Resting Left Ventricular Global Longitudinal Strain to Identify Silent Myocardial Ischemia in Asymptomatic Patients with Diabetes Mellitus

The Diagnostic Value of Plasma NETs Levels and iCEB in Silent Myocardial Ischemia in Maintenance Hemodialysis Patients

Objective

This study evaluated the diagnostic value of plasma Neutrophil extracellular traps (NETs) levels and the index of cardiac electrophysiological balance (iCEB) in identifying silent myocardial ischemia (SMI) in maintenance hemodialysis (MHD) patients.

Methods

This cross-sectional observational study involved patients receiving MHD treatment. Data were collected on coronary angiography performed in our hospital from February 2023 to February 2024. Patients diagnosed with myocardial ischemia via coronary angiography but without obvious symptoms were grouped as the SMI group, while those without SMI were grouped as the control group. Plasma NETs levels were assessed using markers indicative of NETs components including double-stranded DNA (dsDNA), circulating free DNA (cfDNA) and myeloperoxidase, while iCEB (QT/QRS) and electrocardiographic findings were obtained. Additionally, echocardiographic parameters, inflammatory markers, and cardiac biomarkers were analyzed. Receiver operating characteristic (ROC) analysis were employed to evaluate the diagnostic accuracy of plasma NETs levels and iCEB in identifying SMI.

Results

A total of 114 patients were included, with 79 participants in the control group and 35 participants in the SMI group. The SMI group exhibited significantly elevated levels of NETs associated components (dsDNA(37.89±4.55 vs 31.64±5.32, P<0.001), cfDNA(11.27±2.03 vs 8.91±1.84, P<0.001), MPO-DNA(23.69±4.01 vs 17.52±3.41, P<0.001)), as well as higher iCEB compared to the control group(56.45±7.67 vs 45.89±6.23, P<0.001). Furthermore, electrocardiography findings, echocardiographic parameters, inflammatory markers, and cardiac biomarkers showed significant differences between the two groups. The ROC analysis demonstrated the potential diagnostic accuracies of NETs levels and iCEB, with an area under the curve (AUC) of 0.908, sensitivity of 0.987, and specificity of 0.829 for identifying SMI.

Conclusion

The study highlights the combined diagnostic value of plasma NETs levels and iCEB in identifying SMI in MHD patients, providing valuable insights into potential early detection and risk stratification strategies for this population.

Integrating Toe Brachial Index and longitudinal strain echocardiography for detecting coronary artery disease in patients with diabetic foot syndrome

Coronary artery disease (CAD) is a common problem amongst diabetic foot syndrome (DFS) patients, associated with peripheral arterial disease. This analytic cross-sectional study investigates the diagnostic efficacy of the Toe Brachial Index (TBI) in the detection of CAD in 62 DFS patients. The presence of CAD was assessed by longitudinal strain echocardiography, a sensitive method that provides a more accurate measure of intrinsic left ventricular contractility than left ventricular ejection fraction, especially in diabetic patients. Univariate and multivariate logistic regression identified CAD-associated factors. Receiver operating characteristic curve evaluated TBI and toe pressure's diagnostic performance for CAD. p-Values < 0.05 were considered significant. There was a significant association between TBI and CAD, with each 0.01 increase in TBI associated with a 15% decrease in the odds of CAD development (odds ratio = 0.85, 95% CI: 0.72-0.99, p = 0.039). TBI demonstrated an area under the curve of 0.854, a sensitivity of 80.0% and a specificity of 66.7% at a cut-off of 0.69. Additionally, toe pressure exhibited an area under the curve of 0.845, sensitivity of 74.0% and specificity of 75.0% at a cut-off of 68.0 mmHg. Overall accuracy for TBI and toe pressure was 77.4% and 74.2%, respectively, indicating their potential for CAD risk stratification in the DFS population. This study highlights a significant association between low TBI and the presence of CAD in DFS patients. Consequently, TBI emerges as a valuable screening tool for identifying CAD within this population.

Resting strain analysis to identify myocardial ischemia in patients with advanced chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is associated with higher incidence of cardiovascular death. Screening for coronary artery disease in asymptomatic or mildly symptomatic patients is challenging.

OBJECTIVE

The aim of this study was to investigate the incremental value of resting deformation analysis in predicting positive results for myocardial ischemia during stress transthoracic echocardiography in patients with end-stage CKD.

METHODS

Sixty-one patients (mean age: 62.3 ± 11.8, 65.7% men) with end-stage CKD were included in the study. Patients underwent a resting transthoracic echocardiogram and a dobutamine stress contrast echo (DSE) protocol. Positive results of DSE were defined as stress-induced left ventricular (LV) wall motion abnormalities.

RESULTS

The study cohort had normal or mildly impaired systolic function: mean LV ejection fraction (EF) was 49.2% (±10.4) and mean LV global longitudinal strain (GLS) was 14.4% (±4.5). Half of our population had impaired left atrial (LA) strain: mean LA reservoir, conduit, and contractile reserve were 24.1% (±12.6), 10.6% (±5.9), and 13.6% (±9.2), respectively. DSE was positive for ischemia in 55.7%. A significant negative association with DSE results was found for LV EF, LV GLS and the conduit phase of LA strain. Both LV and LA dimensions showed positive correlation with presence of ischemia in DSE. Multivariate logistic regression analysis showed that LV GLS was independently associated with DSE (p = 0.007), after controlling for covariates, with high diagnostic accuracy.

CONCLUSION

Resting LV deformation could predict positive results during DSE, thus may be useful to better identify renal patients who might benefit from coronary artery screening.

Silent Myocardial Ischemia: From Pathophysiology to Diagnosis and Treatment

Silent myocardial ischemia (SMI), characterized by a lack of overt symptoms despite an inadequate blood supply to the myocardium, remains a challenging entity in cardiovascular medicine. The pathogenesis involves intricate interactions of vascular, neurohormonal, and metabolic factors, contributing to perfusion deficits without the characteristic chest pain. Understanding these mechanisms is pivotal for recognizing diverse clinical presentations and designing targeted interventions. Diagnostic strategies for SMI have evolved from traditional electrocardiography to advanced imaging modalities, including stress echocardiography, single-photon emission computed tomography (SPECT), positron emission tomography (PET), and cardiac magnetic resonance imaging (MRI). Treating SMI is a matter of ongoing debate, as the available evidence on the role of invasive versus medical management is controversial. This comprehensive review synthesizes current knowledge of silent myocardial ischemia, addressing its pathophysiology, diagnostic modalities, and therapeutic interventions.

Silent Myocardial Ischemia Revisited, Another Silent Killer, Emphasis on the Diagnostic Value of Stress Echocardiography with Focused Update and Review

Silent myocardial ischemia (SMI) is a relatively common phenomenon in patients with coronary artery disease (CAD). The original description of SMI dates back to the 1970s. We performed an extensive search of the literature starting from 2000, using MEDLINE or PubMed, and 676 documents were analyzed, and only 45 articles found suitable for the study were selected. Data regarding the prevalence and risk factors of SMI were discussed, along with the different mechanistic processes behind it; also, methods for screening and diagnosis are exposed, namely electrocardiographic stress test, stress echocardiography, and single-photon emission computed tomography (SPECT). The silent nature of the condition presumes that patients are diagnosed at a more advanced stage, and screening high-risk patients for early management is essential. Education of patients is necessary, and medical management along with cardiac rehabilitation is valid for mild cases, whereas patients with moderate-to-severe myocardial ischemia might require a more invasive approach. SMI is relatively common, diagnostic approach offers data regarding the presence of ischemia along with its anatomic extent, providing important prognostic value. Given its silent and critical nature, future directions for better screening and management must be searched and implemented extensively.

Association between resting myocardial work indices and stress myocardial perfusion in patients with angina and non-obstructive coronary artery disease

BACKGROUND

Myocardial work (MW) indices and longitudinal strain (LS) are sensitive markers of early left ventricular systolic dysfunction. Stress computed tomography myocardial perfusion imaging (CT-MPI) can assess early myocardial ischemia. The association between resting MW indices and stress myocardial perfusion remains unclear. This study compares resting MW indices with LS to assess stress myocardial perfusion in angina patients with non-obstructive coronary artery disease (CAD).

METHODS

Eighty-four patients who underwent resting echocardiography, coronary computed tomography angiography, and stress CT-MPI were reviewed. Seventeen myocardial segments were divided into three regions according to the epicardial coronary arteries. Global indices included global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE). Regional indices included regional longitudinal strain (RLS), regional work index (RWI), and regional work efficiency (RWE). Reduced global perfusion was defined as an average stress myocardial blood flow (MBF) <116 mL/100 mL/min for the whole heart. Reduced regional perfusion was defined as an average stress MBF <116 mL/100 mL/min for the coronary territories. No patients demonstrated obstructions in the epicardial coronary arteries (stenosis diameter <50%). The MW indices and LS were compared. Receiver operating characteristic curves were constructed and logistic regression analyses were used to investigate the predictors of reduced myocardial perfusion.

RESULTS

Patients with reduced stress perfusion demonstrated reduced GLS, GWI, GCW, and GWE (P<0.05) and increased GWW (P<0.05). After adjustment for age and sex, GWE was still independently associated with reduced myocardial perfusion (odds ratio =0.386, 95% confidence interval: 0.214-0.697; P<0.05). Receiver operating characteristic curves reflected the good diagnostic ability of GWE and its superiority to GLS (area under the curve: 0.858 vs. 0.741). The optimal cutoff GWE value was 95% (sensitivity, 70%; specificity, 90%). Regions with lower stress perfusion showed lower RLS, RWI, and RWE (P<0.05). The optimal cutoff value of RWE for predicting reduced regional perfusion was 95%, with an area under the curve of 0.780, a sensitivity of 62%, and a specificity of 83%.

CONCLUSIONS

Resting MW indices perform well in assessing global and regional stress myocardial perfusion in angina patients with non-obstructive CAD, and GWE is superior to GLS in the global evaluations.

Dynamic evolution of left ventricular strain and microvascular perfusion assessed by speckle tracking echocardiography and myocardial contrast echocardiography in diabetic rats: Effect of dapagliflozin

Background

This experimental study aimed to determine the dynamic changes in myocardial strain and microvascular perfusion in diabetic rats by comprehensive echocardiography while evaluating the effect of dapagliflozin (DAPA).

Materials and methods

Male Sprague-Dawley rats (n = 128) were randomly divided into four groups based on the presence or absence of a high-fat diet and streptozotocin-induced diabetes with or without DAPA treatment (n = 32/group). Serial conventional ultrasound, two-dimensional speckle tracking echocardiography (2D-STE) and myocardial contrast echocardiography (MCE) were performed at 2, 4, 6, and 8 weeks, and left ventricular global longitudinal strain (GLS), myocardial blood flow velocity (MBFV), myocardial blood flow (MBF), and myocardial blood volume (MBV) were determined. All animals were sacrificed immediately after the last echo measurement for histopathological assessment.

Results

Despite similar conventional Doppler-echo indexes among the groups at 2, 4, 6, and 8 weeks (p > 0.05), left ventricular GLS, MBFV, MBF, and MBV were decreased at 8 weeks in diabetic rats (p < 0.05) as detected by both 2D-STE and MCE. These indexes were significantly improved at 6 and 8 weeks after treatment with DAPA for diabetic rats (p < 0.05), reaching similar values observed in non-diabetic controls. DAPA treatment was associated with increased myocardial vacuolization and microvessel density and reduced interstitial fibrosis in diabetic rats.

Conclusions

Combined 2D-STE and MCE is sensitive for detecting left ventricular deformity and impaired microvascular perfusion in prediabetes and the early stage of diabetes mellitus. DAPA exerts a beneficial effect on protecting myocardial perfusion in diabetic rats.

Performance of the 2019 ESC/EASD guideline strategy for the screening of silent coronary artery disease in patients with diabetes

BACKGROUND

The 2019 guidelines for cardiovascular risk stratification by the European Society of Cardiology and European Association for the Study of Diabetes (ESC-EASD) suggested screening for silent coronary disease in very high risk patients with severe target organ damage (TOD) (i.e. peripheral occlusive arterial disease or severe nephropathy) or high coronary artery calcium (CAC) score. This study aimed to test the validity of this strategy.

METHODS

In this retrospective study, we included 385 asymptomatic patients with diabetes and no history of coronary disease but with TOD or ≥ 3 risk factors in addition to diabetes. CAC score was measured using computed tomography scan and a stress myocardial scintigraphy was performed to detect silent myocardial ischemia (SMI), with subsequent coronary angiography in those with SMI. Various strategies to select patients to be screened for SMI were tested.

RESULTS

CAC score was ≥ 100 Agatston units (AU) in 175 patients (45.5%). SMI was present in 39 patients (10.1%) and among the 30 patients who underwent angiography, 15 had coronary stenoses and 12 had a revascularization procedure. The most effective strategy consisted in performing myocardial scintigraphy in the 146 patients with severe TOD and, among the 239 other patients without severe TOD, in those with CAC ≥ 100 AU: this strategy provided 82% sensitivity for SMI diagnosis, and identified all the patients with stenoses.

CONCLUSION

The ESC-EASD guidelines suggesting SMI screening in asymptomatic patients with very high risk assessed by severe TOD or high CAC score appears effective and could identify all the patients with stenoses eligible for revascularization.