Myocardial Deformation Pattern Differs between Ischemic and Non-ischemic Dilated Cardiomyopathy: The Diagnostic Value of Longitudinal Strains

Cine-cardiac magnetic resonance to distinguish between ischemic and non-ischemic cardiomyopathies: a machine learning approach

OBJECTIVE

This work aimed to derive a machine learning (ML) model for the differentiation between ischemic cardiomyopathy (ICM) and non-ischemic cardiomyopathy (NICM) on non-contrast cardiovascular magnetic resonance (CMR).

METHODS

This retrospective study evaluated CMR scans of 107 consecutive patients (49 ICM, 58 NICM), including atrial and ventricular strain parameters. We used these data to compare an explainable tree-based gradient boosting additive model with four traditional ML models for the differentiation of ICM and NICM. The models were trained and internally validated with repeated cross-validation according to discrimination and calibration. Furthermore, we examined important variables for distinguishing between ICM and NICM.

RESULTS

A total of 107 patients and 38 variables were available for the analysis. Of those, 49 were ICM (34 males, mean age 60 ± 9 years) and 58 patients were NICM (38 males, mean age 56 ± 19 years). After 10 repetitions of the tenfold cross-validation, the proposed model achieved the highest area under curve (0.82, 95% CI [0.47-1.00]) and lowest Brier score (0.19, 95% CI [0.13-0.27]), showing competitive diagnostic accuracy and calibration. At the Youden's index, sensitivity was 0.72 (95% CI [0.68-0.76]), the highest of all. Analysis of predictions revealed that both atrial and ventricular strain CMR parameters were important for the identification of ICM patients.

CONCLUSION

The current study demonstrated that using a ML model, multi chamber myocardial strain, and function on non-contrast CMR parameters enables the discrimination between ICM and NICM with competitive diagnostic accuracy.

CLINICAL RELEVANCE STATEMENT

A machine learning model based on non-contrast cardiovascular magnetic resonance parameters may discriminate between ischemic and non-ischemic cardiomyopathy enabling wider access to cardiovascular magnetic resonance examinations with lower costs and faster imaging acquisition.

KEY POINTS

• The exponential growth in cardiovascular magnetic resonance examinations may require faster and more cost-effective protocols. • Artificial intelligence models can be utilized to distinguish between ischemic and non-ischemic etiologies. • Machine learning using non-contrast CMR parameters can effectively distinguish between ischemic and non-ischemic cardiomyopathies.

From ejection fraction, to myocardial strain, and myocardial work in echocardiography: Clinical impact and controversies

Enhancing an echocardiographic tool, aimed to detect even subtle left ventricular (LV) systolic function abnormalities, capable of obtaining both early diagnosis and risk prediction of heart disease, represents an ambitious, attractive, and arduous purpose in the modern era of cardiovascular imaging. Ideally, that tool should be simple, reliable, and reproducible, in order to be concretely applied in routine clinical practice. Importantly, that technique should be physiologically plausible and useful both at the population-level, as well as in the individual subject. For a long time, LV ejection fraction (EF) has been considered the first-line parameter for assessing LV global systolic function, strictly related to the prognosis, at least in some settings. However, LV EF limitations are well-known, even though frequently overemphasized, including its load-dependency. Therefore, myocardial strain techniques have been proposed, deemed able to disclose even subtle early LV function anomalies. Nevertheless, many disadvantages of myocardial strain have been reported as well. More recently, myocardial work (MW) analysis has been introduced as a new echocardiographic tool for the evaluation of LV global systolic function, attempting to overcome EF and strain disadvantages. However, MW has shown many limits as well. Notwithstanding, LV EF still remains a landmark functional classification marker for heart failure and cardiac oncology, allowing reliable fast reassessment of LV function changes during patient management, in order to guide treatment in individual cases as well. Notably, global longitudinal strain and MW parameters seem to show better meaningful results at the population-level, but controversial clinical impact, major limitations, wide cut-offs spread and overlap, when the single value needs to be applied to the single case. Taking into account the recent literature-based evidence, the scope of the present narrative critical review is trying to delineate the different types of information given by the described LV global systolic function parameters, both at the population-level and in the individual case, in order to trace a comparative analysis of advantages and limitations in clinical practice.

CMR feature tracking in patients with dilated cardiomyopathy: patterns of myocardial strain and focal fibrosis

BACKGROUND

There is a paucity of data on cardiovascular magnetic resonance feature tracking (CMR-FT) in patients with dilated cardiomyopathy (DCM). We aimed at describing global and segmental myocardial strain patterns and a potential association with the presence of focal myocardial scarring in DCM patients by CMR-FT.

METHODS

Thirty-nine patients with DCM and reduced left ventricular (LV) ejection fraction (mean 21±8%) underwent CMR including standard cine steady-state free precession (SSFP) sequences and late gadolinium enhancement (LGE). We measured global LV longitudinal as well as global and segmental circumferential and radial strain. The presence of focal myocardial fibrosis was assessed on LGE images.

RESULTS

Nineteen patients had focal myocardial fibrosis on LGE images with the highest prevalence in the basal septal segments II and III, which were affected in 12 (63%) and 13 (68%) patients. Furthermore, there was a significantly lower average short-axis LV radial strain (LV_SAX-RS) in these segments (4.89 (-1.55 to 11.34) %) compared with the average of the other myocardial segments (21.20 (17.36 to 25.05)%; p<0.001) after adjusting for LGE and left-bundle branch block (LBBB). In general, LV segments with LGE had lower model-based mean LV_SAX-RS values (17.65 (10.37 to 24.93) %) compared with those without LGE (19.40 (15.43 to 23.37) %), but this effect was not significant after adjusting for the presence of LBBB (p=0.630).

CONCLUSION

Our findings revealed a coincidence of impaired radial strain and focal myocardial fibrosis in the basal septal LV myocardial segments of patients with DCM. Regardless of this pattern, we did not find a general, significant effect of myocardial fibrosis on strain in our cohort. Future studies are required to assess the potential prognostic implications of myocardial strain patterns in addition to the assessment of myocardial fibrosis in patients with DCM.

Genetic Screening of a Large Panel of Genes Associated with Cardiac Disease in a Spanish Heart Transplanted Cohort

In this study we performed a next generation sequencing of 210 genes in 140 patients with cardiac failure requiring a heart transplantation. We identified a total of 48 candidate variants in 47 patients. Forty-three patients (90%) presented a single variant, and fourpatients (10%) were carriers of two variants. After refining the classification, we identified a pathogenic or likely pathogenic variant in 13 patients (10% of our cohort). In 34 additional cases (25%) the variants were classified as of unknown significance (VUS). In reference to the cause of cardiac failure in the 13 carriers of pathogenic variants, 5 were of dilated non-ischemic cause, 4 hypertrophic and 1 restrictive cardiomyopathy. In the ischemic cases (n = 3) no family history of cardiac disease was recorded, while nineof the non-ischemic had other relatives who were also diagnosed. In conclusion, the NGS of a cardiac transplanted cohort identified a definite or very likely genetic cause in 10% of the cases. Most of them had a family history of cardiac disease, and were thus previously studied as part of a routine screening by a genetic counselor. Pathogenic variants in cases without a family history of cardiac disease were mainly of ischemic origin.

Beyond Ejection Fraction: Novel Clinical Approaches Towards Sudden Cardiac Death Risk Stratification in Patients with Dilated Cardiomyopathy

Implantable Cardioverter-Defibrillator (ICD) therapy is indicated for patients at risk for sudden cardiac death due to ventricular tachyarrhythmia. The most commonly used risk stratification algorithms use Left Ventricular Ejection Fraction (LVEF) to determine which patients qualify for ICD therapy, even though LVEF is a better marker of total mortality than ventricular tachyarrhythmias mortality. This review evaluates imaging tools and novel biomarkers proposed for better risk stratifying arrhythmic substrate, thereby identifying optimal ICD therapy candidates.

Cardiomyopathy Management and In-Hospital Outcomes in a Tertiary Care Center: Clinical Components and Venues of Advanced Care

Background

There are few reports on the prevalence of different types of cardiomyopathy, clinical presentation, severity, short-term outcomes, and implementation of advanced heart failure treatment. This study aimed to assess the prevalence, clinical background of different types of cardiomyopathy and to identify the candidate for advanced treatment in a tertiary care cardiac center with many advantages 

Method

A single-center retrospective cohort study included 1069 patients admitted to our center and diagnosed with cardiomyopathy during 2019 and 2020 

Results

Out of 1069 cardiomyopathy patients admitted and diagnosed at our center between 2019 and 2020, 62% had ischemic cardiomyopathy (ICM), 36% had dilated cardiomyopathy (DCM), and 2% had hypertrophic cardiomyopathy (HOCM). ICM patients were older, showed a higher prevalence of both male gender and pilgrims, and they had more frequent cardiovascular risk factors compared to dilated cardiomyopathy group of patients. However, DCM patients with more severe heart failure symptoms (NYHA class III/IV), much worse LVEF, were subsequently considered deemed for aggressive diuretic therapy, and further advanced therapy (Sacubitril-Valsartan and device therapy) compared to ICM patients. ICM patients showed poor in-hospital outcomes compared to DCM group of patients (0.05 and <0.001) for an indication for mechanical ventilation and in-hospital mortality, respectively). Increased age, presence of renal dysfunction and lower LVEF were found the independent predictors of in-hospital mortality among our studied patients 

Conclusion

There are discrepancies between DCM and ICM patients. Although DCM patients were younger at age and had fewer cardiovascular risk factors, they presented with severe symptoms and dysfunction, hence more eligible candidates for advanced heart failure treatment, and finally showed a lower mortality rate. Increased age, presence of renal dysfunction and lower LVEF were found the independent predictors of in-hospital mortality. 

Right ventricular free wall strain in acutely decompensated heart failure patients with ischemic and non-ischemic cardiomyopathy

AIMS

Right ventricular (RV) dysfunction is a predictor of adverse outcomes among patients with HF with reduced ejection fraction (HFrEF); however, differences in RV parameters in HFrEF patients with ischemic (ICM) and non-ischemic cardiomyopathies (NICM) are not well understood. We investigated echocardiographic characteristics, including RV strain, in patients with acute decompensated heart failure (ADHF) and compared patients with ICM and NICM etiology.

METHODS

Consecutive patients who presented with ADHF and NYHA class III-IV were prospectively enrolled if they had LVEF < 40% and history of ICM or NICM. All patients underwent clinical exam, laboratory evaluation and 2-D echocardiographic assessment of the left ventricular (LV) and RV function, LV and RV global longitudinal strain (LVGLS, RVGLS), and RV free wall strain (RVfwLS).

RESULTS

Of 84 patients, 44 had ICM and 40 NICM. The groups had similar blood pressure, NT-proBNP, and echocardiographic parameters of LV function including LVGLS. Absolute RVGLS values were lower than RVfwLS values in both groups. Patients with NICM had significantly lower RVfwLS, but not RVGLS, compared to patients with ICM (-13% to -17%, p = 0.006). Similar differences in RVfwLS were seen in patients in NYHA class III (NICM vs ICM: -13% and -17%, respectively, 95% CI: -8.5 to -.5) and NYHA class IV (NICM vs ICM: -13.8% and -17%, respectively, 95% CI: -6.4 to -.59).

CONCLUSION

Among patients hospitalized with ADHF, patients with nonischemic etiology compared with the patients with ICM, have more severe RV dysfunction measured by RVfwLS, despite similar extent of LV impairment and the same functional limitation class.

The strain and strain rate imaging paradox in echocardiography: overabundant literature in the last two decades but still uncertain clinical utility in an individual case

Almost two decades ago strain and strain rate imaging were proposed as a new, potentially more sensitive modality for quantifying both regional and global myocardial function. Until now, however, strain and strain rate imaging have been slow to be incorporated into everyday clinical practice. More recently, two dimensional strain has been claimed as of greater clinical utility, given that it is angle independent, with improved feasibility and reproducibility as compared to tissue Doppler strain. Nevertheless, speckle tracking strain is reliant on 2D image quality and frame rates. Three dimensional speckle tracking could eliminate the problem of through-plane motion inherent in 2D imaging, but 3D strain is currently limited by low frame rates. Another limitation of strain imaging is that the results are dependent on the ultrasound machine on which analyses are performed, with variability in measurements between different vendors. Despite the diagnostic and prognostic advantages of 2D strain, there is a lack of specific therapeutic interventions based on strain and a paucity of long-term large-scale randomized trial evidence on cardiovascular outcomes. After overabundant literature the same definition of normal cut-off values is controversial and not univocal. Further studies are needed, involving both manufacturers and medical professionals, on the additive contribution, possibly different case by case, of interfering and artifactual factors, aside from myocardial function per se. These artifactual determinants and motion artifacts components could be dominant in individual cases and should always be taken into account in the clinical decision making process in a single case.

Global longitudinal strain as a predictor of short-term effect of oral antiviral regimens on myocardium in Egyptian patients with chronic viral hepatitis C

Background

Hepatitis C virus (HCV) infection has been noted with various cardiovascular (CV) diseases, and patients with detected HCV-RNA had higher CV mortality than uninfected individuals. The new direct-acting antiviral drugs (DAA) proved to be more effective with fewer side effects compared to interferon in eradicating HCV, but their effect on myocardium is still questionable. In order to get some answers for such question, two-dimensional speckle tracking echocardiography (2D-STE) was studied before and after treatment with different DAA regimens in HCV patients with either mildly impaired or normal basic left ventricular ejection fraction (LVEF).

Results

Global longitudinal strain (GLS) significantly worsened after finishing antiviral treatment in patients with basic impairment of LVEF (n = 100) and those with normal basic LVEF (n = 20) [p = 0.006 and 0.039, respectively]; also, segmental strain showed significant worsening of many segments. Such worsening was significantly more in those with basic impairment of LVEF compared to those with normal basic LVEF (p = 0.036). No significant difference was observed in GLS and segmental strain when classifying and comparing patients according to gender, presence of diabetes mellitus, hypertension, ischemic heart disease and established cardiac medications, or according to DAA regimen received.

Conclusion

DAA may have a cardiotoxic effect that could be early detected by 2D-STE, which was more significant in patients with pre-treatment impairment of LVEF.

Cardiomyopathies in China: A 2018-2019 state-of-the-art review

Cardiomyopathies are diseases of the cardiac muscle and are often characterized by ventricular dilation, hypertrophy, and cardiac arrhythmia. Patients with cardiomyopathies often experience sudden death and cardiac failure and require cardiac transplantation during the course of disease progression. Early diagnosis, differential diagnosis, and genetic consultation depend on imaging techniques, genetic testing, and new emerging diagnostic tools such as serum biomarkers. The molecular genetics of cardiomyopathies has been widely studied recently. The discovery of mechanisms underlying heterogeneity and overlapping of the phenotypes of cardiomyopathies has revealed the existence of disease modifiers, and this has led to the emergence of novel disease-modifying therapy. This 2018-2019 state-of-the-art review outlines the pathogenesis, diagnosis, and treatment of cardiomyopathies in China.

Reversible cardiac dysfunction in severe COVID-19 infection, mechanisms and case report

A previously healthy 49-year-old male patient presented with COVID-19 infection and required mechanical ventilation and extracorporeal membrane oxygenation due to severe hypoxemia. Echocardiography showed cardiac dysfunction with an apical sparing strain pattern, which rapidly normalized within a week. Apical sparing myocardial strain in patients with COVID-19 infection may suggest reverse-type stress cardiomyopathy.