Characterization of dysfunctional remote myocardium in left ventricular anterior aneurysms and improvements following surgical ventricular restoration using cardiac magnetic resonance imaging: preliminary results

Clinical and hemodynamic outcomes of the Dor procedure in adults with ischemic cardiomyopathy

Ischemic cardiomyopathy continues to be a major contributor to congestive heart failure, which places a significant burden on our healthcare system. Improving medications and different coronary revascularization strategies are the mainstays in the management of ischemic cardiomyopathy. Although medications and mechanical circulatory support are playing an ever-increasing role, cardiac transplantation remains the gold standard for treating advanced heart failure. Given the small number of available and suitable donor hearts, transplantation is limited for the majority of patients. Surgical ventricular restoration has repeatedly been suggested as a viable alternative in managing heart failure in select patients, as it is believed that surgically returning the ventricle to its original dimensions is possible and associated with favorable outcomes. The purpose of this manuscript is to comprehensively review the current literature on various surgical strategies for ventricular restoration. We also contextualize the published data with respect to ventricular function, volume, structure, arrhythmias, mitral regurgitation, and clinical outcomes.

Clinical Influencing Factors of Acute Myocardial Infarction Based on Improved Machine Learning

At present, there is no method to predict or monitor patients with AMI, and there is no specific treatment method. In order to improve the analysis of clinical influencing factors of acute myocardial infarction, based on the machine learning algorithm, this paper uses the K-means algorithm to carry out multifactor analysis and constructs a hybrid model combined with the ART2 network. Moreover, this paper simulates and analyzes the model training process and builds a system structure model based on the KNN algorithm. After constructing the model system, this paper studies the clinical influencing factors of acute myocardial infarction and combines mathematical statistics and factor analysis to carry out statistical analysis of test results. The research results show that the system model constructed in this paper has a certain effect in the clinical analysis of acute myocardial infarction.

Heartech® left ventricular partitioning device improves left ventricular systolic function of patients with chronic heart failure post-myocardial infarction at 1-year follow-up

OBJECTIVES

This study presents 1-year follow-up data of echocardiographic outcomes in patients who received the Heartech® left ventricular (LV) partitioning device (LVPD) (Xinrui Medical Equipment Co. Ltd., Shanghai, China).

BACKGROUND

Our first-in-man study of the Heartech® LVPD confirmed its safety and efficacy in patients with chronic heart failure (HF) post-myocardial infarction (MI) 1 month post-implantation. This subsequent study reports the echocardiographic outcomes of these patients at 1 year of follow-up.

METHODS

Fifteen patients with HF post-MI from three cardiac intervention centers in China were successfully implanted with the Heartech® LVPD via percutaneous ventricular restoration procedures. Echocardiographic parameters-including LV systolic function, diastolic function, two-dimensional speckle-tracking analysis, and right ventricular systolic function-were obtained before device implantation and at 1 month and 1 year postoperatively.

RESULTS

There was no deterioration of LV diastolic function, specific strain parameters, or right ventricular function at 1 year. Relative to the echocardiographic parameters recorded before the procedure, the LV ejection fraction (32.47 ± 6.98% vs. 42.5 ± 7.41%; p = .001) was significantly improved at 1 year, while the LV end-diastolic volume index (106.29 ± 28.01 vs. 83.30 ± 31.71; p = .005) and end-systolic volume index were significantly reduced (72.47 ± 22.77 vs. 50.00 ± 19.70; p = .001).

CONCLUSIONS

One-year echocardiographic follow-up results confirmed that no deterioration of LV diastolic function or specific strain parameters was observed and LV systolic function was significantly improved in patients with HF post-MI who were implanted with the Heartech® LVPD.

Basic fibroblast growth factor attenuates left-ventricular remodeling following surgical ventricular restoration in a rat ischemic cardiomyopathy model

OBJECTIVE

Although surgical ventricular restoration for ischemic cardiomyopathy is expected as an alternative or bridge to heart transplantation, post-operative remodeling of left ventricle (LV) needs to be addressed. This study aimed to examine the effect of basic fibroblast growth factor (bFGF), which induces angiogenesis and tissue regeneration in ischemic myocardium, to prevent remodeling after surgical ventricular restoration (SVR) using a rat ischemic cardiomyopathy model.

METHODS

Four weeks after coronary artery ligation, rats were divided into two groups: rats treated with SVR alone (SVR; n = 21), and rats treated with SVR and local sustained release of bFGF using gelatin hydrogel sheet (SVR + bFGF; n = 22). Cardiac function was assessed by serial echocardiography and cardiac catheterization. Cardiac tissue sections were histologically examined for vascular density and fibrosis.

RESULTS

Higher systolic function and lower LV end-diastolic pressure (LVEDP) were observed in rats treated with SVR + bFGF (SVR vs SVR + bFGF; Ees: 0.22 ± 0.11 vs 0.33 ± 0.22 mmHg/μL, p = 0.0328; LVEDP: 12.7 ± 7.0 vs 8.5 ± 4.3 mmHg, p = 0.0230). LV area tended to be lower in rats treated with SVR + bFGF compared to rats treated with SVR alone (left-ventricular end-diastolic area: 0.66 ± 0.07 vs 0.62 ± 0.07 cm², p = 0.071). Vascular density tended to be higher in rats treated with SVR + bFGF than those without bFGF (23.3 ± 8.1 vs 28.8 ± 9.5/mm², p = 0.0509).

CONCLUSIONS

BFGF induced angiogenesis and attenuated remodeling after SVR which secured the efficacy of SVR in a rat ischemic cardiomyopathy model.

Tailoring therapy for ischemic cardiomyopathy: is Laplace's law enough?

The burden of heart failure has long plagued the productive years of the population, with therapeutic advances in the timely treatment of ischemic heart disease decreasing its associated mortality. Angiotensin-converting enzyme inhibitors and β-blockers have impacted heart failure therapeutics in a revolutionary way. The importance of blockade of the renin-angiotensin system and adrenergic stimulation are fully accepted concepts that apply in young and old, symptomatic and asymptomatic, borderline low and very low Ejection Fraction (EF), left ventricular failure and biventricular failure. Despite several interventions, both pharmaceutical and device based for the treatment of ensuing heart failure, the incidence is increasing in large proportions. Newer molecules like sacubitril show more promise. Despite these novel therapies, several patients relentlessly progress to a stage of advanced heart failure. The use of left-ventricular-assist devices has variable clinical benefit, with some patients progressing to heart transplantation.

The Influence of Apical Aneurysm on Left Ventricular Geometry and Clinical Outcomes: 3-Year Follow-Up Using Echocardiography

BACKGROUND

Left ventricular apical aneurysm (LVAA) is a serious complication associated with myocardial infarction. However, the effects of a previously formed LVAA on long-term left ventricular (LV) geometry and clinical outcomes have not been fully evaluated.

METHODS

From January 2009 to May 2015, we retrospectively identified 70 patients (mean age, 66 ± 12 years; males, 72.9%) with an LVAA due to ischemia. These patients were classified into two groups according to the initial apical conicity ratio (ACR): large LVAA group (ACR ≥ 1.5, n = 40) and small LVAA group (ACR < 1.5, n = 30). An adverse outcome was defined as a composite of fatal arrhythmia, embolic infarction, and readmission due to heart failure.

RESULTS

The ACR significantly decreased over the first month and then increased after 1 and 3 years of follow-up. The other examined echocardiographic indexes did not exhibit temporal changes. During the follow-up period (median 1138 days), the large LVAA group experienced a lower event-free survival (P = 0.016). In a multivariate Cox model, the presence of a large LVAA (adjusted hazard ratio [HR] = 2.795, 95% confidence interval [CI] = 1.118-6.986, P = 0.028) and the initial LV ejection fraction (EF) (adjusted HR = 0.964, 95% CI = 0.932-0.997, P = 0.034) were independent predictors of adverse outcomes.

CONCLUSIONS

This study demonstrates that LVAAs undergo a dynamic process and that large LVAAs are associated with adverse outcomes. Our results suggest that the ACR could be helpful for predicting adverse outcomes in patients with apical aneurysm.

cMRI-BED: A novel informatics framework for cardiac MRI biomarker extraction and discovery applied to pediatric cardiomyopathy classification

Background

Pediatric cardiomyopathies are a rare, yet heterogeneous group of pathologies of the myocardium that are routinely examined clinically using Cardiovascular Magnetic Resonance Imaging (cMRI). This gold standard powerful non-invasive tool yields high resolution temporal images that characterize myocardial tissue. The complexities associated with the annotation of images and extraction of markers, necessitate the development of efficient workflows to acquire, manage and transform this data into actionable knowledge for patient care to reduce mortality and morbidity.

Methods

We develop and test a novel informatics framework called cMRI-BED for biomarker extraction and discovery from such complex pediatric cMRI data that includes the use of a suite of tools for image processing, marker extraction and predictive modeling. We applied our workflow to obtain and analyze a dataset of 83 de-identified cases and controls containing cMRI-derived biomarkers for classifying positive versus negative findings of cardiomyopathy in children. Bayesian rule learning (BRL) methods were applied to derive understandable models in the form of propositional rules with posterior probabilities pertaining to their validity. Popular machine learning methods in the WEKA data mining toolkit were applied using default parameters to assess cross-validation performance of this dataset using accuracy and percentage area under ROC curve (AUC) measures.

Results

The best 10-fold cross validation predictive performance obtained on this cMRI-derived biomarker dataset was 80.72% accuracy and 79.6% AUC by a BRL decision tree model, which is promising from this type of rare data. Moreover, we were able to verify that mycocardial delayed enhancement (MDE) status, which is known to be an important qualitative factor in the classification of cardiomyopathies, is picked up by our rule models as an important variable for prediction.

Conclusions

Preliminary results show the feasibility of our framework for processing such data while also yielding actionable predictive classification rules that can augment knowledge conveyed in cardiac radiology outcome reports. Interactions between MDE status and other cMRI parameters that are depicted in our rules warrant further investigation and validation. Predictive rules learned from cMRI data to classify positive and negative findings of cardiomyopathy can enhance scientific understanding of the underlying interactions among imaging-derived parameters.

Computed tomographic analysis of left ventricular volumes and function after implantation of the Parachute® endoventricular partitioning device

BACKGROUND

Preliminary clinical experience with a percutaneous endoventricular partitioning device (Parachute®, CardioKinetix Inc., Menlo Park, CA, USA) suggests that it ameliorates global LV dysfunction and heart failure symptoms in selected patients who have suffered previous anterior myocardial infarction. Less is known of its effect on regional LV function.

OBJECTIVE

To gain insight into device effect on regional LV function by analysis of cardiac computed tomographic (CT) images obtained before and after device implantation.

METHODS

Comparative analysis of pre and 6 months post-implantation contrast-enhanced CT images from 6 subjects enrolled in the phase 1 Parachute clinical trials, including regional LV volume and systolic excursion, as well as device motion.

RESULTS

After implantation, a significant reduction in volume of the "dynamic" LV compartment (that which was not excluded by the device) was accompanied by a significant reduction in dykinetic motion and a trend toward an improved ejection fraction. Penetration of contrast into the excluded compartment was still present at 6 months, however the apical motion was significantly less dyskinetic in 3 subjects and unchanged in the other 3. Overall device surface motion was inward in systole, a significant improvement relative to the overall dyskinetic LV apex pre-implantation. Device motion was spatially heterogeneous, which appeared to be dependent on the motility of the myocardium that anchored its individual splines.

CONCLUSIONS

Our data suggest that the Parachute device acts as a functional impediment to flow and stretch, effectively depressurizing the apical segment.