The heart failure revascularisation trial (HEART): rationale, design and methodology

A treatment algorithm for ischemic cardiomyopathy

Treatment of ischemic cardiomyopathy has been the focus of increased attention by cardiologists due to recent evidence of an important outcome study comparing percutaneous coronary intervention (PCI) plus optimal medical treatment vs optimal medical treatment alone, concluding for the futility of myocardial revascularization by PCI. A relatively older trial of coronary artery bypass grafting (CABG) in the same condition, on the other hand, had concluded for some prognostic improvement at a long-term follow-up. This short manuscript addresses how to triage such patients, frequently encountered in medical practice and considering clinical presentation, imaging results, and surgical risk, to provide practical guidance to treatment.

Myocardial Revascularization in Patients With Ischemic Cardiomyopathy: For Whom and How

Background Myocardial revascularization has been advocated to improve myocardial function and prognosis in ischemic cardiomyopathy (ICM). We discuss the evidence for revascularization in patients with ICM and the role of ischemia and viability detection in guiding treatment. Methods and Results We searched for randomized controlled trials evaluating the prognostic impact of revascularization in ICM and the value of viability imaging for patient management. Out of 1397 publications, 4 randomized controlled trials were included, enrolling 2480 patients. Three trials (HEART [Heart Failure Revascularisation Trial], STICH [Surgical Treatment for Ischemic Heart Failure], and REVIVED [REVascularization for Ischemic VEntricular Dysfunction]-BCIS2) randomized patients to revascularization or optimal medical therapy. HEART was stopped prematurely without showing any significant difference between treatment strategies. STICH showed a 16% lower mortality with bypass surgery compared with optimal medical therapy at a median follow-up of 9.8 years. However, neither the presence/extent of left ventricle viability nor ischemia interacted with treatment outcomes. REVIVED-BCIS2 showed no difference in the primary end point between percutaneous revascularization or optimal medical therapy. PARR-2 (Positron Emission Tomography and Recovery Following Revascularization) randomized patients to imaging-guided revascularization versus standard care, with neutral results overall. Information regarding the consistency of patient management with viability testing results was available in ≈65% of patients (n=1623). No difference in survival was revealed according to adherence or no adherence to viability imaging. Conclusions In ICM, the largest randomized controlled trial, STICH, suggests that surgical revascularization improves patients' prognosis at long-term follow-up, whereas evidence supports no benefit of percutaneous coronary intervention. Data from randomized controlled trials do not support myocardial ischemia or viability testing for treatment guidance. We propose an algorithm for the workup of patients with ICM considering clinical presentation, imaging results, and surgical risk.

A pathway and network review on beta-adrenoceptor signaling and beta blockers in cardiac remodeling

It is well established that cardiac remodeling plays a pivotal role in the development of heart failure, a leading cause of death worldwide. Meanwhile, sympathetic hyperactivity is an important factor in inducing cardiac remodeling. Therefore, an in-depth understanding of beta-adrenoceptor signaling pathways would help to find better ways to reverse the adverse remodeling. Here, we reviewed five pathways, namely mitogen-activated protein kinase signaling, Gs-AC-cAMP signaling, Ca(2+)-calcineurin-NFAT/CaMKII-HDACs signaling, PI3K signaling and beta-3 adrenergic signaling, in cardiac remodeling. Furthermore, we constructed a cardiac-remodeling-specific regulatory network including miRNA, transcription factors and target genes within the five pathways. Both experimental and clinical studies have documented beneficial effects of beta blockers in cardiac remodeling; nevertheless, different blockers show different extent of therapeutic effect. Exploration of the underlying mechanisms could help developing more effective drugs. Current evidence of treatment effect of beta blockers in remodeling was also reviewed based upon information from experimental data and clinical trials. We further discussed the mechanism of how beta blockers work and why some beta blockers are more potent than others in treating cardiac remodeling within the framework of cardiac remodeling network.

TLR4 Expression Is Associated with Left Ventricular Dysfunction in Patients Undergoing Coronary Artery Bypass Surgery

INTRODUCTION

Toll-like receptor 4 (TLR4) is an innate immune receptor expressed in immune cells and the heart. Activation of the immune system following myocardial ischemia causes the release of proinflammatory mediators that may negatively influence heart function.

AIM

The aim of this study is to determine whether TLR4 is activated in peripheral monocytes and heart tissue taken from patients with varying degrees of myocardial dysfunction caused by coronary artery diseases and scheduled for coronary artery bypass graft (CABG) surgery before 12 months following operation.

METHODS AND RESULTS

Patients (n = 44) undergoing CABG surgery having left ventricular ejection fraction ≤ 45% ('reduced EF', n = 20) were compared to patients with preserved EF >45% ('preserved EF' group, n = 24). 'Reduced EF' patients exhibited increased TLR4 expression in monocytes (2.78±0.49 vs. 1.76±0.07 rMFI, p = 0.03). Plasma levels of C-reactive protein, microRNA miR-320a, brain natriuretic peptide (pro BNP) and NADPH oxidase (NOX4) were also significantly different between the 'preserved EF' and 'reduced EF'groups. Elevated TLR4 gene expression levels in the right auricle correlated with those of EF (p<0.008), NOX4 (p<0.008) and miR320, (p<0.04). In contrast, no differences were observed in peripheral monocyte TLR2 expression. After CABG surgery, monocyte TLR4 expression decreased in all patients, reaching statistical significance in the 'reduced EF' group.

CONCLUSION

TLR4 is activated in peripheral monocytes and heart tissue obtained from patients with ischemic heart disease and reduced left ventricular function. Coronary revascularization decreases TLR4 expression. We therefore propose that TLR4 plays a pathogenic role and may serve as an additional marker of ischemic myocardial dysfunction.

Hibernating myocardium in heart failure

Ischemic left ventricular systolic dysfunction may result from myocardial necrosis or from hypocontractile areas of viable myocardium. In some cases, recovery of contractility may occur on revascularization--this reversibly dysfunctional tissue is commonly referred to as hibernating myocardium. Observational data suggest that revascularization of patients with ischemic left ventricular systolic dysfunction and known viable myocardium provides a survival benefit over medical therapy. Identification of viable, dysfunctional myocardium may be especially worthwhile in deciding which patients with ischemic left ventricular systolic dysfunction will benefit from revascularization procedures. Randomized, prospective trials evaluating this are currently ongoing. This review will provide an overview of the complex pathophysiology of viable, dysfunctional myocardium, and will discuss outcomes after revascularization. Of the techniques used to determine the presence of hibernating myocardium, functional methods such as stress echocardiography and cardiac magnetic resonance appear more specific, but less sensitive, than the nuclear modalities, which assess perfusion and metabolic activity. Currently, the availability of all methods is variable.

Noninvasive assessment myocardial viability: current status and future directions

Observations of reversibility of cardiac contractile dysfunction in patients with coronary artery disease and ischemia were first made more than 40 years ago. Since that time a wealth of basic science and clinical data has been gathered exploring the mechanisms of this phenomenon of myocardial viability and relevance to clinical care of patients. Advances in cardiac imaging techniques have contributed greatly to knowledge in the area, first with thallium-201 imaging, then later with Tc-99m-based tracers for SPECT imaging and metabolic tracers used in conjunction with positron emission tomography (PET), most commonly F-18 FDG in conjunction with blood flow imaging with N-13 ammonia or Rb-82 Cl. In parallel, stress echocardiography has made great progress also. Over time observational studies in patients using these techniques accumulated and were later summarized in several meta-analyses. More recently, cardiac magnetic resonance imaging (CMR) has contributed further information in combination with either late gadolinium enhancement imaging or dobutamine stress. This review discusses the tracer and CMR imaging techniques, the pooled observational data, the results of clinical trials, and ongoing investigation in the field. It also examines some of the current challenges and issues for researchers and explores the emerging potential of combined PET/CMR imaging for myocardial viability.

Cardiac resynchronization therapy in pacemaker-dependent patients with left ventricular dysfunction

AIMS

Heart failure and left ventricular (LV) systolic dysfunction (LVSD) are common in patients with permanent pacemakers. The aim was to determine if cardiac resynchronization therapy (CRT) at the time of pulse generator replacement (PGR) is of benefit in patients with unavoidable RV pacing and LVSD.

METHODS AND RESULTS

Fifty patients with unavoidable RV pacing, LVSD, and mild or no symptoms of heart failure, listed for PGR were randomized 1 : 1 to either standard RV-PGR (comparator) or CRT. The primary endpoint was the difference in change in LV ejection fraction (LVEF) between RV-PGR and CRT groups from baseline to 6 months. Secondary endpoints included peak oxygen consumption, quality of life, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. At 6 months there was a difference in change in median (interquartile range) LVEF [9 (6-12) vs. -1.5 (-4.5 to -0.8)%; P < 0.0001] between the CRT and RV-PGR arms. There were also improvements in exercise capacity (P = 0.007), quality of life (P = 0.03), and NT-proBNP (P = 0.007) in those randomized to CRT. After 809 (729-880) days, 17 patients had died or been hospitalized (6 in CRT group and 11 in the comparator RV-PGR group) and two patients in the RV-PGR arm had required CRT for deteriorating heart failure. Patients with standard RV-PGR had more days in hospital during follow-up than those in the CRT group [4 (2-7) vs. 11 (6-16) days; P = 0.047].

CONCLUSION

Performing CRT in pacemaker patients with unavoidable RV pacing and LVSD but without severe symptoms of heart failure, at the time of PGR, improves cardiac function, exercise capacity, quality of life, and NT-pro-BNP levels.

Prevalence of scarred and dysfunctional myocardium in patients with heart failure of ischaemic origin: a cardiovascular magnetic resonance study

BACKGROUND

Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) can provide unique data on the transmural extent of scar/viability. We assessed the prevalence of dysfunctional myocardium, including partial thickness scar, which could contribute to left ventricular contractile dysfunction in patients with heart failure and ischaemic heart disease who denied angina symptoms.

METHODS

We invited patients with ischaemic heart disease and a left ventricular ejection fraction < 50% by echocardiography to have LGE CMR. Myocardial contractility and transmural extent of scar were assessed using a 17-segment model.

RESULTS

The median age of the 193 patients enrolled was 70 (interquartile range: 63-76) years and 167 (87%) were men. Of 3281 myocardial segments assessed, 1759 (54%) were dysfunctional, of which 581 (33%) showed no scar, 623 (35%) had scar affecting ≤50% of wall thickness and 555 (32%) had scar affecting > 50% of wall thickness. Of 1522 segments with normal contractile function, only 98 (6%) had evidence of scar on CMR. Overall, 182 (94%) patients had ≥1 and 107 (55%) patients had ≥5 segments with contractile dysfunction that had no scar or ≤50% transmural scar suggesting viability.

CONCLUSIONS

In this cohort of patients with left ventricular systolic dysfunction and ischaemic heart disease, about half of all segments had contractile dysfunction but only one third of these had > 50% of the wall thickness affected by scar, suggesting that most dysfunctional segments could improve in response to an appropriate intervention.

Effect of revascularization on long-term survival in patients with ischemic left ventricular dysfunction and a wide range of viability

Short-term survival in patients with viability and ischemic left ventricular dysfunction appears improved by revascularization, but no randomized studies have shown a long-term benefit of revascularization in patients with a wide range of viability. Propensity analysis was used as a substitute for randomization in a study comparing the survival of revascularized and medically treated patients with ischemic dysfunction. Dobutamine echocardiography was performed in 274 patients with ischemic left ventricular dysfunction (mean ejection fraction 32%), with 32% having viability in > or =25% of the myocardium. Clinical, angiographic, and echocardiographic characteristics were comparable between treatment groups except for multivessel disease, hyperlipidemia, and the percentage of nonviable myocardium. A propensity score, reflecting the probability of receiving revascularization, was derived for each patient from baseline variables. After stratification by propensity scores, there were no differences between groups. Patients were followed for cardiac death. Revascularization was performed in 130 patients, and 144 were medically treated. There were 114 cardiac deaths (42%) over 4.5 years of follow-up. After propensity score adjustment, survival was better with revascularization (mean survival 5.9 vs 3.3 years, hazard ratio 0.42, 95% confidence interval 027 to 0.65, p <0.0001). Medical and device therapy during follow-up was similar between treatment groups, except that beta-blocker use was more common in revascularized patients. After adjustment for beta-blocker use and propensity score, survival remained better in revascularized patients (hazard ratio 0.47, 95% confidence interval 0.30 to 0.72, p = 0.0006). In conclusion, revascularization improves long-term survival in patients with ischemic left ventricular dysfunction and a wide range of viability.

Myocardial viability imaging and revascularization in chronic ischemic left ventricular systolic dysfunction

The high rate of periprocedural morbidity and mortality associated with revascularization in moderate-to-severe left ventricular systolic dysfunction has provided the rationale for noninvasive viability imaging. The most established viability imaging techniques are PET, single-photon emission computed tomography and dobutamine echocardiography. Cardiac MRI is gaining widespread use and accessibility, and computed tomography is emerging as a promising technique. Each imaging modality has unique advantages but also suffers from limitations. Furthermore, evidence of the impact of viability imaging on patient outcomes has generally been limited to observational studies. Uncertainty remains regarding the optimal treatment strategy in this patient subset. This review describes the current status of viability imaging and revascularization in chronic moderate-to-severe ischemic left ventricular systolic dysfunction.

Cardiac positron emission tomography: current clinical practice

In the last two decades, the field of nuclear cardiology has experienced significant progress. The introduction of positron emission tomography (PET) imaging represented a major breakthrough that has significantly contributed to a better understanding of physiology and pathophysiology of several heart diseases. Currently, PET imaging is recognized as a well-established method to assess cardiac perfusion, function, metabolism, and viability. This article summarizes the main clinical applications of state-of-the art cardiac PET technology.

F-18-fluorodeoxyglucose positron emission tomography imaging-assisted management of patients with severe left ventricular dysfunction and suspected coronary disease: a randomized, controlled trial (PARR-2)

OBJECTIVES

We conducted a randomized trial to assess the effectiveness of F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET)-assisted management in patients with severe ventricular dysfunction and suspected coronary disease.

BACKGROUND

Such patients may benefit from revascularization, but have significant perioperative morbidity and mortality. F-18-fluorodeoxyglucose PET can detect viable myocardium that might recover after revascularization.

METHODS

Included were patients with severe left ventricular (LV) dysfunction and suspected coronary disease being considered for revascularization, heart failure, or transplantation work-ups or in whom PET was considered potentially useful. Patients were stratified according to recent angiography or not, then randomized to management assisted by FDG PET (n = 218) or standard care (n = 212). The primary outcome was the composite of cardiac death, myocardial infarction, or recurrent hospital stay for cardiac cause, within 1 year.

RESULTS

At 1 year, the cumulative proportion of patients who had experienced the composite event was 30% (PET arm) versus 36% (standard arm) (relative risk 0.82, 95% confidence interval [CI] 0.59 to 1.14; p = 0.16). The hazard ratio (HR) for the composite outcome, PET versus standard care, was 0.78 (95% CI 0.58 to 1.1; p = 0.15); for patients that adhered to PET recommendations for revascularization, revascularization work-up, or neither, HR = 0.62 (95% CI 0.42 to 0.93; p = 0.019); in those without recent angiography, for cardiac death, HR = 0.4 (95% CI 0.17 to 0.96; p = 0.035).

CONCLUSIONS

This study did not demonstrate a significant reduction in cardiac events in patients with LV dysfunction and suspected coronary disease for FDG PET-assisted management versus standard care. In those who adhered to PET recommendations and in patients without recent angiography, significant benefits were observed. The utility of FDG PET is best realized in this subpopulation and when adherence to recommendations can be achieved.

Clinical trials update from the American College of Cardiology 2007: ALPHA, EVEREST, FUSION II, VALIDD, PARR-2, REMODEL, SPICE, COURAGE, COACH, REMADHE, pro-BNP for the evaluation of dyspnoea and THIS-diet

This article provides information and a commentary on trials relevant to the pathophysiology, prevention and treatment of heart failure, presented at the American College of Cardiology meeting in March 2007. Unpublished reports should be considered as preliminary data, as analyses may change in the final publication. The ALPHA study suggested that patients with heart failure (HF) due to idiopathic dilated cardiomyopathy who have a negative T-wave alternans test have a good prognosis and are unlikely to benefit from ICD therapy. EVEREST provides some evidence of short-term symptom benefit of tolvaptan in patients with acute decompensated HF but no clinically important long-term benefit. FUSION II failed to show a benefit of nesiritide in patients with chronic decompensated HF. Reducing blood pressure in hypertensive patients improved diastolic dysfunction in VALIDD. Eplerenone did not improve left ventricular remodelling in mild to moderate chronic HF. Selecting HF patients for revascularisation using FDG-PET imaging did not significantly improve outcome. Crataegus extract added to standard HF therapy did not reduce morbidity or mortality in SPICE. The COURAGE study, conducted in patients without HF or major cardiac dysfunction, showed that PCI did not reduce cardiac morbidity or mortality and can be safely deferred in patients with stable coronary disease on optimal medical therapy. The COACH study failed to show that HF nurse-intervention could reduce hospitalisations but did show trends to lower mortality, especially amongst patients with reduced ejection fraction; however, the smaller REMADHE study suggested striking benefits on morbidity and mortality. A large study of BNP provided additional information on its ability to distinguish cardiac and pulmonary breathlessness. The importance of dietary intervention in post-MI patients was highlighted by the findings of THIS-diet study.

The effects of initiation or continuation of statin therapy on cholesterol level and all-cause mortality after the diagnosis of left ventricular systolic dysfunction

BACKGROUND

Statins (3-hydroxy-3-methyl-glutaryl coenzyme A reductase inhibitors) are known to reduce mortality and cardiac events in patients with coronary artery disease who have not progressed to left ventricular systolic dysfunction (LVSD) and/or heart failure (HF). This study investigated the effect of changes in statin therapy and cholesterol level on mortality in patients with LVSD.

METHODS

Data from consecutive patients with LVSD enrolled in a single local hospital HF management program were analyzed. Patients were grouped according to changes in statin treatment within 4 months after their initial visit: groups NS (no statin), IS (initiation of statin), CS (continuation of statin), and SS (statin stopped).

RESULTS

Nine hundred patients were followed for a median of 36 (28-43) months (range, 16-66 months). The 2-year mortality was 16.7%. Groups IS and CS had lower 2-year mortality than groups NS and SS (11.0% and 11.9% vs 22.0% and 34.8%, respectively; P < .001). This was independent of age, sex, severity of LVSD, HF medications, New York Heart Association functional class, and baseline cholesterol. The effect was mainly observed in patients with coronary artery disease. In 734 patients who had completed 1-year follow-up on stable HF treatment, neither baseline cholesterol nor change over 1 year predicted outcome.

CONCLUSION

Initiation and maintenance of treatment with statins is associated with better survival in patients with LVSD. This could not be explained by other measured variables.

Clinical trials update from the American Heart Association 2006: OAT, SALT 1 and 2, MAGIC, ABCD, PABA-CHF, IMPROVE-CHF, and percutaneous mitral annuloplasty

This article provides information and a commentary on trials presented at the American Heart Association meeting held in November 2006, relevant to the pathophysiology, prevention and treatment of heart failure. All reports should be considered as preliminary data, as analyses may change in the final publication. The OAT study failed to show a benefit of PCI over optimal medical therapy in patients with persistent total occlusion of the infarct related artery following a myocardial infarction. In SALT 1 and 2, tolvaptan was found to correct hyponatraemia of various aetiologies; however, whether this has an impact on heart failure prognosis requires further evaluation. A placebo controlled study of myocardial implantation of skeletal myoblasts in patients with moderate to severe LVSD (MAGIC) showed equivocal/uncertain effects, long term follow-up data are awaited. The ABCD study which compared the ability of an invasive and a non-invasive test to identify patients at risk of arrhythmic events prior to ICD implantation, suggested that the two strategies were comparable, although the practical value of either test remains uncertain and the study had many major flaws. The PABA-CHF study hinted that pulmonary vein antrum isolation might be more effective than AV node ablation with bi-ventricular pacing for the treatment of patients with heart failure in atrial fibrillation. In IMPROVE-CHF, an NT-pro BNP guided treatment strategy was found to reduce the cost of managing patients with acute breathlessness.

Fighting against sudden death: A single or multidisciplinary approach

There are many causes of sudden death ranging from accidents and suicide to vascular events and arrhythmias. Most sudden deaths will occur in people who have not been diagnosed with a serious heart condition but at a very low annual rate. Many of these events are probably vascular and might be prevented by reducing the risk of developing coronary disease. Only a minority of sudden deaths occur in people with established cardiac disease, but in patients with major structural heart disease, the annual rate is high. The causes of sudden death are many in this clinical setting also, but dominated by ventricular arrhythmias and vascular events. There is good evidence that conventional treatments for heart failure, including ACE inhibitors, beta-blockers, aldosterone antagonists and cardiac resynchronization devices reduce the risk of sudden death. Evidence that statins, aspirin or revascularisation are safe or effective in patients with heart failure is currently lacking. Implantable defibrillators confer a small but definite additional survival advantage by treating arrhythmias that have not been prevented.

Diagnostic and imaging considerations: role of viability

Left ventricular systolic dysfunction is a recognised feature of heart failure. In developed nations, the leading cause of left ventricular systolic dysfunction is coronary artery disease. Revascularisation is a treatment strategy for patients with predominant symptoms of heart failure and significant left ventricular dysfunction. Presence or absence of myocardial viability has been shown to affect outcome after revascularisation. There are various techniques to assess myocardial viability. However, limitations of current literature, lack of completed randomised trials and high peri-procedural trials create significant uncertainty about the optimal strategy. This review focuses on the role of non-invasive testing for myocardial viability in patients with left ventricular systolic dysfunction and heart failure and also outlines the pros and cons of each technique.

Long term prognosis of heart failure after acute coronary syndromes without ST elevation

BACKGROUND

Information about long term outcomes of patients with acute coronary syndromes (ACS) who have clinically diagnosed heart failure is scarce.

METHODS

In a UK registry, this study evaluated patients with non-ST elevation ACS, recording treatment, and clinical outcomes for six months. In a subgroup, a four year mortality follow up was performed to estimate the impact of the clinical diagnosis of heart failure on survival.

RESULTS

Of 1046 patients, 139 (13%) had a history of clinically diagnosed heart failure. At discharge, ACE inhibitors were prescribed for 58% and 28%, of those with and without a history of heart failure respectively (p<0.001). Rates of angiography, percutaneous intervention, and coronary artery bypass graft were 17.3% and 29.2% (p = 0.003), 5.0% and 8.4% (p = 0.17), and 5.0% and 7.5% (p = 0.3) for these groups respectively. Death or new myocardial infarction at six months occurred in 22% and 10% (p<0.001) and at four years death occurred in 60% and 20% of these groups respectively (p<0.001). In a multivariate analysis prior heart failure carried an odds ratio of 2.0 (p = 0.001) for death or myocardial infarction at six months and 2.4 (p<0.001) for death over four years. New heart failure was associated with an increased risk of death at six months (20% compared with 5%, p<0.001).

CONCLUSION

A clinical history of heart failure carries a substantial risk of death in patients admitted with ACS without ST elevation. Nearly 60% of those with prior heart failure are dead after four years. After adjustment for confounding factors, prior heart failure more than doubles the risk compared with those with no history.

Revascularization for patients with severe coronary artery disease and left ventricular dysfunction

Heart failure is becoming increasingly prevalent, and currently coronary artery disease (CAD) is the primary cause of left ventricular (LV) systolic dysfunction. A potential therapeutic option for patients with severe CAD and LV dysfunction is a strategy of revascularization. In this review, we summarize the available literature regarding revascularization for these patients. The literature suggests that patients with severe CAD and LV dysfunction may benefit from revascularization and those patients with viable myocardium may derive the most benefit.

Myocardial viability testing and the effect of early intervention in patients with advanced left ventricular systolic dysfunction

BACKGROUND

The clinical value of revascularization and other procedures in patients with severe systolic heart failure is unclear. It has been suggested that assessing ischemia and viability by positron emission tomography (PET) with fluorodeoxyglucose (FDG) imaging may identify patients for whom revascularization may lead to improved survival. We performed a propensity analysis to determine whether there might be a survival advantage from revascularization.

METHODS AND RESULTS

We analyzed the survival of 765 consecutive patients (age 64+/-11 years, 80% men) with advanced left ventricular systolic dysfunction (ejection fraction < or =35%) and without significant valvular heart disease who underwent PET/FDG study at the Cleveland Clinic between 1997 and 2002. Early intervention was defined as any cardiac intervention (surgical or percutaneous) within the first 6 months of the PET/FDG study. In the entire cohort, 230 patients (30%) underwent early intervention (188 [25%] had open heart surgery, most commonly coronary artery bypass grafting, and 42 [5%] had percutaneous revascularization); 535 (70%) were treated medically. Using 39 demographic, clinical and PET/FDG variables, we were able to propensity-match 153 of the 230 patients with 153 patients who did not undergo early intervention. Among the propensity-matched group, there were 84 deaths during a median of 3 years follow-up. Early intervention was associated with a markedly lower risk of death (3-year mortality rate of 15% versus 35%, propensity adjusted hazard ratio 0.52, 95% CI 0.33 to 0.81, P=0.0004).

CONCLUSIONS

Among systolic heart failure patients referred for PET/FDG, early intervention may be associated with improved survival irrespective of the degree of viability.

The effect of micronutrient supplementation on quality-of-life and left ventricular function in elderly patients with chronic heart failure

AIMS

Chronic heart failure (CHF) is a common and leading cause of death in industrialized countries. The potential benefits of micronutrient supplementation in CHF are extensive. Therefore, we examined the influence of long-term multiple micronutrient supplementation on left ventricular (LV) function, levels of pro-inflammatory cytokines, and quality-of-life (QoL) in elderly patients with CHF.

METHODS AND RESULTS

Thirty CHF patients [age 75.4 (0.7), mean (SEM), LV ejection fraction (LVEF) < or =35%] were randomized to receive capsules containing a combination of high-dose micronutrients (calcium, magnesium, zinc, copper, selenium, vitamin A, thiamine, riboflavin, vitamin B(6), folate, vitamin B(12), vitamin C, vitamin E, vitamin D, and Coenzyme Q10) or placebo for 9 months in a double-blind fashion. All subjects were on stable optimal medical therapy for at least 3 months before enrolment. At randomization and at study end, tumour necrosis factor-alpha and its soluble receptors TNFR-1 and TNFR-2 were measured and six-minute walk test and QoL were assessed. Cardiac magnetic resonance scanning was performed to evaluate cardiac dimensions and LVEF. Two patients died during follow-up. The remaining patients (14 randomized to placebo and 14 to micronutrients) were well matched for LV function, symptoms, and exercise capacity. At the end of the follow-up period, LV volumes were reduced in the intervention group with no change in the placebo group [-13.1 (17.1)% vs. +3.8 (10.0)%; P<0.05]. LVEF increased by 5.3+/-1.4% in the intervention group and was unchanged in the placebo group (P<0.05). Patients taking micronutrients also had a significant improvement in QoL score between enrolment and study end [+9.5 (1.6)%; P<0.05], whereas those taking placebo had a slight deterioration [-1.1 (0.8)%; P=0.12]. Six-minute walk test and inflammatory cytokine levels remained unchanged in both groups.

CONCLUSION

Long-term multiple micronutrient supplementation can improve LV volumes and LVEF and QoL scores in elderly patients with heart failure due to LV systolic dysfunction.

Revascularization in Severe Left Ventricular Dysfunction

Revascularization is a treatment option for moderate-to-severe ischemic cardiomyopathy. Limitations of the current literature, lack of completed randomized trials, and higher periprocedural risks create significant uncertainty about the optimal treatment strategy. This review focuses on the available literature describing the effect of revascularization on outcome and the role of noninvasive viability testing. It attempts to identify a subset of patients likely to benefit from therapy.

Assessment of Left Ventricular Systolic Function by the Chest X-Ray: Comparison With Radionuclide Ventriculography

BACKGROUND

The value of the plain chest roentgenogram in predicting cardiac status remains controversial.

METHODS AND RESULTS

A total of 111 randomly selected survivors of acute myocardial infarction (age 38 to 83 years) were studied prospectively. X-ray and radionuclide examinations were performed on a morning in the second week after myocardial infarction. From the chest x-ray, left ventricular chamber size and pulmonary vascular congestion were graded visually, and relative cardiac volume was measured to allow for comparison with radionuclide left ventricular end-diastolic volume index (LVEDVI) and left ventricular ejection fraction (LVEF) determined by gated blood pool imaging. Despite significant tendencies for larger radionuclide LVEDVI and lower LVEF with greater radiographic left ventricular size, larger relative cardiac volume, and increasing degrees of pulmonary congestion, wide scatter, and large overlaps between groups precluded reliable radiographic prediction of radionuclide findings. The positive and negative predictive values for radiographic detection of an enlarged LVEDVI ranged from 59% to 80% and 56% to 71%, respectively, and for prediction of a decreased LVEF from 75% to 90% and 40% to 58%, respectively. Accuracy never exceeded 70%.

CONCLUSION

Our findings question the value of the chest roentgenogram in the detection and grading of left ventricular systolic dysfunction in patients with recent myocardial infarction.

Assessment of myocardial viability

The prevalence of left ventricular (LV) dysfunction and resultant congestive heart failure is increasing. Patients with this condition are at high risk for cardiac death and usually have significant limitations in their lifestyles. Although there have been advances in medical therapy resulting in improved survival and well being, the best and most definitive therapy, when appropriate, is revascularization. In the setting of coronary artery disease, accounting for approximately two thirds of cases of congestive heart failure, LV dysfunction often is not the result of irreversible scar but rather caused by impairment in function and energy use of still viable-myocytes, with the opportunity for improved function if coronary blood flow is restored. Patients with LV dysfunction who have viable myocardium are the patients at highest risk because of the potential for ischemia but at the same time benefit most from revascularization. It is important to identify viable myocardium in these patients, and radionuclide myocardial scintigraphy is an excellent tool for this. Single-photon emission computed tomography perfusion scintigraphy, whether using thallium-201, Tc-99m sestamibi, or Tc-99m tetrofosmin, in stress and/or rest protocols, has consistently been shown to be an effective modality for identifying myocardial viability and guiding appropriate management. Metabolic imaging with positron emission tomography radiotracers frequently adds additional information and is a powerful tool for predicting which patients will have an improved outcome from revascularization, including some patients referred instead for cardiac transplantation. Other noninvasive modalities, such as stress echocardiography, also facilitate the assessment of myocardial viability, but there are advantages and disadvantages compared with the nuclear techniques. Nuclear imaging appears to require fewer viable cells for detection, resulting in a higher sensitivity but a lower specificity than stress echocardiography for predicting post-revascularization improvement of ventricular function. Nevertheless, it appears that LV functional improvement may not always be necessary for clinical improvement. Future directions include use of magnetic resonance imaging, as well as larger, multicenter trials of radionuclide techniques. The increasing population of patients with LV dysfunction, and the increased benefit afforded by newer therapies, will make assessment of myocardial viability even more essential for proper patient management.

Stress echocardiography for the diagnosis and risk stratification of patients with suspected or known coronary artery disease: a critical appraisal. Supported by the British Society of Echocardiography

Stress echocardiography today has matured into a robust and reliable technique not only for the diagnosis of suspected coronary artery disease (CAD) but also for the accurate risk stratification of patients with suspected and established CAD. This is mainly because of rapid advances in image acquisition, digital display, and the development of harmonic and contrast imaging. Stress echocardiography today is also utilised in patients with heart failure both for assessing the cause of heart failure and determining the extent of hibernating myocardium. With advances in myocardial perfusion imaging, stress echocardiography now allows simultaneous assessment of myocardial function and perfusion. Tissue Doppler imaging allows quantitation of wall motion. Ready availability and reliability makes stress echocardiography a cost effective technique for the assessment of CAD.

Clinical decision-making and myocardial viability: current perspectives

Not all myocardium involved in a myocardial infarction is dead or irreversibly damaged. The balance between the amount of scar and live tissue, and the nature of the live tissue, determine the likelihood that contractile function will improve after revascularisation. This improvement (which defines viability) may be predicted with about 80% accuracy using several techniques. This review examines the determinants of functional recovery and how they may be integrated in making decisions regarding revascularisation.

Myocardial metabolic manipulation: a new therapeutic approach in heart failure?

Myocardial metabolic manipulation using drugs such as trimetazidine may offer a new therapeutic approach to the treatment of heart failure.

Coronary artery disease and prevention of heart failure

Coronary artery disease is a major contributor to the progression of left ventricular systolic dysfunction and heart failure (HF). Recognizing that coronary artery disease is a leading cause of HF in the United States is critical to reducing mortality resulting from this condition. Although some patients may be candidates for mechanical revascularization to improve left ventricular function, all patients are candidates for aggressive secondary prevention strategies. This review discusses the prevalence of coronary artery disease, prognostic significance and pathophysiology, risk factor modifications, pharmacologic treatments, and the role of revascularization.