated with the plasma concentration of ipazilide determined contemporaneously. We conclude that, as with most antiarrhythmic agents, single-dose administration of ipazilide fumarate can cause clinically significant hemodynamic deterioration.

Beta-blockers for heart failure: where are we now?

The hypothesis that the long-term use of beta-blockers improves symptoms, cardiac function, and ejection fraction in patients with heart failure is increasingly being accepted. Multiple small studies have consistently demonstrated favorable outcomes with beta-blocker use, and a large-scale mortality study is now planned. However, important questions remain regarding which patients with heart failure should be treated and the mechanism by which beta-blockade exerts its beneficial effects. These questions undoubtedly need to be answered before physicians will be willing to prescribe these medications, the use of which is so counterintuitive.

Beneficial effects of metoprolol in heart failure associated with coronary artery disease: a randomized trial

OBJECTIVES

This clinical trial was performed to determine the safety and clinical impact of titrated metoprolol therapy in patients with heart failure, documented coronary artery disease and a low ejection fraction.

BACKGROUND

Despite known cardiodepressant effects, long-term use of beta-adrenergic antagonists appears to be beneficial in patients with idiopathic dilated cardiomyopathy. However, this therapy has not been critically evaluated in patients with heart failure and coronary artery disease.

METHODS

In 50 patients with heart failure, known coronary artery disease and an ejection fraction < or = 0.40, we examined the impact of metoprolol therapy in a 6-month double-blind, placebo-controlled randomized trial, assessing the frequency of heart failure exacerbations and changes in symptoms (New York Heart Association functional class), ejection fraction and exercise duration. Placebo-treated patients who completed 6-month follow-up studies then underwent a trial with metoprolol therapy (crossover group).

RESULTS

Metoprolol was titrated to a mean maximal dose of 87 mg/day (range 25 to 100) without serious adverse reactions. During double-blind therapy, use of a beta-blocker was associated with a significant reduction in the number of hospital admissions (4% vs. 32%, p < 0.05), overall improved functional class (p = 0.02), increased ejection fraction (4 +/- 7% [mean +/- SD] compared with 0 +/- 6%, p < 0.05) and a greater increase in exercise duration (193 +/- 276 vs. 38 +/- 213 s with placebo, p < 0.01). Crossover outcome paralleled the favorable impact seen during randomized metoprolol therapy.

CONCLUSIONS

Cautious use of titrated metoprolol appears to be safe and beneficial when added to standard heart failure therapy in patients with dilated cardiomyopathy associated with coronary artery disease.

High dose oral amiodarone loading exerts important hemodynamic actions in patients with congestive heart failure

OBJECTIVES

The purpose of this study was to use invasive monitoring to analyze the hemodynamic effects of both a large single dose and a 48-h loading regimen of amiodarone in patients with severe heart failure.

BACKGROUND

Amiodarone is frequently used as an antiarrhythmic agent in patients with congestive heart failure, but the impact of this agent on cardiac function remains controversial. Recent successful experience with a rapid oral load of amiodarone makes invasive testing of the hemodynamic effects of oral amiodarone in such patients now feasible.

METHODS

After baseline hemodynamic assessment (using balloon-tipped pulmonary artery catheters) and electrocardiographic measurements, 16 patients received 12.5 mg/kg body weight of amiodarone orally. Hemodynamic measurements were obtained hourly for 4 h. Patients then received this dose an additional seven times over the next 2 days. Hemodynamic variables and QRS, QT and PR intervals were measured after 48 h of treatment.

RESULTS

Vasodilation was seen between 1 and 3 h after drug administration. Systemic vascular resistance decreased 326 +/- 135 dynes.s.cm-5, cardiac index increased 0.24 +/- 0.08 liters/min per m2 and mean arterial pressure decreased 6 +/- 3 mm Hg (mean +/- SEM, all p < 0.05). After 48 h of amiodarone administration, heart rate decreased 23 +/- 3 beats/min (p < 0.005), stroke volume increased 9 +/- 3 ml (p < 0.005), cardiac index decreased 0.23 +/- 0.09 ml/min per m2 (p < 0.05), pulmonary capillary wedge pressure increased 4 +/- 1 mm Hg (p < 0.01), right atrial pressure increased 3 +/- 1 mm Hg (p < 0.005) and QT and PR intervals were markedly prolonged (p < 0.01).

CONCLUSIONS

Although the first dose caused vasodilation, a complete loading regimen of amiodarone produced a decreased heart rate with elevated filling pressures and decreased cardiac index.

Abnormal Valsalva blood pressure response in dilated cardiomyopathy: association with "pseudonormalization" of echocardiographic Doppler transmitral filling velocity pattern

In patients with dilated cardiomyopathies, the presence of an abnormal blood pressure response to the Valsalva maneuver has been shown to correlate well with increased left-sided filling pressures. The presence of a "pseudonormalized" early peak to late peak velocity (E/A) ratio on echocardiographic Doppler transmitral filling pattern has also been correlated with increased left ventricular end-diastolic pressures in these patients. Since both abnormal blood pressure response to the Valsalva maneuver and a "pseudonormalized" Doppler transmitral E/A ratio probably represent elevated left ventricular filling pressure, we postulated that there would be a positive correlation between the two in a group of patients with dilated cardiomyopathy and abnormal systolic function. Twenty-five consecutive male patients with New York Heart Association (NYHA) class II to IV heart failure and dilated cardiomyopathy were included. Patients with abnormal blood pressure responses to Valsalva had significantly larger peak early (E) velocities, smaller peak late (A) velocities, and larger E/A ratios compared with patients with normal responses. E/A ratio < 1.0 was present in eight (100%) of the eight patients with a normal blood pressure response to the Valsalva maneuver and E/A ratio > 1.0 was present in 12 (71%) of 17 patients with an abnormal response (p < 0.01). This correlation supports the hypotheses of the physiologic mechanisms of these phenomena and also provides two noninvasive methods of evaluating left-sided filling pressures useful in the diagnosis and treatment of congestive heart failure caused by dilated cardiomyopathy.

Hemodynamic and neurohormonal effects of the angiotensin II antagonist losartan in patients with congestive heart failure

BACKGROUND

Losartan is a new specific angiotensin II receptor antagonist with no agonist properties that provides the opportunity to study the consequences of angiotensin II blockade. The objective of the present study was to evaluate the hemodynamic and neurohormonal response to losartan in patients with congestive heart failure.

METHODS AND RESULTS

After baseline hemodynamic measurements using balloon-tipped pulmonary artery and radial arterial catheters, patients were randomized to receive a single dose of placebo or 5, 10, 25, 75, or 150 mg losartan in a double-blind, sequential fashion. Hemodynamic and neurohormonal parameters were then measured periodically for 24 hours. Losartan caused vasodilation in a dose-dependent manner. By the area-under-the-curve method, the reduction in the mean arterial pressure and systemic vascular resistance grew larger up to a dose of 25 mg, but the higher 75- and 150-mg doses did not produce additional vasodilation. In response to losartan, there were compensatory increases in both angiotensin II concentrations and in plasma renin activity, which were greatest at the highest doses. Aldosterone concentrations were significantly lowered with losartan.

CONCLUSIONS

Blockade of the angiotensin II receptor with the antagonist losartan causes vasodilator and neurohormonal effects in patients with congestive heart failure. The lack of additional vasodilator response with doses of more than 25 mg suggests that neurohormonal activation might limit the efficacy of high dose of losartan.

Sustained hemodynamic response to flosequinan in patients with heart failure receiving angiotensin-converting enzyme inhibitors

OBJECTIVES

We evaluated the short- and long-term effects of flosequinan in 47 patients with severe heart failure despite ongoing captopril treatment.

BACKGROUND

There have been no previous evaluations of the long-term hemodynamic effects of any direct-acting vasodilator in patients with heart failure receiving an angiotensin-converting enzyme inhibitor. Flosequinan is an arterial and venous vasodilator with actions similar to those of the hydralazine-isosorbide dinitrate combination.

METHODS

After baseline hemodynamic measurements using balloon-tipped pulmonary artery and radial arterial catheters, patients were randomized to receive 50, 100 or 150 mg of flosequinan daily. Hemodynamic variables were measured immediately before and after short-term flosequinan administration and after 8 weeks of therapy.

RESULTS

With short-term flosequinan administration, mean arterial, right atrial and left ventricular filling pressures decreased by 6.4 +/- 1.1, 3.8 +/- 0.5 and 7.3 +/- 0.7 mm Hg, respectively (all p < 0.001). Cardiac index increased by 0.5 +/- 0.1 liters/min per m2, systemic vascular resistance decreased by 616 +/- 105 dynes.s.cm-5 and heart rate increased by 4 +/- 1 beats/min (all p < 0.001). After 8 weeks of long-term flosequinan administration, the vasodilator effect of a dose of flosequinan persisted. Compared with pretreatment baseline values, mean arterial, right atrial and left ventricular filling pressures at the peak effect of flosequinan were decreased by 3.5 +/- 1.3, 2.8 +/- 0.7 and 5.1 +/- 1.3 mm Hg, respectively (all p < 0.01). Systemic vascular resistance had decreased by 585 +/- 95 dynes.s.cm-5, cardiac index had increased by 0.5 +/- 0.1 liters/min per m2 and heart rate had increased by 10 +/- 2 beats/min (all p < 0.001).

CONCLUSIONS

The arterial and venous vasodilator flosequinan exerts both short- and long-term sustained hemodynamic effects in patients with heart failure receiving angiotensin-converting enzyme inhibitors.

Effects of intravenous magnesium sulfate on arrhythmias in patients with congestive heart failure

Intravenous magnesium is an effective treatment for ventricular tachycardia of some etiologies, and in patients with congestive heart failure low serum magnesium concentrations are associated with frequent arrhythmias and high mortality. This suggests that magnesium administration may decrease the frequency of ventricular arrhythmias in patients with heart failure. We therefore assessed the impact of an intravenous magnesium infusion upon the frequency of ventricular premature depolarizations in 40 patients with New York Heart Association (NYHA) class II to IV heart failure and serum magnesium < or = 2.0 mg/dl. Within 1 week of a baseline 6-hour ambulatory electrocardiographic recording, an infusion of 0.2 mEq/kg of MgSO4 was given over 1 hour and a repeat 6-hour recording was obtained. There was an inverse relationship between the change in magnesium concentration and the change in frequency of premature ventricular depolarizations; premature ventricular depolarizations declined by 134 +/- 207 hr-1 in patients in whom serum magnesium concentration increased > or = 0.75 mg/dl, but increased by 72 +/- 393 hr-1 in patients with a change < 0.75 mg/dl (p < 0.05). For all patients, the frequency of premature ventricular depolarizations was 283 +/- 340 hr-1 pretreatment and 220 +/- 269 hr-1 following magnesium infusion (p = 0.21). Patients with > or = 300 premature ventricular depolarizations hr-1 demonstrated a decrease from 794 +/- 309 to 369 +/- 223 hr-1 (p < 0.001). Intravenous magnesium administration decreased the frequency of couplets from 233 +/- 505 to 84 +/- 140 (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)