Longitudinal cognitive performance in older adults with cardiovascular disease: evidence for improvement in heart failure

BACKGROUND

Cardiovascular disease (CVD) and particularly heart failure (HF) have been associated with cognitive impairment in cross-sectional studies, but it is unclear how cognitive impairment progresses over time in older adults with these conditions.

OBJECTIVE

The aim of this study was to prospectively examine cognitive function in patients with HF versus other forms of CVD.

METHOD

Seventy-five older adults (aged 53-84 years) with CVD underwent Doppler echocardiogram to evaluate cardiac status and 2 administrations of the Dementia Rating Scale (DRS), a test of global cognitive functioning, 12 months apart.

RESULTS

Although DRS performance did not statistically differ between groups at either administration, a significant between-group difference in the rate of cognitive change emerged (lambda = 0.87; F = 10.50; P = .002; omega 2 = 0.11). Follow-up analyses revealed that patients with HF improved significantly on global DRS performance, whereas patients with other forms of CVD remained stable. More specifically, patients with HF showed improvement on subscales of attention, initiation/perseveration, and conceptualization. Exploratory analyses indicated that higher diastolic blood pressure at baseline was associated with improved DRS performance in patients with HF (r = 0.38; P = .02).

CONCLUSIONS

Patients with HF exhibited modest cognitive improvements during 12 months, particularly in attention and executive functioning. Higher diastolic blood pressure at baseline was associated with improvement. These results suggest that cognitive impairment in patients with HF may be modifiable and that improved blood pressure control may be an important contributor to improved function. Further prospective studies are needed to replicate results and determine underlying mechanisms.

Controlled-release carvedilol in the management of systemic hypertension and myocardial dysfunction

Cardiovascular disease is the leading cause of death worldwide. Within the treatment armamentarium, beta-blockers have demonstrated efficacy across the spectrum of cardiovascular disease--from modification of a risk factor (ie, hypertension) to treatment after an acute event (ie, myocardial infarction). Recently, the use of beta-blockers as a first-line therapy in hypertension has been called into question. Moreover, beta-blockers as a class are saddled with a misperception of having poor tolerability. However, vasodilatory beta-blockers such as carvedilol have a different hemodynamic action that provides the benefits of beta-blockade with the addition of vasodilation resulting from alpha 1-adrenergic receptor blockade. Vasodilation reduces total peripheral resistance, which may produce an overall positive effect on tolerability. Recently, a new, controlled-release carvedilol formulation has been developed that provides the clinical efficacy of carvedilol but is indicated for once-daily dosing. This review presents an overview of the clinical and pharmacologic carvedilol controlled-release data.

Quantitative analysis of intraventricular dyssynchrony using wall thickness by multidetector computed tomography

OBJECTIVES

We sought to determine the feasibility of cardiac computed tomography (CT) to detect significant differences in the extent of left ventricular dyssynchrony in heart failure (HF) patients with wide QRS, HF patients with narrow QRS, and age-matched controls.

BACKGROUND

The degree of mechanical dyssynchrony has been suggested as a predictor of response to cardiac resynchronization therapy. There have been no published reports of dyssynchrony assessment with the use of CT.

METHODS

Thirty-eight subjects underwent electrocardiogram-gated contrast-enhanced 64-slice multidetector CT. The left ventricular endocardial and epicardial boundaries were delineated from short-axis images reconstructed at 10% phase increments of the cardiac cycle. Global and segmental CT dyssynchrony metrics that used changes in wall thickness, wall motion, and volume over time were assessed for reproducibility. We defined a global metric using changes in wall thickness as the dyssynchrony index (DI).

RESULTS

The DI was the most reproducible metric (interobserver and intraobserver intraclass correlation coefficients >/=0.94, p < 0.0001) and was used to determine differences between the 3 groups: HF-wide QRS group (ejection fraction [EF] 22 +/- 8%, QRS 163 +/- 28 ms), HF-narrow QRS (EF 26 +/- 7%, QRS 96 +/- 11 ms), and age-matched control subjects (EF 64 +/- 5%, QRS 87 +/- 9 ms). Mean DI was significantly different between the 3 groups (HF-wide QRS: 152 +/- 44 ms, HF-narrow QRS: 121 +/- 58 ms, and control subjects: 65 +/- 12 ms; p < 0.0001) and greater in the HF-wide QRS (p < 0.0001) and HF-narrow QRS (p = 0.005) groups compared with control subjects. We found that DI had a good correlation with 2-dimensional (r = 0.65, p = 0.012) and 3-dimensional (r = 0.68, p = 0.008) echocardiographic dyssynchrony.

CONCLUSIONS

Quantitative assessment of global CT-derived DI, based on changes in wall thickness over time, is highly reproducible and renders significant differences between subjects most likely to have dyssynchrony and age-matched control subjects.

Improvement of Young and Elderly Patient's Knowledge of Heart Failure After an Educational Session

Background:

Interest in the role of patient education sessions for optimizing the management of heart failure (HF) is increasing. We determined whether improvements in young and elderly patients’ knowledge of HF and self-care behavior could be analyzed by administering a knowledge test before and after an educational session.

Methods:

Stable heart failure patients (n = 115) were enrolled in a prospective cohort study from our Heart Failure educational centre in a university hospital. Patient knowledge of six major HF-related topics was assessed via a questionnaire distributed once before an educational session and twice afterward. Each answer was assigned a numerical value and the final score for each topic could range from 0 to 20. Scores ≥ 15/20 were considered representative of a good level of knowledge.

Results:

The level of knowledge was low (9.7/20) before the educational session but was significantly higher (16.3/20) during the 1st quarter after the session, and this benefit was maintained for up to 12 months (16.6/20). Knowledge levels increased in both younger and elderly patients, and the number of patients who had a good level of knowledge also increased after the educational session.

Conclusion:

This study confirms that an HF knowledge test is feasible and that educational sessions improve the knowledge and self-management of both younger and elderly patients.

Heart failure: the commonest reason for hospital admission in Germany: medical and economic perspectives

BACKGROUND

Heart failure is now the commonest reason for hospitalization in Germany (German Federal Statistical Office, 2008). Heart failure will continue to be a central public health issue in the future as the population ages. This article focuses on regional differences, the costs of the disease, and the expected rate of increase in cases in the near future.

METHODS

This analysis is based on diagnosis statistics, cause-of-death statistics, and cost of illness data, as reported by the German Federal Statistical Office. Age- and sex-specific differences are taken into account.

RESULTS

2006 was the first year in which heart failure led to more hospital admissions in Germany (317 000) than any other diagnosis. At present, about 141 000 persons in Germany aged 80 and over have heart failure; by the year 2050, it is predicted that more than 350 000 persons in this age group will be affected. The rate of diagnosis of heart failure, its frequency as a cause of death, and the costs associated with it all vary across the individual states of the Federal Republic of Germany. The nationwide cost of heart failure in 2006 was estimated at 2.9 billion euros.

CONCLUSIONS

These findings reveal that heart failure has become more common as an admission diagnosis of hospitalized patients in Germany. Because the population is aging, new concepts for prevention and treatment will be needed in the near future so that the affected patients can continue to receive adequate care.

Regulation of mitochondrial Ca2+ and its effects on energetics and redox balance in normal and failing heart

Ca(2+) has been well accepted as a signal that coordinates changes in cytosolic workload with mitochondrial energy metabolism in cardiomyocytes. During increased work, Ca(2+) is accumulated in mitochondria and stimulates ATP production to match energy supply and demand. The kinetics of mitochondrial Ca(2+) ([Ca(2+)](m)) uptake remains unclear, and we review the debate on this subject in this article. [Ca(2+)](m) has multiple targets in oxidative phosphorylation including the F1/FO ATPase, the adenine nucleotide translocase, and Ca(2+)-sensitive dehydrogenases (CaDH) of the tricarboxylic acid (TCA) cycle. The well established effect of [Ca(2+)](m) is to activate CaDHs of the TCA cycle to increase NADH production. Maintaining NADH level is not only critical to keep a high oxidative phosphorylation rate during increased cardiac work, but is also necessary for the reducing system of the cell to maintain its reactive oxygen species (ROS) -scavenging capacity. Further, we review recent data demonstrating the deleterious effects of elevated Na(+) in cardiac pathology by blunting [Ca(2+)](m) accumulation.

Sex-specific impact of aldosterone receptor antagonism on ventricular remodeling and gene expression after myocardial infarction

Aldosterone receptor antagonism reduces mortality and improves post-myocardial infarction (MI) remodeling. Because aldosterone and estrogen signaling pathways interact, we hypothesized that aldosterone blockade is sex-specific. Therefore, we investigated the impact of eplerenone on left ventricular (LV) remodeling and gene expression of male infarcted rats versus female infarcted rats. MI and Sham animals were randomized to receive eplerenone (100 mg/kg/day) or placebo 3 days post-surgery for 4 weeks and assessed by echocardiography. In the MI placebo group, left ventricular end-diastolic dimension (LVEDD) increased from 7.3 +/- 0.4 mm to 10.2 +/- 1.0 mm (p < 0.05) and ejection fraction (EF) decreased from 82.3 +/- 4% to 45.5 +/- 11% (p < 0.05) in both sexes (p = NS between groups). Eplerenone attenuated LVEDD enlargement more effectively in females (8.8 +/- 0.2 mm, p < 0.05 vs. placebo) than in males (9.7 +/- 0.2 mm, p = NS vs. placebo) and improved EF in females (56.7 +/- 3%, p < 0.05 vs. placebo) but not in males (50.6 +/- 3%, p = NS vs. placebo). Transcriptomic analysis using Rat_230-2.0 microarrays (Affymetrix) revealed that in females 19% of downregulated genes and 44% of upregulated genes post-MI were restored to normal by eplerenone. In contrast, eplerenone only restored 4% of overexpressed genes in males. Together, these data suggest that aldosterone blockade reduces MI-induced cardiac remodeling and phenotypic alterations of gene expression preferentially in females than in males. The use of transcriptomic signatures to detect greater benefit of eplerenone in females has potential implications for personalized medicine.

Resistin, adiponectin, and risk of heart failure the Framingham offspring study

OBJECTIVES

We tested the association of the adipokines resistin and adiponectin with incident heart failure.

BACKGROUND

Abnormal concentrations of adipokines may partially explain the association between obesity and heart failure.

METHODS

We related circulating adipokine concentrations to the incidence of heart failure in 2,739 participants in the Framingham Offspring Study.

RESULTS

During 6 years of follow-up, 58 participants developed new-onset heart failure. In proportional hazards models (adjusting for age, sex, blood pressure, antihypertensive treatment, diabetes, smoking, total/high-density lipoprotein cholesterol ratio, prevalent coronary heart disease, valvular heart disease, left ventricular hypertrophy, and estimated glomerular filtration rate) using the lowest third of the resistin distribution as the referent, the hazard ratios for heart failure in the middle and top thirds were 2.89 (95% confidence interval [CI]: 1.05 to 7.92) and 4.01 (95% CI: 1.52 to 10.57), respectively (p = 0.004 for trend). Additional adjustment for body mass index, insulin resistance (measured with the homeostasis model), C-reactive protein, and B-type natriuretic peptide did not substantively weaken this association (multivariable hazard ratios [HRs]: 2.62 and 3.74, p = 0.007). In the maximally adjusted model, each SD increment in resistin (7.45 ng/ml) was associated with a 26% increase in heart failure risk (95% CI: 1% to 60%). Concentrations of adiponectin were not associated with heart failure (multivariable HRs: 0.87 and 0.97, p = 0.9).

CONCLUSIONS

Increased circulating concentrations of resistin were associated with incident heart failure, even after accounting for prevalent coronary heart disease, obesity, and measures of insulin resistance and inflammation. The findings suggest a role for resistin in human disease and a novel pathway to heart failure.

Years-needed-to-treat to add 1 year of life: a new metric to estimate treatment effects in randomized trials

AIMS

A standard metric to estimate absolute treatment effects is numbers-needed-to-treat (NNT), which implicitly assumes that all benefits reverse at trial-end. However, in-trial survival benefits typically do not reverse until long after trial-end, so that NNT will substantially underestimate lifetime benefits.

METHODS AND RESULTS

We developed a new concept, years-needed-to-treat (YNT) to add 1 year of life, that quantifies the expected average life expectancy for two treatments including the estimated years of life remaining post-trial. Numbers-needed-to-treat and YNT were calculated in the COMET trial, in which carvedilol vs. metoprolol tartrate resulted in 17% lower mortality over 4.8 years. A multivariate Cox model was used to predict survival. Remaining years of life were estimated using the mortality-life-table method. At trial-end, survival was 9% higher in the carvedilol arm. Assuming that patients remained on the same therapy post-trial, the average total years of life for carvedilol vs. metoprolol were 10.63 +/- 0.19 vs. 9.48 +/- 0.18 (P < 0.0001) or 1.15 (95% confidence interval 0.64-1.66) additional years of life. The YNT was 9.2, indicating that 9.2 person-years of treatment added 1 person-year of life, compared with NNT of 59.

CONCLUSION

Compared with NNT, the YNT method more accurately accounts for potential long-term benefits of interventions in randomized trials.

Chronic obstructive pulmonary disease is an independent predictor of death but not atherosclerotic events in patients with myocardial infarction: analysis of the Valsartan in Acute Myocardial Infarction Trial (VALIANT)

AIMS

Chronic obstructive pulmonary disease is an independent predictor of mortality in patients with myocardial infarction (MI). However, the impact on mode of death and risk of atherosclerotic events is unknown.

METHODS AND RESULTS

We assessed the risk of death and major cardiovascular (CV) events associated with chronic obstructive pulmonary disease in 14 703 patients with acute MI enrolled in the Valsartan in Acute Myocardial Infarction (VALIANT) trial. Cox proportional hazards models were used to evaluate the relationship between chronic obstructive pulmonary disease and CV outcomes. A total of 1258 (8.6%) patients had chronic obstructive pulmonary disease. Over a median follow-up period of 24.7 months, all-cause mortality was 30% in patients with chronic obstructive pulmonary disease, compared with 19% in those without. The adjusted hazard ratio (HR) for mortality was 1.14 (95% confidence interval 1.02-1.28). This reflected increased incidence of both non-CV death [HR 1.86 (1.43-2.42)] and sudden death [HR 1.26 (1.03-1.53)]. The unadjusted risk of all pre-specified CV outcomes was increased. However, after multivariate adjustment, chronic obstructive pulmonary disease was not an independent predictor of atherosclerotic events [MI or stroke: HR 0.98 (0.77-1.23)]. Mortality was significantly lower in patients receiving beta-blockers, irrespective of airway disease.

CONCLUSION

In high-risk patients with acute MI, chronic obstructive pulmonary disease is associated with increased mortality and non-fatal clinical events (both CV and non-CV). However, patients with chronic obstructive pulmonary disease did not experience a higher rate of atherosclerotic events.

Gene Variant of the Bradykinin B2 Receptor Influences Pulmonary Arterial Pressures in Heart Failure Patients

BACKGROUND: Pulmonary arterial pressure (PAP) varies considerably in heart failure (HF) despite similar degrees of left ventricular (LV) dysfunction. Bradykinin alters vascular tone and common variations in the kinin B2 receptor (BDKRB2) gene exists. We hypothesized that genetic variation in this receptor would influence PAP in HF. METHODS: 131 HF patients (>1yr history systolic HF), without COPD, not currently smoking, BMI < 40, without atrial fibrillation completed the study which included a blood draw for genotyping and neurohormones (ACE, A-II, Bradykinin, ANP, BNP, and catecholamines), an echocardiogram for cardiac function and systolic PAP (PAPsys). RESULTS: Mean LVEF was 29% ± 12%, NYHA class 2 ± 1, age 56 ± 12 yr, BMI 28 ± 5 kg/m(2). Forty-six patients (35%) were homozygous for the +9 allele, 58 (44%) were heterozygous (+9/-9) and 27 (21%) were homozygous for the -9 allele of the BDKRB2. PAPsys averaged 42 ± 13, 38 ± 12, and 35 ± 11 mmHg for +9/+9, +9/-9 and -9/-9, respectively (p = 0.03). There was a trend towards gene effect for plasma ACE with the highest values in +9/+9 and lowest in -9/-9 patients (9.5 ± 10.7, 7.1 ± 8.7, and 5.4 ± 6.4 U/L, respectively, p = 0.06). There were no differences in plasma bradykinin or A-II, LVEF, or NYHA across genotypes. CONCLUSION: These data suggest the +9/+9 polymorphism of the BDKRB2 receptor influences pulmonary vascular tone in stable HF.

Apoptotic and non-apoptotic programmed cardiomyocyte death in ventricular remodelling

A defining cellular event in the transition from compensated hypertrophy to dilated cardiomyopathy is cardiomyocyte drop-out due to apoptosis, programmed necrosis, and autophagy. The importance of apoptosis in heart failure has been recognized for over a decade, while other forms of programmed cell death have more recently been appreciated, and their pathophysiological roles continue to be defined in experimental and clinical heart failure. The major focus of this review is on apoptosis in heart failure, with a discussion of molecular cross-talk between apoptosis, autophagy, and programmed necrosis.

Different prognostic significance of right and left ventricular diastolic dysfunction in heart failure

BACKGROUND

Left (LV) and right (RV) ventricular diastolic dysfunction is common in heart failure but the prognostic value of RV diastolic dysfunction is not known.

HYPOTHESIS

As a follow-up to a previously undertaken study, this study was carried out to investigate whether LV and RV diastolic dysfunction affect prognosis differently and, in addition, whether changes in diastolic filling patterns over time correlate with clinical outcome.

METHODS

We studied a cohort of 105 patients (mean age 62.7 +/- 1.3 years, 66% male) with heart failure (ejection fraction < 50%) by Doppler echocardiography in both RV and LV.

RESULTS

An LV restrictive filling pattern (RFP) was present in 48% of the patients and, when compared with non-RFP subgroups, it was associated with poorer systolic function, higher New York Heart Association functional class, and higher cardiac mortality at 1 year (all p < 0.001). The coexistence of an LV-RFP and poor LV systolic function (ejection fraction < 25%) markedly decreased the 1-year survival that was significant when compared with other subgroups (p = 0.001). In contrast, RV diastolic dysfunction that occurred in 21% of patients was not a prognostic factor for mortality either alone or in combination with LV diastolic dysfunction, but predicted nonfatal hospital admissions for heart failure or unstable angina (p = 0.016).

CONCLUSION

An LV restrictive filling pattern is a powerful predictor of a poor prognosis, especially when combined with low ejection fraction, but in this study RV diastolic dysfunction did not appear to be an independent predictor of subsequent mortality.

The economic burden of heart failure

Heart failure, a major cause of morbidity and mortality among the elderly, is a serious public health problem. As the population ages and the prevalence of heart failure increases, expenditures related to the care of these patients will climb dramatically. As a result, the health care industry must develop strategies to contain this staggering economic burden. Strategies may include adopting approaches for preventing heart failure and implementing new treatment modalities with proven efficacy into large-scale clinical practice. Successful implementation of these strategies will require intensive physician and patient education and development of innovative approaches to fund support services.

Hemodynamic action of captopril in coronary patients with heart failure tolerant to nitroglycerin

BACKGROUND

At present there is little dispute that clinical tolerance of organic nitrates occurs during long-term treatment of patients with stable angina pectoris and congestive heart failure.

HYPOTHESIS

Captopril exerts a favorable hemodynamic effect in coronary patients with heart failure who are clinically tolerant to nitroglycerin.

METHODS

Development of nitrate tolerance was observed during intravenous nitroglycerin treatment (10 mg/h) in 16 of 19 patients (7 women, 12 men; mean age 56 +/- 8 years) with coronary heart disease [stenosis > or = 75%, New York Heart Association (NYHA) classes II-III). The criterion applied was a loss of efficacy of at least 50% with regard to mean pulmonary capillary wedge pressure compared with the maximum effect of nitrate. The effect of captopril (50 mg p.o.) was determined in a blank test. Captopril (50 mg p.o.) was administered again at the stage of clinically manifest nitrate tolerance.

RESULTS

Compared with the effect of captopril alone, significantly more pronounced reductions in mean pulmonary capillary wedge pressure (33% compared with 27%) and in mean pulmonary arterial pressure (36% compared with 17%) and significantly greater increases in cardiac index (14% compared with 7%) and stroke work index (34% compared with 18%) (p < 0.05 in each case; Wilcoxon test for linked random samples) were measured. Maintaining nitroglycerin infusion, the effect of captopril (at least 90% of the maximum effect) lasted for 123 +/- 24 min. The baseline values (at least 75% decline in the effect of captopril) were only reached after 369 +/- 34 min.

CONCLUSION

The results document a favorable hemodynamic effect of captopril in nitrate tolerance which is significantly better than that of captopril alone.

Reverse remodeling in heart failure with intensification of vasodilator therapy

BACKGROUND

Heart failure therapy with beta-receptor blockade has been shown to effect a partial reversal of left ventricular (LV) remodeling in heart failure.

HYPOTHESIS

We tested the hypothesis that, in the absence of beta blockade, uptitration of angiotensin-converting enzyme (ACE) inhibitor and nitrate therapy over conventional dosages would improve symptoms as well as LV function in patients with severe heart failure.

METHODS

For patients with nonischemic or ischemic cardiomyopathy, intensive high-dose angiotensin-converting enzyme inhibitor and nitrate therapy was uptitrated. Echocardiograms were obtained semiannually and evaluated in a blinded fashion. Of 99 patients in the study, aged 55 +/- 13 years, with heart failure for 5.2 +/- 3.1 years, 74 were men, 69 were Caucasian, and 34 had ischemic cardiomyopathy. The final dosage of enalapril was 40 +/- 23 mg/day of isosorbide dinitrate it was 153 +/- 127 mg/day.

RESULTS

Initial New York Heart Association classification improved from 2.8 +/- 0.9 to 1.7 +/- 0.9 (p < 0.001) in 2.7 years of follow-up. Of the 99 patients, 72 further improved their ejection fraction. For the whole group, ejection fraction increased from 21 +/- 9% to 30 +/- 13% in 6 months (p < 0.001), with a reduction in LV end-diastolic size from 6.6 +/- 0.9 to 6.3 +/- 1.0 cm (p = 0.002), a decrease in the severity of mitral regurgitation from mild/moderate to only mild. Resting heart rate declined with no change over time in systemic systolic blood pressure. Final ejection fraction for nonischemic patients (n = 65) was 36 +/- 16% versus 23 +/- 9% for the ischemic population.

CONCLUSIONS

Uptitration of high-dose ACE inhibitor and nitrate therapy to higher doses is well tolerated in severe heart failure, further improves both clinical status and LV systolic function, and is more effective in nonischemic than in ischemic cardiomyopathy.

Myotonic dystrophy associated with QT prolongation and torsade de pointes

A rare case of myotonic dystrophy (MD) with congestive heart failure, associated with QT prolongation and torsade de pointes (TdP) is reported. A 53-year-old woman was admitted to the hospital because of congestive heart failure. Electrocardiograph (ECG) showed first-degree atrioventricular block and QT prolongation. During hospitalization, TdP appeared but returned to sinus rhythm spontaneously. As the patient had quadriplegia, a myopathic face, cataracts, diabetes mellitus, and an increased number of cytosine-thymineguanine (CTG) repeats (760 repeats), she was diagnosed as having MD. Electrocardiographic analysis of her family also revealed abnormal QT(U) prolongation in her daughter and brother who both had MD, while ECG findings of other family members without MD were normal. Thus, the presence of QT(U) prolongation was associated with MD in this family.

Maximizing management of patients with decompensated heart failure

Patients with decompensated congestive heart failure can be categorized into those with either acute or chronic presentations. Patients with acute decompensated heart failure most often have an acute injury that affects either myocardial performance (i.e., myocardial infarction) or valvular/chamber integrity (mitral regurgitation, ventricular septal rupture), which leads to an acute rise in left ventricular (LV) filling pressures resulting in pulmonary edema and dyspnea. Therapy for these patients is aimed at treating the underlying cause of the myocardial injury as well as pharmacologic strategies to reduce LV filling pressures and to improve cardiac performance. In contrast, the therapy of patients presenting with decompensated heart failure in the setting of chronic LV systolic dysfunction, treated with angiotensin-converting enzyme inhibitors, digoxin, diuretics, and may be beta blockers, represent a poorly defined clinical entity that lacks clear guidelines for treatment. These patients can present with symptoms of volume overload and/or low cardiac output without evidence for a volume overloaded state. Potential diagnostic and therapeutic approaches include (1) a pulmonary artery catheter for invasive hemodynamic monitoring, (2) intravenous inotropic therapy, (3) LV mechanical assist device therapy, and (4) cardiac transplantation. This review presents some of the advantages and disadvantages of each of these interventions for patients with chronic systolic dysfunction who present with decompensated symptoms and require specialized management in the hospital setting.

Sudden death in dilated cardiomyopathy

The purpose of this review is to examine the potential contribution of arrhythmia to the occurrence of sudden death in dilated cardiomyopathy (DCM) and to discuss current treatment options. We performed a search of the MEDLINE database from 1985 to the present and the reference citations of selected articles pertaining to the prognostic significance, management, and pathophysiology of arrhythmias in DCM. A large proportion of patients with DCM die suddenly, most secondary to ventricular arrhythmia and a smaller proportion due to bradyarrhythmia. The presence and severity of ventricular ectopy may predict risk for sudden death, but the role of electrophysiologic study and signal-averaged electrocardiography in further risk stratifying patients remains uncertain. Abnormalities of the autonomic nervous system and renin-angiotensin-aldosterone axis appear to promote the occurrence of ventricular arrhythmias. Angiotensin-converting enzyme inhibitors improve overall mortality in congestive heart failure, and the use of direct angiotensin-receptor antagonists is currently being studied. In addition, beta-receptor antagonists appear to improve morbidity and may prove to improve mortality in heart failure as well. Other interventions still under investigation include amiodarone and the implantable cardioverter-defibrillator. The underlying pathophysiology of sudden death in DCM involves primarily ventricular tachyarrhythmia. Angiotensin-converting enzyme inhibitors remain a mainstay of improving overall mortality, while further study on the roles for newer drugs and devices is ongoing.

Serial circulating concentrations of C-reactive protein, interleukin (IL)-4, and IL-6 in patients with acute left heart decompensation

BACKGROUND

Interleukin (IL)-6 has recently been shown to have negative inotropic effects, and several studies have reported increases in circulating concentrations of this cytokine in patients with depressed left ventricular ejection fraction and chronic left heart failure. However, most previous clinical studies have measured cytokines in compensated chronic heart failure.

HYPOTHESIS

The purpose of this study was to examine the temporal evolution of circulating concentrations of C-reactive protein (CRP) and cytokines in patients with cardiomyopathy and acute cardiac decompensation, free of infection and unstable angina.

METHODS

The time course of circulating concentrations of CRP, an anti-inflammatory cytokine interleukin (IL)-4, and a proinflammatory cytokine IL-6 were studied in eight patients with cardiomyopathy and acute cardiac decompensation in the absence of infection or unstable angina. Control samples were obtained from eight age-matched asymptomatic subjects.

RESULTS

Increased circulating concentrations of CRP (2.6 +/- 0.8 mg/dl), IL-4 (164.6 + 36.5 pg/ml), and IL-6 (17.1 +/- 5.1 pg/ml) were found in all eight patients during acute cardiac decompensation; these values decreased significantly with the resolution of symptoms of cardiac decompensation (0.5 +/- 0.1 mg/dl, 77.8 +/- 23.6 pg/ml, 2.3 +/- 0.1 pg/ml, respectively, p < 0.05 for both). There was a significant correlation between peak CRP and peak IL-6 (p < 0.05).

CONCLUSIONS

In patients with acute left heart decompensation in the absence of infection or coronary events, CRP, IL-4, and IL-6 increased and returned toward normal levels as the symptoms of heart failure resolved. Since the changes in concentrations of CRP, IL-4, and IL-6 in patients with heart failure are dynamic, the distinction between compensated and decompensated state is important when discussing the significance of acute reactive proteins or cytokines in the pathogenesis of heart failure.

Current clinical applications of heart rate variability

Heart rate variability (HRV) has become a popular method for the studies of physiologic mechanisms responsible for the control of heart rate fluctuations, in which the autonomic nervous system appears to play a primary role. Depression of HRV has been observed in many clinical scenarios, including autonomic neuropathy, heart transplantation, congestive heart failure, myocardial infarction (MI), and other cardiac and noncardiac diseases. However, it is important to realize that clinical implication of HRV analysis has been clearly recognized in only two clinical conditions: (1) as a predictor of risk of arrhythmic events or sudden cardiac death after acute MI, and (2) as a clinical marker of evolving diabetic neuropathy. Recently, its role in evaluation and management of heart failure has also been recognized. It is pertinent to recognize the limitations of HRV as far as its clinical utility at present is concerned. The methodology of HRV had remained poorly standardized until the recent publication of the Special Report of the Task Force of ESC/NASPE, and thus has been presenting difficulty in comparing earlier existing data. Also, determination of the exact sensitivity, specificity, and predictive value of HRV, as well as the normal values of standard measures in the general population, still require further investigation before better standards can be set for existing and future clinical applications. This article reviews the major concepts of HRV measurements, their clinical relevance, and the recent advances in this field.

Does left ventricular shape influence clinical outcome in heart failure?

BACKGROUND

Left ventricular (LV) shape tends to become spherical in patients with dilated cardiomyopathy of diverse etiology. Clinical and echocardiographic factors which affect the degree of LV spherical distortion and the impact of altered LV shape on prognosis have not been studied adequately.

HYPOTHESIS

This study was undertaken to investigate the prognostic implications of altered LV shape on clinical outcome in dilated cardiomyopathy.

METHODS

In 112 patients with depressed LV ejection fraction (19 +/- 9%) and symptomatic heart failure, and in 10 age- and gender-matched normal controls, we performed 2-dimensional echocardiography to assess LV shape using the eccentricity index. Eccentricity index was defined as the ratio of the LV long axis to the LV transverse diameter, measured at end systole and end diastole in the apical four-chamber view. We sought univariate and multivariate clinical and echocardiographic correlates of LV shape. Further, we sought correlations between eccentricity index and clinical outcomes (death and composite outcome of death or emergent heart transplant).

RESULTS

Compared with controls, patients with cardiomyopathy had significantly lower systolic (2.04 vs. 1.56; p = 0.001) and diastolic (1.75 vs. 1.53; p = 0.003) eccentricity index, implying a more spherical LV shape. Of all clinical and echocardiographic variables tested, mitral regurgitation, right ventricular dysfunction, and increased LV mass were independently associated with spherical LV shape. At a follow-up period of 17 +/- 12 months, no correlation was found between eccentricity index and the occurrence of death or the combined endpoint of death or emergent heart transplant, in univariate or multivariate analysis.

CONCLUSIONS

In patients with dilated cardiomyopathy, the degree of spherical distortion of the LV does not correlate with prognosis.

L-arginine reduces heart rate and improves hemodynamics in severe congestive heart failure

BACKGROUND

Stimulated endothelium-derived relaxing factor-mediated vasodilation and conduit artery distensibility are impaired in congestive heart failure (CHF). L-arginine could have a potentially beneficial role in CHF, acting through the nitric oxide (NO)-L-arginine pathway or by growth hormone increment.

HYPOTHESIS

This study was undertaken to investigate the effects of L-arginine on heart rate, hemodynamics, and left ventricular (LV) function in CHF.

METHODS

In seven patients (aged 39 +/- 8 years) with CHF, we obtained the following parameters using echocardiography and an LV Millar Mikro-Tip catheter simultaneously under four conditions: basal, during NO inhalation (40 ppm), in basal condition before L-arginine infusion, and after L-arginine intravenous infusion (mean dose 30.4 +/- 1.9 g).

RESULTS

Nitric oxide inhalation increased pulmonary capillary wedge pressure from 25 +/- 9 to 31 +/- 7 mmHg (p < 0.05), but did not change echocardiographic variables or LV contractility by elastance determination. L-arginine decreased heart rate (from 88 +/- 15 to 80 +/- 16 beats/min, p<0.005), mean systemic arterial pressure (from 84 +/- 17 to 70 +/- 18 mmHg, p < 0.007), and systemic vascular resistance (from 24 +/- 8 to 15 +/- 6 Wood units, p<0.003). L-arginine increased right atrial pressure (from 7 +/- 2 to 10 +/- 3 mmHg, p<0.04), cardiac output (from 3.4 +/- 0.7 to 4.1 +/- 0.8 l/min, p < 0.009), and stroke volume (from 40 +/- 9 to 54 +/- 14 ml, p < 0.008). The ratios of pulmonary vascular resistance to systemic vascular resistance at baseline and during NO inhalation were 0.09 and 0.075, respectively, and with L-arginine this increased from 0.09 to 0.12.

CONCLUSION

L-arginine exerted no effect on contractility; however, by acting on systemic vascular resistance it improved cardiac performance. L-arginine showed a negative chronotropic effect. The possible beneficial effect of L-arginine on reversing endothelial dysfunction in CHF without changing LV contractility should be the subject of further investigations.

Treatment with ramipril improves systolic function even in patients with mild systolic dysfunction and symptoms of heart failure after acute myocardial infarction

BACKGROUND

Clinical signs of heart failure such as pulmonary rales and dyspnea, ventricular dysfunction, and ventricular arrhythmia are independent predictors of a poor prognosis after acute myocardial infarction (AMI).

HYPOTHESIS

The study aimed to assess the effect of ramipril treatment on mildly depressed left ventricular (LV) systolic function, assessed by atrioventricular (AV) plane displacement in patients with congestive heart failure after AMI.

METHODS

The study was a substudy in the Acute Infarction Ramipril Efficacy Study, a double-blind, randomized, place-bo-controlled trial of ramipril versus placebo in patients with symptoms of heart failure after AMI. In all, 56 patients were included in the main study, 4 refused to participate in the substudy, and 4 were excluded for logistical reasons. Echocardiography was performed at entry and after 6 months. Patients who underwent coronary artery bypass grafting during the follow-up period were excluded.

RESULTS

At baseline, the patients had modest LV dysfunction, and mean AV plane displacement of 9.7 mm. During follow-up, AV plane displacement increased in ramipril-treated patients from 9.5 to 10.9 mm (p < 0.01). No statistically significant changes were seen in the placebo group.

CONCLUSIONS

Ramipril improves LV systolic function in patients with clinical signs of heart failure and only modest systolic dysfunction after AMI. Measurement of AV plane displacement is a simple and reproducible method for detection of small changes in systolic function and may be used instead of ejection fraction in patients with poor image quality.