Differences in the prognostic relevance of myocardial ischaemia and scar by cardiac magnetic resonance in patients with and without diabetes mellitus

Diabetes mellitus is associated to high-risk late gadolinium enhancement and worse outcomes in patients with nonischemic dilated cardiomyopathy

BACKGROUND

Diabetes mellitus (DM) is associated with a worse prognosis in patients with heart failure. Our aim was to analyze the clinical and imaging features of patients with DM and their association with outcomes in comparison to nondiabetic patients in a cohort of patients with nonischemic dilated cardiomyopathy (DCM).

METHODS

This is a prospective cohort study of patients with DCM evaluated in a tertiary care center from 2018 to 2021. Transthoracic echocardiography and cardiac magnetic resonance findings were assessed. A high-risk late gadolinium enhancement (LGE) pattern was defined as epicardial, transmural, or septal plus free-wall. The primary outcome was a composite of heart failure hospitalizations and all-cause mortality. Multivariable analyses were performed to evaluate the impact of DM on outcomes.

RESULTS

We studied 192 patients, of which 51 (26.6%) had DM. The median left ventricular ejection fraction was 30%, and 106 (55.2%) had LGE. No significant differences were found in systolic function parameters between patients with and without DM. E/e values were higher (15 vs. 11.9, p = 0.025), and both LGE (68.6% vs. 50.4%; p = 0.025) and a high-risk LGE pattern (31.4% vs. 18.5%; p = 0.047) were more frequently found in patients with DM. The primary outcome occurred more frequently in diabetic patients (41.2% vs. 23.6%, p = 0.017). DM was an independent predictor of outcomes (OR 2.01; p = 0.049) and of LGE presence (OR 2.15; p = 0.048) in the multivariable analysis. Patients with both DM and LGE had the highest risk of events (HR 3.1; p = 0.003).

CONCLUSION

DM is related to a higher presence of LGE in DCM patients and is an independent predictor of outcomes. Patients with DM and LGE had a threefold risk of events. A multimodality imaging approach allows better risk stratification of these patients and may influence therapeutic options.

Association of diabetes mellitus and glycemic control with left ventricular function and deformation in patients after acute myocardial infarction: a 3 T cardiac magnetic resonance study

BACKGROUND

Diabetes mellitus (DM) is considered a major risk factor for myocardial infarction (MI), and MI patients with DM have a poor prognosis. Accordingly, we aimed to investigate the additive effects of DM on LV deformation in patients after acute MI.

MATERIALS AND METHODS

One hundred thirteen MI patients without DM [MI (DM-)], 95 with DM [MI (DM+)] and 71 control subjects who underwent CMRscanning were included. LV function, infarct size and LV global peak strains in the radial, circumferential and longitudinal directions were measured. MI (DM+) patients were divided into two subgroups based on the HbA1c level (< 7.0% and ≥ 7.0%). The determinants of reduced LV global myocardial strain for all MI patients and MI (DM+) patients were assessed using multivariable linear regression analyses.

RESULTS

Compared with control subjects, both MI (DM-) and MI (DM+) patients presented higher LV end-diastolic and end-systolic volume index and lower LV ejection fraction. LV global peak strains progressively declined from the control group to the MI(DM-) group to the MI(DM+) group (all p < 0.05). Subgroup analysis showed that LV global radial PS and longitudinal PS were worse in MI(MD+) patients with poor glycemic control than in those with good glycemic control (all p < 0.05). DM was an independent determinant of impaired LV global peak strain in radial, circumferential and longitudinal directions in patients after acute MI (β = - 0.166, 0.164 and 0.262, both p < 0.05). The HbA1c level was independently associated with a decreased LV global radial PS (β =  - 0.209, p = 0.025) and longitudinal PS (β = 0.221, p = 0.010) in MI (DM+) patients.

CONCLUSIONS

DM has an additive deleterious effect on LV function and deformation in patients after acute MI, and HbA1c was independently associated with impaired LV myocardial strain.

Cardiovascular magnetic resonance phenotyping of heart failure with mildly reduced ejection fraction

AIMS

The 2016 European Society of Cardiology Heart Failure Guidelines defined a new category: heart failure with mid-range ejection fraction (HFmrEF) of 40-49%. This new category was highlighted as having limited evidence and research was advocated into underlying characteristics, pathophysiology, and diagnosis. We used multi-parametric cardiovascular magnetic resonance (CMR) to define the cardiac phenotype of presumed non-ischaemic HFmrEF.

METHODS AND RESULTS

Patients (N = 300, 62.7 ± 13 years, 63% males) with a clinical diagnosis of heart failure with no angina symptoms, history of myocardial infarction, or coronary intervention were prospectively recruited. Patients underwent clinical assessment and CMR including T1 mapping, extracellular volume (ECV) mapping, late gadolinium enhancement, and measurement of myocardial blood flow at rest and maximal hyperaemia. Of 273 patients in the final analysis, 93 (34%) patients were categorized as HFmrEF, 46 (17%) as heart failure with preserved ejection fraction (HFpEF), and 134 (49%) as heart failure with reduced ejection fraction (HFrEF). Nineteen (20%) patients with HFmrEF had evidence of occult ischaemic heart disease. Diffuse fibrosis and hyperaemic myocardial blood flow were similar in HFmrEF and HFpEF, but HFmrEF showed significantly lower native T1 (1311 ± 32 vs. 1340 ± 45 ms, P < 0.001), ECV (24.6 ± 3.2 vs. 26.3 ± 3.1%, P < 0.001), and higher myocardial perfusion reserve (2.75 ± 0.84 vs. 2.28 ± 0.84, P < 0.001) compared with HFrEF.

CONCLUSION

Patients with HFmrEF share most phenotypic characteristics with HFpEF, including the degree of microvascular impairment and fibrosis, but have a high prevalence of occult ischaemic heart disease similar to HFrEF. Further work is needed to confirm how the phenotype of HFmrEF responds to medical therapy.

Simple Predictors for Cardiac Fibrosis in Patients with Type 2 Diabetes Mellitus: The Role of Circulating Biomarkers and Pulse Wave Velocity

Cardiac fibrosis is the basis of structural and functional disorders in patients with diabetes mellitus (T2DM). A wide range of laboratory and instrumental methods is used for its prediction. The study aimed to identify simple predictors of cardiac fibrosis in patients with T2DM based on the analysis of circulating fibrosis biomarkers and arterial stiffness. The study included patients with T2DM (n = 37) and cardiovascular risk factors (RF, n = 27) who underwent ECHO, cardiac magnetic resonance imaging (MRI), pulse wave analysis (PWV), reactive hyperemia (RH), peripheral arterial tonometry, carotid ultrasonography, and assessment of serum fibrosis biomarkers. As a control group, 15 healthy subjects were examined. Left ventricular concentric hypertrophy was accompanied by an increased serum galectin-3 level in T2DM patients. There was a relationship between the PICP and HbA1c levels in both main groups (R2 = 0.309; p = 0.014). A negative correlation between PICP level and the global longitudinal strain (GLS) was found (r = −0.467; p = 0.004). The RH index had a negative correlation with the duration of diabetes (r = −0.356; p = 0.03), the carotid-femoral PWV (r = −0.371; p = 0.024), and the carotid intima-media thickness (r = −0.622; p < 0.001). The late gadolinium-enhanced (LGE) cardiac MRI was detected in 22 (59.5%) T2DM and in 4 (14.85%) RF patients. Diabetes, its baseline treatment with metformin, HbA1c and serum TIMP-1 levels, and left ventricle hypertrophy had moderate positive correlations with LGE findings (p < 0.05). Using the multivariate regression analysis, increased TIMP-1 level was identified as an independent factor associated with cardiac fibrosis.

Arrhythmogenesis of Sports: Myth or Reality?

Regular exercise confers health benefits with cardiovascular mortality risk reduction through a variety of mechanisms. At a population level, evidence suggests that undertaking more exercise has greater benefits. In the modern era of sport, there has been an exponential rise in professional and amateur athletes participating in endurance events, with a progressively better understanding of the associated cardiac adaptations, collectively termed ‘athletes heart’. However, emerging data raise questions regarding the risk of potential harm from endurance exercise, with an increased risk of arrhythmia from adverse cardiac remodelling. Cross-sectional studies have demonstrated that athletes may exhibit a higher burden of AF, conduction tissue disease, ventricular arrhythmias, a cardiomyopathy-like phenotype and coronary artery disease. In an attempt to separate myth from reality, this review reports on the evidence supporting the notion of ‘too much exercise’, the purported mechanisms of exercise-induced cardiac arrhythmia and complex interplay with sporting discipline, demographics, genetics and acquired factors.

Association of myocardial fibrosis detected by late gadolinium-enhanced MRI with clinical outcomes in patients with diabetes: a systematic review and meta-analysis

OBJECTIVE

This meta-analysis assessed the associations of myocardial fibrosis detected by late gadolinium-enhanced (LGE)-MRI with the risk of major adverse cardiac and cerebrovascular events (MACCEs) and major adverse cardiac events (MACEs) in patients with diabetes.

DESIGN

Systematic review and meta-analysis reported in accordance with the guidelines of the Meta-analysis of Observational Studies in Epidemiology statement.

DATA SOURCES

We searched the Medline, Embase and Cochrane by Ovid databases for studies published up to 27 August 2021.

ELIGIBILITY CRITERIA

Prospective or respective cohort studies were included if they reported the HR and 95% CIs for MACCEs/MACEs in patients with either type 1 or 2 diabetes and LGE-MRI-detected myocardial fibrosis compared with patients without LGE-MRI-detected myocardial fibrosis and if the articles were published in the English language.

DATA EXTRACTION AND SYNTHESIS

Two review authors independently extracted data and assessed the quality of the included studies. Pooled HRs and 95% CIs were analysed using a random effects model. Heterogeneity was assessed using forest plots and I² statistics.

RESULTS

Eight studies with 1121 patients with type 1 or type 2 diabetes were included in this meta-analysis, and the follow-up ranged from 17 to 70 months. The presence of myocardial fibrosis detected by LGE-MRI was associated with an increased risk for MACCEs (HR: 2.58; 95% CI 1.42 to 4.71; p=0.002) and MACEs (HR: 5.28; 95% CI 3.20 to 8.70; p<0.001) in patients with diabetes. Subgroup analysis revealed that ischaemic fibrosis detected by LGE was associated with MACCEs (HR 3.80, 95% CI 2.38 to 6.07; p<0.001) in patients with diabetes.

CONCLUSIONS

This study demonstrated that ischaemic myocardial fibrosis detected by LGE-MRI was associated with an increased risk of MACCEs/MACEs in patients with diabetes and may be an imaging biomarker for risk stratification. Whether LGE-MRI provides incremental prognostic information with respect to MACCEs/MACEs over risk stratification by conventional cardiovascular risk factors requires further study.

Comprehensive Management of Cardiovascular Risk Factors for Adults With Type 2 Diabetes: A Scientific Statement From the American Heart Association

Cardiovascular disease remains the leading cause of death in patients with diabetes. Cardiovascular disease in diabetes is multifactorial, and control of the cardiovascular risk factors leads to substantial reductions in cardiovascular events. The 2015 American Heart Association and American Diabetes Association scientific statement, "Update on Prevention of Cardiovascular Disease in Adults With Type 2 Diabetes Mellitus in Light of Recent Evidence," highlighted the importance of modifying various risk factors responsible for cardiovascular disease in diabetes. At the time, there was limited evidence to suggest that glucose-lowering medications reduce the risk of cardiovascular events. At present, several large randomized controlled trials with newer antihyperglycemic agents have been completed, demonstrating cardiovascular safety and reduction in cardiovascular outcomes, including cardiovascular death, myocardial infarction, stroke, and heart failure. This AHA scientific statement update focuses on (1) the evidence and clinical utility of newer antihyperglycemic agents in improving glycemic control and reducing cardiovascular events in diabetes; (2) the impact of blood pressure control on cardiovascular events in diabetes; and (3) the role of newer lipid-lowering therapies in comprehensive cardiovascular risk management in adults with diabetes. This scientific statement addresses the continued importance of lifestyle interventions, pharmacological therapy, and surgical interventions to curb the epidemic of obesity and metabolic syndrome, important precursors of prediabetes, diabetes, and comorbid cardiovascular disease. Last, this scientific statement explores the critical importance of the social determinants of health and health equity in the continuum of care in diabetes and cardiovascular disease.

Myocardial Extracellular Volume Fraction and T1 Mapping by Cardiac Magnetic Resonance Compared Between Patients With and Without Type 2 Diabetes, and the Effect of ECV and T2D on Cardiovascular Outcomes

Background: To investigate the difference in myocardial extracellular volume fraction (ECV) by cardiac magnetic resonance (CMR) T1 mapping between patients with and without type 2 diabetes (T2D), and the effect of ECV and T2D on cardiovascular (CV) outcomes. Methods: All patients aged > 18 years with known or suspected coronary artery disease who underwent CMR for assessment of myocardial ischemia or myocardial viability at the Department of Cardiology of the Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand from September 2017 to December 2018 were screened for inclusion eligibility. Left ventricular ejection fraction (LVEF), late gadolinium enhancement, and T1 mapping were performed. ECV values were derived from myocardial native T1 and contrast-enhanced T1 values that were obtained using modified Look-Locker inversion recovery at the septum of the mid-cavity short-axis map. Demographic data, clinical characteristics, and CV outcomes were collected by retrospective chart review. Composite CV outcomes included CV death, acute coronary syndrome, heart failure hospitalization, or ventricular tachycardia (VT)/ventricular fibrillation. Results: A total of 739 subjects (mean age: 69.5 ± 14.0 years, 49.3% men) were included. Of those, 188 subjects had T2D (25.4%). ECV was significantly higher in T2D than in non-T2D (30.0 ± 5.9% vs. 28.8 ± 4.7%, p = 0.004). During the mean follow-up duration of 26.2 ± 8.5 months, 43 patients (5.8%) had a clinical composite outcome, as follows: three CV death (0.4%), seven acute coronary syndrome (0.9%), 33 heart failure hospitalization (4.5%), and one VT (0.1%). T2D, low LVEF, and high ECV were all identified as independent predictors of CV events. Patients with T2D and high ECV had the highest risk of CV events. Conclusion: Among patients with known or suspected coronary artery disease, patients with T2D had a higher ECV. T2D and high ECV were both found to be independent risk factors for adverse CV outcomes.

Distinct non-ischemic myocardial late gadolinium enhancement lesions in patients with type 2 diabetes

Background

Cardiovascular magnetic resonance imaging (CMR) have described localised non-ischemic late gadolinium enhancement (LGE) lesions of prognostic importance in various non-ischemic cardiomyopathies. Ischemic LGE lesions are prevalent in diabetes (DM), but non-ischemic LGE lesions have not previously been described or systematically studied in DM.

Methods

296 patients with type 2 DM (T2DM) and 25 sex-matched control subjects underwent echocardiography and CMR including adenosine-stress perfusion, T₁-mapping and LGE.

Results

264 patients and all control subjects completed the CMR protocol. 78.4% of patients with T2DM had no LGE lesions; 11.0% had ischemic LGE lesions only; 9.5% had non-ischemic LGE lesions only; and 1.1% had both one ischemic and one non-ischemic lesion. The non-ischemic LGE lesions were situated mid-myocardial in the basal lateral or the basal inferolateral part of the left ventricle and the affected segments showed normal to high wall thickness and normal contraction. Patients with non-ischemic LGE lesions in comparison with patients without LGE lesions had increased myocardial mass (150 ± 34 vs. 133 ± 33 g, P = 0.02), average E/e’(9.9 IQR8.7–12.6 vs. 8.8 IQR7.4–10.7, P = 0.04), left atrial maximal volume (102 IQR84.6–115.2 vs. 91 IQR75.2–100.0 mL, P = 0.049), NT-proBNP (8.9 IQR5.9–19.7 vs. 5.9 IQR5.9–10.1 µmol/L, P = 0.02) and high-sensitive troponin (15.6 IQR13.0–26.1 vs. 13.0 IQR13.0–14.6 ng/L, P = 0.007) and a higher prevalence of retinopathy (48 vs. 25%, P = 0.009) and autonomic neuropathy (52 vs. 30.5%, P = 0.005).

Conclusion

A specific LGE pattern with lesions in the basal lateral or the basal inferolateral part of the left ventricle was found in patients with type 2 diabetes.

Trial registrationhttps://www.clinicaltrials.gov. Unique identifier: NCT02684331.

Cardiac Involvement in Myotonic Dystrophy Type 2 Patients With Preserved Ejection Fraction: Detection by Cardiovascular Magnetic Resonance

BACKGROUND

Myotonic dystrophy type 2 (DM2) is a genetic disorder characterized by skeletal muscle symptoms, metabolic changes, and cardiac involvement. Histopathologic alterations of the skeletal muscle include fibrosis and fatty infiltration. The aim of this study was to investigate whether subclinical cardiac involvement in DM2 is already detectable in preserved left ventricular function by cardiovascular magnetic resonance.

METHODS AND RESULTS

Twenty-seven patients (mean age, 54±10 years; 20 females) with a genetically confirmed diagnosis of DM2 were compared with 17 healthy age- and sex-matched controls using a 1.5 T magnetic resonance imaging. For myocardial tissue differentiation, T1 and T2 mapping, fat/water-separated imaging, focal fibrosis imaging (late gadolinium enhancement [LGE]), and (1)H magnetic resonance spectroscopy were performed. Extracellular volume fraction was calculated. Conduction abnormalities were diagnosed based on Groh criteria. LGE located subepicardial basal inferolateral was detectable in 22% of the patients. Extracellular volume was increased in this region and in the adjacent medial inferolateral segment (P=0.03 compared with healthy controls). In 21% of patients with DM2, fat deposits were detectable (all women). The control group showed no abnormalities. Myocardial triglycerides were not different in LGE-positive and LGE-negative subjects (P=0.47). Six patients had indicators for conduction disease (60% of LGE-positive patients and 12.5% of LGE-negative patients).

CONCLUSIONS

In DM2, subclinical myocardial injury was already detectable in preserved left ventricular ejection fraction. Extracellular volume was also increased in regions with no focal fibrosis. Myocardial fibrosis was related to conduction abnormalities.