Metabolic syndrome and the risk of adverse cardiovascular events in patients with myocardial infarction with non-obstructive coronary arteries

Influence of Metabolic Syndrome on the Long-Term Prognosis of Patients with Myocardial Infarction: A Meta-Analysis

The influence of metabolic syndrome (MetS) on long-term prognosis of patients with myocardial infarction (MI), the most severe type of coronary artery disease, remains not fully determined. This systematic review and meta-analysis were conducted to investigate the association between MetS and long-term clinical outcomes of patients with MI. A systematic search of Medline, Web of Science, and Embase databases from inception to June 25, 2023, was conducted to obtain eligible studies. Only studies with follow-up duration for at least one year were considered. A random-effects model was utilized to pool the results, accounting for heterogeneity. Ten observational studies were included, which included 33 197 patients with MI. Among them, 17 244 (51.9%) were with MetS at baseline. During a follow-up duration of 12 to 48 months (mean: 22.5 months), patients with MetS were associated with higher incidence of major adverse cardiovascular events [risk ratio (RR): 1.35. 95% confidence interval (CI): 1.19 to 1.54, p<0.001; I2=64%] and all-cause deaths (RR: 1.34, 95% CI: 1.18 to 1.52, p<0.001; I2=23%), as compared to those without MetS at baseline. Subgroup analyses showed that the results were not significantly affected by study characteristics such as study country, design, type of MI, mean age of the patients, treatment with percutaneous coronary intervention, follow-up durations, or study quality scores (p for subgroup difference all>0.05). In patients with MI, MetS may be a risk factor of poor long-term prognosis.

Effect of Metabolic Syndrome on Left Atrial and Left Ventricular Deformation and Atrioventricular Interactions in Patients With Myocardial Infarction

BACKGROUND

Metabolic syndrome (MetS) is associated with worse prognosis in patients with myocardial infarction (MI). However, it is unclear how MetS in MI patients is associated with left atrial (LA) and left ventricular (LV) deformation.

PURPOSE

To determine the effect of MetS on LA and LV deformation and atrioventricular interactions in MI patients.

STUDY TYPE

Retrospective.

POPULATION

One hundred eighty-one MI patients (73 MetS+ and 108 MetS-), 107 age- and sex-matched controls (49 MetS+ and 58 MetS-).

FIELD STRENGTH/SEQUENCE

3.0 T/balanced steady-state free precession (SSFP)/segmented phase-sensitive inversion recovery SSFP sequence.

ASSESSMENT

LA strain and strain rates (reservoir, conduit, and active), left atrioventricular coupling index (LACI), and LV geometry and radial, circumferential and longitudinal global peak strains (PS) were compared among groups.

STATISTICAL TESTS

Two-way analysis of variance, Spearman and Pearson's correlation coefficients, and multivariable linear regression analysis. P value <0.05 indicated statistical significance.

RESULTS

Compared with controls, the MI patients with or without MetS showed impaired LA function (reservoir, conduit, and active) and LV deformation (radial, circumferential, and longitudinal PS) and higher LACI. The MetS+ group had lower LA reservoir and conduit function and LV deformation than MetS- group. The MetS-MI interaction was not statistically significant. Furthermore, multivariable linear regression showed that MetS was independently associated with LA and LV deformation (β = -0.181 to -0.209) in MI patients; LA function was independently associated with LV circumferential PS (β = 0.230 to 0.394) and longitudinal PS (β = 0.189 to 0.420), and LA passive strain and strain rate were negatively associated with LV mass (β = -0.178 and -0.298).

DATA CONCLUSION

MetS may be associated with the LA and LV dysfunction in MI patients. Impaired LV deformation and LV hypertrophy are independently associated with LA dysfunction in MI patients, and the MI patients have higher LACI than controls, suggesting atrioventricular interaction alterations.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: 3.

MINOCA: A Working Diagnosis

Cases of patients presenting with myocardial infarction (MI) without angiographic obstructive CAD are not trivial and have significant prevalence. "The Fourth Universal Definition of MI" (4UDMI) published in 2018 introduced MI with non-obstructive coronary arteries (MINOCA). The new section was of great importance as it validated the diagnosis by defining its criteria and recognizing its presence in the community and the need for further investigation. Given the nature of the diagnosis of MINOCA, coronary angiography provides limited information about prognosis and risk stratification for future major adverse cardiovascular events (MACE). Thus, additional imaging to understand the underlying etiology of MINOCA in conjunction with a better understanding of prognostic factors is necessary to expand on the current guidelines and aid in screening for possible complications, risk of MACE, and all-cause mortality. Discerning the etiology of the presentation is crucial, and physiologic studies, as well as additional imaging, are an important part of this evaluation. These modalities include intravascular studies such as optical coherence tomography (OCT), intravascular ultrasound (IVUS), fractional flow reserve (FFR), and imaging in the form of cardiac CT (CCT) and cardiac MRI (CMR). This step is essential to target treatment regimens more efficiently. The purpose of promoting multiple imaging modalities beyond traditional angiography is to address the working MINOCA diagnosis, with the finality of identifying the specific ischemic pathophysiology. MINOCA has multiple causative mechanisms, making it a heterogeneous collection of etiologies, resulting in acute MI: atherosclerotic, and non-atherosclerotic. This literature revision demonstrates that MINOCA prevalence and mortality are not trivial, and the diagnosis affects quality of life. MINOCA presents a definitive risk of MACE without proper stratification and targeted medical therapy. Several prognostic factors of morbidity and mortality in MI-CAD patients have been identified to correlate with MINOCA patients, especially inflammatory markers. MINOCA is not an exclusion diagnosis but a working diagnosis for which further imaging studies should be performed.

Triglyceride-glucose index and coronary artery disease: a systematic review and meta-analysis of risk, severity, and prognosis

BACKGROUND

The TyG index is an indicator of insulin resistance (IR), which is associated with the development and prognosis of cardiovascular disease. This study aimed to summarize the relationship between the TyG index and the risk, severity, and prognosis of coronary artery disease (CAD) by performing a systematic review and meta-analysis.

METHODS

The PubMed, EMBASE, The Cochrane Library, and Web of Science databases were searched for articles published from inception until May 1, 2023. Cross-sectional studies, retrospective or prospective cohort studies recruiting patients with CAD were included. For the analysis of CAD severity, the outcomes were coronary artery calcification, coronary artery stenosis, coronary plaque progression, multi-vessel CAD, and in-stent re-stenosis. For the analysis of CAD prognosis, the primary outcome was major adverse cardiovascular events (MACE).

RESULTS

Forty-one studies were included in this study. Compared to patients with the lowest TyG index, those with the highest TyG index had a higher CAD risk [odds ratio (OR): 1.94, 95% confidence interval (CI) 1.20-3.14, I2 = 91%, P = 0.007]. Additionally, these patients were more likely to have stenotic coronary arteries (OR: 3.49, 95% CI 1.71-7.12, I2 = 0%, P = 0.0006), progressed plaques (OR: 1.67, 95% CI 1.28-2.19, I2 = 0%, P = 0.002), and with more vessels involved (OR: 2.33, 95% CI 1.59-3.42, I2 = 0%, P < 0.0001). When calculated as a categorized variable, it appears that acute coronary syndrome (ACS) patients with higher TyG index levels may have a higher incidence rate of MACE [hazard ratio (HR): 2.09, 95% CI 1.68-2.62, I2 = 87%, P < 0.00001], whereas chronic coronary syndrome (CCS) or stable CAD patients with higher TyG index levels showed a trend towards an increased incidence rate of MACE (HR: 1.24, 95% CI 0.96-1.60, I2 = 85%, P = 0.09). When calculated as a continuous variable, ACS patients had an HR of 2.28 per 1-unit/1-standard deviation increment of the TyG index (95% CI 1.44-3.63, I2 = 95%, P = 0.0005). Similarly, CCS or stable CAD patients had an HR of 1.49 per 1-unit/1-standard deviation increment of the TyG index (95% CI 1.21-1.83, I2 = 75%, P = 0.0001). Myocardial infarction with non-obstructive coronary arteries patients had an HR of 1.85 per 1-unit increment of the TyG index (95% CI 1.17-2.93, P = 0.008).

CONCLUSIONS

The TyG index is a simple new synthetic index that has been proven to be a valuable tool in the whole-course management of CAD patients. Patients with higher TyG index levels are at a higher risk of CAD, more severe coronary artery lesions, and worse prognosis compared to those with lower TyG index levels.

Association of stress hyperglycemia ratio and poor long-term prognosis in patients with myocardial infarction with non-obstructive coronary arteries

BACKGROUND

Stress hyperglycemia ratio (SHR) is a novel biomarker of true acute hyperglycemia condition and is associated with a worse prognosis in patients with myocardial infarction (MI). However, the effects of SHR in the setting of MI with non-obstructive coronary arteries (MINOCA) have not been investigated. This study aimed to explore the association between SHR and long-term clinical outcomes among MINOCA patients.

METHODS

A total of 410 MINOCA patients were included in the final analysis of this study. The patients were divided into three groups based on the SHR tertiles: [SHR1 group (SHR ≤ 0.73), (n = 143); SHR2 group (SHR 0.73-0.84), n = 131; and SHR3 group (SHR ≥ 0.84), n = 136]. Follow-up for major adverse cardiovascular events (MACE) was conducted on all patients. Cox regression and Kaplan-Meier curve analysis were used to evaluate the relationship between SHR and MACE. The receiver operating curve (ROC) analysis was applied to obtain the optimal cut-off value of SHR for predicting clinical MACE.

RESULTS

A total of 92 patients developed MACE during the mean 34 months of follow-up. A significant increase in MACE was observed in the SHR3 group compared to the SHR1 and SHR2 groups (35.3% vs. 15.4% and 16.8%, respectively; P < 0.001). The Kaplan-Meier curves demonstrate that SHR3 patients had the highest MACE risk compared to SHR1 and SHR2 patients (log-rank P < 0.001). In addition, when both SHR tertiles and diabetes status were considered, those with SHR3 and diabetes had the highest hazard of MACE (log-rank P < 0.001). Multivariate Cox regression analysis showed that the SHR3 is associated with a 2.465-fold increase in the risk of MACE (adjusted HR, 2.465; 95% CI 1.461-4.159, P = 0.001). The ROC curve analysis showed that the optimal SHR cut-off value for predicting clinical MACE among MINOCA was 0.86.

CONCLUSION

Our data indicates, for the first time, that SHR is independently associated with poor long-term prognosis in patients suffering from MINOCA. The optimal SHR cut-off value for predicting clinical MACE among MINOCA patients was 0.86. These findings suggest that SHR may play a potential role in the cardiovascular risk stratification of the MINOCA population.