Clinical profile and outcomes of atrial fibrillation in elderly patients with acute myocardial infarction:

Early inhibition of the ATM/p53 pathway reduces the susceptibility to atrial fibrillation and atrial remodeling following acute myocardial infarction

Atrial fibrillation (AF) emerges as a critical complication following acute myocardial infarction (AMI) and is associated with a significant increased risk of heart failure, stroke and mortality. Ataxia telangiectasia mutated (ATM), a key player in DNA damage repair (DDR), has been implicated in multiple cardiovascular conditions, however, its involvement in the development of AF following AMI remains unexplored. This study seeks to clarify the contribution of the ATM/p53 pathway in the onset of AF post-AMI and to investigate the underlying mechanisms. The rat model of AMI was established by ligating left anterior descending coronary artery in the presence or absence of Ku55933 (an ATM kinase inhibitor, 5 mg/kg/d) treatment. Rats receiving Ku55933 were further divided into the early administration group (administered on days 1, 2, 4, and 7 post-AMI) and the late administration group (administered on days 8, 9, 11 and 14 post-AMI). RNA-sequencing was performed 14 days post-operation. In vitro, H2O2-challenged HL-1 atrial muscle cells were utilized to evaluate the potential effects of different ATM inhibition schemes, including earlier, middle, and late periods of intervention. Fourteen days post-AMI injury, the animals exhibited significantly increased AF inducibility, exacerbated atrial electrical/structural remodeling, reduced ventricular function and exacerbated atrial DNA damage, as evidenced by enhanced ATM/p53 signaling as well as γH2AX level. These effects were partially consistent with the enrichment results of bioinformatics analysis. Notably, the deleterious effects were ameliorated by early, but not late, administration of Ku55933. Mechanistically, inhibition of ATM signaling successfully suppressed atrial NLRP3 inflammasome-mediated pyroptotic pathway. Additionally, the results were validated in the in vitro experiments demonstrating that early inhibition of Ku55933 not only attenuated cellular ATM/p53 signaling, but also mitigated inflammatory response by reducing NLRP3 activation. Collectively, hyperactivation of ATM/p53 contributed to the pathogenesis of AF following AMI. Early intervention with ATM inhibitors substantially mitigated AF susceptibility and atrial electrical/structural remodeling, highlighting a novel therapeutic avenue against cardiac arrhythmia following AMI.

Effects of using primary percutaneous coronary interventions on the incidence of new-onset atrial fibrillation following an acute myocardial infarction

BACKGROUND

Acute ST-segment elevation myocardial infarction (STEMI) and new-onset atrial fibrillation (AF) are associated with increased risk of mortality.

HYPOTHESIS

This study aimed to determine the proportion of patients who go on to develop new-onset a AF after undergoing a primary or delayed percutaneous coronary intervention (PCI) for an acute STEMI and to explore possible risk factors.

METHODS

One hundred and fifty-four patients who underwent PCI after STEMI were included in the study. Patient characteristics, baseline blood tests and cardiac parameters, type of PCI, and incidence of new-onset AF within 3 months of PCI were recorded and analyzed.

RESULTS

Fifteen developed new-onset AF following the PCI, and 139 patients maintained a sinus rhythm. Univariate analysis showed significant differences between the two patient groups in terms of age, nature of the PCI (primary vs. delayed), left atrial diameter, and left ventricular diastolic dysfunction (p < .05). Age (odds ratio [OR] = 1.065, 95% confidence interval [CI]: 1.007-1.127, p < .05) and left atrial diameter (OR = 1.165, 95% CI: 1.008-1.347, p < .05), were independent predictors of new-onset AF after PCI. Primary PCI (OR = 0.232, 95% CI: 0.066-0.814, p < .05) was an independent protective factor.

CONCLUSION

Age and left atrial diameter were independent risk factors of new-onset AF in patients undergoing a PCI following an acute myocardial infarction, while primary PCI was a protective factor. This discovery can help reduce mortality rate, improve long-term prognosis, and provide a theoretical basis for the prevention of new-onset AF.

A Predictive Model of New-Onset Atrial Fibrillation After Percutaneous Coronary Intervention in Acute Myocardial Infarction Based on the Lymphocyte to C-Reactive Protein Ratio

Purpose

Lymphocyte to C-reactive protein ratio (LCR) is a recognized systemic inflammatory marker and novel prognostic indicator for several cancers. This study investigated the relationship between preoperative LCR and new-onset atrial fibrillation (NOAF) in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI).

Patients and Methods

Patients with AMI (n=662) with no history of atrial fibrillation (AF) were enrolled and classified into NOAF and non-NOAF groups based on the occurrence of postoperative NOAF during hospitalization. Logistic regression models were used to analyze NOAF risk factors and to assess the association between preoperative LCR and NOAF incidence. We constructed a new nomogram from the selected NOAF risk factors, and tested its predictive performance, degree of calibration, and clinical utility using receiver operating characteristic and calibration curves, decision curve analysis, and clinical impact curves.

Results

Overall, 84 (12.7%) patients developed NOAF during hospitalization. The LCR was significantly lower in the NOAF group. Preoperative LCR accurately predicted NOAF after AMI and was correlated with increased NOAF risk. Age, body mass index, diabetes, serum albumin levels, uric acid levels, left atrium (LA) diameter, left ventricular ejection fraction, left circumflex artery stenosis > 50%, and Killip class II status were independent predictors of NOAF after AMI. In addition, a new nomogram combined with LCR was constructed to stratify the risk of NOAF in patients with AMI. The performance of the new nomogram was satisfactory, as shown by the receiver operating characteristic curve, calibration curve, decision curve analysis and clinical impact curve.

Conclusion

Preoperative LCR was an independent predictor of NOAF in patients with AMI after PCI. The novel nomogram combined with LCR could rapidly and individually identify and treat patients at a high risk of NOAF.

Atrial fibrillation and mortality in patients with acute myocardial infarction: a systematic overview and meta-analysis

Atrial fibrillation (AF) confers an increased risk of mortality in patients hospitalized for acute myocardial infarction (AMI). However, it is unclear whether new-onset and preexisting AF portend a different risk. We extracted data from studies that evaluated in-hospital mortality in patients with AMI and included information on cardiac rhythm. Overall, the risk of mortality was higher in patients with AF than in those in sinus rhythm (OR 2.00, 95 % CI: 1.93-2.08; P < 0.0001). Compared with patients who remained in sinus rhythm, the risk of death was increased in patients with new AF certain (sinus rhythm on admission, new AF during hospitalization, and history of no evidence of prior AF; OR 3.38, 95 % CI: 2.98-3.83; P < 0.0001), new AF uncertain (sinus rhythm on admission, AF during hospitalization, but no clear information about previous history of AF; OR 1.90, 95 % CI:1.83-1.98; P < 0.0001), and permanent AF (AF before and during hospitalization; OR 2.01, 95 % CI:1.70-2.38;P < 0.0001). In a meta-regression analysis, the risk of death was 87 % higher in patients with new AF certain than in those with permanent AF (P = 0.013) or AF uncertain (P = 0.003), and not dissimilar in patients with new AF uncertain and permanent AF (P = 0.706).

Mortality associated with atrial fibrillation in patients with myocardial infarction: a systematic review and meta-analysis

BACKGROUND

Atrial fibrillation (AF) is a common finding in patients with myocardial infarction (MI). Atrial fibrillation is not generally perceived by clinicians as a critical event during the acute phase of MI; however, its prognostic influence in MI remains controversial. Furthermore, contradictory data exist concerning the risk of death according to AF timing. This article, a systematic review and first meta-analysis, aims to quantify the mortality risk associated with AF in MI patients and its timing.

METHODS AND RESULTS

A comprehensive search of several electronic databases (1970 to 2010; adults, any language) identified MI studies that evaluated mortality related to AF. Evidence was reviewed by 2 blinded reviewers with a formal assessment of the methodological quality of the studies. Adjusted odds ratios were pooled across studies using the random-effects model. The I(2) statistic was used to assess heterogeneity. In the 43 included studies (278 854 subjects), the mortality odds ratio associated with AF was 1.46 (95% confidence interval, 1.35 to 1.58; I(2)=76%; 23 studies). This worse prognosis persisted regardless of the timing of AF; the odds ratio of mortality for new AF with no prior history of AF was 1.37 (95% confidence interval, 1.26 to 1.49), I(2)=28%, 9 studies), and for prior AF was 1.28 (95% confidence interval, 1.16 to 1.40; I(2)=24%; 4 studies). The sensitivity analysis of new AF studies adjusting for confounding factors did not show a decrease in risk of death.

CONCLUSIONS

Atrial fibrillation is associated with increased risk of mortality in MI patients. New AF with no history of AF before MI remained associated with an increased risk of mortality even after adjustment for several important AF risk factors. These subsequent increases in mortality suggest that AF can no longer be considered a nonsevere event during MI.