HIVAN and medication use in chronic dialysis patients in the United States: analysis of the USRDS DMMS Wave 2 study

BACKGROUND

The use and possible effects of factors known to improve outcomes in patients with human immunodeficiency virus associated nephropathy (HIVAN), namely of angiotensin converting enzyme inhibitors (ACE) and antiretroviral therapy, has not been reported for a national sample of dialysis patients.

METHODS

We conducted a historical cohort study of the United States Renal Data System (USRDS) Dialysis Morbidity and Mortality Study (DMMS) Wave 2 to identify risk factors associated with increased mortality in these patients. Data were available for 3374 patients who started dialysis and were followed until March 2000. Cox Regression analysis was used to model adjusted hazard ratios (AHR) with HIVAN as a cause of end stage renal disease (ESRD) and its impact on mortality during the study period, adjusted for potential confounders.

RESULTS

Of the 3374 patients who started dialysis, 36 (1.1%) had ESRD as a result of HIVAN. Only 22 (61%) of patients with HIVAN received antiretroviral agents, and only nine patients (25%) received combination antiretroviral therapy, and only 14% received ACE inhibitors. Neither the use of multiple antiretroviral drugs (AHR, 0.62, 95% CI, 0.10, 3.86, p = 0.60), or ACE inhibitors were associated with a survival advantage. Patients with HIVAN had an increased risk of mortality (adjusted hazard ratio, 4.74, 95% Confidence Interval, 3.12, 7.32, p < 0.01) compared to patients with other causes of ESRD.

CONCLUSIONS

Medications known to improve outcomes in HIV infected patients were underutilized in patients with HIVAN. Adjusted for other factors, a primary diagnosis of HIVAN was associated with increased mortality compared with other causes of ESRD.

Samuel Johnson: his ills, his pills and his physician friends

Samuel Johnson (1709-1784) was one of the greatest men of his age. Although famed for his writings, especially his Dictionary and his folio on Shakespeare, he is remembered for his tavern conversations, his literary clubs and the great biography of his life by Boswell. He always enjoyed having physicians as his friends, and took a great interest in all branches of medicine. He would advise and prescribe for friends who regularly consulted him, and he was not unhappy when mistaken for a physician. Particularly in his last years he had need of physicians for his own care, but held his own distinct views on whether to take their medicines and in what dose--usually much higher than prescribed. His many illnesses and his knowledge and views on medicine make him of continuing interest to physicians and give us insight into medical practice and beliefs in the Age of Enlightenment.

Detection of scarred and viable myocardium using a new magnetic resonance imaging technique: blood oxygen level dependent (BOLD) MRI

BACKGROUND

The identification of viable myocardium in patients with impaired left ventricular contraction secondary to coronary heart disease is important clinically as such myocardium is likely to benefit from revascularisation. Blood oxygen level dependent (BOLD) magnetic resonance imaging (MRI) relies on changes in deoxyhaemoglobin concentration under stress for signal generation and could be used for the differentiation between scarred and viable myocardium.

AIM

To assess the signal change on BOLD MRI in viable and scarred myocardium as identified by positron emission tomography (PET).

METHOD

19 patients with impaired left ventricular contraction and at least one akinetic area were enrolled. They underwent rest and dipyridamole stress MRI, using a double breath hold T2* weighted, ECG gated sequence to produce BOLD contrast images, and cine-MRI for wall thickening assessment. Dynamic perfusion and metabolic PET images followed the MRI. Signal change on BOLD MRI and the wall thickening were compared between rest and stress images in hibernating and scarred segments identified by PET on two short axis slices of mid ventricle, with eight segments each.

RESULTS

Using PET, 68 segments were identified as hibernating and 42 as scarred. The hibernating segments were found on BOLD MRI to have an average signal change between rest and stress of -9.53%, compared with -2.15% in the scarred segments (p = 0.008). The average wall thickening was 8.7 mm in the hibernating segments compared with 5.9 mm in the scarred segments (p < 0.0001).

CONCLUSIONS

BOLD MRI with wall thickening may differentiate scarred and viable myocardium and help identify suitable patients for revascularisation. Further larger studies are needed to establish a threshold for detection, sensitivity, and specificity.

The influence of age, sex and other variables on the plasma level of N-terminal pro brain natriuretic peptide in a large sample of the general population

OBJECTIVE

To identify potentially confounding variables for the interpretation of plasma N-terminal pro brain natriuretic peptide (NT-proBNP).

DESIGN

Randomly selected subjects filled in a heart failure questionnaire and underwent pulse and blood pressure measurements, ECG, echocardiography, and blood sampling.

SETTING

Subjects were recruited from four Copenhagen general practices located in the same urban area and were examined in a Copenhagen University Hospital.

PATIENTS

382 women and 290 men in four age groups: 50-59 years (n = 174); 60-69 years (n = 204); 70-79 years (n = 174); and > 80 years (n = 120).

MAIN OUTCOME MEASURES

Associations between the plasma concentration of NT-proBNP and a range of clinical variables.

RESULTS

In the undivided study sample, female sex (p < 0.0001), greater age (p < 0.0001), increasing dyspnoea (p = 0.0001), diabetes mellitus (p = 0.01), valvar heart disease (p = 0.002), low heart rate (p < 0.0001), left ventricular ejection fraction < or = 45% (p < 0.0001), abnormal ECG (p < 0.0001), high log10[plasma creatinine] (p = 0.0009), low log10[plasma glycosylated haemoglobin A1c] (p = 0.0004), and high log10[urine albumin] (p < 0.0001) were independently associated with a high plasma log10[plasma NT-proBNP] by multiple linear regression analysis.

CONCLUSIONS

A single reference interval for the normal value of NT-proBNP is unlikely to suffice. There are several confounders for the interpretation of a given NT-proBNP concentration and at the very least adjustment should be made for the independent effects of age and sex.

Probucol prevents early coronary heart disease and death in the high-density lipoprotein receptor SR-BI/apolipoprotein E double knockout mouse

Mice with homozygous null mutations in the high-density lipoprotein receptor SR-BI (scavenger receptor class B, type I) and apolipoprotein E genes fed a low-fat diet exhibit a constellation of pathologies shared with human atherosclerotic coronary heart disease (CHD): hypercholesterolemia, occlusive coronary atherosclerosis, myocardial infarctions, cardiac dysfunction (heart enlargement, reduced systolic function and ejection fraction, and ECG abnormalities), and premature death (mean age 6 weeks). They also exhibit a block in RBC maturation and abnormally high plasma unesterified-to-total cholesterol ratio (0.8) with associated abnormal lipoprotein morphology (lamellar/vesicular and stacked discoidal particles reminiscent of those in lecithin/cholesterol acyltransferase deficiency and cholestasis). Treatment with the lipid-lowering, antiatherosclerosis, and antioxidation drug probucol extended life to as long as 60 weeks (mean 36 weeks), and at 5-6 weeks of age, virtually completely reversed the cardiac and most RBC pathologies and corrected the unesterified to total cholesterol ratio (0.3) and associated distinctive abnormal lipoprotein morphologies. Manipulation of the timing of administration and withdrawal of probucol could control the onset of death and suggested that critical pathological changes usually occurred in untreated double knockout mice between approximately 3 (weaning) and 5 weeks of age and that probucol delayed heart failure even after development of substantial CHD. The ability of probucol treatment to modulate pathophysiology in the double knockout mice enhances the potential of this murine system for analysis of the pathophysiology of CHD and preclinical testing of new approaches for the prevention and treatment of cardiovascular disease.

Predicting mortality in patients with heart failure: a pragmatic approach

OBJECTIVE

To develop a comprehensive and easily applicable prognostic model predicting mortality risk in patients with moderate to severe heart failure.

DESIGN

Prospective follow up study.

SETTING

Seven general hospitals in the Netherlands.

PATIENTS

152 outpatients with heart failure or patients admitted to hospital because of heart failure, who were included in a randomised trial to assess the impact of a pharmacist led intervention to improve drug compliance. Duration of follow up was at least 18 months.

MAIN OUTCOME MEASURES

Multivariable logistic regression modelling was used to evaluate information from history, physical examination (for example, blood pressure), drug use, and quality of life questionnaires that independently contributed to the prediction of death. The area under receiver operating characteristic curves (AUC) was used to estimate the predictive ability of the prognostic models.

RESULTS

During the 18 months of follow up, 51 patients (34%) died. Independent predictors of mortality were diabetes mellitus, a history of renal dysfunction (or higher creatinine), New York Heart Association (NYHA) functional class III or IV, lower weight or body mass index, lower blood pressure, ankle oedema, and higher scores on a disease specific quality of life questionnaire. The use of beta blockers was predictive of a better prognosis. These factors were used to derive various prediction formulas. A model based on medical history, weight, presence of oedema, and lower blood pressure had an AUC of 0.77. Addition of use of beta blockers to this model improved the AUC to 0.80. Addition of NYHA class increased the AUC to 0.84. Data on quality of life did not improve the AUC further (AUC 0.85).

CONCLUSIONS

A prognostic model produced on the basis of easily obtainable information from medical history and physical examination can adequately stratify heart failure patients according to their short term risk of death.

Prognosis for patients newly admitted to hospital with heart failure: survival trends in 12 220 index admissions in Leicestershire 1993-2001

OBJECTIVE

To examine rates of, prognosis following, and the influences on first hospital admission with heart failure in Leicestershire during 1993-2001.

DESIGN

Historical cohort study using record linked discharge and mortality data.

SETTING

Leicestershire, England.

PATIENTS

12 220 individual patients newly hospitalised with heart failure between 1 April 1993 and 31 March 2001.

MAIN OUTCOME MEASURES

30 day and one year survival, temporal trends in survival, and the influence on prognosis of age, sex, comorbidity, social deprivation, and year of hospital admission.

METHODS AND RESULTS

Between 1993/94 and 2000/01, rates of first hospitalisation increased by 62%, from 29 to 47/10 000 population, confined largely to those aged > 65 years. Rates did not increase after 1998. Median age at presentation increased from 74 years in 1993/94 to 77 years in 2000/01 for men but was unchanged (80 years) for women. Overall one and five year survival was 57% and 27%, respectively. There was a 43-45% increase in risk of death for each decade of age at admission and a 14-17% increase associated with male sex. There was a clear influence on outcome of comorbidity but no influence of social deprivation score. Both one month and one year survival were lower for patients whose first heart failure admission was concomitant with acute myocardial infarction. Between 1993/94 and 2000/01 postdischarge cardiovascular survival improved by 50% (p < 0.001).

CONCLUSIONS

Rates of first hospital admission with heart failure reached a plateau in the late 1990s. Case fatality rates remain high and prognosis poor, in particular for those of increasing age, for men, and for patients with concomitant acute myocardial infarction. However, clear trends to improved survival were seen over this time.

Different responses to dobutamine in the presence of carvedilol or metoprolol in patients with chronic heart failure

OBJECTIVE

To determine whether patients with congestive heart failure on different beta adrenoreceptor blocking drugs have similar haemodynamic responses to dobutamine.

DESIGN

Single centre, single blind, randomised, two period crossover study comparing carvedilol with metoprolol CR/XL.

PATIENTS

Ten patients with stable chronic congestive heart failure (ejection fraction < 40%) on chronic treatment with metoprolol CR/XL.

METHODS

Patients were treated with carvedilol or metoprolol CR/XL (target dose 50 mg twice daily and 200 mg once daily, respectively) for eight weeks. Stress echocardiography was undertaken at the end of each maintenance period, using dobutamine 5 and 15 microg/kg/min.

RESULTS

No significant haemodynamic differences were seen at rest on the two treatments. There was a more pronounced increase in heart rate and cardiac output during dobutamine infusion when the patients were on metoprolol than when they were on carvedilol. Mean arterial pressure increased significantly when the patients were on carvedilol, and cardiac output increased during low dose dobutamine, without further change during high dose dobutamine. During the dobutamine infusion, there was no significant difference in ejection fraction between carvedilol and metoprolol treatment.

CONCLUSIONS

Patients with congestive heart failure on a non-selective beta adrenoreceptor blocker or beta1 selective blocker responded differently to the inotropic drug dobutamine: the beta1 blockade caused by metoprolol could be counteracted by dobutamine, whereas with carvedilol a low dose of dobutamine increased cardiac output, and a higher dose of dobutamine caused a pressor effect. These findings may be clinically relevant when choosing an inotropic drug.

Opportunities for improvement in the diagnosis and treatment of heart failure

BACKGROUND

Improved treatment of congestive heart failure (CHF) can slow disease progression, promote clinical stability, and prolong survival.

HYPOTHESIS

Patterns in diagnostic test utilization and pharmacotherapy among patients with newly diagnosed heart failure may affect outcomes.

METHODS

Claims data were analyzed from all diagnostic procedures and prescriptions from 1995 to 1998 in 3,353 patients with heart failure diagnosed within 1 year. Rates of diagnostic testing and categories of drugs prescribed were the main outcome measures. Demographic variables and type of provider were analyzed within a setting whose access to care was controlled.

RESULTS

Rates of diagnostic testing with respect to basic, metabolic/endocrine, alternative diagnoses, underlying ischemia, and left ventricular function varied as a function of gender, age, race, and primary versus specialty care provider. Only 4.7% of patients underwent all diagnostics and treatments recommended in current guidelines. However, those patients (27.5%) who underwent an evaluation for ischemic heart disease and were prescribed vasodilators or beta blockers enjoyed the lowest crude mortality.

CONCLUSIONS

There are multiple opportunities apparent to improve the initial diagnostic and therapeutic care of patients with heart failure. There appears to be an early survival benefit with respect to use of vasodilators and beta blockers within the first year of treatment.

The therapeutic potential of new insights into myocardial excitation-contraction coupling

The physiological mechanisms that link myocyte depolarisation and contraction are referred to collectively as excitation-contraction coupling. This important process uses calcium as a second messenger to convert electrical depolarisation of the myocyte sarcolemma into the coordinated contraction of the cell's internal myofilament apparatus. The inotropic properties of the cell are determined by the efficiency of this process and when this efficiency is lost contractile dysfunction and heart failure develop, along with a propensity for arrhythmias. Previous attempts to use positive inotropic drugs in the management of chronic heart failure have been disappointing. Such drugs have been associated with unacceptable side effects and worse morbidity and mortality outcomes, primarily through their non-specific amplification of intracellular cascade pathways that modify the cell's inotropic state. As a result of recent advances in our understanding of how excitation-contraction coupling works in both health and disease it may be possible to design more specifically targeted drug treatment that has the potential to avoid the detrimental effect of currently available drugs while at the same time improving the inotropic properties of the cell.

CB(1) cannabinoid receptor antagonism promotes remodeling and cannabinoid treatment prevents endothelial dysfunction and hypotension in rats with myocardial infarction

1. To study the long-term effects of altered cannabinoid receptor activity on myocardial and vascular function, Wistar rats were treated with the selective CB(1) antagonist AM-251 (0.5 mg kg(-1) d(-1)), the potent synthetic cannabinoid HU-210 (50 micro g kg(-1) d(-1)) or vehicle for 12 weeks after coronary artery ligation or sham operation. 2. AM-251 further reduced the pressure-generating capacity, shifted the pressure volume curve to the right (P<0.05) and increased the left-ventricular operating volume (AM-251: 930+/-40 micro l vs control: 820+/-40 micro l vs HU-210: 790+/-50 micro l; P<0.05) in rats with large myocardial infarction (MI). 3. Left-ventricular CB(1) immunoactivity in rats 12 weeks after large MI was unaltered as compared with noninfarcted hearts. 4. Cannabinoid receptor activation through HU-210, a cannabinoid that alters cardiovascular parameters via CB(1) receptors, increased the left-ventricular end-diastolic pressure (LVEDP, P<0.05). However, it prevented the drop in left-ventricular systolic pressure (HU-210: 142+/-5 mm Hg; P<0.05 vs control: 124+/-3 mm Hg; and P<0.001 vs AM-251: 114+/-3 mm Hg) and prevented endothelial dysfunction (ED) in aortic rings of rats with large MI (P<0.05). 5. Compared with AM-251, HU-210 prevented the decline in the maximal rate of rise of left-ventricular pressure and the maximum pressure-generating ability (P<0.05). In rats with small MI, HU-210 increased cardiac index (P<0.01) and lowered the total peripheral resistance (P<0.05). 6. The study shows that during the development of congestive heart failure post-large MI, cannabinoid treatment increases LVEDP and prevents hypotension and ED. Presumed CB(1) antagonism promotes remodeling despite unchanged myocardial CB(1) expression.

Sympathetic nervous system activity and ventricular tachyarrhythmias: recent advances

Sympathetic nervous system activity (SNSA) is believed to participate in the genesis of ventricular tachyarrhythmias (VTA) but understanding has been impeded by the number and complexity of effects and the paucity of data from humans. New information from studies of genetic disorders, animal models, and spontaneous human arrhythmias indicates the importance of the temporal pattern of SNSA in arrhythmia development. The proarrhythmic effects of short-term elevations of SNSA are exemplified by genetic disorders and include enhancement of early and delayed afterdepolarizations and increased dispersion of repolarization. The role of long-term elevations of SNSA is suggested by animal models of enhanced SNSA signaling that results in apoptosis, hypertrophy, and fibrosis, and sympathetic nerve sprouting caused by infusion of nerve growth factor. Processes that overlap short- and long-term effects are suggested by changes in R-R interval variability (RRV) that precede VTA in patients by several hours. SNSA-mediated alterations in gene expression of ion channels may account for some intermediate-term effects. The propensity for VTA is highest when short-, intermediate, and long-term changes are superimposed. Because the proarrhythmic effects are related to the duration and intensity of SNSA, normal regulatory processes such as parasympathetic activity that inhibits SNSA, and oscillations that continuously vary the intensity of SNSA may provide vital antiarrhythmic protection that is lost in severe heart failure and other disorders. These observations may have therapeutic implications. The recommended use of beta-adrenergic receptor blockers to achieve a constant level of inhibition does not take into account the temporal patterns and regional heterogeneity of SNSA, the proarrhythmic effects of alpha-adrenergic receptor stimulation, or the potential proarrhythmic effects of beta-adrenergic receptor blockade. Further research is needed to determine if other approaches to SNSA modulation can enhance the antiarrhythmic effects.

Treatment of chronic heart failure with beta adrenergic blockade beyond controlled clinical trials: the BRING-UP experience

BACKGROUND

Several large controlled trials have shown that beta blockers given to patients with heart failure (New York Heart Association functional class II-IV) reduce morbidity and mortality. Despite these impressive results, implementing the use of beta blockade in clinical practice appears slow and difficult. The BRING-UP study was designed to tackle this problem.

OBJECTIVES

To accelerate the adoption of beta blockade in clinical practice; to provide an epidemiological estimate of the proportion of patients with heart failure suitable for this treatment in general cardiology care; and to assess effectiveness of these drugs outside the setting of clinical trials.

METHODS

The design of the study and recommendations derived from available evidence on the use of beta blockers were discussed with cardiologists during regional meetings. All consecutive heart failure patients in a one month period, whether treated or not with beta blockers, were eligible for the study. In each patient, the decision to prescribe a beta blocker was a free choice for the participating physicians. All centres were provided with carvedilol, metoprolol, and bisoprolol at appropriate doses; the choice of the drug and dosage was left to the responsible clinician. All patients were followed for one year.

RESULTS

197 cardiological centres enrolled 3091 patients, 24.9% of whom were already on beta blocker treatment at baseline. beta Blockers were newly prescribed in 32.7% of cases, more often in younger and less severely ill patients. The mean daily dose of the drugs used at one year corresponded to about 70% of the maximum dose used in clinical trials. Starting treatment with beta blockers did not affect the prescription or dosage of other recommended drugs. The overall rate of beta blocker treatment increased over the year of the study from 24.9% to 49.7%. During the 12 month period, 351 deaths occurred (11.8%). In multivariate analysis, the use of beta blockers was independently associated with a better prognosis, with a relative risk of 0.60 and a lower incidence of hospital admissions for worsening heart failure.

CONCLUSIONS

The implementation of beta blockers in clinical practice is feasible and could be accelerated. These drugs are associated with a lower mortality and reduced hospital admission rates, not only in clinical trials but also in the normal clinical setting.

Relation between heart rate, heart rhythm, and reverse left ventricular remodelling in response to carvedilol in patients with chronic heart failure: a single centre, observational study

OBJECTIVE

To determine whether the process of reverse left ventricular remodelling in response to carvedilol is dependent on baseline heart rate (BHR), heart rhythm, or heart rate reduction (HRR) in response to carvedilol.

DESIGN

Retrospective analysis of serial echocardiograms in 257 patients with chronic systolic heart failure at baseline and at 12-18 months after starting carvedilol. Reverse left ventricular remodelling was determined by changes in left ventricular end diastolic dimension (LVEDD), end systolic dimension (LVESD), and fractional shortening (LVFS).

SETTING

Heart failure clinic within a university teaching hospital.

MAIN OUTCOME MEASURES

Changes in LVEDD, LVESD, and LVFS.

RESULTS

LVEDD and LVESD decreased by 2.6 (0.4) mm and 4.9 (0.5) mm, respectively (mean (SEM)), and LVFS increased by 4.3 (0.5)% (all p < 0.0001 v baseline). Simple regression revealed no significant relation between BHR or HRR and the changes in LVEDD, LVESD, or LVFS. Stratification of patients into high and low BHR groups (above and below the mean) or according to the baseline heart rhythm (sinus rhythm v atrial fibrillation) showed no differences between groups in the extent of reverse left ventricular remodelling. Improvements in left ventricular function and dimensions were associated with significant improvements in New York Heart Association functional class.

CONCLUSIONS

The benefits of carvedilol in terms of reverse left ventricular remodelling and symptomatic improvement in patients with chronic heart failure are independent of BHR, heart rhythm, and the HRR that occurs in response to carvedilol.

Therapeutic inhibition of tumour necrosis factor alpha in patients with heart failure: cooling an inflamed heart

Heart failure is a systemic disorder characterised by tissue hypoxia and secondary organ dysfunction which occurs in response to various myocardial insults that include ischaemia, viral infections, and toxins. In addition to maladaptive neurohumoral activation, heart failure is associated with an inflammatory state that appears to have a detrimental effect on cardiac function and prognosis. This has led to the suggestion that anti-inflammatory interventions may have therapeutic potential in the symptomatic and prognostic treatment of patients with heart failure. This review considers the role of inhibition of the cytokine tumour necrosis factor alpha in the treatment of heart failure.

Heart failure and the aging population: an increasing burden in the 21st century?

BACKGROUND

Despite an overall decline in age adjusted mortality from coronary heart disease in developed countries, the number of patients with heart failure may be increasing.

OBJECTIVE

To project the future burden of heart failure in Scotland from contemporary epidemiological data.

METHODS

Scotland, like many industrialised countries, has an aging though numerically stable population (5.1 million). Current estimates of prevalence, general practice (GP) consultation rates, and hospital admission rates related to heart failure were applied to the whole Scottish population. These estimates were then projected over the period 2000 to 2020, on an age and sex specific basis, using expected changes in the age structure of the Scottish population.

RESULTS

There are currently estimated to be 40 000 men and 45 000 women aged > or = 45 years with heart failure in Scotland. On the basis of population changes alone, these figures will rise in men and women by 2300 (6%) and 1500 (3%) by year 2005, and by 12 300 (31%) and 7800 (17%) in the longer term (2020), respectively. On the same basis, the annual number of male and female GP visits is likely to rise by 6400 (6%) and 2500 (2%) by year 2005, and by 35 200 (40%) and 17 300 (16%) in the longer term (124 000 and 126 000 visits), respectively. In the year 2000 about 3500 men and 4300 women in Scotland had an incident hospital admission for heart failure. By the year 2020 these figures are likely to increase by 52% (1800 more) and 16% (717 more) in men and women, respectively. If recent trends in short term case fatality rates continue to improve, the number of men who survive this event will increase by 59% (1700 more). Overall, by 2020 the annual number of male and female hospital admissions associated with a principal diagnosis of heart failure is expected to increase by 34% (from 5500 to 7500) and by 12% (from 7800 to 8500), respectively.

CONCLUSIONS

Unless rapid and major changes occur in the incidence of heart failure, the burden of this disorder will continue to increase in both primary and secondary care over the next two decades. The greatest increase is likely to occur in men. Future health service planning must take this into account.

High prevalence of left ventricular systolic and diastolic asynchrony in patients with congestive heart failure and normal QRS duration

OBJECTIVE

To study the possible occurrence of left ventricular (LV) systolic and diastolic asynchrony in patients with systolic heart failure (HF) and narrow QRS complexes.

DESIGN

Prospective study.

SETTING

University teaching hospital.

PATIENTS

200 subjects were studied by echocardiography. 67 patients had HF and narrow QRS complexes (< or = 120 ms), 45 patients had HF and wide QRS complexes (> 120 ms), and 88 served as normal controls.

INTERVENTIONS

Echocardiography with tissue Doppler imaging was performed using a six basal, six mid-segmental model.

MAIN OUTCOME MEASURES

Severity and prevalence of systolic and diastolic asynchrony, as assessed by the maximal difference in time to peak myocardial systolic contraction (T(S)) and early diastolic relaxation (T(E)), and the standard deviation of T(S) (T(S)-SD) and of T(E) (T(E)-SD) of the 12 LV segments.

RESULTS

The mean (SD) maximal difference in T(S) (controls 53 (23) ms v narrow QRS 107 (54) ms v wide QRS 130 (51) ms, both p < 0.001 v controls) and in T(S)-SD (controls 17.0 (7.8) ms v narrow QRS 33.8 (16.9) ms v wide QRS 42.0 (16.5) ms, both p < 0.001 v controls) was prolonged in the narrow QRS group compared with normal controls. Similarly, the maximal difference in T(E) (controls 59 (19) ms v narrow QRS 104 (71) ms v wide QRS 148 (87) ms, both p < 0.001 v controls) and in T(E)-SD (controls 18.5 (5.8) ms v narrow QRS 33.3 (27.7) ms v wide QRS 48.6 (30.2) ms, both p < 0.001 v controls) was prolonged in the narrow QRS group. The prevalence of systolic and diastolic asynchrony was 51% and 46%, respectively, in the narrow QRS group, and 73% and 69%, respectively, in the wide QRS group. Stepwise multiple regression analysis showed that a low mean myocardial systolic velocity from the six basal LV segments and a large LV end systolic diameter were independent predictors of systolic asynchrony, while a low mean myocardial early diastolic velocity and QRS complex duration were independent predictors of diastolic asynchrony.

CONCLUSIONS

LV systolic and diastolic mechanical asynchrony is common in patients with HF with narrow QRS complexes. As QRS complex duration is not a determinant of systolic asynchrony, it implies that assessment of intraventricular synchronicity is probably more important than QRS duration in considering cardiac resynchronisation treatment.

Heart failure: a hemodynamic disorder complicated by maladaptive proliferative responses

Heart failure has traditionally been viewed as a hemodynamic syndrome characterized by fluid retention, high venous pressure, and low cardiac output. Over the past decade, however, it has become clear that because of deterioration and progressive dilatation (remodeling) of the diseased heart, this is also a rapidly fatal syndrome. The importance of prognosis came to be appreciated when clinical trials showed that therapy which initially improves such functional abnormalities, as high venous pressure and low cardiac output, often fail to improve survival, and that some drugs which improve hemodynamics worsen long-term prognosis. The latter is true for most vasodilators which, in spite of alleviating the adverse short-term consequences of high afterload, shorten survival. Notable exceptions are ACE inhibitors, whose vasodilator effects do not explain their ability to prolong survival; instead, these drugs slow both deterioration and remodeling of the failing heart. Inotropic agents, while providing immediate relief of symptoms, generally shorten long-term survival, whereas beta-blockers slow deterioration and remodeling, and reduce mortality. Aldosterone antagonists exert beneficial effects on prognosis that are not easily explained by their diuretic effects, but instead can be explained by their ability to inhibit signaling pathways that stimulate maladaptive hypertrophy, remodeling, apoptosis and other deleterious responses that cause deterioration of the failing heart. These and other findings demonstrate that heart failure is more than a hemodynamic disorder; these patients suffer from maladaptive proliferative responses that cause cardiac cell death and progressive dilatation that play a key role in determining the poor prognosis in this syndrome.

Beta blockers in older persons with heart failure: tolerability and impact on quality of life

OBJECTIVE

To determine tolerability and symptom changes associated with the introduction of bisoprolol treatment in older patients with heart failure.

DESIGN

Prospective observational cohort study.

SETTING

Geriatric medicine outpatient department of a university hospital.

PATIENTS

51 patients (mean age 78 years, range 70-89 years) with stable symptomatic heart failure caused by left ventricular systolic dysfunction.

INTERVENTIONS

Bisoprolol tablets, 1.25-10.0 mg.

MAIN OUTCOME MEASURES

Tolerability; changes in symptoms and exercise tolerance.

RESULTS

69% of patients tolerated bisoprolol. Mean tolerated dose was 7.6 mg. There was no change in symptoms or exercise capacity in those who tolerated bisoprolol. Perceived health status and symptoms of anxiety and depression improved during the titration period.

CONCLUSIONS

The rate of withdrawal from bisoprolol treatment in older patients with congestive heart failure was twice that previously reported in younger patients. The mean tolerated dose was similar to that found in trials reporting clinical efficacy. There was no evidence of a negative impact on symptoms or exercise capacity in patients who tolerated bisoprolol.

Heart failure: aetiology, diagnosis, and treatment

A two day meeting on heart failure, organised by the Cardiovascular Research Funders Forum, took place at the Royal College of Physicians, London, earlier this year. The meeting brought together over 60 researchers from the UK, North America, and continental Europe, representing basic and molecular scientists and clinicians (cardiologists, surgeons, and nurses) plus patient representatives

Nitric oxide and myocardial function in heart failure: friend or foe?

There is good evidence that nitric oxide has important autocrine/paracrine effects in the myocardium, serving to optimise and fine tune cardiac function

Cardiac remodelling in end stage heart failure: upregulation of matrix metalloproteinase (MMP) irrespective of the underlying disease, and evidence for a direct inhibitory effect of ACE inhibitors on MMP

OBJECTIVE

To investigate matrix metalloproteinases (MMP-2 and MMP-9) in heart failure caused by ischaemic and idiopathic dilated cardiomyopathy, and the impact of angiotensin converting enzyme (ACE) inhibition on MMP.

DESIGN AND MAIN OUTCOME MEASURES

MMP were extracted from myocardium of patients with heart failure (coronary artery disease, n = 13; idiopathic dilated cardiomyopathy (IDCM), n = 16) and from controls (n = 6). The active form of MMP-2 and MMP-9 was measured by enzyme linked immunosorbent assay; activity of MMPs by zymography; mRNA expression of MMPs by reverse transcriptase polymerase chain reaction.

RESULTS

Active MMP-9 was significantly increased in coronary artery disease (mean (SD) 1.6 (0.35) ng/ml) and IDCM (2.11 (0.54) ng/ml) in comparison with controls (0.53 (0.15) ng/ml). Increased MMP-2 was only found in IDCM (3.68 (0.41) ng/ml). There were corresponding increases in MMP activity but no upregulation of mRNA expression was found. The ACE inhibitors captopril and ramiprilate inhibited MMP-2 and MMP-9 activity in vitro (inhibitory capacity (IC50), in mmol/l: MMP-2: captopril 2.0 (0.16), ramiprilate 2.1 (0.3); MMP-9: captopril 1.65 (0.18), ramiprilate 2.0 (0.3)). Lisinopril inhibited MMP-9 significantly but did not inhibit MMP-2 in vitro (IC50 MMP-2: 7.4 (0.88); MMP-9: 7.86 (2.23)). Inhibition of MMP activity by ACE inhibitors was blunted by zinc excess.

CONCLUSIONS

Upregulation of MMP-9 activity is common in the failing myocardium, independent of the underlying disease. Missing upregulation of transcription suggests that activation of latent forms of MMP is the source of increased MMP activity, rather than increased de novo synthesis. Some ACE inhibitors may influence MMP activity by a direct effect.

Right ventricular diastolic function in canine models of pressure overload, volume overload, and ischemia

By limiting filling, abnormalities of right ventricular (RV) diastolic function may impair systolic function and affect adaptation to disease. To quantify diastolic RV pressure-volume relations and myocardial compliance (MC), a new sigmoidal model was developed. RV micromanometric and sonomicrometric data in alert dogs at control (n = 16) and under surgically induced subacute (2-5 wk) RV pressure overload (n = 6), volume overload (n = 7), and ischemia (n = 6) were analyzed. The conventional exponential model detected no changes from control in the passive filling pressure-volume (P(pf)-V) relations. The new sigmoidal model revealed significant quantifiable changes in P(pf)-V relations. Maximum RV MC (MC(max)), attained during early filling, is reduced from control in pressure overload (P = 0.0016), whereas filling pressure at maximum MC (P(MCmax)) is increased (P = 0.0001). End-diastolic RV MC increases significantly in volume overload (P = 0.0131), whereas end-diastolic pressure is unchanged. In ischemia, MC(max) is decreased (P = 0.0102), with no change in P(MCmax). We conclude that the sigmoidal model quantifies important changes in RV diastolic function in alert dog models of pressure overload, volume overload, and ischemia.

Does lung diffusion impairment affect exercise capacity in patients with heart failure?

OBJECTIVE

To determine whether there is a relation between impairment of lung diffusion and reduced exercise capacity in chronic heart failure.

DESIGN

40 patients with heart failure in stable clinical condition and 40 controls participated in the study. All subjects underwent standard pulmonary function tests plus measurements of resting lung diffusion (carbon monoxide transfer, TLCO), pulmonary capillary volume (VC), and membrane resistance (DM), and maximal cardiopulmonary exercise testing. In 20 patients and controls, the following investigations were also done: (1) resting and constant work rate TLCO; (2) maximal cardiopulmonary exercise testing with inspiratory O2 fractions of 0.21 and 0.16; and (3) rest and peak exercise blood gases. The other subjects underwent TLCO, DM, and VC measurements during constant work rate exercise.

RESULTS

In normoxia, exercise induced reductions of haemoglobin O2 saturation never occurred. With hypoxia, peak exercise uptake (peak O2) decreased from (mean (SD)) 1285 (395) to 1081 (396) ml/min (p < 0.01) in patients, and from 1861 (563) to 1771 (457) ml/min (p < 0.05) in controls. Resting TLCO correlated with peak O2 in heart failure (normoxia < hypoxia). In heart failure patients and normal subjects, TLCO and peak O2 correlated with O2 arterial content at rest and during peak exercise in both normoxia and hypoxia. TLCO, VC, and DM increased during exercise. The increase in TLCO was greater in patients who had a smaller reduction of exercise capacity with hypoxia. Alveolar-arterial O2 gradient at peak correlated with exercise capacity in heart failure during normoxia and, to a greater extent, during hypoxia.

CONCLUSIONS

Lung diffusion impairment is related to exercise capacity in heart failure.

Perindopril improves six minute walking distance in older patients with left ventricular systolic dysfunction: a randomised double blind placebo controlled trial

OBJECTIVE

To evaluate the effects of the angiotensin converting enzyme inhibitor perindopril on six minute walking distance and quality of life in very old patients with left ventricular systolic dysfunction.

DESIGN

Prospective, double blind placebo controlled trial.

SETTING

Medicine for the elderly day hospital.

PATIENTS

66 patients (average age 81) with left ventricular systolic dysfunction identified by echocardiography.

INTERVENTIONS

10 weeks of treatment with titrated doses of perindopril or placebo.

MAIN OUTCOME MEASURES

Six minute walking distance 10 weeks following treatment, quality of life measurements including the Minnesota living with heart failure questionnaire and the 36 item short form health survey.

RESULTS

In patients with left ventricular systolic dysfunction, six minute walking distance was significantly increased in the treatment group (37.1 m) compared with the placebo group (-0.3 m, p < 0.001). The medication was well tolerated and there were no significant adverse events.

CONCLUSIONS

Six minute walking distance is improved considerably by treatment with perindopril in older patients with heart failure caused by left ventricular systolic dysfunction.

Ventilatory variables are strong prognostic markers in elderly patients with heart failure

OBJECTIVE

To evaluate the safety and prognostic capacity of cardiopulmonary exercise testing in patients > or = 60 years old who are hospitalised with heart failure caused by left ventricular dysfunction.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENTS

Study participants were 67 patients (66% men) with clinical heart failure stabilised on medical treatment. The study is a part of a nursing intervention study. Mean (SD) age was 74 (6) years, New York Heart Association functional class II-III, and ejection fraction 0.36 (0.11).

INTERVENTIONS

Cardiopulmonary exercise testing and echocardiography.

MAIN OUTCOME MEASURES

Peak oxygen consumption (VO2), peak ventilatory equivalents for carbon dioxide (VE/VCO2) and oxygen (VE/VO2), left ventricular volumes, and mortality.

RESULTS

Mean (SD) peak VO2 was 11.7 (3.7) ml/kg/min, peak VE/VCO2 43 (9), and peak VE/VO2 46 (11). During 12-59 months of follow up, 14 patients died. In univariate analyses peak VO2, VE/VO2, and VE/VCO2 were all strongly related (p < 0.01) to mortality. In a multivariate Cox regression analysis, peak VE/VCO2 was the strongest predictor of mortality (p < 0.001), followed by left ventricular end systolic volume (p < 0.001). A cut off of peak VE/VCO2 at > or = 45 gave a univariate hazard ratio of 6.7 for death during follow up. No adverse events occurred during the exercise test.

CONCLUSION

These findings extend results found in selected middle aged patients to elderly patients with heart failure and show that ventilatory parameters from a cardiopulmonary exercise test, such as peak VO2, VE/O2, and VE/VCO2 are powerful predictors of mortality.

Prevalence of myocardial viability assessed by single photon emission computed tomography in patients with chronic ischaemic left ventricular dysfunction

OBJECTIVE

To assess the prevalence of myocardial viability by technetium-99m (Tc-99m)-tetrofosmin/fluorine-18-fluorodeoxyglucose (FDG) single photon emission computed tomography (SPECT) in patients with ischaemic cardiomyopathy.

DESIGN

A retrospective observational study.

SETTING

Thoraxcenter Rotterdam (a tertiary referral centre).

PATIENTS

104 patients with chronic coronary artery disease and severely depressed left ventricular function presenting with heart failure symptoms.

MAIN OUTCOME MEASURES

Prevalence of myocardial viability as evaluated by Tc-99m-tetrofosmin/FDG SPECT imaging. Two strategies for assessing viability in dysfunctional myocardium were used: perfusion imaging alone, and the combination of perfusion and metabolic imaging.

RESULTS

On perfusion imaging alone, 56 patients (54%) had a significant amount of viable myocardium, whereas 48 patients (46%) did not. Among the 48 patients with no significant viability by perfusion imaging alone, seven additional patients (15%) had significantly viable myocardium on combined perfusion and metabolic imaging. Thus with a combination of perfusion and metabolic imaging, 63 patients (61%) had viable myocardium and 41 (39%) did not.

CONCLUSIONS

On the basis of the presence of viable dysfunctional myocardium, 61% of patients with chronic coronary artery disease and depressed left ventricular ejection fraction presenting with heart failure symptoms may be considered for coronary revascularisation. The combination of perfusion and metabolic imaging identified more patients with significant viability than myocardial perfusion imaging alone.

Incremental changes in QRS duration in serial ECGs over time identify high risk elderly patients with heart failure

AIMS

To investigate the hypothesis that changes in the ECG over time may be an important and readily available marker of prognostic value in patients with heart failure.

METHODS

112 elderly patients (81 men) with stable heart failure, a mean (SD) age of 73.3 (4.4) years, left ventricular ejection fraction 38 (17)%, and peak oxygen consumption 15.1 (4.7) ml/kg/min had ECG measurements on two occasions a minimum of 12 (5) months apart.

RESULTS

During the subsequent follow up period (mean 27 (17) months) 45 patients died. QRS duration (p = 0.001) and heart rate (p = 0.03) at baseline were found by Cox proportional hazard method analysis to predict adverse outcomes in these patients. Of the changes in ECG parameters between the first and second visit, broadening of QRS duration (p = 0.001) predicted mortality. On Kaplan-Meier survival analysis, patients with < 5% change in QRS duration had fewer end points than patients with 5-20% change. A > 20% increase in QRS duration was associated with the worst prognosis. Progressive prolongation of QRS duration correlated closely with deterioration of LV systolic and diastolic function.

CONCLUSION

A single measurement of QRS duration has significant prognostic value in elderly patients with heart failure and the increase in QRS duration over time is an even better predictor of adverse out comes.

Comparison of permanent left ventricular and biventricular pacing in patients with heart failure and chronic atrial fibrillation: prospective haemodynamic study

OBJECTIVE

To compare clinical and haemodynamic variables between left ventricular and biventricular pacing in patients with severe heart failure; and to analyse haemodynamic changes during daily life and maximum exercise during chronic left ventricular and biventricular pacing.

DESIGN

Prospective single blinded randomised study with crossover.

SETTING

University hospital (tertiary referral centre).

PATIENTS AND METHODS

13 patients (mean (SD) age, 62 (6) years) with chronic atrial fibrillation, severe heart failure (mean ejection fraction 24 (8)%), and QRS prolongation of > or = 140 ms had His bundle ablation and installation of a pacemaker providing left ventricular and biventricular pacing. The pacemaker was equipped with a peak endocardial acceleration (PEA) sensor. The PEA pattern was used as a haemodynamic marker during exercise as it is highly correlated with left ventricular dP/dt. After a baseline period of right ventricular pacing, all patients had two months of left ventricular pacing and two months of biventricular pacing in random order. At the end of each phase, an echocardiogram, a haemodynamic analysis at rest and on exercise during a six minute walk test, and a cardiopulmonary exercise test were performed.

RESULTS

PEA values were higher with left ventricular pacing (0.58 (0.38) m/s) and biventricular pacing (0.62 (0.24) m/s) than at baseline (0.49 (0.18) m/s) (p < 0.05). The six minute walk test showed similar performance in both pacing modes, but patients had more symptoms with left ventricular pacing at the end of the test (p = 0.035). On cardiopulmonary exercise testing, there was a greater increase in mean percentage variation of PEA with biventricular pacing than with left ventricular pacing (125 (18)% v 97 (36)%, respectively; p = 0.048) and better performance figures (92 (34) W v 77 (23) W; p = 0.03).

CONCLUSIONS

During symptom limited and daily life exercise tests, chronic biventricular pacing provides better haemodynamic performance than left ventricular pacing. In heart failure patients with wide QRS complexes, the interventricular dyssynchronisation induced by left ventricular pacing may impair myocardial function during exercise.

Left ventricular assist device as bridge to transplantation in patients with end-stage heart failure: Eight-year experience with the implantable HeartMate LVAS

OBJECTIVE

To evaluate the use of left ventricular assist devices (LVAD) as bridge to heart transplantation (HTx) in patients with end-stage heart failure.

METHOD

Between March 1993 and December 2001, 38 patients with refractory end-stage heart failure underwent HeartMate LVAD (Thoratec, Pleasanton Calif.) implantation.

RESULTS

A total of 33 of the 38 patients (87%) survived the implantation and perioperative period. There were five perioperative deaths (13%), two due to right ventricular failure, two as a result of bleeding and one probably due to septic shock at the time of LVAD implantation. Three patients (9%) died late in the postoperative period due to septic shock, mechanical failure of the device and a cerebral embolus resulting from LVAD endocarditis, initiated by an acute cholecystitis. Twelve patients (32%) had one or more infectious episodes during long-term assist, of which one patient died. Four patients are still on the device, waiting for a heart transplantation. Twenty-six patients (76%) underwent HTx after 206±129 days of support.

CONCLUSION

These results show the efficacy of LVAD support as a bridge to heart transplantation in patients with end-stage heart failure. Major long-term complications are infections and mechanical failure of the device.

Reduced coronary vasodilator responses to amlodipine in pacing-induced heart failure in conscious dogs: role of nitric oxide

1. This study examined whether NO is involved in the in-vivo coronary vasodilator effects of amlodipine (a calcium channel blocker) and whether heart failure (HF) alters the coronary responses to amlodipine. 2. Nine conscious dogs were chronically instrumented to measure circumflex coronary blood flow (CBF) and coronary diameter (CD). Drugs were administered directly into the circumflex artery through an indwelling catheter to avoid systemic changes. HF was induced by right ventricular pacing (240 b.p.m., 3 weeks). 3. Compared with control (C), in HF, coronary responses to acetylcholine (1 - 10 ng kg(-1)) were reduced while responses to nitroglycerin (0.1 - 0.5 microg kg(-1)) were unchanged. In C, amlodipine (30 - 150 microg kg(-1)), increased dose-dependently CBF and CD. After LNA (a NO synthase inhibitor, 2 mg kg(-1)), amlodipine produced less increases in CBF and CD (+121+/-26 ml min(-1) and +76+/-35 microm versus +196+/-40 ml min(-1) and +153+/-39 microm respectively for 150 microg kg(-1) amlodipine alone, both P<0.05). In HF, the coronary responses to amlodipine were reduced (150 microg kg(-1) of amlodipine increased CBF and CD +121+/-23 ml min(-1) and +77+/-21 microm respectively, both P<0.05). After LNA, the CBF responses to amlodipine tended to be reduced (+94+/-19 ml min(-1) at 150 microg kg(-1)) but CD responses were significantly reduced (+41+/-16 microm, P<0.05). The supplementation with L-arginine did not enhance the coronary responses to amlodipine. 4. These results indicate that, in conscious dogs, NO participates in the coronary responses to amlodipine and in HF, the coronary responses to amlodipine are reduced, which is related to a reduced NO production.

Effect of multisite pacing on ventricular coordination

OBJECTIVE

To determine the effect of multisite pacing on left ventricular function.

DESIGN

Prospective observational study.

PATIENTS

18 patients with heart failure with a dilated poorly functioning left ventricle (LV) and left bundle branch block.

INTERVENTIONS

Pacing for 5 minutes in random order at the right ventricle (RV) apex, RV outflow tract, mid posterolateral LV, RV apex and LV simultaneously, and RV outflow tract and LV simultaneously. The best achieved measurements with RV, LV, and biventricular pacing were compared.

MAIN OUTCOME MEASURES

LV dimension, filling characteristics, and long axis indices were measured on echocardiography simultaneously with LV pressure. Cycle efficiency (%)--that is, the ratio of the area of the acquired pressure dimension loop to that of the ideal loop for that segment--quantified coordination.

RESULTS

The pacing site that gave the best achieved cycle efficiency differed between patients (biventricular in five, LV in two, RV in seven, and no site in four). In patients with baseline incoordination (cycle efficiency < or = 72%, n = 12) cycle efficiency improved significantly with RV pacing (cycle efficiency 76%, p = 0.01) but not with LV (65%) or biventricular (67%) pacing. LV based pacing induced premature short axis contraction in a subset of patients (n = 4), which was associated with a prolonged time from the Q wave on the ECG to the onset of inward movement of the long axis (from apex to mitral ring): biventricular 145 ms, LV 105 ms, RV 85 ms (biventricular v RV, p < 0.05). Excluding patients with baseline incoordination in whom premature activation occurred, pacing at all sites led to a similar increase in cycle efficiency (RV 78%, LV 72%, biventricular 73%).

CONCLUSIONS

Ventricular coordination can be improved with pacing in patients with baseline incoordination. Short and long axis fibres may be asynchronised in a subset of patients with LV or biventricular pacing, which may worsen coordination. The clinical significance of these findings remains to be defined.

Increased pericardial fluid concentrations of the mature form of adrenomedullin in patients with cardiac remodelling

BACKGROUND

There is evidence that adrenomedullin has autocrine or paracrine activities that oppose cardiac remodelling. However, it remains unclear whether it exerts those local functions in heart failure patients.

OBJECTIVE

To investigate the relation between plasma and pericardial fluid concentrations of adrenomedullin and left ventricular haemodynamic variables.

DESIGN

Samples of plasma and pericardial fluid were obtained from 50 patients undergoing cardiac surgery. They were classified into two groups: group N (n = 27) with a left ventricular end diastolic volume index (LVEDVI) < or = 90 ml/m(2); and group R (n = 23) with LVEDVI > 90 ml/m(2). Plasma and pericardial fluid concentrations of total adrenomedullin (tAM) and mature adrenomedullin (mAM) were measured and related to the preoperative haemodynamic variables.

RESULTS

Pericardial fluid concentrations of mAM were much higher than the plasma concentration in both group N and group R (mean (SEM), 10.6 (1.7) v 3.3 (0.2) fmol/ml, p = 0.0001; and 21.2 (2.8) v 3.9 (0.3) fmol/ml, p < 0.0001, respectively). The ratio mAM/tAM in pericardial fluid was significantly higher than in plasma (0.56 (0.02) v 0.28 (0.02), p < 0.0001). Pericardial fluid concentrations of mAM, but not plasma concentrations, were significantly correlated with LVEDVI, left ventricular end systolic volume index, left ventricular ejection fraction, and left ventricular mass index (r = 0.60, 0.63, -0.54, and 0.47, respectively).

CONCLUSIONS

Raised pericardial fluid concentrations of mAM may reflect the actions of adrenomedullin as a local mediator against cardiac remodelling in patients with left ventricular dysfunction.

Targeting phospholamban by gene transfer in human heart failure

BACKGROUND

Myocardial cells from failing human hearts are characterized by abnormal calcium handling, a negative force-frequency relationship, and decreased sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) activity. In this study, we tested whether contractile function can be improved by decreasing the inhibitory effects of phospholamban on SERCA2a with adenoviral gene transfer of antisense phospholamban (asPL).

METHODS AND RESULTS

Myocardial cells isolated from 9 patients with end-stage heart failure and 18 donor nonfailing hearts were infected with adenoviruses encoding for either the antisense of phospholamban (Ad.asPL), the SERCA2a gene (Ad.SERCA2a), or the reporter genes beta-galactosidase and green fluorescent protein (Ad.betagal-GFP). Adenoviral gene transfer with Ad.asPL decreased phospholamban expression over 48 hours, increasing the velocity of both contraction and relaxation. Compared with cardiomyocytes infected with Ad.asPL (n=13), human myocytes infected with Ad.betagal-GFP (n=8) had enhanced contraction velocity (20.3 +/- 3.9% versus 8.7 +/- 2.6% shortening/second; P<0.01) and relaxation velocity (26.0 +/- 6.2% versus 8.6 +/- 4.3% shortening/second; P<0.01). The improvement in contraction and relaxation velocities was comparable to cardiomyocytes infected with Ad.SERCA2a. Failing human cardiomyocytes had decreased contraction and Ca2+ release with increasing frequency (0.1 to 2 Hz). Phospholamban ablation restored the frequency response in the failing cardiomyocytes to normal; increasing frequency resulted in enhanced sarcoplasmic reticulum Ca2+ release and contraction.

CONCLUSION

These results show that gene transfer of asPL can improve the contractile function in failing human myocardium. Targeting phospholamban may provide therapeutic benefits in human heart failure.

Evidence for a role of mast cells in the evolution to congestive heart failure

Mast cells are believed to be involved in the pathophysiology of heart failure, but their precise role in the process is unknown. This study examined the role of mast cells in the progression of heart failure, using mast cell-deficient (WBB6F1-W/W(v)) mice and their congenic controls (wild-type [WT] mice). Systolic pressure overload was produced by banding of the abdominal aorta, and cardiac function was monitored over 15 wk. At 4 wk after aortic constriction, cardiac hypertrophy with preserved left ventricular performance (compensated hypertrophy) was observed in both W/W(v) and WT mice. Thereafter, left ventricular performance gradually decreased in WT mice, and pulmonary congestion became apparent at 15 wk (decompensated hypertrophy). In contrast, decompensation of cardiac function did not occur in W/W(v) mice; left ventricular performance was preserved throughout, and pulmonary congestion was not observed. Perivascular fibrosis and upregulation of mast cell chymase were all less apparent in W/W(v) mice. Treatment with tranilast, a mast cell-stabilizing agent, also prevented the evolution from compensated hypertrophy to heart failure. These observations suggest that mast cells play a critical role in the progression of heart failure. Stabilization of mast cells may represent a new approach in the management of heart failure.

Effects of cardioselective KATP channel antagonism on basal, stimulated, and ischaemic myocardial function in in vivo failing canine heart

Inhibition of cardiomyocyte-specific ATP-sensitive potassium (K(ATP)) channels prolongs the action potential during intense ischaemia with attendant antiarrhythmic effects. However, this is accompanied by contractile depression in some models. These changes may be particularly troublesome in dilated cardiomyopathic hearts that display basal systolic dysfunction, limited energy reserve, and prolonged repolarization favouring arrhythmia. Mechanical effects of selective myocyte K(ATP) channel blockade on basal, beta-adrenergic stimulated, and ischemic responses were therefore tested in dogs with cardiac failure induced by tachypacing. Cardiovascular function was assessed by pressure - dimension relationships in 10 conscious, chronically instrumented dogs (sonomicrometry/micromanometry), with or without cardiac failure. Cardiomyocyte K(ATP) channels were inhibited by HMR 1098, and data obtained under basal conditions, during epinephrine infusion to raise metabolic demand, during regional ischaemia, and with combined ischaemia+epinephrine. HMR 1098 had no effect on baseline cardiac function nor did it induce arrhythmia in normal or failing hearts. Epinephrine raised cardiac work 65% and oxygen consumption 55%, yet HMR 1098 had no functional effect in either heart condition. Regional ischaemia with or without epinephrine co-stimulation depressed regional and global function, yet both were also unaffected by HMR 1098. There was minimal arrhythmia without HMR 1098, and drug infusion did not alter this. Thus, myocyte-K(ATP) channels play a negligible role modulating intact in vivo cardiac contraction or arrhythmia in normal and failing heart with and without increased metabolic demand and/or regional ischaemia. This supports the feasibility of administering such agents to depressed hearts, despite underlying contractile and electrophysiologic abnormalities.

Tumour necrosis factor alpha gene polymorphism: a predisposing factor to non-ischaemic myocardial dysfunction?

BACKGROUND

Tumour necrosis factor alpha (TNF alpha) is implicated in the pathophysiology of heart failure. Plasma TNF alpha is raised in patients with myocardial dysfunction in proportion to the symptoms.

OBJECTIVE

To determine whether this genetic variant is over represented in heart transplant recipients.

PATIENTS

175 heart transplant recipients and a control group of 212 healthy volunteers were studied. The reason for transplantation was severe symptomatic myocardial dysfunction in all cases.

METHODS

The TNF alpha genotype was determined by polymerase chain reaction and gel electrophoresis. The populations were compared for their fit to Hardy-Weinberg equilibrium by calculating the expected frequencies of each genotype and comparing them to the observed values. A chi(2) test was used to determine the significance of the difference between the observed and expected values.

RESULTS

No differences were found in the frequency of the TNF2 allele between all heart transplant recipients taken together (54/175, 31%) and healthy volunteers (58/212, 27%). A higher proportion of TNF2 allele carriers was present in cardiac recipients with a pretransplant diagnosis of viral mediated or idiopathic heart failure than in those with ischaemic myocardial dysfunction (26/69 (37.7%) v 28/106 (26.4%), p = 0.03). PATIENTS with a non-ischaemic aetiology had a higher prevalence of TNF2 than healthy volunteers (26/69 (37.7%) v 58/212 (27%), p = 0.05).

CONCLUSIONS

The TNF2 allele is overrepresented in patients with end stage non-ischaemic myocardial dysfunction. This may represent a genetic predisposition in a small subset of patients who could respond favourably to anti-TNF alpha treatment.