Ischemic Left Ventricular Dysfunction Research Articles

The prognostic impact of inducible ischemia in severe ischaemic cardiomyopathy: a randomised comparison of medical therapy and revascularisation

Abstract Background The presence of inducible myocardial ischaemia is used to select patients with stable coronary artery disease for revascularisation, based on observational data in patients with preserved left ventricular function. It is unclear if identification of a substrate for ischaemia is prognostic in patients with severe ischaemic left ventricular systolic dysfunction (LVSD). Purpose To determine if the extent of inducible ischaemia by stress perfusion CMR relates to clinical outcomes and/or the response to revascularisation in patients with ischaemic LVSD. Methods Patients enrolled in the REVIVED-BCIS2 randomised trial were eligible for inclusion if they had undergone stress perfusion CMR prior to randomisation (1). Visual assessment of myocardial perfusion and late gadolinium enhancement (LGE) was performed by an independent core laboratory, by consensus of two expert readers who were blinded to trial-group assignment and clinical or outcome data. For this analysis, segmental ischaemia was classified in a binary manner and the overall volume of ischaemia is expressed in relation to total LV mass, defined as [number of ischaemic segments]/16 * 100. The primary composite outcome was all-cause death or aborted sudden death. Secondary outcomes included left ventricular ejection fraction change at 6 and 12-months, cardiovascular death and sustained ventricular arrhythmias. Data are presented as median [IQR] or mean ± standard deviation. Results Of 700 participants enrolled, stress perfusion CMR was acquired in 200, 181 of whom had scans of sufficient quality for core laboratory analysis (91 randomised to percutaneous coronary intervention and 90 to optimal medical therapy; age 69±8 years, 86% male, 40% diabetic, baseline jeopardy score 10 [8-12]). On CMR, LVEF was 28±8%, scar burden was 18% [9-26] and ischaemic burden was 31% [13-56]. There was no association between ischaemic burden and the primary outcome (HR 1.0, p=0.997, CI 0.92-1.09) or any of the secondary outcomes (Figure 1). There was no relationship between ischaemia and randomised treatment group (Figure 2). Conclusion The REVIVED-BCIS2 trial incudes the largest cohort to date of stress perfusion CMR in severe LVSD, randomised to relief of ischaemia or medical therapy alone. In this study, ischaemic burden was not associated with clinical outcomes or the outcome following revascularisation.Figure 1 – HRs for 10% ischaemic burdenFigure 2 - KM plots for primary outcome

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

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. 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. 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.

Efficacy of revascularization in CTO patients based on hibernating myocardium therapy.

The effectiveness of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is still uncertain, especially for patients with ischemic left ventricular dysfunction. This study aimed to assess hibernating myocardium (HM), as determined by single-photon emission computed tomography (SPECT) and 18F-FDG positron emission tomography (PET), and to compare the benefits of PCI and optimal medical therapy (OMT). A retrospective study collected data from 332 patients with CTO and ischemic left ventricular dysfunction. The study compared patients who underwent PCI or OMT via propensity score matching (PSM) analysis which was performed with a 1:2 matching protocol using the nearest neighbour matching algorithm. The primary endpoint of the study was the occurrence of major adverse cardiac events (MACE), defined as a composite of cardiac death, readmission for worsening heart failure (WHF), revascularization and myocardial infarction (MI). After PSM, there were a total of 246 individuals in the PCI and OMT groups. Following Cox regression, hibernating myocardium/total perfusion defect (HM/TPD) was identified as an independent risk factor (hazard ratio (HR): 1.03, 95% confidence interval (CI): 1.008-1.052, p = .007). The cut-off value of HM/TPD was 38%. The results of the subgroup analysis suggest that for patients with HM/TPD >38%, the OMT group had a greater risk of MACE (p = .035). A sensitivity analysis restricting patients with single-vessel CTO lesions, HM/TPD remained an independent predictor (HR 1.025, 95% CI 1.008-1.043, p = .005). HM/TPD is an independent predictor of MACE, and for patients with HM/TPD > 38%, CTO-PCI had a lower risk of MACE compared with OMT. However, further validation is still needed through large-scale studies.

REVIVED BCIS-2: update and key learnings.

This review summarises the shifting paradigms in the treatment of ischemic left ventricular dysfunction, spotlighting the revascularization for ischemic ventricular dysfunction-British cardiovascular intervention society-2 (REVIVED-BCIS2) trial results and its impact on key therapeutic goals: survival, left ventricular function, arrhythmia prevention, quality of life and viability testing. The REVIVED-BCIS2 trial, and its subsequent sub studies highlighted that (PCI) does not provide additional benefits to optimal medical therapy in terms of improving survival, left ventricular (LV) function, arrhythmic risk or quality of life. Additionally, viability testing did not differentiate patients who could benefit from PCI, although scar burden was found to be a significant predictor of outcome in these patients. The outcomes of REVIVED have challenged multiple existing beliefs in the field of ischaemic left ventricular dysfunction management, emphasising the importance of investigating evidence free areas in our practice. Future work, including the STICH3 international consortium of trials, aims to answer some of the remaining unanswered questions.

Myocardial viability: when and how to look for it, its prognostic impact and interaction with benefits of revascularization

Ischemic left ventricular dysfunction results from the combination of scar and areas of dysfunctional but viable myocardium that may improve contractile function with revascularization. The traditional paradigm states that an improvement in function after revascularization leads to improved health outcomes and that assessment of myocardial viability has a key role in predicting the benefit of revascularization and, therefore, is a prerequisite for the selection of patients to undergo this treatment option. A range of retrospective observational studies supported this "viability hypothesis". However, randomized prospective trials have not confirmed the interaction between myocardial viability and the treatment effect of revascularization, challenging the recovery of left ventricular function as the principal mechanism by which surgical revascularization improves prognosis. A conceptual shift from the traditional paradigm centered on the assessment of viability as a dichotomous variable to a more comprehensive approach founded on an alternative concept that the main goal of revascularization is to prevent further damage by protecting the residual viable myocardium from subsequent acute coronary events and ventricular arrhythmias is required.

Metabolomics of repetitive myocardial stunning in chronic multivessel coronary artery stenosis: Effect of non-selective and selective β1-receptor blockers.

Chronic coronary artery stenosis can lead to regional myocardial dysfunction in the absence of myocardial infarction by repetitive stunning, hibernation or both. The molecular mechanisms underlying repetitive stunning-associated myocardial dysfunction are not clear. We used non-targeted metabolomics to elucidate responses to chronically stunned myocardium in a canine model with and without β-adrenergic blockade treatment. After development of left ventricular systolic dysfunction induced by ameroid constrictors on the coronary arteries, animals were randomized to 3months of placebo, metoprolol or carvedilol. We compared these two β-blockers with their different β-adrenergic selectivities on myocardial function, perfusion and metabolic pathways involved in tissue undergoing chronic stunning. Control animals underwent sham surgery. Dysfunction in stunned myocardium was associated with reduced fatty acid oxidation and enhanced ketogenic amino acid metabolism, together with alterations in mitochondrial membrane phospholipid composition. These changes were consistent with impaired mitochondrial function and were linked to reduced nitric oxide and peroxisome proliferator-activated receptor signalling, resulting in a decline in adenosine monophosphate-activated protein kinase. Mitochondrial changes were ameliorated by carvedilol more than metoprolol, and improvement was linked to nitric oxide and possibly hydrogen sulphide signalling. In summary, repetitive myocardial stunning commonly seen in chronic multivessel coronary artery disease is associated with adverse metabolic remodelling linked to mitochondrial dysfunction and specific signalling pathways. These changes are reversed by β-blockers, with the non-selective inhibitor having a more favourable impact. This is the first investigation to demonstrate that β-blockade-associated improvement of ventricular function in chronic myocardial stunning is associated with restoration of mitochondrial function. KEY POINTS: The mechanisms responsible for the metabolic changes associated with repetitive myocardial stunning seen in chronic multivessel coronary artery disease have not been fully investigated. In a canine model of repetitive myocardial stunning, we showed that carvedilol, a non-selective β-receptor blocker, ameliorated adverse metabolic remodelling compared to metoprolol, a selective β1-receptor blocker, by improving nitric oxide synthase and adenosine monophosphate protein kinase function, enhancing calcium/calmodulin-dependent protein kinase, probably increasing hydrogen sulphide, and suppressing cyclic-adenosine monophosphate signalling. Mitochondrial fatty acid oxidation alterations were ameliorated by carvedilol to a larger extent than metoprolol; this improvement was linked to nitric oxide and possibly hydrogen sulphide signalling. Both β-blockers improved the cardiac energy imbalance by reducing metabolites in ketogenic amino acid and nucleotide metabolism. These results elucidated why metabolic remodelling with carvedilol is preferable to metoprolol when treating chronic ischaemic left ventricular systolic dysfunction caused by repetitive myocardial stunning.

Machine learning predictions of the adverse events of different treatments in patients with ischemic left ventricular systolic dysfunction.

This study aimed to develop several new machine learning models based on hibernating myocardium to predict the major adverse cardiac events(MACE) of ischemic left ventricular systolic dysfunction(LVSD) patients receiving either percutaneous coronary intervention(PCI) or optimal medical therapy(OMT). This study included 329 LVSD patients, who were randomly assigned to the training or validation cohort. Least absolute shrinkage and selection operator(LASSO) regression was used to identify variables associated with MACE. Subsequently, various machine learning models were established. Model performance was compared using receiver operating characteristic(ROC) curves, the Brier score(BS), and the concordance index(C-index). A total of 329 LVSD patients were retrospectively enrolled between January 2016 and December 2021. Utilizing LASSO regression analysis, five factors were selected. Based on these factors, RSF, GBM, XGBoost, Cox, and DeepSurv models were constructed. In the development and validation cohorts, the C-indices were 0.888 vs. 0.955 (RSF). The RSF model (0.991 vs. 0.982 vs. 0.980) had the highest area under the ROC curve (AUC) compared with the other models. The BS (0.077 vs. 0.095vs. 0.077) of RSF model were less than 0.25 at 12, 18, and 24months. This study developed a novel predictive model based on RSF to predict MACE in LVSD patients who underwent either PCI or OMT.

Percutaneous Coronary Intervention Versus Optimal Medical Therapy for Severe Ischemic Left Ventricular Systolic Dysfunction

Coronary artery disease is the most common cause of heart failure, which is the leading cause of cardiovascular-related death worldwide. There are insufficient data to make strong recommendations for percutaneous coronary intervention (PCI) in patients with severe ischemic left ventricular systolic dysfunction (LVSD). In that context, we performed a meta-analysis to compare the outcomes of PCI with those of optimal medical therapy alone in patients with severe ischemic LVSD. A systematic search was conducted in PubMed, EMBASE, and ClinicalTrials.gov from inception to December 2023. Our outcome of interest was all-cause mortality in patients undergoing PCI vs medical therapy. We used random effects models to aggregate data and to calculate pooled incidence and relative risk with 95% CIs. Four studies including 2 randomized controlled trials with 2080 patients (PCI, 1082; optimal medical therapy, 998) were included. All-cause mortality did not differ significantly between the groups: 168 patients (15.5%) in the PCI group vs 200 patients (20.0%) in the optimal medical therapy group (relative risk, 0.88; 95% CI, 0.75-1.09; P=.25). In conclusion, the available evidence indicates that PCI does not improve all-cause mortality in patients with severe LVSD without lifestyle-limiting anginal symptoms. Further data are needed to identify subgroups of patients better served by each modality.

Effect of PCI on Health Status in Ischemic Left Ventricular Dysfunction: Insights From REVIVED-BCIS2

BackgroundIn the REVIVED-BCIS2 (Revascularization for Ischemic Ventricular Dysfunction) trial, percutaneous coronary intervention (PCI) did not reduce the incidence of death or hospitalization for heart failure (HHF). ObjectivesThis prespecified secondary analysis investigated the effect of PCI on health status measured with the Kansas City Cardiomyopathy Questionnaire (KCCQ) combined with the primary outcome in a win ratio. MethodsParticipants with severe ischemic left ventricular dysfunction were randomized to either PCI in addition to optimal medical therapy (OMT) (PCI) or OMT alone (OMT). The primary outcome was a hierarchical composite of all-cause death, HHF, and KCCQ–Overall Summary Score (OSS) at 24 months analyzed using the unmatched win ratio. The key secondary endpoint was a KCCQ-OSS responder analysis. ResultsA total of 347 participants were randomized to PCI and 353 to OMT. Median age was 70.0 years (Q1-Q3: 63.3-76.1 years). Mean left ventricular ejection fraction was 27.0 ± 6.7%. PCI did not improve the primary endpoint (win ratio for PCI vs OMT: 1.05; 95% CI: 0.88-1.26; P = 0.58). PCI resulted in more KCCQ-OSS responders than OMT at 6 months (54.1% vs 40.7%; OR: 1.96; 95% CI: 1.41-2.71; P < 0.001) and fewer deteriorators (25.2% vs 31.4%; OR: 0.69; 95% CI: 0.47-1.00; P = 0.048). PCI did not impact KCCQ-OSS responders or deteriorators at 12 or 24 months. ConclusionsPCI did not improve the hierarchical composite of death, HHF, and health status at 2 years. PCI improved KCCQ-OSS at 6 months, but this benefit was not sustained to 1- or 2-year follow-up. (Revacularization for Ischemic Ventricular Dysfunction [REVIVED-BCIS2]; NCT01920048)

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.

Limitations of Diagnosis of Ischemic Left Ventricular Dysfunction Using the Values of Strain, Twist and Untwist in Patients With Myocardial Infarction of Various Localization.

To compare capabilities for diagnosing regional and global myocardial dysfunction using the values of longitudinal and circular strain, left ventricular (LV) torsion and untwisting in patients with myocardial infarction (MI) of various locations. Patients included in the study (n=121) were divided into three groups: patients with unstable angina (n=30), patients with anterior MI (n=45), and patients with inferior MI (n=46). Clinical, laboratory and instrumental test were performed, including echocardiography. For a quantitative analysis of LV contractility, the maximum systolic peaks of regional and global longitudinal and circular strain, systolic and diastolic rotation, LV torsion and untwisting were measured. Anterior MI was characterized by injury of the LV apical segments, while inferior MI was characterized by injury of the basal segments. In anterior MI, the longitudinal strain was reduced less than 14.5% and circular strain less than 19.3% in the apical segment of the LV anteroseptal wall (ASW). In akinesia of the LV ASW apical segment, longitudinal and circular strains were reduced less than 10%. The magnitude of the circular strain of the LV ASW apical segment (diagnostic threshold 19.3%, sensitivity (Se) 87%, specificity (Sp) 90%) was superior to that of the longitudinal strain as a diagnostic marker for regional ischemic dysfunction in anterior MI. The magnitude of the circular strain of the basal segment of the LV inferior wall in inferior MI has a greater diagnostic value for identifying regional systolic dysfunction than the value of the longitudinal strain of this LV segment. The diagnostic threshold was 17.3%, Se 79%, Sp 80%. A decrease in the circular strain of the LV ASW less than 19.3% in the LV apical segment is more specific (Sp 90%) for diagnosing regional systolic dysfunction in anterior MI than a decrease in longitudinal strain. A circular strain value of less than 17.3% in the basal segment of the LV inferior wall is more specific (Sp 80%) than the longitudinal strain of this segment for diagnosing regional systolic dysfunction in inferior MI. Predominant injury to the LV apex in anterior MI can cause systolic and diastolic myocardial dysfunction, which is manifested by a decrease in LV circular deformation, torsion and untwisting.

Association of revascularization with mortality in ischemic left ventricular dysfunction

Abstract Background Revascularization in patients with left ventricular (LV) dysfunction has been a subject of ongoing uncertainty and conflicting results. This is further complicated by factors including viability, severity of LV dysfunction, and method of revascularization using percutaneous coronary intervention (PCI) versus coronary-artery bypass grafting (CABG). The purpose of this meta-analysis is to evaluate the association of coronary revascularization with mortality in patients with ischemic LV dysfunction. Methods A literature search was conducted for studies reporting on all-cause mortality after revascularization with PCI or CABG compared to optimal medical therapy (OMT) in patients with ischemic LV dysfunction. The search included the following databases: Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status. Results A total of 21 studies with 6062 participants (2838 revascularized, 3224 on OMT) met inclusion criteria. Mean follow-up was 37 months (11-68 months), mean LV ejection fraction (EF) was 29%, mean age was 61, 85% of patients were male. Revascularization was significantly associated with lower all-cause mortality compared to patients on OMT (OR 0.57, 95% CI 0.46-0.71; p&amp;lt;0.01). The association was statistically significant regardless of severity of LV dysfunction or method of revascularization. Heterogeneity between subgroups was low and test for subgroup difference was not statistically significant by EF cutoff of 35% or by revascularization method (p=0.43, I2=0%; p=0.12, I2=59.7%). Subgroup analysis by viability demonstrated that revascularization was significantly associated with lower all-cause mortality compared to OMT for patients with viability and mixed cohorts with or without viability, but not patients without viability (OR 0.47, 95% CI 0.33-0.66; p&amp;lt;0.01; OR 0.57, 95% CI 0.38-0.84; p&amp;lt;0.01; OR 0.73, 95% CI 0.51-1.02; p=0.07). The effect size was larger in the subgroup with viable myocardium compared to mixed patients with viable or non-viable myocardium (Z=4.33 vs 2.79). Conclusions Revascularization in patients with ischemic LV dysfunction is associated with lower risk of all-cause mortality independent of severity of LV dysfunction or method of revascularization. Revascularization is not associated with lower risk of all-cause mortality in patients without evidence of viable myocardium.

Abstract 16635: Cost Effectiveness Analysis of the Percutaneous Revascularization for Ischemic Left Ventricular Dysfunction REVIVED Trial Data

Introduction. Evidence on survival benefits of percutaneous coronary intervention (PCI) in patients with severe ischemic left ventricular systolic dysfunction (ILVD) is scant. The REVIVED trial showed that, compared to optimal medical therapy (OMT), revascularisation by PCI did not reduce the incidence of death from any cause or heart failure hospitalization (HF); it also failed to provide sustained improvements in health-related quality of life. REVIVED data are used to evaluate the economic consequences and health outcomes of PCI+OMT and OMT alone in HF patients in the UK. Methods. 700 patients with ILVD were randomised to either PCI+OMT or OMT. Healthcare resource use and patient-reported health outcomes data EuroQol on each patient were collected at baseline and over a period of 8 years post randomisation (median follow up of 3.5 years). Health resources were costed using publicly available national unit costs from the perspective of the UK health system. Within trial mean total costs and quality adjusted life years (QALYs) were estimated and incremental cost effectiveness was evaluated. Regression analysis on total costs and total QALYs was used to adjust for clinically relevant baseline covariables. Probabilistic sensitivity analysis was used to reflect parameter uncertainty. Results. Statistical modelling identified gender, BMI, hypertension, diabetes, NYHA grade and previous hospitalisation as the most relevant baseline predictors of costs and benefits. Over the 8 years of fu, patients undergoing PCI yielded, on average, similar health benefits (4.13 QALYs IC [4.10 - 4.16]) at higher costs (£14,674 IC[£14,334 - £15,014]), compared to OMT (4.16 QALYs [4.13 - 4.19]; £5154 IC [£5,034 - £5,273]). Conclusion. We found no difference in total QALYs between arms and PCI+OMT was not cost-effective compared to OMT, given its additional costs. Therefore, a strategy of routine PCI to treat ILVSD does not appear to be a justifiable use of healthcare resources.

Abstract 16558: Revascularization in Patients With Ischemic Cardiomyopathy and Viability: A Meta-Analysis of Randomized Controlled Trials

Introduction: Observational studies have suggested that revascularization improves survival in patients with ischemic cardiomyopathy (ICM) with left ventricular ejection fraction less than less than or equal to 35% and demonstrable myocardial viability compared to medical therapy alone. However, the recent Revascularization for Ischemic Ventricular Dysfunction (REVIVED) trial revealed that among patients with severe ischemic left ventricular systolic dysfunction receiving optimal medical therapy, percutaneous coronary intervention did not reduce the incidence of major adverse cardiac events. Hypothesis: This meta-analysis aims to evaluate the impact of revascularization on patients with ICM and demonstrable myocardial viability, specifically focusing on randomized controlled trials (RCTs). Methods: We conducted a systematic search of MEDLINE, Embase, and the Cochrane Database of Systematic Reviews from inception to February 8th, 2023. The primary outcome assessed in this study was mortality. A random-effects models were applied to pool effect sizes. Results: Four RCTs involving 1365 patients with ICM and viability met the inclusion criteria. Among them, 684 patients were included in the revascularization group, while 681 patients received optimal medical therapy. In the revascularization group, 232 patients (34%) died, compared to 266 patients (39%) in the medical therapy group. The meta-analysis revealed that revascularization in this patient population was not associated with a significant improvement in survival (pooled odds ratio [OR]: 0.82; 95% CI: 0.59-1.14; p = 0.24). Furthermore, revascularization did not show a significant reduction in major adverse cardiac events (pooled odds ratio [OR]: 0.56; 95% CI: 0.27-1.16; p = 0.12). Conclusions: This meta-analysis of randomized controlled trials does not provide evidence supporting the effectiveness of revascularization in patients with ICM and demonstrable myocardial viability

Viability and Outcomes With Revascularization or Medical Therapy in Ischemic Ventricular Dysfunction

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. To determine the effect of the extent of viable and nonviable myocardium on the effectiveness of PCI, prognosis, and improvement in left ventricular function. 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. Percutaneous coronary intervention in addition to optimal medical therapy. 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. 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. 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. ClinicalTrials.gov Identifier: NCT01920048.

Extreme Risk of Sudden Cardiac Death within Three Months after Revascularization in Patients with Ischemic Left Ventricular Systolic Dysfunction.

The risk of sudden cardiac death (SCD) after coronary revascularization in patients with left ventricular (LV) systolic dysfunction has not been characterized completely. This study aims to evaluate the incidence and time course of SCD after revascularization in such patients. The determinants of SCD within 3 months after revascularization were also assessed. A cohort study of patients with reduced ejection fraction (EF 40%), who underwent revascularization was performed. The incidence of SCD was estimated to account for the competing risk of deaths due to other causes. 2317 patients were enrolled. With a median follow-up of 3.5 years, 162 (32.1%) of the 504 deaths were due to SCD. The risk of SCD was highest in the first 3 months after revascularization, with an incidence rate of 0.37%/month. The event rate decreased to 0.12%/month, 0.08%/month, 0.09%/month, 0.14%/month, and 0.19%/month at 3-6 months, 6-12 months, 1-3 years, 3-5 years, and 5-10 years, respectively. A history of ventricular tachycardia/ventricular fibrillation (hazard ratio [HR], 5.55; 95% confidence interval [CI], 1.33-23.19; p = 0.019) and triple vessel disease (HR, 3.90; 95% CI, 1.38-11.05; p = 0.010) were associated with the risk of SCD within 3 months. However, preoperative EF (in 5% increments) was not predictive (HR per 5% increase, 0.98; 95% CI, 0.62-1.55; p = 0.935). For patients with LV dysfunction, the risk of SCD was the highest during the first 3 months after revascularization. Further risk classification and treatment strategy are warranted. The name of the registry: Coronary Revascularization in Patients with Ischemic Heart Failure and Prevention of Sudden Cardiac Death. Registration number: ChiCTR2100044378.

Outcomes of coronary revascularization vs. optimal medical therapy alone for ischemic left ventricular dysfunction: A meta-analysis of randomized controlled trials.

Outcomes of coronary revascularization vs. optimal medical therapy alone for ischemic left ventricular dysfunction: A meta-analysis of randomized controlled trials.

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.

Breathing pattern and pulmonary gas exchange in elderly patients with and without left ventricular dysfunction-modification with exercise-based cardiac rehabilitation and prognostic value.

Inefficient ventilation is an established prognostic marker in patients with heart failure. It is not known whether inefficient ventilation is also linked to poor prognosis in patients with left ventricular dysfunction (LVD) but without overt heart failure. To investigate whether inefficient ventilation in elderly patients with LVD is more common than in patients without LVD, whether it improves with exercise-based cardiac rehabilitation (exCR), and whether it is associated with major adverse cardiovascular events (MACE). In this large multicentre observational longitudinal study, patients aged ≥65 years with acute or chronic coronary syndromes (ACS, CCS) without cardiac surgery who participated in a study on the effectiveness of exCR in seven European countries were included. Cardiopulmonary exercise testing (CPET) was performed before, at the termination of exCR, and at 12 months follow-up. Ventilation (VE), breathing frequency (BF), tidal volume (VT), and end-expiratory carbon dioxide pressure (PETCO2) were measured at rest, at the first ventilatory threshold, and at peak exercise. Ventilatory parameters were compared between patients with and without LVD (based on cardio-echography) and related to MACE at 12 month follow-up. In 818 patients, age was 72.5 ± 5.4 years, 21.9% were women, 79.8% had ACS, and 151 (18%) had LVD. Compared to noLVD, in LVD resting VE was increased by 8%, resting BF by 6%, peak VE, peak VT, and peak PETCO2 reduced by 6%, 8%, and 5%, respectively, and VE/VCO2 slope increased by 11%. From before to after exCR, resting VE decreased and peak PETCO2 increased significantly more in patients with compared to without LVD. In LVD, higher resting BF, higher nadir VE/VCO2, and lower peak PETCO2 at baseline were associated with MACE. Similarly to patients with HF, in elderly patients with ischemic LVD, inefficient resting and exercise ventilation was associated with worse outcomes, and ExCR alleviated abnormal breathing patterns and gas exchange parameters.

Current Role of Myocardial Viability Imaging Using Positron Emission Tomography in Patients with Chronic Ischemic Heart Failure and Left Ventricular Dysfunction

Current Role of Myocardial Viability Imaging Using Positron Emission Tomography in Patients with Chronic Ischemic Heart Failure and Left Ventricular Dysfunction