Association between depressive symptoms and fibrosis markers: the Cardiovascular Health Study

OBJECTIVE

Fibrosis plays an important role in heart failure (HF) and other diseases that occur more frequently with increasing age. Depression is associated with an increased risk of heart failure and other age-related diseases. This study examined the association between depressive symptoms and fibrosis markers in adults aged 65 years and above.

METHODS

Fibrosis markers and depressive symptoms were assessed in 870 participants (age=80.9+/-5.9 yrs, 49% women) using a case-control design based on heart failure status (307 HF patients and 563 age- and sex-matched controls, of whom 284 with CVD risk factors (hypertension, diabetes mellitus, or hypercholesterolemia) and 279 controls without these CVD risk factors). Fibrosis markers were procollagen type I (PIP), type I collagen (CITP), and procollagen type III (PIIINP). Inflammation markers included C-reactive protein, white blood cell counts and fibrinogen. Depression was assessed using the Center for Epidemiological Studies-Depression (CES-D) scale using a previously validated cut-off point for depression (CES-D > or = 8). Covariates included demographic and clinical variables.

RESULTS

Depression was associated with higher levels of PIP (median=411.0, inter-quartile range (IQR)=324.4-472.7 ng/mL vs. 387.6, IQR=342.0-512.5 ng/mL, p=0.006) and CITP (4.99, IQR=3.53-6.85 vs. 4.53, IQR=3.26-6.22 microg/L, p=0.024), but not PIIIINP (4.07, IQR=2.75-5.54 microg/L vs. 3.58, IQR=2.71-5.01 microg/L, p=0.29) compared to individuals without depression. Inflammation markers were also elevated in depressed participants (CRP, p=0.014; WBC, p=0.075; fibrinogen, p=0.074), but these inflammation markers did not account for the relationship between depression and fibrosis markers.

CONCLUSIONS

Depression is associated with elevated fibrosis markers and may therefore adversely affect heart failure and other age-related diseases in which extra-cellular matrix formation plays a pathophysiological role.

Hypoxia, not the frequency of sleep apnea, induces acute hemodynamic stress in patients with chronic heart failure

OBJECTIVES

This study was conducted to evaluate whether brain (B-type) natriuretic peptide (BNP) changes during sleep are associated with the frequency and severity of apneic/hypopneic episodes, intermittent arousals, and hypoxia.

BACKGROUND

Sleep apnea is strongly associated with heart failure (HF) and could conceivably worsen HF through increased sympathetic activity, hemodynamic stress, hypoxemia, and oxidative stress. If apneic activity does cause acute stress in HF, it should increase BNP.

METHODS

Sixty-four HF patients with New York Heart Association functional class II and III HF and ejection fraction <40% underwent a baseline sleep study. Five patients with no sleep apnea and 12 with severe sleep apnea underwent repeat sleep studies, during which blood was collected every 20 min for the measurement of BNP. Patients with severe sleep apnea also underwent a third sleep study with frequent BNP measurements while they were administered oxygen. This provided 643 observations with which to relate apnea to BNP. The association of log BNP with each of 6 markers of apnea severity was evaluated with repeated measures regression models.

RESULTS

There was no relationship between BNP and the number of apneic/hypopneic episodes or the number of arousals. However, the burden of hypoxemia (the time spent with oxygen saturation <90%) significantly predicted BNP concentrations; each 10% increase in duration of hypoxemia increased BNP by 9.6% (95% confidence interval: 1.5% to 17.7%, p = 0.02).

CONCLUSIONS

Hypoxemia appears to be an important factor that underlies the impact of sleep abnormalities on hemodynamic stress in patients with HF. Prevention of hypoxia might be especially important for these patients.

New York Heart Association functional class predicts exercise parameters in the current era

BACKGROUND

The New York Heart Association (NYHA) functional class is a subjective estimate of a patient's functional ability based on symptoms that do not always correlate with the objective estimate of functional capacity, peak oxygen consumption (peak V(O2)). In addition, relationships between these 2 measurements have not been examined in the current medical era when patients are using beta-blockers, aldosterone antagonists, and cardiac resynchronization therapy (CRT). Using baseline data from the HF-ACTION (Heart Failure and A Controlled Trial Investigating Outcomes of Exercise TraiNing) study, we examined this relationship.

METHODS

One thousand seven hundred fifty-eight patients underwent a symptom-limited metabolic stress test and stopped exercise due to dyspnea or fatigue. The relationship between NYHA functional class and peak V(O2) was examined. In addition, the effects of beta-blockers, aldosterone antagonists, and CRT therapy on these relationships were compared.

RESULTS

The NYHA II patients have a significantly higher peak Vo(2) (16.1 +/- 4.6 vs 13.0 +/- 4.2 mL/kg per minute), a lower ventilation (Ve)/V(CO2) slope (32.8 +/- 7.7 vs 36.8 +/- 10.4), and a longer duration of exercise (11.0 +/- 3.9 vs 8.0 +/- 3.4 minutes) than NYHA III/IV patients. Within each functional class, there was no difference in any of the exercise parameters between patients on or off of beta-blockers, aldosterone antagonists, or CRT therapy. Finally, with increasing age, a significant difference in peak Vo(2), Ve/V(CO2) slope, and exercise time was found.

CONCLUSION

For patients being treated with current medical therapy, there still is a difference in true functional capacity between NYHA functional class II and III/IV patients. However, within each NYHA functional class, the presence or absence or contemporary heart failure therapies does not alter exercise parameters.

Relation of depression to severity of illness in heart failure (from Heart Failure And a Controlled Trial Investigating Outcomes of Exercise Training [HF-ACTION])

Depression is common in patients with heart failure (HF), prognostic for adverse outcomes and purportedly related to disease severity. Psychological and physiologic factors relevant to HF were assessed in HF-ACTION, a large randomized study of aerobic exercise training in patients with systolic HF. The relation of objective and subjective parameters was compared with scores on the Beck Depression Inventory (BDI) to examine the hypothesis that depressive symptoms are better associated with perception of disease severity than with objective markers of HF severity. At baseline, 2,322 of 2,331 subjects entered into HF-ACTION completed questionnaires to assess depression (BDI) and quality of life (Kansas City Cardiomyopathy Questionnaire [KCCQ]). Objective markers of HF severity included ejection fraction, B-type natriuretic peptide, and peak oxygen consumption (using cardiopulmonary exercise testing, with evaluation of duration and respiratory exchange ratio also performed). Measures more likely to be affected by perceived functional status included New York Heart Association (NYHA) classification and the 6-minute walk test. Objective assessments of disease severity were slightly related (peak oxygen consumption) or not related (B-type natriuretic peptide and ejection fraction) to BDI scores. Using multivariate analysis (KCCQ not included), only age, gender, cardiopulmonary exercise testing duration, NYHA class, 6-minute walk distance, and peak respiratory exchange ratio independently correlated with BDI scores. In conclusion, depression was minimally related to objective assessments of severity of disease in patients with HF, but was associated with patient (and clinician) perceptions of disease severity. Addressing depression might improve symptoms in patients with HF.

Adenosine A1 antagonists and the cardiorenal syndrome

Adenosine A1 antagonists are being developed for the treatment of renal dysfunction in patients with congestive heart failure. After early small studies prompted hope that these agents could increase urine output without worsening the glomerular filtration rate, larger studies published and presented in 2007 confirmed their beneficial impact on weight and renal function. However, in many studies the renal benefits disappear with higher doses, suggesting that specificity may be lost with higher doses of these drugs. Investigations in animals indicate that there may also be direct benefits on the myocardium and in the lung. Although studies have not shown adverse effects at optimal dosing, the widespread actions of adenosine mandate that safety be established. Ongoing studies should be able to demonstrate whether adenosine A1 antagonists can be used to improve renal function without adversely affecting patients with heart failure.

Changes in psychosocial distress in outpatients with heart failure with implantable cardioverter defibrillators

Patients given implantable cardioverter defibrillators (ICDs) after arrhythmic events or sudden cardiac arrest (SCA) experience psychosocial distress. ICDs now are inserted for the primary prevention of SCA in patients with heart failure; the psychosocial impact of ICDs on patients with heart failure is unknown. Changes in psychosocial status in these ICD recipients were examined. ICD recipients (n = 57) completed depression, anxiety, and social support inventories every 6 months for up to 2 years. Initially, 35% of recipients were depressed and 45% of recipients were anxious. In linear mixed models, depression decreased over time overall but increased in those who experienced ICD shocks. Anxiety decreased in New York Heart Association class III ICD recipients but not in class II ICD recipients. Decreases in social support were related to age: the younger the patient the greater the decrease. A significant proportion of ICD recipients were depressed or anxious, or had diminished social support even after 2 years. Investigation of strategies to improve ICD recipients' psychosocial status is warranted.

Test-retest reliability of assessment for intraventricular dyssynchrony by tissue Doppler imaging echocardiography

The purpose of this study was to evaluate the test-retest reliability of intraventricular dyssynchrony (IVD) assessment by tissue Doppler imaging (TDI) echocardiography. Limited response rates to cardiac resynchronization may improve with TDI screening for appropriate recipients. However, the clinical applicability of TDI will depend on the reliability of the test. Repeat TDI was prospectively performed (11 +/- 11 days apart) in 15 patients with QRS intervals >120 ms and left ventricular ejection fractions <35% and 25 normal controls using the same machine, sonographer, and blinded readers for the 2 tests. There was no change in clinical status or treatment between tests. Established and clinically feasible criteria for IVD were evaluated. These were based on differences of TDI-derived activation time between 2, 4, or 12 left ventricular segments. Reliability was assessed by linear correlation and Bland-Altman analysis for quantified measures, along with percentage agreement and kappa statistics for IVD diagnosis. Despite good intrareader (r = 0.98, p <0.0001) and interreader (2 segments: r = 0.96, p <0.0001; 4 segments: r = 0.85, p <0.0001) reliability, test-retest correlations were uniformly modest for the 2-segment (r = 0.26, p = 0.11), 4-segment (r = 0.36, p = 0.021), and 12-segment (r = 0.50, p = 0.0009) measures. Test-retest agreement for IVD diagnosis by either criterion was equally limited (2 segments: 83%, kappa = 0.27; 4 segments: 75%, kappa = 0.47; 12 segments: 68%, kappa = 0.35). Bland-Altman analysis demonstrated wide confidence intervals, exceeding the diagnostic cutoff values for the respective criteria. In conclusion, the accurate assessment of IVD by TDI may be limited by poor test-retest reliability.

A randomized, controlled trial of the renal effects of ultrafiltration as compared to furosemide in patients with acute decompensated heart failure

OBJECTIVES

This study was designed to evaluate the consequences of ultrafiltration (UF) and standard intravenous diuretic (furosemide) therapy on glomerular filtration rate (GFR) and renal plasma flow in patients with acute decompensated heart failure.

BACKGROUND

It has been hypothesized that treatment with diuretics may worsen renal function as the result of systemic neurohormonal activation and direct renal vascular effects. UF also removes fluid, but its actions on intrarenal hemodynamics, and therefore renal function, are unknown.

METHODS

Patients hospitalized for acute decompensated heart failure with an ejection fraction less than 40% and two or more signs of hypervolemia were randomized to receive UF or intravenous diuretics. Urine output, GFR (as measured by iothalamate), and renal plasma flow (as measured by para-aminohippurate) were assessed before fluid removal and after 48 hours.

RESULTS

Nineteen patients (59 +/- 16 years, 68% were male) were randomized to receive UF (n = 9) or intravenous diuretics (n = 10). The change in GFR (-3.4 +/- 7.7 mL/min vs. -3.6 +/- 11.5 mL/min; P = .966), renal plasma flow (26.6 +/- 62.7 mL/min vs. 16.1 +/- 42.0 mL/min; P = .669), and filtration fraction (-6.9 +/- 13.6 mL/min vs. -3.9 +/- 13.6 mL/min; P = .644) after treatment were not significantly different between the UF and furosemide treatment groups, respectively. There was no significant difference in net 48-hour fluid removal between the groups (-3211 +/- 2345 mL for UF and -2725 +/- 2330 mL for furosemide, P = .682). UF removed 3666 +/- 2402 mL. Urine output during 48 hours was significantly greater in the furosemide group (5786 +/- 2587 mL) compared with the UF group (2286 +/- 915 mL, P < .001).

CONCLUSIONS

During a 48-hour period, UF did not cause any significant differences in renal hemodynamics compared with the standard treatment of intravenous diuretics.

The characteristics and prognostic importance of NT-ProBNP concentrations in critically ill patients

BACKGROUND

There are limited data for prognostic and diagnostic use of natriuretic peptides in intensive care unit (ICU) patients. We evaluate amino-terminal brain natriuretic peptide (NT-proBNP) in the medical ICU, specifically its correlation with noncardiac admission diagnosis and prognosis of critically ill patients.

METHODS

NT-proBNP (pg/mL) was measured in 179 ICU patients without acute decompensated heart failure or acute coronary syndrome. Death during hospitalization (mortality), APACHE II score, laboratory data, echocardiograms, medical history, and demographics were assessed. NT-proBNP concentrations were compared with established cutoffs for congestive heart failure (>450 pg/mL for patients <50 years of age, >900 pg/mL for patients 50-70 years of age, and >1800 pg/mL for patients >70 years of age). Predictors of mortality and of NT-proBNP were analyzed by regression analysis. Tertiles were compared by analysis of variance and chi-squared test.

RESULTS

NT-proBNP was elevated in these ICU patients (median 2139 pg/mL, 25th percentile 540 pg/mL, 75% percentile 7389 pg/mL). Severity of illness and renal dysfunction (APACHE II score and serum creatinine) increased with rising NT-proBNP. The incidence of acute respiratory distress syndrome, sepsis, death, history of coronary artery disease (CAD) or congestive heart failure (all P <.05) increased with each tertile. Independent predictors of increased NT-proBNP were creatinine (P <.001), CAD (P <.001), APACHE II score (P <.05), and sepsis (P < or =.001). Overall hospital mortality was 26%, and log NT-proBNP (P <.05), APACHE II (P < or =.001), and CAD (P <.05) were independent predictors of mortality.

CONCLUSIONS

For patients admitted to the ICU without decompensated heart failure or acute coronary syndrome, NT-proBNP concentrations are markedly elevated, especially in patients with sepsis. NT-proBNP strongly and independently predicts mortality. However, NT-proBNP should not be used to direct volume management in critically ill patients.

Metoprolol Reverses Left Ventricular Remodeling in Patients With Asymptomatic Systolic Dysfunction

Background— There are no randomized, controlled trial data to support the benefit of β-blockers in patients with asymptomatic left ventricular systolic dysfunction. We investigated whether β-blocker therapy ameliorates left ventricular remodeling in asymptomatic patients with left ventricular systolic dysfunction.

Method and Results— Patients with left ventricular ejection fraction <40%, mild left ventricular dilation, and no symptoms of heart failure (New York Heart Association class I) were randomly assigned to receive extended-release metoprolol succinate (Toprol-XL, AstraZeneca) 200 mg or 50 mg or placebo for 12 months. Echocardiographic assessments of left ventricular end-systolic volume, end-diastolic volume, mass, and ejection fraction were performed at baseline and at 6 and 12 months. The 149 patients randomized to the 3 treatment groups (200 mg, n=48; 50 mg, n=48; and placebo, n=53) were similar with regard to all baseline characteristics including age (mean, 66 years), gender (74% male), plasma brain natriuretic peptide (79 pg/mL), left ventricular end-diastolic volume index (110 mL/m 2 ), and left ventricular ejection fraction (27%). At 12 months in the 200-mg group, there was a 14±3 mL/m 2 decrease (least square mean±SE) in end-systolic volume index and a 6±1% increase in left ventricular ejection fraction ( P <0.05 versus baseline and placebo for both). The decrease in end-diastolic volume index (14±3) was different from that seen at baseline ( P <0.05) but not with placebo. In the 50-mg group, end-systolic and end-diastolic volume indexes decreased relative to baseline but were not different from what was seen with placebo, whereas ejection fraction increased by 4±1% ( P <0.05 versus baseline and placebo).

Conclusion— β-Blocker therapy can ameliorate left ventricular remodeling in asymptomatic patients with left ventricular systolic dysfunction.

Effect of Chronic Changes in Heart Rate on Congestive Heart Failure

BACKGROUND

Heart rate can affect cardiac function, but the importance of rates lower than 100 paced beats per minute is unknown. We therefore sought to evaluate the impact of different heart rates on ejection fraction, 6-minute walk, and peak oxygen consumption (VO2) in heart failure patients.

METHODS AND RESULTS

We studied 13 pacemaker-dependent New York Heart Association Class III patients with ejection fraction <40%, age 66 +/- 13. Eligible patients included those pacing at least 75% of the time at a lower set rate of 60 ppm. This was a 3-period randomized blinded crossover study. Patients were assigned to pace at 60, 75, or 90 ppm (with rate responsivity to 20 ppm above the lower rate) for 2 months at each setting. At the end of each period, ejection fraction (by nuclear ventriculography) and exercise tolerance (by peak VO2 and 6-minute walk) were assessed. Ejection fraction, peak VO2, and 6-minute walk distance were significantly different among the 3 heart rates. All 3 were depressed at 90 ppm. A heart rate of 90 also led to more clinical deterioration and premature discontinuation from that period.

CONCLUSIONS

Pacing at a heart rate of 90 led to lower ejection fraction, VO2, 6-minute walk distance and clinical evidence of worsening heart failure as compared with slower heart rates.

A double-blind placebo-controlled pilot study of controlled-release paroxetine on depression and quality of life in chronic heart failure

BACKGROUND

Depression is frequently observed in patients with heart failure and is associated with poor quality of life and adverse prognosis. However, the prevalence of depression in heart failure could be overestimated because symptoms of depression overlap with those of heart failure. Similarly, the importance of depression may be overestimated if depression merely reflects worse heart failure. Because the response to depression treatment has not been evaluated in this patient population, we evaluated the efficacy of controlled-release paroxetine (paroxetine CR), a selective serotonin reuptake inhibitor, on depression and quality of life in chronic heart failure.

METHODS

A double-blind, randomized, placebo-controlled design was used to evaluate reductions in depression following 12 weeks of treatment with paroxetine CR (n = 14, age 62.1 +/- 12.3 years) or placebo (n = 14, age = 61.9 +/- 9.0 years). Patients with symptomatic congestive heart failure and a score of at least 10 on the Beck Depression Inventory (BDI) were eligible. Beck Depression Inventory was obtained at baseline and 4, 8, and 12 weeks of follow-up. Quality of life was assessed using the Medical Outcomes Study Short Form and the Minnesota Living with Heart Failure Questionnaire.

RESULTS

Controlled-release paroxetine resulted in significantly more recovery from depression (BDI <10) than placebo (69% vs 23%, P = .018) and resulted in lower continuous BDI scores throughout the intervention (P = .024). Controlled-release paroxetine was associated with higher general health levels compared with placebo on the Medical Outcomes Study 36-Item Short Form survey (38 +/- 10 vs 30 +/- 6, P = .016) at 12 weeks of follow-up. Reductions in depression were correlated with improvements in psychological aspects of quality of life (P < .05) but not with physical quality of life measures (P > .10).

CONCLUSION

Antidepressant therapy with paroxetine CR results in significant reductions in depression among patients with heart failure. The reductions in depression with paroxetine CR are accompanied by improvements in psychological aspects of quality of life. Larger controlled trials are needed to further document the effectiveness of paroxetine CR and other selective serotonin reuptake inhibitors in patients with heart failure and to determine patient subgroups that are most likely to benefit from antidepressive interventions.

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.

Robust gene expression with amplified RNA from biopsy-sized human heart tissue

The need to assess heart failure at an early stage highlights the importance of accurate microarray analysis using small tissue samples. To test our ability to obtain high quality RNA from biopsy-sized cardiac specimens, amplification was performed on RNA from biopsy-sized samples of left ventricle (LV) tissue from one explanted failing human heart and one non-failing heart. Two methods were used: one-cycle (1C) amplification of 1.6 microg of RNA, and two-cycle (2C) amplification of 50 ng of RNA. The resulting cRNA was hybridized to Affymetrix GeneChip arrays. Over 65% of all differentially expressed genes for failing vs non-failing hearts were concordant between 1C and 2C RNA amplification. Differentially expressed genes between 1C and 2C RNA amplification in our study were highly correlated (R(2) = 0.957 and changes in gene expression agreed with prior studies on genes and heart failure; e.g., decreased alpha-myosin heavy chain and alpha-tropomyosin, as well as increased expression of insulin-like growth factor). Two cycles of amplification from cardiac biopsies will permit accurate transcription profiling of heart failure at pre-symptomatic stages. Ability to measure gene expression from nanogram amounts of RNA will provide new opportunities to predict progression to symptomatic heart failure, and to identify potential targets for therapy.

B-type natriuretic peptide and N-terminal pro B-type natriuretic peptide are depressed in obesity despite higher left ventricular end diastolic pressures

BACKGROUND

B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are frequently used in diagnosing and monitoring patients with heart failure. Recent studies have demonstrated that concentrations of these peptides are decreased in obese patients, but whether lower natriuretic peptide concentrations are really due to different hemodynamics is unknown. The relationship between these markers and left ventricular end diastolic pressure (LVEDP) in obesity has not been elucidated.

METHODS

We examined patients undergoing cardiac catheterization who had creatinine of < 2.0, no evidence of myocardial infarction or pulmonary embolism, and no cardiac transplant. Body mass index and LVEDP were determined, and BNP and NT-proBNP obtained at the start of each case. Obesity was defined as body mass index of > or = 30 kg/m2.

RESULTS

Of 203 patients enrolled, 101 were obese. The groups were similar in respect to race, creatinine, cholesterol, and history of dyslipidemia and cardiomyopathy. The obese patients tended to be younger, were more likely to have diabetes and hypertension, and were less likely to have coronary artery disease. The obese patients had higher LVEDP but reduced BNP and NT-pro-BNP. The relationship between the natriuretic peptides and LVEDP was poor, with r values of < 0.1.

CONCLUSIONS

Obese patients have reduced concentrations of BNP and NT-proBNP compared to nonobese patients despite having elevated LVEDP. This suggests that factors other than cardiac status impact on BNP and NT-proBNP concentrations. The poor relationship between natriuretic peptide concentrations and LVEDP also suggests that these concentrations should not be considered surrogates for cardiac filling pressures or volumes.

Relationship of depression, anxiety, and social isolation to chronic heart failure outpatient mortality

OBJECTIVES

The Psychosocial Factors Outcome Study (PFOS) investigated the prevalence of depression and anxiety and the relationship of psychosocial factors to mortality in outpatients with heart failure (HF).

BACKGROUND

Considerable evidence links psychosocial factors to coronary heart disease mortality and sudden cardiac death (SCD). The contribution of psychosocial factors independent of disease severity to HF outpatient mortality is not well elucidated.

METHODS

Patients (N = 153) from 20 Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) sites participated in the PFOS. SCD-HeFT provided demographic, medical history, and cardiac data. Participants completed questionnaires to assess psychosocial status at PFOS entry.

RESULTS

Depression and anxiety were common in HF outpatients (36% Beck Depression Inventory-II > or = 13; 45% State Trait Anxiety Inventory > or = 40). Depression, anxiety, and social support amount did not differ in the SCD-HeFT treatment groups: implantable cardioverter defibrillator, amiodarone, and placebo medication. Fifteen (9.8%) patients died during mean follow-up at 23.6 months (SD = 8.2). In Cox regression controlling for treatment, depression, anxiety, and social isolation separately predicted mortality; perceived HF-specific functional status did not. Depression (ln) [P = .04, hazard ratio (HR) = 1.81] and social isolation (P = .04, HR = 2.25), but not anxiety, predicted mortality independent of demographics, clinical predictors, and treatment. When simultaneously including significant demographic, clinical, and psychosocial predictors and treatment groups, depression (ln) (P = .022, HR = 2.2) and social isolation (P = .094, HR = 1.75) predicted mortality. All-cause mortality was 12% for depressed patients and 9% for others.

CONCLUSION

This study finds a high prevalence of anxiety and confirms the high prevalence of depression in the HF outpatient population. Depression and social isolation predicted mortality independent of demographic and clinical status in HF outpatients.

Impedance cardiography: More questions than answers

Thoracic electrical bioimpedance, also known as impedance cardiography (ICG), is a noninvasive method to obtain hemodynamic measurements, including cardiac output. Recently, there has been a flurry of reports on the clinical use of ICG. Authors have suggested that ICG measurements are useful for a myriad of situations, including diagnosis of heart failure, monitoring of a patient's clinical status, and assisting in medicine titration decisions. However, data continue to suggest poor correlation between current generation ICG devices and invasive measurements of cardiac output, especially in heart failure patients. ICG is also not able to accurately measure left ventricular filling pressures. There are limited data demonstrating any improved outcomes using ICG in the clinical setting. Given the available data, ICG use should be limited to the research setting.