Myocardial Viability and Long-Term Outcomes in Ischemic Cardiomyopathy

Revascularization and outcomes in ischaemic left ventricular dysfunction after heart failure admission: The RevascHeart study

AIMS

Despite numerous trials on revascularization in patients with heart failure (HF) and ischaemic left ventricular (LV) dysfunction, its role remains unsettled. Guideline-directed medical therapy (GDMT) for HF has shown benefits on outcomes. This multicentre study aims to compare long-term mortality between revascularization and GDMT in patients with ischaemic LV dysfunction following admission for HF.

METHODS AND RESULTS

Between 2012 and 2023, 408 patients admitted for HF with a LV ejection fraction (LVEF) of 40% or less and documented coronary artery disease (CAD) were included. Patients were categorized into two groups based on their initial treatment decision: revascularization (percutaneous coronary intervention [PCI] or coronary artery bypass graft [CABG]) or GDMT. The primary outcome was rate of all-cause or cardiovascular mortality, and secondary outcomes included type of revascularization (PCI vs. CABG) and LV reverse remodelling. After a median 44.6-month follow-up, 100 patients (33%) died in the revascularization group, compared to 44 (43%) in the GDMT group. Multivariate analysis showed no significant benefit of revascularization on all-cause mortality (hazard ratio [HR] 0.81, 95% confidence interval [CI] 0.48-1.39, p = 0.45) or cardiovascular mortality (HR 0.97, 95% CI 0.62-1.52, p = 0.90) compared to GDMT. Neither CABG (HR 0.74, 95% CI 0.51-1.08, p = 0.13) nor PCI (HR 0.98, 95% CI 0.62-1.55, p = 0.93) demonstrated a mortality reduction compared to GDMT. Both groups experienced significant reductions in LV size and improvements in LVEF, greater in the revascularization group.

CONCLUSION

Revascularization did not outperform GDMT in ischaemic LV dysfunction following HF admission in this retrospective analysis. Larger prospective studies are needed to clarify the potential role of revascularization in improving outcomes.

Myocardial viability assessment during Impella support with 18-fluorodesoxyglucose PET imaging

Formal assessment of myocardial viability (MV) is challenging in acute myocardial infarction-related cardiogenic shock (AMI-CS) patients receiving Impella mechanical circulatory support, as the cardiac magnetic resonance gold standard technique is not feasible due to the metallic components of the device. 18-fluorodesoxyglucose metabolic myocardial positron emission tomography (18FDG-PET) may represent a valid and feasible alternative to obtain semi-quantitative and objective evidence of MV during Impella support. We hereby report the first series of sequential AMI-CS patients who received 18FDG-PET scanning to assess MV during Impella support to demonstrate the safety and feasibility of this approach. In this cohort no adverse events occurred during 18FDG-PET scans, and all images were of excellent quality. This study provides a pragmatic guidance on how to perform this imaging modality during Impella support and finally confirms the safety and feasibility of this advanced imaging method also in this vulnerable cohort of patients.

Clinical impact of multimodality assessment of myocardial viability

Coronary artery disease (CAD) is a prevalent cause of left ventricular dysfunction. Nevertheless, effective elective revascularization, particularly surgical revascularization, can enhance long-term outcomes and, in selected cases, global left ventricular contractility. The assessment of myocardial viability and scars is still relevant in guiding treatment decisions and selecting patients who are likely to benefit most from blood flow restoration. Although the most recent randomized studies challenge the notion of "hibernating myocardium" and the clinical usefulness of assessing myocardial viability, the advancement of imaging techniques still renders this assessment valuable in specific situations. According to the guidelines of the European Society of Cardiology, non-invasive stress imaging may be employed to define myocardial ischemia and viability in patients with CAD and heart failure before revascularization. Currently, several non-invasive imaging techniques are available to evaluate the presence and extent of viable myocardium. The selection of the most suitable technique should be based on the patient, clinical context, and resource availability. This narrative review evaluates the characteristics of available imaging modalities for assessing myocardial viability to determine the most appropriate therapeutic strategy.

Assessment of Myocardial Viability in Ischemic Cardiomyopathy With Reduced Left Ventricular Function Undergoing Coronary Artery Bypass Grafting

BACKGROUND

We aim to provide a comprehensive review of the current state of knowledge of myocardial viability assessment in patients undergoing coronary artery bypass grafting (CABG), with a focus on the clinical markers of viability for each imaging modality. We also compare mortality between patients with viable myocardium and those without viability who undergo CABG.

METHODS

A systematic database search with meta-analysis was conducted of comparative original articles (both observations and randomized controlled studies) of patients undergoing CABG with either viable or nonviable myocardium, in EMBASE, MEDLINE, Cochrane database, and Google Scholar, from inception to 2022. Imaging modalities included were dobutamine stress echocardiography (DSE), cardiac magnetic resonance (CMR), single-photon emission computed tomography (SPECT), and positron emission tomography (PET).

RESULTS

A total of 17 studies incorporating a total of 2317 patients were included. Across all imaging modalities, the relative risk of death post-CABG was reduced in patients with versus without viability (random-effects model: odds ratio: 0.42; 95% confidence interval: 0.29-0.61; p < 0.001). Imaging for myocardial viability has significant clinical implications as it can affect the accuracy of the diagnosis, guide treatment decisions, and predict patient outcomes. Generally, based on local availability and expertise, either SPECT or DSE should be considered as the first step in evaluating viability, while PET or CMR would provide further evaluation of transmurality, perfusion metabolism, and extent of scar tissue.

CONCLUSION

The assessment of myocardial viability is an essential component of preoperative evaluation in patients with ischemic heart disease undergoing surgical revascularization. Careful patient selection and individualized assessment of viability remain paramount.

Surgical Management of Ischemic Cardiomyopathy Patients with Severe Left Ventricular Dysfunction: Is It Time to Reconsider Revascularization Surgery?

Ischemic cardiomyopathy patients with severe left ventricular dysfunction are a specific group of patients with poor surgical outcomes. There are few surgical treatment options in practice for the treatment of these patients such as heart transplantation, coronary artery bypass surgery, surgical ventricular restoration, etc. Despite multiple treatment options, there are no explicit clinical guidelines available to guide surgeons in choosing the most appropriate option and ensuring that the specific patient can benefit from the selected surgical treatment. Heart transplantation is the gold standard treatment for ischemic cardiomyopathy patients with severe left ventricular dysfunction, but it is limited to very few highly equipped centers around the world due to donor shortages, complex perioperative and surgical management, and limited technological and human resources. It is evident from some studies that heart transplant-eligible candidates can benefit from alternative surgical options such as coronary artery bypass surgery alone or combined with surgical ventricular restoration. Therefore, alternative surgical options that are used for most of the population, especially in developing and underdeveloped countries, need to be discussed to improve their outcomes. A challenge in the recent era which has yet to find a solution is to determine which heart transplant candidate can benefit from simple revascularization compared to a complex heart transplantation procedure. Myocardial viability testing was one of the most important determinants in deciding whether a patient should undergo revascularization, but its role in guiding appropriate surgical options has been challenged. This review aims to discuss the available surgical management options and their long-term outcomes for patients with ischemic cardiomyopathy, which will eventually help surgeons when choosing a surgical procedure.

82-rubidium positron emission tomography determined myocardial flow reserve and outcomes following cardiac revascularisation - A multicentre registry study

BACKGROUND

Finding patients with chronic coronary syndromes (CCS) whom revascularization could benefit, is complicated. Myocardial flow reserve (MFR), a measurement of myocardial perfusion, has proven prognostic value on survival and risk of major adverse cardiac events (MACE). We investigated if MFR identifies who may benefit from revascularization.

METHODS

Among 7462 patients from Danish hospitals examined with 82Rb PET between January 2018 and August 2020, patients with ≥5% reversible perfusion defects were followed for MACE and all-cause mortality. Associations between revascularisation (within 90 days) and outcomes according to MFR (< and ≥ 2) was assessed by Cox regression adjusted by inverse probability weighting for demographics, cardiovascular risk factors, comorbidities, and 82Rb PET variables.

RESULTS

Of 1806 patients with ≥5% reversible perfusion defect, 893 (49%) had MFR < 2 and 491 underwent revascularisation (36.6% in MFR < 2 versus 17.9% MFR ≥ 2, p < 0.001). During a median follow-up of 37.0 [31.0-45.8 IQR] months, 251 experienced a MACE and 173 died. Revascularisation was associated with lower adjusted risk of all-cause mortality (hazard ratio [HR], 0.51 [95% CI, 0.30-0.88], p = 0.015) and MACE (HR, 0.54 [0.33-0.87], p = 0.012) in patients with MFR < 2 but not MFR ≥ 2 for all-cause mortality (HR 1.33 [0.52-3.40], p = 0.542) and MACE (HR 1.50 [0.79-2.84], p = 0.211). MFR significantly modified the association between revascularisation and MACE, but not all-cause mortality (interaction p-value 0.021 and 0.094, respectively).

CONCLUSIONS

Revascularization was associated with improved prognosis among patients with impaired MFR. No association was seen in patients with normal MFR. In patients with regional ischemia, MFR may identify patients with a prognostic benefit from revascularization.

SUVmean ratios of liver/muscle and lung/muscle from 13N-NH3 PET perfusion outperformed traditional myocardial viability parameters in predicting survival after CABG

PURPOSE

Myocardial viability evaluation in predicting survival after coronary artery bypass graft (CABG) remains debatable. Thus, this study aimed to investigate the role of 13N-NH3/18F-FDG PET myocardial viability scan in predicting treatment outcomes and survival.

METHODS

90 patients with CABG and pre-surgical PET-based myocardial viability scan were retrospectively reviewed. Perfusion-metabolism features, myocardium motion parameters, and patient characteristics were recorded. Additionally, the SUVmean of blood pool, lung, liver, spleen, and muscle were measured and the SUVmean ratios were calculated. Factors associated with treatment outcomes and survival were analyzed by Logistic and Cox regressions. Nomogram models were subsequently established to predict ejection fraction (EF) improvement and survival outcomes.

RESULTS

The mean EF of these 90 patients was 38.1 ± 9.5% and 46.0 ± 9.2% before and after CABG surgery, and 35 patients (38.9%) achieved EF improvement ≥ 10%. EF measurements by PET and echocardiogram showed a reasonable linear correlation (R = 0.752). Sex, pre-surgical EF, mismatch of the left ventricle, total perfusion deficit (TPD), and peak ejection rate (PER) were independent predictive factors of EF improvements. Surgery waiting time, valve damage, and SUVmean ratio of Liver/Muscle were independently predictive of event-free survival (EFS), while valve damage, together with SUVmean ratio of either Liver/Muscle or Lung/Muscle, were independently predictive of overall survival (OS).

CONCLUSION

Although traditional cardiac parameters from PET-based myocardial viability can effectively predict EF improvements after CABG, SUVmean ratios of liver/muscle and lung/muscle from 13N-NH3 PET perfusion outperformed these parameters in predicting survival.

Medical Decision-Making and Revascularization in Ischemic Cardiomyopathy

Ischemic cardiomyopathy (ICM) is the most common underlying etiology of heart failure in the United States and is a significant contributor to deaths due to cardiovascular disease worldwide. The diagnosis and management of ICM has advanced significantly over the past few decades, and the evidence for medical therapy in ICM is both compelling and robust. This contrasts with evidence for coronary revascularization, which is more controversial and favors surgical approaches. This review will examine landmark clinical trial results in detail as well as provide a comprehensive overview of the current epidemiology, diagnostic approaches, and management strategies of ICM.

Coronary microvascular dysfunction: prevalence and aetiology in patients with suspected myocardial ischaemia

AIM

To evaluate the prevalence, aetiology, and corresponding morbidity of coronary microvascular dysfunction (CMD) in patients with suspected myocardial ischaemia.

MATERIALS AND METHODS

The present study included 115 patients with suspected myocardial ischaemia who underwent stress perfusion cardiac magnetic resonance imaging. CMD was assessed visually based on the myocardial perfusion results. The CMR-derived myocardial perfusion reserve index (MPRI) and left ventricular (LV) strain parameters obtained using the post-processing software CVI42 were employed to evaluate LV myocardial perfusion and deformation. LV strain parameters included global longitudinal, circumferential, and radial strain (GLS, GCS, and GRS), global systolic/diastolic longitudinal, circumferential, and radial strain rates (SLSR, SCSR, SRSR, DLSR, DCSR, and DRSR).

RESULTS

Of the 115 patients, 12 patients were excluded and 103 patients were finally included in the study. CMD was observed in 79 % (81 patients, aged 53 ± 12 years) of patients. Regarding aetiology, 91 (88 %) patients had non-obstructive coronary artery disease (CAD), eight (8 %) had obstructive CAD, and four (4 %) had hypertrophic cardiomyopathy (HCM). The incidence of CMD was highest (100 %) in patients with HCM, followed by those with non-obstructive CAD (up to 79 %). There were no statistical differences between CMD and non-CMD groups in GCS, GRS, GLS, SRSR, SCSR, SLSR, DCSR, DRSR and DLSR.

CONCLUSION

The incidence of CMD was higher in patients with signs and symptoms of ischaemia. CMD occurred with non-obstructive CAD, obstructive CAD, and HCM, with the highest prevalence of CMD in HCM.

Selecting the appropriate patients for coronary artery bypass grafting in ischemic cardiomyopathy-importance of myocardial viability

Patients who undergo coronary artery bypass graft (CABG) surgery in ischemic cardiomyopathy have a survival advantage over medical therapy at 10 years. The survival advantage of CABG over medical therapy is due to its ability to reduce future myocardial infarction, and by conferring electrical stability. The presence of myocardial viability does not provide a differential survival advantage for CABG over medical therapy. Presence of angina and inducible ischemia are also less predictive of outcome. Moreover, CABG is associated with significant early mortality. Hence, careful patient selection is more important for reducing the early mortality and improving the long-term outcome than relying on results of myocardial viability. Younger patients with good exercise tolerance benefit the most, while patients who are frail and patients with renal dysfunction and dysfunctional right ventricle seem to have very high operative mortality. Elderly patients, because of poor life expectancy, do not benefit from CABG, but the age cutoff is not clear. Patients also need to have revascularizable targets, but this decision is often based on experience of the surgical team and heart team discussion. These recommendations are irrespective of the myocardial viability tests. Optimal medical treatment remains the cornerstone for management of ischemic cardiomyopathy.

Myocardial viability on trial

The concept of myocardial viability is usually referred to areas of the myocardium, which show contractile dysfunction at rest and in which contractility is expected to improve after revascularization. The traditional paradigm states that an improvement in function after revascularization leads to improved health outcomes and that assessment of myocardial viability in patients with ischaemic left ventricular dysfunction (ILVD) is a prerequisite for clinical decisions regarding treatment. A range of retrospective observational studies supported this 'viability hypothesis'. However, data from prospective trials have diverged from earlier retrospective studies and challenge this hypothesis. Traditional binary viability assessment may oversimplify ILVD's complexity and the nuances of revascularization benefits. A conceptual shift from the traditional paradigm centred on the assessment of viability as a dichotomous variable to a more comprehensive approach encompassing a thorough understanding of ILVD's complex pathophysiology and the salutary effect of revascularization in the prevention of myocardial infarction and ventricular arrhythmias is required.

Stem Cell Therapy against Ischemic Heart Disease

Ischemic heart disease, which is one of the top killers worldwide, encompasses a series of heart problems stemming from a compromised coronary blood supply to the myocardium. The severity of the disease ranges from an unstable manifestation of ischemic symptoms, such as unstable angina, to myocardial death, that is, the immediate life-threatening condition of myocardial infarction. Even though patients may survive myocardial infarction, the resulting ischemia-reperfusion injury triggers a cascade of inflammatory reactions and oxidative stress that poses a significant threat to myocardial function following successful revascularization. Moreover, despite evidence suggesting the presence of cardiac stem cells, the fact that cardiomyocytes are terminally differentiated and cannot significantly regenerate after injury accounts for the subsequent progression to ischemic cardiomyopathy and ischemic heart failure, despite the current advancements in cardiac medicine. In the last two decades, researchers have realized the possibility of utilizing stem cell plasticity for therapeutic purposes. Indeed, stem cells of different origin, such as bone-marrow- and adipose-derived mesenchymal stem cells, circulation-derived progenitor cells, and induced pluripotent stem cells, have all been shown to play therapeutic roles in ischemic heart disease. In addition, the discovery of stem-cell-associated paracrine effects has triggered intense investigations into the actions of exosomes. Notwithstanding the seemingly promising outcomes from both experimental and clinical studies regarding the therapeutic use of stem cells against ischemic heart disease, positive results from fraud or false data interpretation need to be taken into consideration. The current review is aimed at overviewing the therapeutic application of stem cells in different categories of ischemic heart disease, including relevant experimental and clinical outcomes, as well as the proposed mechanisms underpinning such observations.

Identifying and mitigating risk of postcardiotomy cardiogenic shock in patients with ischemic and nonischemic cardiomyopathy

OBJECTIVES

To identify preoperative predictors of postcardiotomy cardiogenic shock in patients with ischemic and nonischemic cardiomyopathy and evaluate trajectory of postoperative ventricular function.

METHODS

From January 2017 to January 2020, 238 patients with ejection fraction <30% (206/238) or 30% to 34% with at least moderately severe mitral regurgitation (32/238) underwent conventional cardiac surgery at Cleveland Clinic, 125 with ischemic and 113 with nonischemic cardiomyopathy. Preoperative ejection fraction was 25 ± 4.5%. The primary outcome was postcardiotomy cardiogenic shock, defined as need for microaxial temporary left ventricular assist device, extracorporeal membrane oxygenation, or vasoactive-inotropic score >25. RandomForestSRC was used to identify its predictors.

RESULTS

Postcardiotomy cardiogenic shock occurred in 27% (65/238). Pulmonary artery pulsatility index <3.5 and pulmonary capillary wedge pressure >19 mm Hg were the most important factors predictive of postcardiotomy cardiogenic shock in ischemic cardiomyopathy. Cardiac index <2.2 L·min-1 m-2 and pulmonary capillary wedge pressure >21 mm Hg were the most important predictive factors in nonischemic cardiomyopathy. Operative mortality was 1.7%. Ejection fraction at 12 months after surgery increased to 39% (confidence interval, 35-40%) in the ischemic group and 37% (confidence interval, 35-38%) in the nonischemic cardiomyopathy group.

CONCLUSIONS

Predictors of postcardiotomy cardiogenic shock were different in ischemic and nonischemic cardiomyopathy. Right heart dysfunction, indicated by low pulmonary artery pulsatility index, was the most important predictor in ischemic cardiomyopathy, whereas greater degree of cardiac decompensation was the most important in nonischemic cardiomyopathy. Therefore, preoperative right heart catheterization will help identify patients with low ejection fraction who are at greater risk of postcardiotomy cardiogenic shock.

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.

Cell Therapy Improves Quality-of-Life in Heart Failure: Outcomes From a Phase III Clinical Trial

Patients with heart failure experience limitations in daily activity and poor quality-of-life. Prospective surveillance of health-related quality-of-life supplemented traditional death and hospitalization outcomes in the multinational, randomized, double-blinded CHART-1 clinical trial that assessed cardiopoiesis-guided cell therapy in ischemic heart failure patients with reduced left ventricular ejection fraction. The Minnesota Living with Heart Failure Questionnaire (MLHFQ), a Food and Drug Administration qualified instrument for evaluating therapeutic effectiveness, was applied through the 1-year follow-up. Cell treated (n = 109) and sham procedure (n = 140) cohorts reported improved MLHFQ scores comparable between the 2 study arms (mean treatment difference with baseline adjustment -3.2 points, P = .107). Superiority of cell treatment over sham in betterment of the MLHFQ score was demonstrated in patients with pre-existing advanced left ventricular enlargement (baseline-adjusted mean treatment difference -6.4 points, P = .009). In this highly responsive subpopulation, benefit on the MLHFQ score paralleled reduction in death and hospitalization post-cell therapy (adjusted Mann-Whitney odds 1.43, 95% CI, 1.01-2.01; P = .039). The potential of cell therapy in addressing the quality-of-life dimension of heart failure requires further evaluation for disease relief.

A review of the conservative versus invasive management of ischemic heart failure with reduced ejection fraction

Heart failure is increasing in terms of prevalence, morbidity, and mortality rates. Clinical trials and studies are focusing on heart failure as it is the destiny end-stage for several cardiovascular disorders. Recently, medical therapy has dramatically progressed with novel classes of medicines providing better quality of life and survival outcomes. However, heart failure remains a heavy impactful factor on societies and populations. Current guidelines from the American and European cardiac societies are not uniform with respect to the class and level of treatment recommendations for coronary artery disease patients with heart failure and reduced ejection fraction. The discrepancy among international recommendations, stemming from the lack of evidence from adequately powered randomized trials, challenges physicians in choosing the optimal strategy. Hybrid therapy including optimal medical therapy with revascularization strategies are commonly used for the management of ischemic heart failure. Coronary artery bypass graft (CABG) has proved its efficacy on improving long term outcome and prognosis while no large randomized clinical trials for percutaneous coronary intervention (PCI) are still available. Regardless of the lack of data and recommendations, the trends of performing PCI in ischemic heart failure prevailed over CABG whereas lesion complexity, chronic total occlusion and complete revascularization achievement are limiting factors. Lastly, regenerative medicine seems a promising approach for advanced heart failure enhancing cardiomyocytes proliferation, reverse remodeling, scar size reduction and cardiac function restoration.

Myocardial ischemia/reperfusion: Translational pathophysiology of ischemic heart disease

Ischemic heart disease is the greatest health burden and most frequent cause of death worldwide. Myocardial ischemia/reperfusion is the pathophysiological substrate of ischemic heart disease. Improvements in prevention and treatment of ischemic heart disease have reduced mortality in developed countries over the last decades, but further progress is now stagnant, and morbidity and mortality from ischemic heart disease in developing countries are increasing. Significant problems remain to be resolved and require a better pathophysiological understanding. The present review attempts to briefly summarize the state of the art in myocardial ischemia/reperfusion research, with a view on both its coronary vascular and myocardial aspects, and to define the cutting edges where further mechanistic knowledge is needed to facilitate translation to clinical practice.

Programmatic approach to patients with advanced ischemic cardiomyopathy: Integrating microaxial support into strategies for the modern era

Patients with advanced ischemic cardiomyopathy manifesting as left ventricular dysfunction exist along a spectrum of severity and risk, and thus decision-making surrounding optimal management is challenging. Treatment pathways can include medical therapy as well as revascularization through percutaneous coronary intervention or coronary artery bypass grafting. Additionally, temporary and durable mechanical circulatory support, as well as heart transplantation, may be optimal for select patients. Given this spectrum of risk and the complexity of treatment pathways, patients may not receive appropriate therapy given their perceived risk, which can lead to sub-satisfactory outcomes. In this review, we discuss the identification of high-risk ischemic cardiomyopathy patients, along with our programmatic approach to patient evaluation and perioperative optimization. We also discuss our strategies for therapeutic decision-making designed to optimize both short- and long-term patient outcomes.

Long-term survival of ischemic cardiomyopathy patients with severe left ventricular dysfunction after CABG vs heart transplantation: A single center retrospective analysis

BACKGROUND

There are no guidelines on the surgical management for ischemic cardiomyopathy (ICM) patients with severe left ventricular dysfunction. The present study aims to assess the long-term survival of these patients treated with two different surgical techniques, coronary artery bypass grafting (CABG) and heart transplantation (HTx).

METHODS

This retrospective study included 218 ICM patients with left ventricular ejection fraction (LVEF) ≤35% who underwent CABG (n = 106) and HTx (n = 112) from 2011 to 2021 in a single center. After propensity adjustment analysis each group consisted of 51 patients. Clinical characteristics were evaluated for all-cause follow-up mortality by the Cox proportional hazards regression model. A risk prediction model was generated from multivariable-adjusted Cox regression analysis and applied to stratify patients with different clinical risks. The long-term survival was estimated by Kaplan-Meier analysis for different surgery groups.

RESULTS

Long-term survival was comparable between CABG and HTx groups. After being stratified into different risk subgroups according to risk predictors, the HTx group exhibited superior survival outcomes compared to the CABG group among the high-risk patients (67.8% vs 44.4%, 64.1% vs 38.9%, and 64.1% vs 33.3%, p = 0.047) at 12, 36, and 60 months respectively, while the survival was comparable between HTx and CABG groups among low-risk patients (87.0% vs 97.0%, 82.4% vs 97.0%, and 70.2% vs 91.6%, p = 0.11) at 12, 36, and 60 months respectively in the PSM cohort.

CONCLUSION

Long-term survival in ICM patients with severe left ventricular dysfunction who received CABG or HTx was comparable in general. Nonetheless, a favorable outcome of HTx surgery compared to CABG was observed among high-risk patients.

Comparison of cardiac magnetic resonance imaging and fluorodeoxyglucose positron emission tomography in the assessment of myocardial viability: meta-analysis and systematic review

AIM

Contrast-enhanced cardiac magnetic resonance (Ce-CMR) and Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) are frequently utilized in clinical practice to assess myocardial viability. However, studies evaluating direct comparison between Ce-CMR and FDG-PET have a smaller sample size, and no clear distinction between the two imaging modalities has been defined. To address this gap, we conducted a meta-analysis of studies comparing Ce-CMR and FDG-PET for the assessment of myocardial viability.

METHODS

We searched PubMed, EMBASE, Scopus, and Web of Science databases from their inception to 4/20/2022 with search terms "viability" AND "heart diseases" AND "cardiac magnetic resonance imaging" AND "positron-emission tomography." We extracted patient characteristics, segment level viability assessment according to Ce-CMR and FDG-PET, and change in regional wall motion abnormalities (RWMA) at follow-up.

RESULTS

We included four studies in the meta-analysis which provided viability assessment with Ce-CMR and FDG-PET in all patients and change in RWMA at follow-up. There were 82 patients among the four included studies, and 585 segments were compared for viability assessment. There were 59 (72%) males, and mean age was 65 years. The sensitivity (95% confidence interval-CI) and specificity (CI) of Ce-CMR for predicting myocardial recovery were 0.88 (0.66-0.96) and 0.64 (0.49-0.77), respectively. The sensitivity (CI) and specificity (CI) of FDG-PET for predicting myocardial recovery were 0.91 (0.63-0.99) and 0.67 (0.49-0.81), respectively.

CONCLUSION

FDG-PET and Ce-CMR have comparable diagnostic parameters in myocardial viability assessment and are consistent with prior research.

Viability and Outcomes With Revascularization or Medical Therapy in Ischemic Ventricular Dysfunction: A Prespecified Secondary Analysis of the REVIVED-BCIS2 Trial

Importance

In the Revascularization for Ischemic Ventricular Dysfunction (REVIVED-BCIS2) trial, percutaneous coronary intervention (PCI) did not improve outcomes for patients with ischemic left ventricular dysfunction. Whether myocardial viability testing had prognostic utility for these patients or identified a subpopulation who may benefit from PCI remained unclear.

Objective

To determine the effect of the extent of viable and nonviable myocardium on the effectiveness of PCI, prognosis, and improvement in left ventricular function.

Design, Setting, and Participants

Prospective open-label randomized clinical trial recruiting between August 28, 2013, and March 19, 2020, with a median follow-up of 3.4 years (IQR, 2.3-5.0 years). A total of 40 secondary and tertiary care centers in the United Kingdom were included. Of 700 randomly assigned patients, 610 with left ventricular ejection fraction less than or equal to 35%, extensive coronary artery disease, and evidence of viability in at least 4 myocardial segments that were dysfunctional at rest and who underwent blinded core laboratory viability characterization were included. Data analysis was conducted from March 31, 2022, to May 1, 2023.

Intervention

Percutaneous coronary intervention in addition to optimal medical therapy.

Main Outcomes and Measures

Blinded core laboratory analysis was performed of cardiac magnetic resonance imaging scans and dobutamine stress echocardiograms to quantify the extent of viable and nonviable myocardium, expressed as an absolute percentage of left ventricular mass. The primary outcome of this subgroup analysis was the composite of all-cause death or hospitalization for heart failure. Secondary outcomes were all-cause death, cardiovascular death, hospitalization for heart failure, and improved left ventricular function at 6 months.

Results

The mean (SD) age of the participants was 69.3 (9.0) years. In the PCI group, 258 (87%) were male, and in the optimal medical therapy group, 277 (88%) were male. The primary outcome occurred in 107 of 295 participants assigned to PCI and 114 of 315 participants assigned to optimal medical therapy alone. There was no interaction between the extent of viable or nonviable myocardium and the effect of PCI on the primary or any secondary outcome. Across the study population, the extent of viable myocardium was not associated with the primary outcome (hazard ratio per 10% increase, 0.98; 95% CI, 0.93-1.04) or any secondary outcome. The extent of nonviable myocardium was associated with the primary outcome (hazard ratio, 1.07; 95% CI, 1.00-1.15), all-cause death, cardiovascular death, and improvement in left ventricular function.

Conclusions and Relevance

This study found that viability testing does not identify patients with ischemic cardiomyopathy who benefit from PCI. The extent of nonviable myocardium, but not the extent of viable myocardium, is associated with event-free survival and likelihood of improvement of left ventricular function.

Trial Registration

ClinicalTrials.gov Identifier: NCT01920048.

Echocardiographic functional determinants of survival in heart failure with abnormal ejection fraction

Background and Aims

Patients with heart failure (HF) with reduced left ventricular (LV) ejection fraction (EF) have a heterogeneous prognosis, and assessment of coronary physiology with coronary flow velocity (CFV) and coronary flow velocity reserve (CFVR) may complement established predictors based on wall motion and EF.

Methods and results

In a prospective multicenter study design, we enrolled 1,408 HF patients (age 66 ± 12 years, 1,035 men), with EF <50%, 743 (53%) with coronary artery disease, and 665 (47%) with normal coronary arteries. Recruitment (years 2004-2022) involved 8 accredited laboratories, with inter-observer variability <10% for CFV measurement. Baseline CFV (abnormal value >31 cm/s) was obtained by pulsed-wave Doppler in mid-distal LAD. CFVR (abnormal value ≤2.0) was assessed with exercise (n = 99), dobutamine (n = 100), and vasodilator stress (dipyridamole in 1,149, adenosine in 60). Inducible myocardial ischemia was identified with wall motion score index (WMSI) stress > rest (cut-off Δ ≥ 0.12). LV contractile reserve (CR) was identified with WMSI stress < rest (cutoff Δ ≥ 0.25). Test response ranged from score 0 (EF > 30%, CFV ≥ 32 cm/s, CFVR > 2.0, LVCR present, ischemia absent) to score 5 (all steps abnormal). All-cause death was the only endpoint. Results. During a median follow-up of 990 days, 253 patients died. Independent predictors of death were EF (HR: 0.956, 95% CI: 0.943-0.968, p < 0.0001), CFV (HR: 2.407, 95% CI: 1.871-3.096, p < 0.001), CFVR (HR: 3.908, 95% CI: 2.903-5.260, p < 0.001), stress-induced ischemia (HR: 2.223, 95% CI: 1.642-3.009, p < 0.001), and LVCR (HR: 0.524, 95% CI: 0.324-.647, p = 0.008). The annual mortality rate was lowest (1.2%) in patients with a score of 0 (n = 61) and highest (31.9%) in patients with a score of 5 (n = 15, p < 0.001).

Conclusion

High resting CFV is associated with worse survival in ischemic and nonischemic HF with reduced EF. The value is independent and additive to resting EF, CFVR, LVCR, and inducible ischemia.

Coronary artery bypass grafting in left ventricular dysfunction: when and how

PURPOSE OF REVIEW

The surgical management of patients undergoing coronary artery bypass grafting (CABG) with low ejection fraction presents unique challenges that require meticulous attention to details and good surgical technique and judgement. This review details the latest evidence and best practices in the care of such patients.

RECENT FINDINGS

CABG in patients with low ejection fraction carries a significant risk of perioperative mortality and morbidity related to the development of postcardiotomy shock. Preoperative optimization with pharmacological or mechanical support is required, especially in patients with cardiogenic shock. Rapid and complete revascularization is what CABG surgeons aim to achieve. Multiple arterial revascularization should be reserved to selected patients. Off-pump CABG, on-pump breathing heart CABG, and new cardioplegic solutions remain of uncertain benefit compared with traditional CABG.

SUMMARY

Tremendous advancements in CABG allowed surgeons to offer revascularization to patients with severe left ventricular dysfunction and multivessel disease with acceptable risk. Despite that, there is a lack of comprehensive and robust studies particularly on long-term outcomes. Individualized patient assessment and a heart team approach should be used to determine the optimal surgical strategy for each patient.

Current Landscape and Future Directions of Coronary Revascularization in Ischemic Systolic Heart Failure: A Review

Ischemic heart disease is the largest cause of death worldwide and the most common cause of heart failure (HF). The incidence and prevalence of HF are increasing owing to an aging population and improvements in the acute cardiac care of previously fatal conditions such as myocardial infarction. Strategies to improve outcomes in patients with ischemic systolic HF are urgently needed. There is systematic underutilization of testing for coronary artery disease in patients with HF, and revascularization is performed in an even smaller minority despite evidence for reduced mortality with coronary artery bypass grafting (CABG) over medical therapy in the Surgical Treatment for Ischemic Heart Failure Extension Study. Percutaneous coronary intervention (PCI) is a less-invasive approach to coronary revascularization; however, the recent Revascularization for Ischemic Ventricular Dysfunction (REVIVED)-British Cardiovascular Intervention Society (BCIS2) trial failed to demonstrate a benefit of PCI compared with that of medical therapy in patients with ischemic systolic HF. The comparative effectiveness of PCI and CABG for patients with ischemic systolic HF remains unknown, particularly in the era of contemporary medical therapy. In this review, we discuss the benefit of CABG in ischemic systolic HF, its underutilization, and the unmet clinical need. We also review the recent REVIVED-BCIS2 trial comparing PCI to medical therapy, as well as upcoming randomized controlled trials of PCI for ischemic systolic HF and persistent evidence gaps that will exist despite anticipated data from ongoing trials. There remains a need for an adequately powered randomized controlled trials to establish the comparative clinical effectiveness of PCI vs CABG in ischemic systolic HF in the era of contemporary revascularization approaches and medical therapy, as well as trials of coronary revascularization in patients with HF with preserved ejection fraction or less severe forms of left ventricular systolic dysfunction.

Understanding the role of coronary artery revascularization in patients with left ventricular dysfunction and multivessel disease

Coronary artery disease (CAD) is the most common cause of heart failure with reduced ejection fraction (HFrEF). Advances and innovations in medical therapy have been shown to play a crucial role in improving the prognosis of patients with CAD and HFrEF; however, mortality rate in these patients remains high, and the role of surgical and/or percutaneous revascularization strategy is still debated. The Surgical Treatment for Ischemic Heart Failure (STICH) trial and the Revascularization for Ischemic Ventricular Dysfunction (REVIVED) trial have attempted to provide an answer to this issue. Nevertheless, the results of these two trials have generated further uncertainties. Their findings do not provide a definitive answer about the ideal clinical phenotype for surgical or percutaneous coronary revascularization and dispute the historical dogma on myocardial viability and the theory of myocardial hibernation, raising new questions about the proper selection of patients who are candidates for coronary revascularization. The aim of this review is to provide an overview on the actual available evidence of coronary artery revascularization in patients with CAD and left ventricular dysfunction and to suggest new insights on the proper selection and management strategies in this high-risk clinical setting.

National trends in emergency coronary artery bypass grafting

OBJECTIVES

Emergency coronary artery bypass grafting (CABG) is often omitted from current research, and volumes as well as outcomes are unknown. The purpose of this research is to examine national trends in emergency CABG.

METHODS

The Society of Thoracic Surgeons national adult cardiac surgical database was queried from 2005 to 2017 for patients who underwent emergency and emergency salvage isolated CABG procedures, and 92 607 patients were included for analysis. Generalized linear mixed models were used to assess time trends, taking into account the clustering effect of region.

RESULTS

Over the study period, volumes of emergency and emergency salvage CABG declined from 7991 to 6916 cases/year. Emergency and emergency salvage cases accounted for ∼4.9% of all CABG procedures performed nationwide in 2005 and 4.1% in 2017. The predicted risk of mortality (PROM) declined in the entire patient cohort over time from 12% to 8% (P < 0.0001). Rates of important postoperative morbidities also declined including prolonged intubation, re-exploration for haemorrhage and postoperative pneumonia (P < 0.001). Observed-to-expected mortality rates rose over the study period from 0.81 to 1.06 as the overall PROM declined from 9.3% to 7.6%. Emergency salvage CABG rates also declined over the course of the study from 358 to 323 cases/year. The observed-to-expected ratios for mortality increased for emergency salvage CABG during the study from 1.16 to 1.66, and emergency salvage mortality rates averaged 46.5%.

CONCLUSIONS

The volume of patients undergoing emergency and emergency salvage CABG in the USA has declined. Increases in mortality are largely driven by emergency salvage cases, and the PROM algorithm may not accurately reflect the risk involved for these patients.

Hybrid PET/MR in Cardiac Imaging

In the last few years, technological advances in MR imaging, PET detectors, and attenuation correction algorithms have allowed the creation of truly integrated PET/MR imaging systems, for both clinical and research applications. These machines allow a comprehensive investigation of cardiovascular diseases, by offering a wide variety of detailed anatomical and functional data in combination. Despite significant pathophysiologic mechanisms being clarified by this new data, its clinical relevance and prognostic significance have not been demonstrated yet.

The Evolving Paradigm of Revascularization in Ischemic Cardiomyopathy: from Recovery of Systolic Function to Protection Against Future Ischemic Events

PURPOSE OF REVIEW

We aim to reevaluate how the assessment of myocardial viability can guide optimal treatment strategies for patients with ischemic cardiomyopathy (ICM) based on a more contemporary understanding of the mechanism of benefit of revascularization.

RECENT FINDINGS

The assessment of viability in left ventricular (LV) segments with diminished contraction has been proposed as key to predict the benefit of revascularization and, therefore, as a requisite for the selection of patients to undergo this form of treatment. However, data from prospective trials have diverged from earlier retrospective studies. Traditional binary viability assessment may oversimplify ICM's complexity and the nuances of revascularization benefits. A conceptual shift from the traditional paradigm centered on the assessment of viability as a dichotomous variable to a more comprehensive approach encompassing a thorough understanding of ICM's complex pathophysiology and the salutary effect of revascularization in the prevention of myocardial infarction and ventricular arrhythmias is required.

The Utility of Low-Dose-Dobutamine Stress Echocardiography in Patients with Heart Failure with Reduced Ejection Fraction: An Update

Despite significant advancements in medical therapy, heart failure with reduced ejection fraction (HFrEF) continues to be a significant cause of death and disability. Reversible ischaemic left ventricular dysfunction due to viable myocardium is one such contributing factor. In these cases, coronary revascularization has shown promise in improving left ventricular function and prognosis. For patients with HFrEF and wide QRS, cardiac resynchronization therapy (CRT) is an effective option to address electromechanical dyssynchrony. However, approximately 30% of patients do not respond positively to CRT, highlighting the need to refine candidate selection for this treatment. In some patients with reduced HFrEF, there is a condition known as classical low-flow, low-gradient aortic stenosis (AS) that may be observed. This condition is characterized by a low transaortic flow, which leads to reductions in both the transaortic mean gradient and aortic valve area. Decision-making regarding revascularization, CRT, and pharmacological treatment play a crucial role in managing HFrEF. Cardiac imaging can be valuable in guiding decision-making processes and assessing the prognosis of patients with HFrEF. Among the imaging modalities, dobutamine stress echocardiography has come a long way in establishing itself as a feasible, safe, effective, relatively cheap non-invasive technique. The aim of this review is to explore the current literature on the utility of low-dose stress echocardiography in diagnosing and prognosticating patients with HFrEF.

Revascularisation for Ischaemic Cardiomyopathy

Coronary artery disease is a leading cause of heart failure with reduced ejection fraction. Coronary artery bypass grafting appears to provide clinical benefits such as improvements in quality of life, reductions in readmissions and MI, and favourable effects on long-term mortality; however, there is a significant short-term procedural risk when left ventricular function is severely impaired, which poses a conundrum for many patients. Could percutaneous coronary intervention provide the same benefits without the hazard of surgery? There have been no randomised studies to support this practice until recently. The REVIVED-BCIS2 trial (NCT01920048) assessed the outcomes of percutaneous coronary intervention in addition to optimal medical therapy in patients with ischaemic left ventricular dysfunction and stable coronary artery disease. This review examines the trial results in detail, suggests a pathway for investigation and revascularisation in ischaemic cardiomyopathy, and explores some of the remaining unanswered questions.

STICH3C: Rationale and Study Protocol

BACKGROUND

Coronary artery bypass grafting (CABG) is the recommended mode of revascularization in patients with ischemic left ventricular dysfunction (iLVSD) and multivessel disease. However, contemporary percutaneous coronary intervention (PCI) outcomes have improved with the integration of novel technologies and refinement of revascularization strategies, and PCI is often used in clinical practice in this population. There is a lack of evidence from randomized trials comparing contemporary state-of-the-art PCI versus CABG for the treatment of iLVSD and multivessel disease. This was the impetus for the STICH3C trial (Canadian CABG or PCI in Patients With Ischemic Cardiomyopathy), described here.

METHODS

The STICH3C trial is a prospective, unblinded, international, multicenter trial with an expected sample size of 754 participants from ≈45 centers. Patients with multivessel/left main coronary artery disease and iLVSD with left ventricular ejection fraction ≤40% considered by the local Heart Team appropriate for and amenable to revascularization by both modes of revascularization will be randomized in a 1:1 ratio to state-of-the-art PCI or CABG.

RESULTS

The primary end point is the composite of death from any cause, stroke, spontaneous myocardial infarction, urgent repeat revascularization, or heart failure readmission, summarized as a time-to-event outcome. The key hierarchical end point is time to death and frequency of hospitalizations for heart failure. The key safety outcome is a composite of major adverse events. Disease-specific quality-of-life and health economics measures will be compared between groups. Participants will be followed for a median of 5 years, with a minimum follow-up of 4 years.

CONCLUSIONS

STICH3C will directly inform patients, clinicians, and international practice guidelines about the efficacy and safety of CABG versus PCI in patients with iLVSD. The results will provide novel and broad evidence, including clinical events, health status, and economic assessments, to guide care for patients with iLVSD and severe coronary artery disease.

REGISTRATION

URL: https://clinicaltrials.gov/; Unique identifier: NCT05427370.

Effect of atrial fibrillation on plasma galectin-3 and soluble CD40 ligand levels in patients with ischemic cardiomyopathy

OBJECTIVE

To reveal the significance of plasma galectin-3 and soluble CD40 ligand (sCD40L) levels in patients with ischemic cardiomyopathy (ICM) combined with atrial fibrillation.

METHODS

In this case-control study, the case group comprised 60 patients with ICM combined with atrial fibrillation and the control group comprised patients with ICM without atrial fibrillation. Plasma galectin-3 and sCD40L levels, left atrial diameter (LAD), left ventricular ejection fraction (LVEF), and left ventricular diameter (LVD) were compared.

RESULTS

The plasma galectin-3 and sCD40L levels, LAD, and LVD were higher and the LVEF was lower in the case than control group. In the case group, the plasma galectin-3 and sCD40L levels were positively correlated with the LAD and LVD but negatively correlated with the LVEF. The area under the receiver operating characteristic curve of the plasma galectin-3 and sCD40L levels in the diagnosis of ICM combined with atrial fibrillation was 0.857 (95% confidence interval, 0.792-0.923) and 0.724 (95% confidence interval, 0.634-0.814), respectively.

CONCLUSION

The plasma galectin-3 and sCD40L levels are significantly elevated in patients with ICM combined with atrial fibrillation. Although both may have predictive value in the diagnosis of ICM combined with atrial fibrillation, galectin-3 may have the higher predictive value.

Coronary revascularization for heart failure with coronary artery disease: A systematic review and meta-analysis of randomized trials

AIMS

Coronary artery disease (CAD) is a common cause of heart failure (HF). Whether coronary revascularization improves outcomes in patients with HF receiving guideline-recommended pharmacological therapy (GRPT) remains uncertain; therefore, we conducted a systematic review and meta-analysis of relevant randomized controlled trials (RCTs).

METHODS AND RESULTS

We searched in public databases for RCTs published between 1 January 2001 and 22 November 2022, investigating the effects of coronary revascularization on morbidity and mortality in patients with chronic HF due to CAD. All-cause mortality was the primary outcome. We included five RCTs that enrolled, altogether, 2842 patients (most aged <65 years; 85% men; 67% with left ventricular ejection fraction ≤35%). Overall, compared to medical therapy alone, coronary revascularization was associated with a lower risk of all-cause mortality (hazard ratio [HR] 0.88, 95% confidence interval [CI] 0.79-0.99; p = 0.0278) and cardiovascular mortality (HR 0.80, 95% CI 0.70-0.93; p = 0.0024) but not the composite of hospitalization for HF or all-cause mortality (HR 0.87, 95% CI 0.74-1.01; p = 0.0728). There were insufficient data to show whether the effects of coronary artery bypass graft surgery or percutaneous coronary intervention were similar or differed.

CONCLUSIONS

For patients with chronic HF and CAD enrolled in RCTs, the effect of coronary revascularization on all-cause mortality was statistically significant but neither substantial (HR 0.88) nor robust (upper 95% CI close to 1.0). RCTs were not blinded, which may bias reporting of the cause-specific reasons for hospitalization and mortality. Further trials are required to determine which patients with HF and CAD obtain a substantial benefit from coronary revascularization by either coronary artery bypass graft surgery or percutaneous coronary intervention.

Tracers for Cardiac Imaging: Targeting the Future of Viable Myocardium

Ischemic heart disease is the leading cause of mortality worldwide. In this context, myocardial viability is defined as the amount of myocardium that, despite contractile dysfunction, maintains metabolic and electrical function, having the potential for functional enhancement upon revascularization. Recent advances have improved methods to detect myocardial viability. The current paper summarizes the pathophysiological basis of the current methods used to detect myocardial viability in light of the advancements in the development of new radiotracers for cardiac imaging.

Impact of in-Hospital Left Ventricular Ejection Fraction Recovery on Long-Term Outcomes in Patients Who Underwent Impella Support for HR PCI or Cardiogenic Shock: A Sub-Analysis from the IMP-IT Registry

(1) Background: Percutaneous left ventricle assist devices (pLVADs) demonstrated an improvement in mid-term clinical outcomes in selected patients with severely depressed left ventricular ejection fraction (LVEF) undergoing percutaneous coronary interventions. However, the prognostic impact of in-hospital LVEF recovery is unclear. Accordingly, the present sub-analysis aims to evaluate the impact of LVEF recovery in both cardiogenic shock (CS) and high-risk percutaneous coronary intervention (HR PCI) supported with pLVADs in the IMP-IT registry. (2) Methods: A total of 279 patients (116 patients in CS and 163 patients in HR PCI) treated with Impella 2.5 or CP in the IMP-IT registry were included in this analysis, after excluding those who died while in the hospital or with missing data on LVEF recovery. The primary study objective was a composite of all-cause death, rehospitalisation for heart failure, left ventricle assist device (LVAD) implantation, or heart transplantation (HT), overall referred to as the major adverse cardiac events (MACE) at 1 year. The study aimed to evaluate the impact of in-hospital LVEF recovery on the primary study objective in patients treated with Impella for HR PCI and CS, respectively. (3) Results: The mean in-hospital change in LVEF was 10 ± 1% (p < 0.001) in the CS cohort and 3 ± 7% (p < 0.001) in the HR PCI group, achieved by 44% and 40% of patients, respectively. In the CS group, patients with less than 10% in-hospital LVEF recovery experienced higher rates of MACE at 1 year of follow-up (FU) (51% vs. 21%, HR 3.8, CI 1.7-8.4, p < 0.01). After multivariate analysis, LVEF recovery was the main independent protective factor for MACE at FU (HR 0.23, CI 0.08-0.64, p = 0.02). In the HR PCI group, LVEF recovery (>3%) was not associated with lower MACE at multivariable analysis (HR 0.73, CI 0.31-1.72, p = 0.17). Conversely, the completeness of revascularisation was found to be a protective factor for MACE (HR 0.11, CI 0.02-0.62, p = 0.02) (4) Conclusions: Significant LVEF recovery was associated with improved outcomes in CS patients treated with PCI during mechanical circulatory support with Impella, whereas complete revascularisation showed a significant clinical relevance in HR PCI.

Coronary Artery Disease and Prognosis of Heart Failure with Reduced Ejection Fraction

Our aim was to determine the prognostic impact of coronary artery disease (CAD) on heart failure with reduced ejection fraction (HFrEF) mortality and readmissions. From a prospective multicenter registry that included 1831 patients hospitalized due to heart failure, 583 had a left ventricular ejection fraction of <40%. In total, 266 patients (45.6%) had coronary artery disease as main etiology and 137 (23.5%) had idiopathic dilated cardiomyopathy (DCM), and they are the focus of this study. Significant differences were found in Charlson index (CAD 4.4 ± 2.8, idiopathic DCM 2.9 ± 2.4, p < 0.001), and in the number of previous hospitalizations (1.1 ± 1, 0.8 ± 1.2, respectively, p = 0.015). One-year mortality was similar in the two groups: idiopathic DCM (hazard ratio [HR] = 1), CAD (HR 1.50; 95% CI 0.83-2.70, p = 0.182). Mortality/readmissions were also comparable: CAD (HR 0.96; 95% CI 0.64-1.41, p = 0.81). Patients with idiopathic DCM had a higher probability of receiving a heart transplant than those with CAD (HR 4.6; 95% CI 1.4-13.4, p = 0.012). The prognosis of HFrEF is similar in patients with CAD etiology and in those with idiopathic DCM. Patients with idiopathic DCM were more prone to receive heart transplant.

Hot spot imaging in cardiovascular diseases: an information statement from SNMMI, ASNC, and EANM

This information statement from the Society of Nuclear Medicine and Molecular Imaging, American Society of Nuclear Cardiology, and European Association of Nuclear Medicine describes the performance, interpretation, and reporting of hot spot imaging in nuclear cardiology. The field of nuclear cardiology has historically focused on cold spot imaging for the interpretation of myocardial ischemia and infarction. Hot spot imaging has been an important part of nuclear medicine, particularly for oncology or infection indications, and the use of hot spot imaging in nuclear cardiology continues to expand. This document focuses on image acquisition and processing, methods of quantification, indications, protocols, and reporting of hot spot imaging. Indications discussed include myocardial viability, myocardial inflammation, device or valve infection, large vessel vasculitis, valve calcification and vulnerable plaques, and cardiac amyloidosis. This document contextualizes the foundations of image quantification and highlights reporting in each indication for the cardiac nuclear imager.

Myocardial Scar and Revascularization on Mortality in Ischemic Cardiomyopathy (from the Late Gadolinium Enhancement Cardiac Magnetic Resonance Study)

Myocardial viability test to guide revascularization remains uncertain in patients with ischemic cardiomyopathy. We evaluated the different impacts of revascularization on cardiac mortality according to the extent of myocardial scar assessed by cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) in patients with ischemic cardiomyopathy. A total of 404 consecutive patients with significant coronary artery disease and an ejection fraction ≤35% were assessed by LGE-CMR before revascularization. Of them, 306 patients underwent revascularization and 98 patients received medical treatment alone. The primary outcome was cardiac death. During a median follow-up of 6.3 years, cardiac death occurred in 158 patients (39.1%). Revascularization was associated with a significantly lower risk of cardiac death than medical treatment alone in the overall population (adjusted hazard ratio [aHR] 0.29, 95% confidence interval (CI) 0.19 to 0.45, p <0.001). There was a significant interaction between the number of segments with >75% transmural LGE and revascularization on the risk of cardiac death (p = 0.037 for interaction). In patients with limited myocardial scar (<6 segments with >75% transmural LGE, n = 354), revascularization had a significantly lower risk of cardiac death than medical treatment alone (aHR 0.24, 95% CI 0.15 to 0.37, p <0.001); in patients with extensive myocardial scar (≥6 segments with >75% transmural LGE, n = 50), there was no significant difference between revascularization and medical treatment alone regarding the risk of cardiac death (aHR 1.33, 95% CI 0.46 to 3.80, p = 0.60). In conclusion, the assessment of myocardial scar by LGE-CMR may be helpful in the decision-making process for revascularization in patients with ischemic cardiomyopathy.

The impact of viability assessment using cardiac MRI and echocardiogram on the outcome of revascularization in patients with multi-vessels coronary artery disease and moderate to severe ischemic cardiomyopathy

OBJECTIVES

To investigate the influence of viability assessment in the management of patients with ischemic cardiomyopathy (ICM).

METHODS

This retrospective cohort study included all patients with ICM with moderate to severely reduced left ventricular ejection fraction (LVEF) who underwent viability assessment using cardiac magnetic resonance imaging (MRI) and echocardiogram as modalities of imaging. In addition, LVEF, modality of choice, and treatment plans were all extracted as main variables from the electronic database. One hundred 6 patients who met the inclusion criteria from December 2014 to December 2019 were included.

RESULTS

Posttreatment LVEF improved by 5% in the viable group compared to the nonviable group (p=0.016). Regardless of the treatment received, 6 (8.8%) patients in the viable group died due to cardiac causes after an 18-month follow-up period; in contrast, 7 (18.4%) patients died due to cardiac causes in the nonviable group. However, despite that difference, this was not statistically significant (p=0.153). Medical therapy alone was observed in 32 (84.2%) patients in the nonviable group compared to 32 (47.1%) in the viable group (p<0.001). Although the reduction in hospitalization for cardiac reasons was not statistically significant, the viable arm had 50% fewer hospitalizations than the nonviable arm (p=0.051).

CONCLUSION

Patients with viable myocardium had better outcomes in which LVEF significantly improved posttreatment. Additionally, there was a reduction in the number of hospitalizations for cardiac reasons in the viable group compared to the nonviable group, even though the difference was not statistically significant. However, further studies with a larger number of patients are needed to determine a definite conclusion.

Predicting left ventricular functional recovery in ischaemic cardiomyopathy: needs and challenges

Left ventricular (LV) systolic function is an essential parameter for the evaluation of patients with ischaemic heart disease, and therapeutic choices are significantly driven by LV ejection fraction (LVEF) in the early stage of the disease and during follow-up. After an acute coronary syndrome, ventricular dysfunction may be reversible when caused by transient myocardial stunning. Therefore, the identification of clinical, laboratory, and instrumental predictors of improvement in LV systolic function (in addition to LVEF) is essential for an adequate prognostic stratification. In the setting of chronic ischaemic heart disease, there is no evidence that an improvement in LV systolic function is invariably associated with a better prognosis and LVEF is only one of many parameters that should be considered for the risk stratification. This state-of-the-art review will critically analyse the scientific evidence regarding known predictors of LVEF recovery, trying to elucidate their pathophysiological principles and clinical value.

What is the role of coronary revascularization to recover the contractility of the dysfunctional heart?

Coronary artery disease is the predominant aetiology of heart failure and left ventricular dysfunction in industrialized countries. The pathophysiological substrate of hibernating myocardium constitutes the conceptual target of coronary revascularization by coronary artery bypass graft (CABG) or coronary angioplasty or percutaneous coronary intervention (PCI). Studies, mainly observational, conducted in the past have demonstrated a prognostic benefit of CABG on survival. These findings were confirmed by the long-term follow-up of the STICH study in which, however, documentation of inducible ischaemia or myocardial viability was not predictive of a prognostic benefit of CABG. Revascularization via PCI in the recent REVIVED-BCIS2 study did not demonstrate a significant benefit in terms of death or heart failure hospitalization compared with optimal medical therapy. Pending the long-term follow-up of the REVIVED-BCIS2 study, optimized medical therapy, cardiac resynchronization therapy, and the implantable cardioverter defibrillator, where indicated, are the mainstay of treatment in patients with dilated ischaemic cardiomyopathy. The decision for coronary revascularization is made in the individual patient, possibly with a higher bias in patients with angina, three-vessel coronary artery disease, severe left ventricular dysfunction, and cardiac remodelling.