Background: With the advancement of the world population aging, more attention should be paid to the prognosis of elderly patients with acute coronary syndrome (ACS). Triglyceride-glucose (TyG) index is a reliable indicator of insulin resistance (IR) and is closely related to traditional risk factors of cardiovascular disease (CVD). However, the effect of TyG index on the prognosis of long-term adverse events in elderly ACS patients has not been reported. This study evaluated the prognostic power of TyG index in predicting adverse events in elderly ACS patients. Methods: In this study, 662 ACS patients > 80 years old who were hospitalized from January 2006 to December 2012 were enrolled consecutively and the general clinical data and baseline blood biochemical indicators were collected. The follow-up time after discharge was 40–120 months (median, 63 months; interquartile range, 51‒74 months). In addition, the following formula was used to calculate the TyG index: Ln [fasting TG (mg/dL) × FBG (mg/dL)/2], and patients were divided into three groups according to the tertile of the TyG index. Results: The mean age of the subjects was 81.87 ± 2.14 years, the proportion of females was 28.10%, and the mean TyG index was 8.76 ± 0.72. The TyG index was closely associated with the traditional risk factors of CVD. In the fully-adjusted Cox regression model, the Hazard ratio (95% CI) of all-cause mortality (in tertile 3) was 1.64 (1.06, 2.54) and major adverse cardiac event (MACE) (in tertile 3) was 1.36 (1.05, 1.95) for each SD increase in the TyG index. The subgroup analyses also confirmed the significant association of the TyG index and long-term prognosis. Conclusion: The TyG index is an independent predictor of long-term all-cause mortality and MACE in elderly ACS patients.

Melatonin is a pleiotropic, indole secreted and synthesized by the human pineal gland. Melatonin has biological effects including anti-apoptosis, protecting mitochondria, anti-oxidation, anti-inflammation, and stimulating target cells to secrete cytokines. Its protective effect on cardiomyocytes in acute myocardial infarction (AMI) has caused widespread interest in the actions of this molecule. The effects of melatonin against oxidative stress, promoting autophagic repair of cells, regulating immune and inflammatory responses, enhancing mitochondrial function, and relieving endoplasmic reticulum stress, play crucial roles in protecting cardiomyocytes from infarction. Mitochondrial apoptosis and dysfunction are common occurrence in cardiomyocyte injury after myocardial infarction. This review focuses on the targets of melatonin in protecting cardiomyocytes in acute myocardial infarction, the main molecular signaling pathways that melatonin influences in its endogenous protective role in myocardial infarction, and the developmental prospect of melatonin in myocardial infarction treatment.

Background: Acute coronary syndrome (ACS) and diabetes mellitus (DM) are the leading health risks for the elderly. Triglyceride-glucose (TyG) index is a novel and reliable indicator of insulin resistance (IR). This study aims to explore the relationship between the TyG index and all-cause mortality in oldest-old patients with ACS and DM. Methods: Seven hundred twenty hospitalized patients with ACS aged ≥ 80 years were enrolled, and 699 patients signed informed consent for the study. During the follow-up period, 37 were lost to follow-up, and the follow-up rate was 94.7%. 231 ACS patients with DM were selected for the study’s analyses. Kaplan–Meier curve, Cox regression model and receiver operating characteristic (ROC) curve were used to analyze the association between the TyG index and all-cause mortality. Results: The mean age of participants was 81.58 ± 1.93 years, and 32.47% were women. Compared to TyG tertile 1, the Hazard Ratio (HR) [95% confidence interval (CI)] of all-cause mortality was 2.04 (1.09, 3.81) for TyG tertile 3 in the fully adjusted model. For the TyG index per standard deviation (SD) increment, the HR (95% CI) of all-cause mortality was 1.44 (1.13, 1.83). Further, the association between the TyG index and all-cause mortality was dose–response (P for trend = 0.026). ROC curve analyses indicated that the TyG index outperformed FBG and TG in the prediction of mortality risk and improved the prognostic value of the Gensini score combined with LVEF. Conclusion: The TyG index predicts the risk of all-cause mortality in the oldest-old ACS patients with DM.

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress contribute to postischemic myocardial damage, but the upstream regulatory mechanisms have not been identified. In this study, we analyzed the role of mitogen‐activated protein kinase (MAPK) phosphatase 1 (MKP‐1) in the regulation of mitochondrial function and ER stress in hypoxic cardiomyocytes. Our results show that MKP‐1 overexpression sustains viability and reduces hypoxia‐induced apoptosis among H9C2 cardiomyocytes. MKP‐1 overexpression attenuates ER stress and expression of ER stress genes and improves mitochondrial function in hypoxia‐treated H9C2 cells. MKP‐1 overexpression also increases ATP production and mitochondrial respiration and attenuates mitochondrial oxidative damage in hypoxic cardiomyocytes. Moreover, our results demonstrate that ERK and JNK are the downstream signaling targets of MKP‐1 and that MKP‐1 overexpression activates ERK, while it inhibits JNK. Inhibition of ERK reduces the ability of MKP‐1 to preserve mitochondrial function and ER homeostasis in hypoxic cardiomyocytes. These results show that MKP‐1 plays an essential role in the regulation of mitochondrial function and ER stress in hypoxic H9C2 cardiomyocytes through normalization of the ERK pathway and suggest that MKP‐1 may serve as a novel target for the treatment of postischemic myocardial injury.

Objective: To evaluate the prognostic value of homocysteine (Hcy) in Chinese acute coronary syndrome (ACS) octogenarians. Methods: The study cohort comprised 660 consecutive ACS octogenarians who underwent coronary angiography. We classified the patients into three groups according to Hcy tertiles. Kaplan–Meier method was performed for survival and major adverse cardiac events (MACE) rates. Multivariate Cox regression was performed to identify mortality predictors. Receiver operating characteristic curve analysis was performed to predict the cutoff value of Hcy for all-cause mortality. Results: The follow-up period was 28 (inter-quartile range: 16–38) months. Diastolic blood pressure, ratios of male, renal failure and old myocardial infarction in high plasma level Hcy (H-Hcy) group were higher than those in low (L-Hcy) and middle (M-Hcy) plasma level of Hcy groups (P<0.05). The Hcy level was positively correlated with uric acid level (r=0.211, P=0.001) and Cystatin C (Cys C) level (r=0.212, P=0.001) and negatively correlated with estimated glomerular filtration rate (r=−0.148, P=0.018). For the long-term outcomes, the cumulative survival rate of H-Hcy group was significantly lower than that of L-Hcy and M-Hcy groups (P=0.006). All-cause mortality and MACE of H-Hcy group were higher than those of L-Hcy and M-Hcy group (P=0.0001, P=0.0008). Hcy is an independent predictor for long-term all-cause mortality (odds ratio =2.26, 95% CI=1.23–4.16, P=0.023) and MACE (odds ratio =1.91, 95% CI=1.03–3.51, P=0.039). Receiver operating characteristic curve analysis indicated the predictive cutoff value of Hcy for all-cause mortality was 17.67 µmol/L (0.667, 0.681). Conclusion: In ACS octogenarians, hyperhomocysteinemia is an important predictor for long-term all-cause mortality and MACE.