Our study established and validated a predictive model for NOAF in 551 AMI patients post-PCI, identifying age, serum creatinine, the TyG index, LA diameter, and the SIRI as independent risk factors. We developed a regression model using these predictors, which demonstrated good calibration, discrimination, and clinical utility after validation through multiple methods.
IR is known to be associated with several diseases, including hypertension and CAD18,23. The TyG index serves as a reliable surrogate marker of IR14. Research has shown that the TyG index is positively associated with metabolic risk factors and cardiovascular outcomes. For instance, Zheng et al. demonstrated that the TyG index was independently associated with an increased risk of hypertension, even after adjusting for potential confounding variables18. Additionally, Li et al. analyzed 1516 patients with symptomatic CAD at Tianjin Union Medical Center from January 2016 to December 2022, finding that higher TyG index values were predictive of a high rate of coronary lesions and plaques24. The TyG index has also been recognized as an effective indicator of postoperative NOAF following septal myectomy25. Furthermore, Wang et al. conducted a retrospective survey of 2242 AF patients over a one-year follow-up period, from June 2018 to January 2022, at two hospitals in China, concluding that the TyG index could be independently associated with AF recurrence following ablation26. Several mechanisms may explain the correlation between the TyG index and AF. Primarily, insulin resistance (IR) can lead to excessive lipid accumulation in cardiomyocytes, resulting in a phenomenon known as "cardiotoxicity." This accumulation causes cellular dysfunction, cardiomyocyte apoptosis, and impaired myocardial metabolism, potentially altering the function and structure of cardiomyocytes and increasing the risk of AF27. IR also promotes CaMKIIδ oxidation, leading to abnormal intracellular calcium homeostasis and atrial structural remodeling28. Animal studies have demonstrated that IR impairs the transport and expression of the major myocardial isoform of the glucose transporter protein (GLUT) 4 and the novel subtype GLUT8, heightening susceptibility to AF. IR is associated with various aspects of left atrial (LA) remodeling, including increased oxidative stress, elevated expression of hyperphosphorylated calcium-related proteins, and cardiac fibrosis29. Increased oxidative stress and inflammation related to impaired IR and insulin secretion contribute to atrial electrical remodeling, LA fibrosis, and the formation of LA low-pressure areas30.
Regarding the other four variables, previous studies have identified advancing age as an independent risk factor for the development of AF. With aging, the myocardium undergoes anatomical and electrophysiological changes, including the loss of lateral electrical connections between myofibers and reduced electrical conduction in the sinoatrial node, atrioventricular node, and atria31. Left atrial diameter has been recognized as an independent predictor for NOAF, with increased left atrial diameter indicating progressive dilatation and remodeling of the left atrial myocardium, which serves as a substrate for AF initiation and maintenance32.
As we know, inflammation plays a role in the development and prognosis of AMI, with certain inflammatory markers, such as C-reactive protein and the SII, correlated with both short- and long-term prognosis of myocardial infarction33,34. Previous studies have shown that the SIRI can predict prognosis in cardiovascular diseases35,36. Furthermore, a recent retrospective study of 526 ischemic stroke patients confirmed that SIRI is an independent predictor of AF36. SIRI encompasses neutrophils, lymphocytes, and monocytes. Monocyte aggregation leads to the production of inflammatory factors, such as interleukin (IL)-6 and IL-1β, which contribute to atrial structural and electrical remodeling, ultimately leadingii to atrial fibrillation37. Additionally, neutrophils can produce proinflammatory cytokines, proteases, peroxidases, and reactive oxygen species, which may result in atrial fibrosis38. Finally, T cells and B cells, which are lymphocytes, play roles in AF—T cells primarily regulate the innate immune response, and B cells may affect the condition by secreting autoantibodies. Concerning creatinine, renal dysfunction is associated with both electrical and structural remodeling of the LA, potentially leading to new-onset POAF39.
We constructed a new nomogram that includes the TyG index, SIRI, creatinine, age, and LA diameter. Our model demonstrates high clinical predictive performance and is a practical fit. The nomogram can identify patients who are at high risk of NOAF, facilitating early inter