New-onset atrial fibrillation and acute coronary syndrome

Synthesis of pyrrolo[3,2-d]pyrimidineone derivatives as novel FXa inhibitors

A series of pyrrolo[3,2-d]pyrimidineone compounds have been designed and synthesized as novel FXa inhibitors. Bioassay of the tested compounds showed moderate to excellent anticoagulant potency in vitro. Further FXa inhibitory and bioactivity evaluation in rats, the FeCl₃-induced venous thrombosis model, showed that the compound 17a has good FXa inhibitory activity (IC₅₀ = 1.57 nM) and in vivo antithrombotic potency. The anticoagulant effects of compound 17a were dose dependent whether in vitro or in vivo. The results further confirmed our hypothesis that the large conjugated structure is an ideal skeleton binding FXa.

Prior statin use and the incidence of in-hospital arrhythmia in acute coronary syndrome: A systematic review and meta-analysis

BACKGROUND

The benefit of prior statin use to reduce the incidence of arrhythmia in acute coronary syndrome (ACS) is still a matter of debate. Statins have multiple pleiotropic effects, which may reduce the incidence of in-hospital arrhythmia. A systematic review and meta-analysis were performed to evaluate prior statin use and the incidence of in-hospital arrhythmia in ACS.

METHODS

This systematic review was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). We performed a literature search through Pubmed, Proquest, EBSCOhost, and Clinicaltrial.gov. A random-effect model was used due to moderate heterogeneity. Quality assessment was performed using Newcastle Ottawa Scale. Sensitivity analysis was performed by using leave one or two out method. PROSPERO registration number: CRD42022336402.

RESULTS

Nine eligible studies consisting of 86,795 patients were included. A total of 22,130 (25.5%) patients were in statin use before the index ACS event. The prevalence of old myocardial infarction, heart failure, hypertension, diabetes mellitus, and chronic renal failure and concomitant treatment with aspirin, clopidogrel, and beta blocker was higher in the prior statin group compared to no previous statin. Overall, prior statin use was associated with a significantly lower incidence of in-hospital arrhythmia during ACS compared to no previous statin (OR 0.60; 95% CI 0.49-0.72; P < 0.00001; I2 = 54%, P-heterogeneity = 0.03). In subgroup analysis, previous statin use reduced the incidence of atrial fibrillation or atrial flutter (OR 0.64; 95% CI 0.43-0.95; P = 0.03; I2 = 73%, P-heterogeneity = 0.01) and ventricular tachycardia or ventricular fibrillation (OR 0.57; 95% CI 0.49-0.65; P < 0.00001; I2 = 8%, P-heterogeneity = 0.35).

CONCLUSIONS

Based on aggregate patient data, prior statin use may reduce the incidence of in-hospital arrhythmia during ACS, particularly atrial fibrillation or atrial flutter and ventricular tachycardia or ventricular fibrillation.

Circulating plasma galectin-3 predicts new-onset atrial fibrillation in patients after acute myocardial infarction during hospitalization

Background

New-onset atrial fibrillation (NOAF) is a common complication in patients with acute myocardial infarction (AMI) during hospitalization. Galectin-3 (Gal-3) is a novel inflammation marker that is significantly associated with AF. The association between post-AMI NOAF and Gal-3 during hospitalization is yet unclear.

Objective

The present study aimed to investigate the predictive value of plasma Gal-3 for post-AMI NOAF.

Methods

A total of 217 consecutive patients admitted with AMI were included in this retrospective study. Peripheral venous blood samples were obtained within 24 h after admission and plasma Gal-3 concentrations were measured.

Results

Post-AMI NOAF occurred in 18 patients in this study. Patients with NOAF were older (p < 0.001) than those without. A higher level of the peak brain natriuretic peptide (BNP) (p < 0.001) and Gal-3 (p < 0.001) and a lower low-density lipoprotein cholesterol level (LDL-C) (p = 0.030), and an estimated glomerular filtration rate (e-GFR) (p = 0.030) were recorded in patients with post-AMI NOAF. Echocardiographic information revealed that patients with NOAF had a significantly decreased left ventricular eject fraction (LVEF) (p < 0.001) and an increased left atrial diameter (LAD) (p = 0.004) than those without NOAF. The receiver operating characteristic (ROC) curve analysis revealed a significantly higher value of plasma Gal-3 in the diagnosis of NOAF for patients with AMI during hospitalization (area under the curve (p < 0.001), with a sensitivity of 72.22% and a specificity of 72.22%, respectively. Multivariate logistic regression model analysis indicated that age (p = 0.045), plasma Gal-3 (p = 0.018), and LAD (p = 0.014) were independent predictors of post-MI NOAF.

Conclusions

Plasma Gal-3 concentration is an independent predictor of post-MI NOAF.

Early and late new-onset of atrial fibrillation in acute coronary syndromes: Their differences in mortality and cardiac event

Background

In a stressful situation like acute coronary syndrome (ACS), the occurrence of the first episode of atrial fibrillation is more frequent. The impact of the timing occurrence of AF new-onset (nAF) in the setting of ACS is still debatable.

Methods

Multicenter retrospective study based on the Acute Coronary Syndrome Portuguese National Registry, including 29 851 patients admitted for ACS between 1/10/2010 and 4/09/2019. The group with early nAF - nAF in the first 48 h of hospitalization; and late nAF - patients with nAF after the first 48 h of in-hospital admission.

Results

New-onset AF was identified in 1067 patients, nonetheless, just 38.1% had late nAF. The group with late nAF presented more cardiovascular comorbidities and worse left ventricular ejection fraction. Late nAF patients received more anti-arrhythmic therapy, and early nAF had a higher beta-block prescription. Early nAF had higher rates of in-hospital complications, on the other hand, late nAF group exhibited more mortality and readmission at one year follow-up. Multiple logistic regression revealed that symptoms onset to the first medical contact time, admission hemoglobin <12 g/dl, right bundle branch block at admission, and diuretic therapy during the hospitalization for ACS were predictors of late nAF in ACS.

Conclusions

The ACS population could be divided by the timing of nAF occurrence into the two groups with different characteristics, therapeutic approaches, and outcomes. Late nAF patients had a worse prognosis at 1 year follow-up, however, the early nAF group had more major adverse cardiac events during the hospitalization for ACS.

Gender Differences in the Impact of New-Onset Atrial Fibrillation on Long-Term Risk of Ischemic Stroke after Acute Myocardial Infarction

BACKGROUND

Atrial fibrillation (AF) has been identified as a major risk factor for mortality after acute coronary syndrome (ACS). However, the long-term risk of ischemic stroke associated with new-onset atrial fibrillation (NOAF) in ACS remains controversial, and its gender-specific association is unknown.

METHODS

We analyzed the data of 10,137 ACS survivors included in a multicenter, prospective registry for Korean patients with acute myocardial infarction (AMI) between January 2004 and August 2014. Subjects were categorized into three groups (non-AF vs. NOAF vs. previous AF) based on medical history and electrocardiographic evidence of AF, either at admission or during hospitalization.

RESULTS

Among the total study population (72.3% men), 370 patients (3.6%) had NOAF and 130 (1.3%) had previous AF. During a median follow-up of 61 months (interquartile range, 38.8 to 89.3 months), 245 (2.4%) patients (218 (2.3%) non-AF vs. 15 (4.1%) NOAF vs. 12 (9.2%) previous AF, p < 0.001) experienced ischemic stroke. After adjustment for confounding variables, both NOAF (adjusted hazard ratio (HR) 1.87, 95% confidence interval (CI) 1.09-3.24, p = 0.024) and previous AF (adjusted HR 4.00, 95% CI 2.03-7.87, p < 0.001), along with older age, diabetes, current smoker, and previous stroke were independent risk factors of ischemic stroke. In the gender-stratified analysis, men with previous AF but not NOAF had a significantly higher risk of ischemic stroke (adjusted HR 4.14, 95% CI 1.79-9.55, p = 0.001) than those without AF. In women, NOAF (adjusted HR 2.54, 95% CI 1.21-5.35, p = 0.014) as well as previous AF (adjusted HR 3.72, 95% CI 1.16-11.96, p = 0.028) was a strong predictor of ischemic stroke, and the predictive value was comparable to that of previous AF among patients with a CHA₂DS₂-VASc score ≥ 2.

CONCLUSIONS

Both NOAF and previous AF were associated with ischemic stroke after AMI, but the impact of NOAF as a risk factor of ischemic stroke was significant only in women.

Coronary Flow Disturbance Phenomenon After Percutaneous Coronary Intervention Is Associated with New-Onset Atrial Fibrillation in Patients with Acute Myocardial Infarction

Atrial fibrillation (AF) is a common complication of acute myocardial infarction (AMI). Although previous studies have investigated mortality rates and the incidences of adverse events associated with new-onset AF (NOAF) in patients with AMI, the effects of emergency percutaneous coronary intervention (PCI) on the incidence of NOAF in patients with AMI remain unclear. The purpose of this study was to investigate the relationship of clinical characteristics, medical history, and the coronary flow disturbance phenomenon (TIMI < 3) following emergency PCI with NOAF in patients with AMI. Between 2012 and 2016, 731 patients with AMI underwent PCI at our facility. Among these, 52 had a history of chronic/paroxysmal AF before admission and were excluded. The remaining 679 patients (mean age 66.4 years, 532 males) were analyzed in this retrospective observational study.New-onset AF was observed in 45 patients (6.6%). In univariate analysis, the hazard ratios (HRs) for patient age (HR 1.04, 95%CI 1.02-1.07), Killip II-IV (HR 2.34, 95%CI 1.29-4.23), elevated D-dimer level (> 1.0 μg/mL; HR 3.32; 95%CI 1.77-6.23), and coronary flow disturbance phenomenon (HR 5.61; 95%CI 2.88-10.9) were significantly higher in the NOAF group. In multivariate analysis, an elevated D-dimer level (> 1.0 μg/mL; HR 2.44; 95%CI 1.17-5.11) and coronary flow disturbance phenomenon (HR 4.61; 95%CI 2.29-9.27) were found to be independent risk factors for NOAF. An elevated D-dimer level at admission and the presence of coronary flow disturbance phenomenon after PCI were risk factors for NOAF following emergency PCI in patients with AMI.

Antithrombotic management of patients with acute coronary syndrome and atrial fibrillation undergoing coronary stenting: a prospective, observational, nationwide study

OBJECTIVE

The aim of the study was to assess current management of patients with atrial fibrillation (AF) and acute coronary syndrome (ACS) undergoing coronary stenting.

DESIGN

Non-interventional, prospective, nationwide study.

SETTING

76 private or public cardiology centres in Italy.

PARTICIPANTS

Patients with ACS with concomitant AF undergoing percutaneous coronary intervention (PCI).

PRIMARY AND SECONDARY OUTCOME MEASURES

To obtain accurate and up-to-date information on pharmacological management of patients with AF admitted for an ACS and undergoing PCI with stent implantation.

RESULTS

Over a 12-month period, 598 consecutive patients were enrolled: 48.8% with AF at hospital admission and 51.2% developing AF during hospitalisation. At discharge, a triple antithrombotic therapy (TAT) was prescribed in 64.8%, dual antiplatelet therapy (DAPT) in 25.7% and dual antithrombotic therapy (DAT) in 8.8% of patients. Among patients with AF at admission, TAT and DAT were more frequently prescribed compared with patients with new-onset AF (76.3% vs 53.8% and 12.5% vs 5.3%, respectively; both p<0.0001), while a DAPT was less often used (11.2% vs 39.5%; p<0.0001). At multivariable analysis, a major bleeding event (OR: 5.40; 95% CI: 2.42 to 12.05; p<0.0001) and malignancy (OR: 5.11; 95% CI: 1.77 to 14.78; p=0.003) resulted the most important independent predictors of DAT prescription.

CONCLUSIONS

In this contemporary registry of patients with ACS with AF treated with coronary stents, TAT still resulted as the antithrombotic strategy of choice, DAT was reserved for high bleeding risk and DAPT was mainly prescribed in those developing AF during hospitalisation.

TRIAL REGISTRATION NUMBER

NCT03656523.

Early Versus Late New-Onset Atrial Fibrillation in Acute Myocardial Infarction: Differences in Clinical Characteristics and Predictors

New-onset atrial fibrillation (NOAF) during acute myocardial infarction (AMI) has significant consequences but is often misdiagnosed. The aim of the study was to evaluate predictors of NOAF throughout different phases of AMI. Patients with AMI admitted to a tertiary medical center were analyzed. Exclusion criteria were preexisting AF, AMI onset ≥24 hours prior to admission, in-hospital death, significant valvular disease, and in-hospital coronary artery bypass graft. Study population were AMI without-NOAF, early-AF (AF terminated within 24 hours of admission), and late-AF (beyond the first 24 hours). Overall 5946 patients were included, age: 64.8 ±14.8 years; 30% women. The incidence of NOAF was 4.6%: 1.6% early-AF, and 3% late-AF. Patients with NOAF comprised greater rate of women, cardiovascular risk-factors burden, severe left ventricular-dysfunction, pulmonary hypertension, valvular disorders, and left atrial enlargement compared with patients without-NOAF. Non-ST-elevation myocardial infarction and inferior-ST-elevation myocardial infarction (STEMI) were significantly more prevalent among early-AF group, while anterior-STEMI, in late-AF. The final multivariate models showed c-statistics of 0.73 and 0.76 for the prediction of new-onset early-AF and late-AF, respectively. In conclusion, there are different clinical predictors of early- versus late-NOAF. The study points out “high risk” AMI population for more meticulous heart rate monitoring for NOAF.

Atrial Fibrillation and Acute Myocardial Infarction – An Inflammation-Mediated Association

Atrial fibrillation (AF) is an increasingly widespread healthcare problem. AF can frequently present as a complication in acute coronary syndromes (ACS), especially in ST-elevation acute myocardial infarction (AMI), in which case it is the most frequent supraventricular rhythm disturbance with an estimated incidence of 6.8-21%. The presence of AF in ACS heralds worse outcomes in comparison to subjects in sinus rhythm, and several studies have shown that in AMI patients, both new-onset and pre-existing AF are associated with a higher risk of major adverse cardiovascular and cerebrovascular events during hospitalization. The cause of newonset AF in AMI is multifactorial. Although still incompletely understood, the mechanisms involved in the development of AF in acute myocardial ischemic events include the neurohormonal activation of the sympathetic nervous system that accompanies the AMI, ischemic involvement of the atrial myocytes, ventricular dysfunction, and atrial overload. The identification of patients at risk for AF is of great significance as it may lead to prompt therapeutic interventions and closer follow-up, thus improving prognosis and decreasing cardiovascular and cerebrovascular events. The present manuscript aims to summarize the current research findings related to new-onset AF in AMI patients, as well as the predictors and prognostic impact of this comorbid association.

NEW-ONSET ATRIAL FIBRILLATION IN SETTINGS OF ACUTE CORONARY SYNDROME. CURRENT ISSUES

The present review is focuses on new onset atrial fibrillation (AF) in conditions of acute coronary syndrome (ACS). Literature sources from PubMed and Scopus was used. AF is common in the general population and in the ACS population, at that new onset AF, and AF, which was by the time of ACS development are determined. Appearance of AF is more likely amongst the elderly patients with congestive heart failure, with signs of the hemodynamic instability and with the left atrium dilatation. It is well-known about the predictors of adverse outcome in ACS. According to some literature data new onset AF leads to worsening of prognosis, and in line with other sources a reason of its association with high level of mortality is due to the severity of ACS and appearance of AF is not independent predictor of death. The absence of subjective symptoms at the time of paroxysm of new onset AF does not allow estimating its duration and distinguishing between the new onset AF, persistent and constant AF. It is possible to trace the relationship between the myocardial ischemia and AF appearance. Inefficient reperfusion during percutaneous coronary intervention or thrombolytic therapy is accompanied by the onset of AF, on the contrary, when effective patency of coronary artery is achieved, AF appears significantly less often. New onset AF in ACS, in particular, accompanied by cardiogenic shock, requires emergency pharmacological or electrical cardioversion. In some cases, active cardioversion is not necessary, because of spontaneous cardiac rhythm conversion. In conclusions, it is necessary to point out, that ambiguity and multifactority of this problem demands investigation of arrhythmogenesis mechanisms and development of special risk stratification instruments for the new onset AF in ACS.

Left ventricular ejection fraction and left atrium diameter related to new-onset atrial fibrillation following acute myocardial infarction: a systematic review and meta-analysis

Background

New-onset atrial fibrillation (NOAF) occurs frequently in patients with acute myocardial infarction (AMI), and is associated with increased subsequent cardiovascular mortality. However, only a few studies directly evaluated the relationship of left ventricular ejection fraction (LVEF) or left atrium diameter (LAD) and NOAF following AMI.

Materials and Methods

MEDLINE^®, EMBASE^® and the Cochrane Library were carried out to find studies until January 2017. Pooled mean difference (MD) and 95% confidence interval (CI) were calculated to evaluate the value of LVEF and LAD in the prediction of NOAF after AMI. We performed sensitivity analyses to explore the potential sources of heterogeneity. Statistical analyses were carried out using the Revman 5.3.

Result

We included 10 qualifying studies comprising a total of 708 patients with NOAF and 6785 controls. Overall, decreased LVEF and increased LAD levels had a significant positive association with NOAF in patients with AMI. The MD in the LVEF levels between the patients with and those without NOAF was −4.91 units (95% Cl: −5.70 to −4.12), test for overall effect z-score = 12.18 (p < 0.00001, I² = 35%). Moreover, in a subgroup analysis, the MD for LAD and NOAF was 2.55 units (95% Cl: 1.91 to 3.19), test for overall effect z-score = 7.80 (p < 0.00001, I² = 57%).

Conclusions

Our meta-analysis demonstrated that both decreased LVEF and increased LAD levels were associated with greater risk of NOAF following AMI.

Novel Anthranilamide-Based FXa Inhibitors: Drug Design, Synthesis and Biological Evaluation

Factor Xa (FXa) plays a significant role in the blood coagulation cascade and it has become a promising target for anticoagulation drugs. Three oral direct FXa inhibitors have been approved by the FDA for treating thrombotic diseases. By structure-activity relationship (SAR) analysis upon these FXa inhibitors, a series of novel anthranilamide-based FXa inhibitors were designed and synthesized. According to our study, compounds 1a, 1g and 1s displayed evident FXa inhibitory activity and excellent selectivity over thrombin in in vitro inhibition activities studies. Compounds 1g and 1s also exhibited pronounced anticoagulant activities in in vitro anticoagulant activity studies.

New insights into symptomatic or silent atrial fibrillation complicating acute myocardial infarction

Atrial fibrillation (AF) is the most frequent heart rhythm disorder in the general population and contributes not only to a major deterioration in quality of life but also to an increase in cardiovascular morbimortality. The onset of AF in the acute phase of myocardial infarction (MI) is a major event that can jeopardize the prognosis of patients in the short-, medium- and long-term, and is a powerful predictor of a poor prognosis after MI. The suspected mechanism underlying the excess mortality is the drop in coronary flow linked to the acceleration and arrhythmic nature of the left ventricular contractions, which reduce the left ventricular ejection fraction. The principal causes of AF-associated death after MI are linked to heart failure. Moreover, the excess risk of death in these heart failure patients has also been associated with the onset of sudden death. Whatever its form, AF has a major negative effect on patient prognosis. In recent studies, symptomatic AF was associated with inhospital mortality of 17.8%, to which can be added mortality at 1year of 18.8%. Surprisingly, silent AF also has a negative effect on the prognosis, as it is associated with an inhospital mortality rate of 10.4%, which remains high at 5.7% at 1year. Moreover, both forms of AF are independent predictors of mortality beyond traditional risk factors. The frequency and seriousness of silent AF in the short- and long-term, which were until recently rarely studied, raises the question of systematically screening for it in the acute phase of MI. Consequently, the use of continuous ECG monitoring could be a simple, effective and inexpensive solution to improve screening for AF, even though studies are still necessary to validate this strategy. Finally, complementary studies also effect of oxidative stress and endothelial dysfunction, which seem to play a major role in triggering this rhythm disorder.

Synthesis of 3,4-diaminobenzoyl derivatives as factor Xa inhibitors

The coagulation factor Xa (FXa) plays a central role in the blood coagulation cascade. Recent studies have shown that FXa is a particularly attractive target for the development of oral antithrombotic agents. In view of the excellent pharmaceutical properties of 1,2-phenylenediamine-based FXa inhibitors and the reported structure-activity relationship (SAR) analysis of FXa inhibitors, we designed and synthesized a series of 3,4-diaminobenzoyl-based FXa inhibitors. Intensive SAR studies on this new series led to the discovery of 3,4-dimethoxyl substituted compound 7b. 7b is a highly potent, selective, direct FXa inhibitor with excellent in vivo antithrombotic activity.

Impact of atrial fibrillation type during acute coronary syndromes: Clinical features and prognosis

INTRODUCTION

Atrial fibrillation (AF) is widely recognized as an adverse prognostic factor during acute myocardial infarction, although the impact of AF type - new-onset (nAF) or pre-existing (pAF) - is still controversial.

OBJECTIVES

To identify the clinical differences and prognosis of nAF and pAF during acute coronary syndromes (ACS).

METHODS

We performed a retrospective observational cohort study including 1373 consecutive patients (mean age 64 years, 77.3% male) admitted to a single center over a three-year period, with a six-month follow-up.

RESULTS

AF rhythm was identified in 14.5% patients, of whom 71.4% presented nAF and 28.6% pAF. When AF types were compared, patients with nAF more frequently presented with ST-elevation ACS (p=0.003). Patients with pAF, in turn, were older (p=0.032), had greater left atrial diameter (p=0.001) and were less likely to have significant coronary lesions (p=0.034). Regarding therapeutic strategy, nAF patients were more often treated by rhythm control during hospital stay (p<0.001) and were less often anticoagulated at discharge (p=0.001). Compared with the population without AF, nAF was a predictor of death during hospital stay in univariate (p<0.001) and multivariate analysis (OR 2.67, p=0.047), but pAF was not. During follow-up, pAF was associated with higher mortality (p=0.014), while nAF patients presented only a trend towards worse prognosis.

CONCLUSIONS

AF during the acute phase of ACS appears to have a negative prognostic impact only in patients with nAF and not in those with pAF.

New-onset atrial fibrillation during acute coronary syndromes: predictors and prognosis

INTRODUCTION

New-onset atrial fibrillation (AF) frequently complicates myocardial infarction, with an incidence of 6-21%.

OBJECTIVE

To assess the predictors and prognosis of new-onset AF during acute coronary syndromes (ACS).

METHODS

We performed a retrospective observational cohort study including 902 consecutive patients (mean age 64 years, 77.5% male) admitted to a single center over a two-year period, with a six-month follow-up.

RESULTS

AF rhythm was identified in 13.8% patients, of whom 73.3% presented new-onset AF and 26.8% pre-existing AF. New-onset AF was more frequent in older (p<0.001) and hypertensive patients (p=0.001) and in those with previous valvular heart disease (p<0.001) and coronary artery bypass grafting (p=0.049). During hospitalization, patients with new-onset AF more often had respiratory infection (p=0.002) and heart failure (p<0.001), and higher values of NT-proBNP (p=0.007) and peak creatinine (p=0.001). On echocardiography they had greater left atrial (LA) diameter (p<0.001) and more frequent significant mitral regurgitation (p<0.001) and left ventricular ejection fraction (LVEF) ≤40% (p<0.001) and were less likely to have significant coronary lesions (p=0.009) or to have undergone coronary revascularization (p<0.001). In multivariate analysis, age (OR 1.06, p=0.021), LVEF ≤40% (OR 4.91, p=0.002) and LA diameter (OR 1.14, p=0.008) remained independent predictors of new-onset AF. Together with age, diabetes and maximum Killip class, this arrhythmia was an independent predictor of overall mortality (OR 3.11, p=0.032).

CONCLUSIONS

Age, LVEF ≤40% and LA diameter are independent predictors of new-onset AF during ACS. This arrhythmia is associated with higher overall mortality (in-hospital and in follow-up).

Outcomes associated with comorbid atrial fibrillation and heart failure in Medicare beneficiaries with acute coronary syndrome

Background

Atrial fibrillation (AF) and heart failure (HF) are both common comorbid conditions of elderly patients with acute coronary syndrome (ACS), but published data on their associated clinical and economic outcomes are limited.

Methods

Our study included patients from the Medicare Current Beneficiary Survey with an incident hospitalization for ACS between 03/01/2002 and 12/31/2006. Applying population weights, we identified 795 incident ACS patients, representing more than 2.5 million Medicare beneficiaries. Of this population, 13.1% had comorbid AF, and 22.9% had HF, which were identified from Medicare claims during the 6 months prior to the first ACS event (index date) Subsequent cardiovascular (CV) hospitalizations and mortality were compared using Kaplan–Meier curves. Cox proportional hazards regressions were used to estimate the relative risk of AF and HF on CV events and mortality. Healthcare costs were summarized for the calendar year in which the incident ACS event occurred.

Results

HF was associated with a 41% higher risk of mortality (HR = 1.41; 95% confidence interval [CI] 1.05–1.89). Both AF (HR = 1.46; 95% CI 1.14–1.87) and HF (HR = 1.61; 95% CI 1.26–2.06) were associated with higher risks of subsequent CV events. During the year of the incident ACS event, ACS patients with comorbid AF or HF had approximately $18,000 higher total healthcare costs than those without these comorbidities.

Conclusion

Using a nationally representative sample of Medicare beneficiaries, we observed a significantly higher clinical and economic burden of patients hospitalized for ACS with comorbid AF and HF compared with those without these conditions.

Structural and Functional Remodeling of the Left Atrium: Clinical and Therapeutic Implications for Atrial Fibrillation

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice. Despite advances in our understanding of the pathophysiology of this complex arrhythmia, current therapeutic options remain suboptimal. This review aimed to delineate the atrial structural and functional remodeling leading to the perpetuation of AF. We explored the complex changes seen in the atria in various substrates for AF and the therapeutic options available to prevent these changes or for reverse remodeling. Here we also highlighted the emerging role of aggressive risk factor management aimed at the arrhythmogenic atrial substrate to prevent or retard AF progression.

Myocardial infarction and atrial fibrillation: importance of atrial ischemia

BACKGROUND

Myocardial infarction (MI) is associated with the development of atrial fibrillation (AF). We aimed to characterize the atrial abnormalities because of MI and determine the role of ischemia to the AF substrate.

METHODS AND RESULTS

Forty-four sheep were studied. MI was induced by occlusion of the left circumflex artery (LCX) or left anterior descending artery (LAD). Excluding 11 with fatal arrhythmias, equal groups of animals (LCX; LAD; and sham-operated) underwent sequential electrophysiology study for 45 minutes to determine atrial effective refractory periods, conduction velocity, conduction heterogeneity index, and AF inducibility. Postmortem evaluation was performed with 2,3,5 triphenyl tetrazolium chloride staining. MI resulted in greater left ventricular dysfunction (P<0.05), LA pressure (P<0.0003), and reduction in atrial effective refractory periods (P<0.0001) compared with control. 2,3,5 triphenyl tetrazolium chloride staining demonstrated that the left circumflex artery, and not the LAD, group had atrial infarction. The left circumflex artery group demonstrated the following compared with the LAD or control groups: greater slowing in atrial conduction velocity (P<0.0001 and P<0.001); increased absolute range of conduction phase delay (P<0.001 and P<0.001); increased conduction heterogeneity index (P<0.0001 and P<0.001); greater AF vulnerability (P<0.05 for both); and longer AF duration (P<0.05 for both). LAD group had modest but significant slowing in conduction velocity (P<0.01) but no change in conduction heterogeneity index or AF duration compared with control.

CONCLUSIONS

Left ventricular infarction, which is known to result in atrial stretch, hemodynamic change, and neurohumoral activation, contributes partially to the atrial abnormalities in MI. Atrial ischemia/infarction results in greater atrial electrophysiological changes and propensity for AF forming the dominant substrate for AF in MI.

Prognostic Significance of Prevalent and Incident Atrial Fibrillation Among Patients Hospitalized with Acute Coronary Syndrome

There is a paucity of data on atrial fibrillation (AF) complicating acute coronary syndrome (ACS) in Arabian Gulf countries. Thus, we assessed the incidence of AF in patients with ACS in these countries and examined the associated in-hospital, 30-day, and 1-year adverse outcomes. The population comprised 7930 patients enrolled in the second Gulf Registry of Acute Coronary Events (Gulf RACE-2). Of 7930 patients with ACS, 217 (2.7%) had AF. Compared with patients without AF, patients with AF were less likely to be male (65.9 vs 79.1%) and were older (mean age 64.6 vs 56.6 years). Compared with patients without AF, in-hospital, 30-day, and 1-year mortality were significantly higher in patients with any AF (odds ratio [OR]: 2.7, 2.2, 1.9, respectively; P < .001) and in patients with new-onset AF (OR: 5.2, 3.9, 3.1, respectively; P < .001. In conclusion, AF in patients with ACS was associated with significantly higher short- and long-term mortality.