Admission macrophage migration inhibitory factor predicts long-term prognosis in patients with ST-elevation myocardial infarction

Triglyceride-glucose index is associated with in-stent restenosis in patients with acute coronary syndrome after percutaneous coronary intervention with drug-eluting stents

Background

The triglyceride-glucose (TyG) index is an alternative marker of insulin resistance (IR) and is closely associated with the prevalence and prognosis of atherosclerotic cardiovascular disease (ASCVD). However, the association between the TyG index and in-stent restenosis (ISR) after drug-eluting stent (DES) implantation in patients with acute coronary syndrome (ACS) remains unknown.

Methods

The present study retrospectively recruited patients who were admitted for ACS and underwent coronary angiography at 6 to 24 months after successful DES-based percutaneous coronary intervention (PCI). In addition, we calculated the TyG index with the following formula: Ln(fasting triglyceride [mg/dL] × fasting blood glucose [mg/dL]/2) and divided patients into 3 groups according to the tertile of the TyG index. Most importantly, multivariate logistic regression analysis models were also constructed to assess the association between the TyG index and DES-ISR in patients with ACS.

Results

A total of 1574 patients with ACS (58.4 ± 9.4 years, 77.4% male) were included in this study. At the median follow-up time of 12 (9–14) months, the prevalence of DES-ISR increased stepwise with the increasing tertile of the TyG index (11.6% vs 17.3% vs 19.4%, p = 0.002), and the TyG index was also higher in the ISR group than in the non-ISR group (9.00 ± 0.58 vs 8.84 ± 0.61, p < 0.001). In addition, the positive association between the TyG index and the prevalence of DES-ISR was also determined in the fully adjusted model (TyG, per 1-unit increase: OR 1.424, 95% CI 1.116 to 1.818, p = 0.005; tertile of TyG, the OR (95% CI) values for tertile 2 and tertile 3 were 1.454 (1.013 to 2.087) and 1.634 (1.125 to 2.374), respectively, with tertile 1 as a reference). The association was also reflected in most subgroups. Moreover, adding the TyG index to the predictive model for DES-ISR in patients with ACS could contribute to an increase in C-statistics (0.675 vs 0.659, p = 0.010), categorical net reclassification improvement (0.090, p < 0.001), and integrated discrimination improvement (0.004, p = 0.040).

Conclusion

An elevated TyG index was independently and positively associated with DES-ISR in patients with ACS who underwent PCI. However, the incremental predictive value of the TyG index for DES-ISR was slight. To further confirm our findings, future studies are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01332-4.

Autophagy mediates the secretion of macrophage migration inhibitory factor from cardiomyocytes upon serum-starvation

Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine. It is elevated early in the blood of acute myocardial infarction patients. However, it is unclear whether and how MIF is released. This study investigated the cellular source and mechanism of MIF release from hearts. An ischemia-mimic treatment induced the secretion of MIF from neonatal rat cardiomyocytes but not from fibroblasts. The treatment did not cause significant leakage of lactate dehydrogenase, suggesting that ischemia induced the MIF secretion without causing severe cell damage. Plasma samples from patients with acute chest pain at the emergency department were collected for the detection of MIF. MIF levels in patients with acute coronary syndrome (ACS) increased early, when cardiac injury markers were not yet elevated, suggesting that ischemia can induce MIF secretion before the occurrence of severe myocardial damage. Serum-starvation caused MIF secretion from rat cardiomyocytes and Langendorff-perfused rat hearts. The secretion was suppressed by the inhibition of autophagy by inhibitors or by silencing of Atg5. In conclusion, serum-starvation induces the secretion of MIF from cardiomyocytes via autophagy dependent pathway. Clarifying the mechanism of MIF secretion will be helpful for its application in the early diagnosis and treatment of ACS.