In the critically ill patient, diabetes predicts mortality independent of statin therapy but is not associated with acute lung injury: a cohort study

OBJECTIVES

Patients with diabetes mellitus form 23%-30% of published cohorts of critically ill patients. Conflicting published evidence links diabetes mellitus to both higher and lower mortality. Other cohort studies suggest that diabetes mellitus protects against acute lung injury. We hypothesized that diabetes mellitus is an independent risk factor for mortality. We further hypothesized that diabetes mellitus is a risk factor for cardiac overload and not for acute lung injury.

DESIGN

Retrospective cohort study.

SETTING

The intensive care unit of a tertiary referral hospital.

PATIENTS

From November 1, 2004, to October 1, 2007, a cohort of patients admitted ≥48 hrs to the intensive care unit.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 2,013 patients, 317 had diabetes mellitus. Ninety-day mortality was higher in the diabetes mellitus patients compared to patients without diabetes mellitus (hazard ratio 1.53, 95% confidence interval 1.29-1.80). This association strengthened after adjusting for confounders and for medication (hazard ratio 1.53, 95% confidence interval 1.07-2.17).We found no association between diabetes mellitus and acute lung injury (relative risk ratio 1.01, 95% confidence interval 0.78-1.32; adjusted relative risk ratio 0.99, 95% confidence interval 0.75-1.31), but diabetes mellitus was a risk factor for cardiac overload (relative risk ratio 1.91, 95% confidence interval 1.30-2.81; adjusted relative risk ratio 1.45, 95% confidence interval 0.97-2.18). Statins were associated with both a reduced risk of mortality (hazard ratio 0.74, 95% confidence interval 0.63-0.87; adjusted hazard ratio 0.53, 95% confidence interval 0.44-0.64) and a decreased risk of developing acute lung injury (relative risk ratio 0.71, 95% confidence interval 0.56-0.89; adjusted relative risk ratio 0.61, 95% confidence interval 0.47-0.79).

CONCLUSIONS

Diabetes mellitus is an independent risk factor for mortality in critically ill patients and failure to adjust for statins underestimates the size of this association. Diabetes mellitus is not associated with acute lung injury but is associated with cardiac overload. A diagnosis of cardiac overload excludes a diagnosis of acute lung injury. Investigators who do not account for cardiac overload as a competing alternative outcome may therefore falsely conclude that diabetes mellitus protects from acute lung injury.

Techniques for estimating health care costs with censored data: an overview for the health services researcher

Objective

The aim of this study was to review statistical techniques for estimating the mean population cost using health care cost data that, because of the inability to achieve complete follow-up until death, are right censored. The target audience is health service researchers without an advanced statistical background.

Methods

Data were sourced from longitudinal heart failure costs from Ontario, Canada, and administrative databases were used for estimating costs. The dataset consisted of 43,888 patients, with follow-up periods ranging from 1 to 1538 days (mean 576 days). The study was designed so that mean health care costs over 1080 days of follow-up were calculated using naïve estimators such as full-sample and uncensored case estimators. Reweighted estimators – specifically, the inverse probability weighted estimator – were calculated, as was phase-based costing. Costs were adjusted to 2008 Canadian dollars using the Bank of Canada consumer price index (http://www.bankofcanada.ca/en/cpi.html).

Results

Over the restricted follow-up of 1080 days, 32% of patients were censored. The full-sample estimator was found to underestimate mean cost ($30,420) compared with the reweighted estimators ($36,490). The phase-based costing estimate of $37,237 was similar to that of the simple reweighted estimator.

Conclusion

The authors recommend against the use of full-sample or uncensored case estimators when censored data are present. In the presence of heavy censoring, phase-based costing is an attractive alternative approach.

Developmental Changes in the ECG of a Hamster Model of Muscular Dystrophy and Heart Failure

Aberrant autonomic signaling is being increasingly recognized as an important symptom in neuromuscular disorders. The δ-sarcoglycan-deficient BIO TO-2 hamster is recognized as a good model for studying mechanistic pathways and sequelae in muscular dystrophy and heart failure, including autonomic nervous system (ANS) dysfunction. Recent studies using the TO-2 hamster model have provided promising preclinical results demonstrating the efficacy of gene therapy to treat skeletal muscle weakness and heart failure. Methods to accelerate preclinical testing of gene therapy and new drugs for neuromuscular diseases are urgently needed. The purpose of this investigation was to demonstrate a rapid non-invasive screen for characterizing the ANS imbalance in dystrophic TO-2 hamsters. Electrocardiograms were recorded non-invasively in conscious ∼9-month old TO-2 hamsters (n = 10) and non-myopathic F1B control hamsters (n = 10). Heart rate was higher in TO-2 hamsters than controls (453 ± 12 bpm vs. 311 ± 25 bpm, P < 0.01). Time domain heart rate variability, an index of parasympathetic tone, was lower in TO-2 hamsters (12.2 ± 3.7 bpm vs. 38.2 ± 6.8, P < 0.05), as was the coefficient of variance of the RR interval (2.8 ± 0.9% vs. 16.2 ± 3.4%, P < 0.05) compared to control hamsters. Power spectral analysis demonstrated reduced high frequency and low frequency contributions, indicating autonomic imbalance with increased sympathetic tone and decreased parasympathetic tone in dystrophic TO-2 hamsters. Similar observations in newborn hamsters indicate autonomic nervous dysfunction may occur quite early in life in neuromuscular diseases. Our findings of autonomic abnormalities in newborn hamsters with a mutation in the δ-sarcoglycan gene suggest approaches to correct modulation of the heart rate as prevention or therapy for muscular dystrophies.

Barriers to guideline implementation and educational needs of general practitioners regarding heart failure: a qualitative study

Objectives: A clinical practice guideline (CPG) contains specifically developed recommendations that can serve physicians as a decision aid in evidence-based practice. The implementation of heart failure (HF) CPGs represents a challenge in general practice. As part of the development of a tailored curriculum, aim of this study was to identify barriers of guideline adherence and needs for medical education (CME) in HF care.

Methods: We conducted a modified focus group with elements of a workshop of three hours duration. Thirteen GPs collected and discussed together and parallel in smaller groups barriers of guideline implementation. Afterwards they performed a needs assessment for a tailored CME curriculum for chronic HF. The content of the discussions was analysed qualitatively according to Mayring and categorised thematically.

Results: Barriers of guideline adherence were found in the following areas: doctor: procedural knowledge (knowledge gaps), communicative and organisational skills (e.g. time management) and attitude (dissatisfaction with time-money-relation). Patients: individual case-related problems (multimorbidity, psychiatric comorbidity, expectations and beliefs). Doctor and patient: Adherence and barriers of communication. Main measures for improvement of care concerned the areas of the identified barriers of guideline adherence with the focus on application-oriented training of the abovementioned procedural knowledge and skills, but also the supply of tools (like patient information leaflets) and patient education.

Conclusion: For a CME-curriculum for HF tailored to the needs of GPs, a comprehensive educational approach seems necessary. It should be broad-based and include elements of knowledge and skills to be addressed and trained case-related. Additional elements should include support in the implementation of organisational processes in the practice and patient education.

Discovery of Selective Small Molecule ROMK Inhibitors as Potential New Mechanism Diuretics

The renal outer medullary potassium channel (ROMK or Kir1.1) is a putative drug target for a novel class of diuretics that could be used for the treatment of hypertension and edematous states such as heart failure. An internal high-throughput screening campaign identified 1,4-bis(4-nitrophenethyl)piperazine (5) as a potent ROMK inhibitor. It is worth noting that this compound was identified as a minor impurity in a screening hit that was responsible for all of the initially observed ROMK activity. Structure-activity studies resulted in analogues with improved rat pharmacokinetic properties and selectivity over the hERG channel, providing tool compounds that can be used for in vivo pharmacological assessment. The featured ROMK inhibitors were also selective against other members of the inward rectifier family of potassium channels.

Impact of KChIP2 on Cardiac Electrophysiology and the Progression of Heart Failure

Electrophysiological remodeling of cardiac potassium ion channels is important in the progression of heart failure. A reduction of the transient outward potassium current (I_to) in mammalian heart failure is consistent with a reduced expression of potassium channel interacting protein 2 (KChIP2, a K_V4 subunit). Approaches have been made to investigate the role of KChIP2 in shaping cardiac I_to, including the use of transgenic KChIP2 deficient mice and viral overexpression of KChIP2. The interplay between I_to and myocardial calcium handling is pivotal in the development of heart failure, and is further strengthened by the dual role of KChIP2 as a functional subunit on both K_V4 and Ca_V1.2. Moreover, the potential arrhythmogenic consequence of reduced I_to may contribute to the high relative incidence of sudden death in the early phases of human heart failure. With this review, we offer an overview of the insights into the physiological and pathological roles of KChIP2 and we discuss the limitations of translating the molecular basis of electrophysiological remodeling from animal models of heart failure to the clinical setting.

Dual color photoactivation localization microscopy of cardiomyopathy-associated desmin mutants

Mutations in the DES gene coding for the intermediate filament protein desmin may cause skeletal and cardiac myopathies, which are frequently characterized by cytoplasmic aggregates of desmin and associated proteins at the cellular level. By atomic force microscopy, we demonstrated filament formation defects of desmin mutants, associated with arrhythmogenic right ventricular cardiomyopathy. To understand the pathogenesis of this disease, it is essential to analyze desmin filament structures under conditions in which both healthy and mutant desmin are expressed at equimolar levels mimicking an in vivo situation. Here, we applied dual color photoactivation localization microscopy using photoactivatable fluorescent proteins genetically fused to desmin and characterized the heterozygous status in living cells lacking endogenous desmin. In addition, we applied fluorescence resonance energy transfer to unravel short distance structural patterns of desmin mutants in filaments. For the first time, we present consistent high resolution data on the structural effects of five heterozygous desmin mutations on filament formation in vitro and in living cells. Our results may contribute to the molecular understanding of the pathological filament formation defects of heterozygous DES mutations in cardiomyopathies.

Advantage of recording single-unit muscle sympathetic nerve activity in heart failure

Elevated sympathetic activation is a characteristic feature of heart failure (HF). Excessive sympathetic activation under resting conditions has been shown to increase from the early stages of the disease, and is related to prognosis. Direct recording of multiunit efferent muscle sympathetic nerve activity (MSNA) by microneurography is the best method for quantifying sympathetic nerve activity in humans. To date, this technique has been used to evaluate the actual central sympathetic outflow to the periphery in HF patients at rest and during exercise; however, because the firing occurrence of sympathetic activation is mainly synchronized by pulse pressure, multiunit MSNA, expressed as burst frequency (bursts/min) and burst incidence (bursts/100 heartbeats), may have limitations for the quantification of sympathetic nerve activity. In HF, multiunit MSNA is near the maximum level, and cannot increase further than the heartbeat. Single-unit MSNA analysis in humans is technically demanding, but provides more detailed information regarding central sympathetic firing. Although a great deal is known about the response of multiunit MSNA to stress, little information is available regarding the responses of single-unit MSNA to physiological stress and disease. The purposes of this review are to describe the differences between multiunit and single-unit MSNA during stress and to discuss the advantages of single-unit MSNA recording in improving our understanding the pathology of increased sympathetic activity in HF.

Nutrient deprivation regulates DNA damage repair in cardiomyocytes via loss of the base-excision repair enzyme OGG1

Oxidative stress contributes to the pathogenesis of many diseases, including heart failure, but the role and regulation of oxidative DNA damage in many cases have not been studied. Here, we set out to examine how oxidative DNA damage is regulated in cardiomyocytes. Compared to normal healthy controls, human hearts in end-stage cardiomyopathy (EsCM) showed a high degree of DNA damage by histological evidence of damage markers, including 8-oxoG and γH2AX (8-oxoG: 4.7±0.88 vs. 99.9±0.11%; γH2AX: 2.1±0.33 vs. 85.0±13.8%; P<0.01) This raised the possibility that defective DNA repair may be partly responsible. Indeed, nutrient deprivation led to impaired base-excision repair (BER) in cardiomyocytes in vitro, accompanied by loss of the BER enzyme OGG1, while BER activity was rescued by recombinant OGG1 (control vs. nutrient deprived vs. nutrient deprived+OGG1; 100±2.96 vs. 68.2±7.53 vs. 94.0±0.72%; ANOVA, P<0.01). Hearts from humans with EsCM and two murine models of myocardial stress also showed a loss of OGG1 protein. OGG1 loss was inhibited by the autophagy inhibitor bafilomycin and in autophagy-deficient Atg5(-/-) mouse embryonic fibroblasts. However, pharmacological activation of autophagy, itself, did not induce OGG1 loss, suggesting that autophagy is necessary but not sufficient for OGG1 turnover, and OGG1 loss requires concurrent nutrient deprivation. Finally, we found that the role of autophagy in nutrient starvation is complex, since it balanced the positive effects of ROS inhibition against the negative effect of OGG1 loss. Therefore, we have identified a central role for OGG1 in regulating DNA repair in cardiomyopathy. The manipulation of OGG1 may be used in future studies to examine the direct contribution of oxidative DNA damage to the progression of heart failure.

Plasticity of surface structures and β(2)-adrenergic receptor localization in failing ventricular cardiomyocytes during recovery from heart failure

BACKGROUND

Cardiomyocyte surface morphology and T-tubular structure are significantly disrupted in chronic heart failure, with important functional sequelae, including redistribution of sarcolemmal β(2)-adrenergic receptors (β(2)AR) and localized secondary messenger signaling. Plasticity of these changes in the reverse remodeled failing ventricle is unknown. We used AAV9.SERCA2a gene therapy to rescue failing rat hearts and measured z-groove index, T-tubule density, and compartmentalized β(2)AR-mediated cAMP signals, using a combined nanoscale scanning ion conductance microscopy-Förster resonance energy transfer technique.

METHODS AND RESULTS

Cardiomyocyte surface morphology, quantified by z-groove index and T-tubule density, was normalized in reverse-remodeled hearts after SERCA2a gene therapy. Recovery of sarcolemmal microstructure correlated with functional β(2)AR redistribution back into the z-groove and T-tubular network, whereas minimal cAMP responses were initiated after local β(2)AR stimulation of crest membrane, as observed in failing cardiomyocytes. Improvement of β(2)AR localization was associated with recovery of βAR-stimulated contractile responses in rescued cardiomyocytes. Retubulation was associated with reduced spatial heterogeneity of electrically stimulated calcium transients and recovery of myocardial BIN-1 and TCAP protein expression but not junctophilin-2.

CONCLUSIONS

In summary, abnormalities of sarcolemmal structure in heart failure show plasticity with reappearance of z-grooves and T-tubules in reverse-remodeled hearts. Recovery of surface topology is necessary for normalization of β(2)AR location and signaling responses.

Rheumatic heart disease and risk of incident heart failure among community-dwelling older adults: a prospective cohort study

BACKGROUND

Little is known about the association of rheumatic heart disease (RHD) with incident heart failure (HF) among older adults.

DESIGN

Cardiovascular Health Study, a prospective cohort study.

METHODS

Of the 4,751 community-dwelling adults ≥ 65 years, free of prevalent HF at baseline, 140 had RHD, defined as self-reported physician-diagnosed RHD along with echocardiographic evidence of left-sided valvular disease. Propensity scores for RHD, estimated for each of the 4,751 participants, were used to assemble a cohort of 720, in which 124 and 596 participants with and without RHD, respectively, were balanced on 62 baseline characteristics.

RESULTS

Incident HF developed in 33% and 22% of matched participants with and without RHD, respectively, during 13 years of follow-up (hazard ratio when RHD was compared to no-RHD 1.60; 95% confidence interval 1.13-2.28; P = 0.008). Pre-match unadjusted, multivariable-adjusted, and propensity-adjusted hazard ratios (95% confidence intervals) for RHD-associated incident heart failure were 2.04 (1.54-2.71; P < 0.001), 1.32 (1.02-1.70; P = 0.034), and 1.55 (1.14-2.11; P = 0.005), respectively. RHD was not associated with all-cause mortality (HR 1.09; 95% CI 0.82-1.45; P = 0.568).

CONCLUSION

RHD is an independent risk factor for incident HF among community-dwelling older adults free of HF, but has no association with mortality.

Procedure intensity and the cost of care

BACKGROUND

The intensive practice style of hospitals with high procedure rates may result in higher costs of care for medically managed patients. We sought to determine how costs for patients with heart failure (HF) not receiving procedures compare between hospital groups defined by their overall use of procedures.

METHODS AND RESULTS

We identified all 2009 to 2010 adult HF hospitalizations in hospitals capable of performing invasive procedures that had at least 25 HF hospitalizations in the Perspective database from Premier, Inc. We divided hospitals into 2 groups by the proportion of patients with HF receiving invasive percutaneous or surgical procedures: low (>0%-10%) and high (≥ 10%). The standard costs of hospitalizations at each hospital were risk adjusted using patient demographics and comorbidities. We used the Wilcoxon rank sum test to assess cost, length of stay, and mortality outcome differences between the 2 groups. Median risk-standardized costs among low-procedural HF hospitalizations were $5259 (interquartile range, $4683-$6814) versus $6965 (interquartile range, $5981-$8235) for hospitals with high procedure use (P<0.001). Median length of stay was 4 days for both groups. Risk-standardized mortality rates were 5.4% (low procedure) and 5.0% (high procedure) (P=0.009). We did not identify any single service area that explained the difference in costs between hospital groups, but these hospitals had higher costs for most service areas.

CONCLUSION

Among patients who do not receive invasive procedures, the cost of HF hospitalization is higher in more procedure-intense hospitals compared with hospitals that perform fewer procedures.

Impact of comorbidity on mortality among older persons with advanced heart failure

BACKGROUND

Care for patients with advanced heart failure (HF) has traditionally focused on managing HF alone; however, little is known about the prevalence and contribution of comorbidity to mortality among this population. We compared the impact of comorbidity on mortality in older adults with HF with high mortality risk and those with lower mortality risk, as defined by presence or absence of a prior hospitalization for HF, respectively.

METHODS

This was a retrospective cohort study (2002-2006) of 18,322 age-matched and gender-matched Medicare beneficiaries. We used the baseline year of 2002 to ascertain HF hospitalization history, in order to identify beneficiaries at either high or low risk of future HF mortality. We calculated the prevalence of 19 comorbidities and overall comorbidity burden, defined as a count of conditions, among both high and low risk beneficiaries, in 2002. Proportional hazards regressions were used to determine the effect of individual comorbidity and comorbidity burden on mortality between 2002 and 2006 among both groups.

RESULTS

Most comorbidities were significantly more prevalent among hospitalized versus non-hospitalized beneficiaries; myocardial infarction, atrial fibrillation, kidney disease (CKD), chronic obstructive pulmonary disease (COPD), and hip fracture were more than twice as prevalent in the hospitalized group. Among hospitalized beneficiaries, myocardial infarction, diabetes, COPD, CKD, dementia, depression, hip fracture, stroke, colorectal cancer and lung cancer were each significantly associated with increased hazard of dying (hazard ratios [HRs]: 1.16-1.93), adjusting for age, gender and race. The mortality risk associated with most comorbidities was higher among non-hospitalized beneficiaries (HRs: 1.32-3.78).

CONCLUSIONS

Comorbidity confers a significantly increased mortality risk even among older adults with an overall high mortality risk due to HF. Clinicians who routinely care for this population should consider the impact of comorbidity on outcomes in their overall management of HF. Such information may also be useful when considering the risks and benefits of aggressive, high-intensity life-prolonging interventions.

The health services burden of heart failure: an analysis using linked population health data-sets

BACKGROUND

The burden of patients with heart failure on health care systems is widely recognised, although there have been few attempts to quantify individual patterns of care and differences in health service utilisation related to age, socio-economic factors and the presence of co-morbidities. The aim of this study was to assess the typical profile, trajectory and resource use of a cohort of Australian patients with heart failure using linked population-based, patient-level data.

METHODS

Using hospital separations (Admitted Patient Data Collection) with death registrations (Registry of Births, Deaths and Marriages) for the period 2000-2007 we estimated age- and gender-specific rates of index admissions and readmissions, risk factors for hospital readmission, mean length of stay (LOS), median survival and bed-days occupied by patients with heart failure in New South Wales, Australia.

RESULTS

We identified 29,161 index admissions for heart failure. Admission rates increased with age, and were higher for males than females for all age groups. Age-standardised rates decreased over time (256.7 to 237.7/100,000 for males and 235.3 to 217.1/100,000 for females from 2002-3 to 2006-7; p = 0.0073 adjusted for gender). Readmission rates (any cause) were 27% and 73% at 28-days and one year respectively; readmission rates for heart failure were 11% and 32% respectively. All cause mortality was 10% and 28% at 28 days and one year. Increasing age was associated with more heart failure readmissions, longer LOS and shorter median survival. Increasing age, increasing Charlson comorbidity score and male gender were risk factors for hospital readmission. Cohort members occupied 954,888 hospital bed-days during the study period (any cause); 383,646 bed-days were attributed to heart failure admissions.

CONCLUSIONS

The rates of index admissions for heart failure decreased significantly in both males and females over the study period. However, the impact on acute care hospital beds was substantial, with heart failure patients occupying almost 200,000 bed-days per year in NSW over the five year study period. The strong age-related trends highlight the importance of stabilising elderly patients before discharge and community-based outreach programs to better manage heart failure and reduce readmissions.

Correlation of natriuretic peptides and inferior vena cava size in patients with congestive heart failure

BACKGROUND

The inferior vena cava (IVC) diameter and degree of inspiratory collapse are used as echocardiographic indices in the estimation of right atrial pressure. Brain-natriuretic peptides (BNPs) are established biomarkers of myocardial wall stress. There is no information available regarding the association between the IVC diameter and BNPs in patients with heart failure and various degrees of systolic performance. The purpose of this investigation is to quantify the degree to which natriuretic peptides (BNP and N-terminal pro-B natriuretic peptide [NT-ProBNP]) and echocardiographic-derived indices of right atrial pressure correlate in this patient population.

METHODS

We examined 77 patients (mean age 61 ± 17 years, 44% male) with decompensated heart failure who underwent transthoracic echocardiography and, within a timeframe of 24 hours, determination of BNP and NT-ProBNP levels in venous blood. BNP and NT-ProBNP were analyzed after log transformation. The degree of association was measured by the correlation coefficient using the Pearson's method.

RESULTS

The mean ejection fraction was 50% ± 20%, and 33% of the study cohort had a remote history of heart failure. The mean IVC diameter was 1.85 cm ± 0.5, the mean BNP was 274 pg/mL, the confidence interval (CI) was 95% (95% CI: 197-382), and the mean NT-ProBNP was 1994 pg/mL (95% CI: 1331-2989). There was a positive, albeit small, association between IVC diameter and BNP (r = 0.24, 95% CI: 0.01-0.44; P = 0.03) and NT-ProBNP (r = 0.27, 95% CI: 0.05-0.47; P = 0.01). Among patients with different degrees of IVC collapse in response to inspiration, values for BNP and NT-ProBNP did not differ substantially (P = 0.36 and 0.46 for BNP and NT-ProBNP, respectively).

CONCLUSION

Natriuretic peptides correlate weakly with IVC size and do not predict changes in response to intrathoracic pressure.

Dietary Omega-3 Polyunsaturated Fatty Acids Suppress NHE-1 Upregulation in a Rabbit Model of Volume- and Pressure-Overload

BACKGROUND

Increased consumption of omega-3 polyunsaturated fatty acids (ω3-PUFAs) from fish oil (FO) may have cardioprotective effects during ischemia/reperfusion, hypertrophy, and heart failure (HF). The cardiac Na(+)/H(+)-exchanger (NHE-1) is a key mediator for these detrimental cardiac conditions. Consequently, chronic NHE-1 inhibition appears to be a promising pharmacological tool for prevention and treatment. Acute application of the FO ω3-PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) inhibit the NHE-1 in isolated cardiomyocytes. We studied the effects of a diet enriched with ω3-PUFAs on the NHE-1 activity in healthy rabbits and in a rabbit model of HF induced by volume- and pressure-overload.

METHODS

Rabbits were allocated to four groups. The first two groups consisted of healthy rabbits, which were fed either a diet containing 1.25% (w/w) FO (ω3-PUFAs), or 1.25% high-oleic sunflower oil (ω9-MUFAs) as control. The second two groups were also allocated to either a diet containing ω3-PUFAs or ω9-MUFAs, but underwent volume- and pressure-overload to induce HF. Ventricular myocytes were isolated by enzymatic dissociation and used for intracellular pH (pH(i)) and patch-clamp measurements. NHE-1 activity was measured in HEPES-buffered conditions as recovery rate from acidosis due to ammonium prepulses.

RESULTS

In healthy rabbits, NHE-1 activity in ω9-MUFAs and ω3-PUFAs myocytes was not significantly different. Volume- and pressure-overload in rabbits increased the NHE-1 activity in ω9-MUFAs myocytes, but not in ω3-PUFAs myocytes, resulting in a significantly lower NHE-1 activity in myocytes of ω3-PUFA fed HF rabbits. The susceptibility to induced delayed afterdepolarizations (DADs), a cellular mechanism of arrhythmias, was lower in myocytes of HF animals fed ω3-PUFAs compared to myocytes of HF animals fed ω9-MUFAs. In our rabbit HF model, the degree of hypertrophy was similar in the ω3-PUFAs group compared to the ω9-MUFAs group.

CONCLUSION

Dietary ω3-PUFAs from FO suppress upregulation of the NHE-1 activity and lower the incidence of DADs in our rabbit model of volume- and pressure-overload.

Novel strategies for the treatment of heart failure

Heart failure is a leading cause of morbidity and mortality with a prevalence that is rising throughout the world. Currently the pharmaceutical therapy of heart failure is mainly based on inhibition of the neurohumoral pathways that are activated secondary to the deterioration of cardiac function, and diuretics to alleviate the salt and water overload. With our increasing understanding of the pathophysiology of heart failure, it is now clear that the macroscopic and functional changes in the failing heart result from remodeling at the cellular, interstitial, and molecular levels. Therefore, emerging therapies propose to intervene directly in the remodeling process at the cellular and the molecular levels. Here, several experimental strategies that aim to correct the abnormalities in receptor and post-receptor-function, calcium handling, excitation and contraction coupling, signaling, and changes in the extra-cellular matrix in the failing heart will be discussed. These novel approaches, aiming to reverse the remodeling process at multiple levels, may appear on the clinical arena in the coming years.

Effect of cardiac resynchronization therapy in patients without left intraventricular dyssynchrony

AIMS

To evaluate the effects of cardiac resynchronization therapy (CRT) on long-term survival of patients without baseline left ventricular (LV) mechanical dyssynchrony.

METHODS AND RESULTS

A total of 290 heart failure patients (age 67 ± 10 years, 77% males) without significant baseline LV dyssynchrony (<60 ms as assessed with tissue Doppler imaging) were treated with CRT. Patients were divided according to the median LV dyssynchrony measured after 48 h of CRT into two groups. All-cause mortality was compared between the subgroups. In addition, the all-cause mortality rates of these subgroups were compared with the all-cause mortality of 290 heart failure patients treated with CRT who showed significant LV dyssynchrony (≥60 ms) at baseline. In the group of patients without significant LV dyssynchrony, median LV dyssynchrony increased from 22 ms (inter-quartile range 16-34 ms) at baseline to 40 ms (24-56 ms) 48 h after CRT. The cumulative mortality rates at 1-, 2-, and 3-year follow-up of patients with LV dyssynchrony ≥40 ms 48 h after CRT implantation were significantly higher when compared with patients with LV dyssynchrony <40 ms (10, 17, and 23 vs. 3, 8, and 10%, respectively; log-rank P< 0.001). Finally, the cumulative mortality rates at 1-, 2-, and 3-year follow-up of patients with baseline LV dyssynchrony were 3, 8, and 11%, respectively (log-rank P= 0.375 vs. patients with LV dyssynchrony <40 ms). Induction of LV dyssynchrony after CRT was an independent predictor of mortality (hazard ratio: 1.247; P= 0.009).

CONCLUSION

In patients without significant LV dyssynchrony, the induction of LV dyssynchrony after CRT may be related to a less favourable long-term outcome.

Biological Heart Rate Reduction Through Genetic Suppression of Gα(s) Protein in the Sinoatrial Node

BACKGROUND

Elevated heart rate represents an independent risk factor for cardiovascular outcome in patients with heart disease. In the sinoatrial node, rate increase is mediated by β(1) adrenoceptor mediated activation of the Gα(s) pathway. We hypothesized that genetic inactivation of the stimulatory Gα(s) protein in the sinoatrial node would provide sinus rate control and would prevent inappropriate heart rate acceleration during β-adrenergic activation.

METHODS AND RESULTS

Domestic pigs (n=10) were evenly assigned to receive either Ad-small interfering RNA (siRNA)-Gα(s) gene therapy to inactivate Gα(s) or adenovirus encoding for green fluorescent protein (Ad-GFP) as control. Adenoviruses were applied through virus injection into the sinoatrial node followed by epicardial electroporation, and heart rates were evaluated for 7 days. Genetic inhibition of Gα(s) protein significantly reduced mean heart rates on day 7 by 16.5% compared with control animals (110±8.8 vs 131±9.4 beats per minute; P<0.01). On β-adrenergic stimulation with isoproterenol, we observed a tendency toward diminished rate response in the Ad-siRNA-Gα(s) group (Ad-siRNA-Gα(s), +79.3%; Ad-GFP, +61.7%; n=3 animals per group; P= 0.294). Adverse effects of gene transfer on left ventricular ejection fraction (LVEF) were not detected following treatment (LVEF(Ad-siRNA-Gαs), 66%; LVEF(Ad-GFP), 60%).

CONCLUSIONS

In this preclinical proof-of-concept study targeted Ad-siRNA-Gα(s) gene therapy reduced heart rates during normal sinus rhythm compared with Ad-GFP treatment and prevented inappropriate rate increase after β-adrenergic stimulation. Gene therapy may provide an additional therapeutic option for heart rate reduction in cardiac disease. (J Am Heart Assoc. 2012;1:jah3-e000372 doi: 10.1161/JAHA.111.000372).

The evolving landscape of quality measurement for heart failure

Heart failure (HF) is a major cause of mortality and morbidity, representing a leading cause of death and hospitalization among U.S. Medicare beneficiaries. Advances in science have generated effective interventions to reduce adverse outcomes in HF, particularly in patients with reduced left ventricular ejection fraction. Unfortunately, effective therapies for heart failure are often not utilized in an effective, safe, timely, equitable, patient-centered, and efficient manner. Further, the risk of adverse outcomes for HF remains high. The last decades have witnessed the growth of efforts to measure and improve the care and outcomes of patients with HF. This paper will review the evolution of quality measurement for HF, including a brief history of quality measurement in medicine; the measures that have been employed to characterize quality in heart failure; how the measures are obtained; how measures are employed; and present and future challenges surrounding quality measurement in heart failure.

Missed opportunities for advance care planning communication during outpatient clinic visits

BACKGROUND

Early provider-patient communication about future care is critical for patients with heart failure (HF); however, advance care planning (ACP) discussions are often avoided or occur too late to usefully inform care over the course of the disease.

OBJECTIVE

To identify opportunities for physicians to engage in ACP discussions and to characterize physicians' responses to these opportunities.

DESIGN

Qualitative study of audio-recorded outpatient clinic visits.

PARTICIPANTS

Fifty-two patients ≥ 65 years recently hospitalized for HF with one or more post-discharge follow-up outpatient visits, and their physicians (n = 44), at two Veterans Affairs Medical Centers.

APPROACH

Using content analysis methods, we analyzed and coded transcripts of outpatient follow-up visits for 1) patient statements pertaining to their future health or their future physical, psychosocial and spiritual/existential care needs, and 2) subsequent physician responses to patient statements, using an iterative consensus-based coding process.

RESULTS

In 13 of 71 consultations, patients expressed concerns, questions, and thoughts regarding their future care that gave providers opportunities to engage in an ACP discussion. The majority of these opportunities (84%) were missed by physicians. Instead, physicians responded by terminating the conversation, hedging their responses, denying the patient's expressed emotion, or inadequately acknowledging the sentiment underlying the patient's statement.

CONCLUSIONS

Physicians often missed the opportunity to engage in ACP despite openers patients provided that could have prompted such discussions. Communication training efforts should focus on helping physicians identify patient openers and providing a toolbox to encourage appropriate physician responses; in order to successfully leverage opportunities to engage in ACP discussions.

The rise of cardiovascular medicine

Modern cardiology was born at the turn of the nineteenth to twentieth centuries with three great discoveries: the X ray, the sphygmomanometer, and the electrocardiograph. This was followed by cardiac catheterization, which led to coronary angiography and to percutaneous coronary intervention. The coronary care units and early reperfusion reduced the early mortality owing to acute myocardial infarction, and the discovery of coronary risk factors led to the development of Preventive Cardiology. Other major advances include several cardiac imaging techniques, the birth and development of cardiac surgery, and the control of cardiac arrhythmias. The treatment of heart failure, although greatly improved, remains a challenge. Current cardiology practice is evidence-based and global in scope. Research and practice are increasingly conducted in cardiovascular centres and institutes. It is likely that in the future, a greater emphasis will be placed on prevention, which will be enhanced by genetic information.