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

Construction of a predictive model for new-onset atrial fibrillation after acute myocardial infarction based on P-wave amplitude in lead V1

BACKGROUND

In this study, we aimed to identify the risk factors for new-onset atrial fibrillation (NOAF) after postcoronary intervention in patients with acute myocardial infarction (AMI) and to establish a nomogram prediction model.

METHODS

The clinical data of 506 patients hospitalized for AMI from March 2020 to February 2023 were retrospectively collected, and the patients were randomized into a training cohort (70%; n = 354) and a validation cohort (30%; n = 152). Independent risk factors were determined using least absolute shrinkage and selection operator and multivariate logistic regression. Predictive nomogram modeling was performed using R software. Nomograms were evaluated based on discrimination, correction, and clinical efficacy using the C-statistic, calibration plot, and decision curve analysis, respectively.

RESULTS

The multivariate logistic regression analysis showed that P-wave amplitude in lead V1, age, and infarct type were independent risk factors for NOAF, and the area under the receiver operating characteristic curve of the training and validation sets was 0.760 (95% confidence interval [CI] 0.674-0.846) and 0.732 (95% CI 0.580-0.883), respectively. The calibration curves showed good agreement between the predicted and observed values in both the training and validation sets, supporting that the actual predictive power was close to the ideal predictive power.

CONCLUSIONS

P-wave amplitude in lead V1, age, and infarct type were independent risk factors for NOAF in patients with AMI after intervention. The nomogram model constructed in this study can be used to assess the risk of NOAF development and has some clinical application value.

Atrial fibrillation increases the risk of new-onset myocardial infarction amongst working-age population: a propensity-matched study

OBJECTIVE

The aim of this study was to investigate the association between atrial fibrillation (AF) and new-onset myocardial infarction (MI) among a working-age population in an industrial city of North China.

METHODS

In total 77,670 participants aged under 60 years were selected for this cohort study. Participants were divided into an AF group (n = 121) and a non-AF group (n = 74,565) based on their medical histories. Thereafter, 121 participants from the AF group were propensity-matched with 363 participants from the non-AF group. All participants were followed up from June 2006 to December 2020; new-onset MI was regarded as the endpoint of this study. Multivariate Cox proportional hazards regression analysis models were designed to analyze the correlation between AF and new-onset MI.

RESULTS

During the 14-year follow-up, eight cases of new-onset MI were documented in the AF group, while five cases were documented in the non-AF group. The cumulative incidence of new-onset MI in the AF group (7.40%) was markedly higher than in the non-AF group (1.41%; p < 0.001). Atrial fibrillation was associated with an increased risk of new-onset MI in both univariate analysis (hazard ratio: 5.202, 95% confidence interval [CI]: 1.700-15.913) and multivariable-adjusted analysis (hazard ratio: 5.335, 95% CI: 1.683-16.910).

CONCLUSION

Atrial fibrillation increased the risk of new-onset MI amongst working-age individuals in an industrial city of North China.

Serum fibrinogen-to-albumin ratio predicts new-onset atrial fibrillation risk during hospitalization in patients with acute myocardial infarction after percutaneous coronary intervention: a retrospective study

BACKGROUND

New-onset atrial fibrillation (NOAF) is a common adverse outcome of percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) and is closely correlated with hospital stay and prognosis. In recent years, serum fibrinogen-to-albumin ratio (FAR), a novel biomarker for inflammation and thrombosis, has been used to predict the severity and prognosis of coronary artery disease. Our study aimed to investigate the relationship between FAR and NOAF during hospitalization after PCI in patients with AMI.

METHODS

We retrospectively analyzed the incidence of NOAF during hospitalization and follow-up in 670 patients with AMI after PCI. Data were collected on patient age, sex, body mass index, medical history, current medication, heart failure, laboratory tests, culprit blood vessels, echocardiographic characteristics, and AMI type. The enrolled patients were divided into NOAF and non-NOAF groups. The baseline characteristics of patients in the two groups were compared, and the predictive correlation between FAR and NOAF was evaluated using logistic regression analysis and the receiver operating characteristic curve.

RESULTS

Fifty-three (7.9%) patients developed NOAF during hospitalization. The occurrence of NOAF was found to be independently associated with higher FAR besides older age, higher neutrophil count, greater left atrial size, worse Killip class upon admission, lower body mass index, lower platelet count, lower left ventricle ejection fraction, and target left circumflex artery disease. FAR exhibited a better predictive value for the occurrence of NOAF during hospitalization (area under the curve, 0.732; 95% confidence interval, 0.659-0.808).

CONCLUSIONS

FAR is a robust tool for predicting NOAF risk during hospitalization in patients with AMI after PCI and has a better predictive value than serum fibrin and serum albumin levels alone.

Predicting new onset atrial fibrillation post acute myocardial infarction: Echocardiographic assessment of left atrial size

BACKGROUND

Atrial fibrillation (AF) commonly occurs following acute myocardial infarction (AMI). Left atrial (LA) size has been reported to predict new onset AF in this cohort, however, the optimal metric of left atrial size for risk stratification following AMI is unknown.

METHODS

Patients presenting to a tertiary hospital with incident AMI (NSTEMI or STEMI) and no history of AF were recruited. All patients underwent guideline-based workup and management for AMI, including transthoracic echocardiographic assessment. Three alternative metrics of left atrial size were determined: LA area, maximal and minimal LA volume indexed to body surface area (LAVImax and LAVImin). The primary endpoint was new onset AF diagnoses.

RESULTS

Four hundred thirty three patients were included in the analysis, of which 7.1% had a new diagnosis of AF within a median follow-up of 3.8 years. Univariate predictors of incident AF included age, hypertension, revascularization with CABG, NSTEMI presentation, right atrial area, and all three metrics of LA size. Among three multivariable models created for the prediction of new onset AF utilizing alternate metrics of LA size, LAVImin was the only LA size metric found to be an independent predictor.

CONCLUSIONS

LAVImin is an independent predictor of new onset AF post AMI. LAVImin outperforms echocardiographic assessment of diastolic dysfunction and alternative metrics of LA size (including LA area and LAVImax) for risk stratification. Further studies are needed to validate our findings in post AMI patients, and evaluate whether LAVImin holds similar advantages over LAVImax in other cohorts.

Prediction Model of New Onset Atrial Fibrillation in Patients with Acute Coronary Syndrome

OBJECTIVE

Atrial fibrillation (AF) is one of the most common complications of acute coronary syndrome (ACS) patients. Possible risk factors related to new-onset AF (NOAF) in ACS patients have been reported in some studies, and several prediction models have been established. However, the predictive power of these models was modest and lacked independent validation. The aim of this study is to define risk factors of NOAF in patients with ACS during hospitalization and to develop a prediction model and nomogram for individual risk prediction.

METHODS

Retrospective cohort studies were conducted. A total of 1535 eligible ACS patients from one hospital were recruited for model development. External validation was performed using an external cohort of 1635 ACS patients from another hospital. The prediction model was created using multivariable logistic regression and validated in an external cohort. The discrimination, calibration, and clinical utility of the model were evaluated, and a nomogram was constructed. A subgroup analysis was performed for unstable angina (UA) patients.

RESULTS

During hospitalization, the incidence of NOAF was 8.21% and 6.12% in the training and validation cohorts, respectively. Age, admission heart rate, left atrial diameter, right atrial diameter, heart failure, brain natriuretic peptide (BNP) level, less statin use, and no percutaneous coronary intervention (PCI) were independent predictors of NOAF. The AUC was 0.891 (95% CI: 0.863-0.920) and 0.839 (95% CI: 0.796-0.883) for the training and validation cohort, respectively, and the model passed the calibration test (P > 0.05). The clinical utility evaluation shows that the model has a clinical net benefit within a certain range of the threshold probability.

CONCLUSION

A model with strong predictive power was constructed for predicting the risk of NOAF in patients with ACS during hospitalization. It might help with the identification of ACS patients at risk and early intervention of NOAF during hospitalization.

Impact of de novo tachyarrhythmias in patients with prior acute coronary syndrome

Although the incidence of acute coronary syndrome (ACS) has increased over the decades, the overall prognosis has improved with newer stents, tailored medication, and better intervention techniques. Atrial fibrillation (AF) and ventricular arrhythmia at the time of ACS diagnosis are known indicators of a poor acute prognosis. However, there is a lack of data regarding the long-term arrhythmic impact of ventricular tachyarrhythmia (VA) on mortality in ACS patients. This study sought to elucidate the impact of tachyarrhythmia on mortality during long-term follow-up in patients with a history of ACS. This retrospective study was conducted in a single university hospital, and it evaluated the clinical outcomes, especially regarding cardiovascular mortality and readmission. The enrolled patients underwent percutaneous coronary intervention (PCI) for ACS between February 2004 and March 2018. Clinical information was attained by a thorough chart review. We retrospectively analyzed 560 ACS patients. We reviewed all electrocardiograms (ECGs) before and immediately after PCI, during hospitalization, and within 3 months of the index PCI. Three months after the index PCI procedure, any Holter monitoring or ECG was also reviewed for arrhythmia diagnosis. During follow-up, 91 patients were diagnosed with AF and 36 patients were diagnosed with VA. Overall mortality was related to the presence of anemia, low body mass index, low left ventricular ejection fraction after PCI, late-diagnosed AF, and any VA during follow-up. Readmission was higher in patients with chronic kidney disease and newly diagnosed AF during the follow-up. Diagnosis of late tachyarrhythmia during follow-up was associated with increased mortality in post-ACS patients.

Smoking may be more harmful to vasospastic angina patients who take antiplatelet agents due to the interaction: Results of Korean prospective multi-center cohort

Background

The interaction between smoking and the use of antiplatelet agents on the prognosis of vasospastic angina (VA) is rarely investigated.

Methods

VA-Korea is a nation-wide multi-center registry with prospective design (n = 1812). The primary endpoint was the composite occurrence of acute coronary syndrome (ACS), symptomatic arrhythmia, and cardiac death. Log-rank test and Cox proportional hazard model were for statistical analysis. Also, we conducted interaction analysis in both additive and multiplicative scales between smoking and antiplatelet agents among VA patients. For additive scale interaction, relative excess risk due to interaction (RERI) was calculated and for multiplicative scale interaction, the ratio of hazard ratio (HR) was calculated. All statistical analysis conducted by Stata Ver 16.1.

Results

Patients who were smoking and using antiplatelet agents had the highest incidence rate in the primary composite outcome. The incidence rate was 3.49 per 1,000 person-month (95% CI: 2.30-5.30, log-rank test for primary outcome p = 0.017) and HR of smoking and using antiplatelet agents was 1.66 (95%CI: 0.98-2.81). The adjusted RERI of smoking and using antiplatelet agents was 1.10 (p = 0.009), and the adjusted ratio of HR of smoking and using antiplatelet agents was 3.32 (p = 0.019). The current study observed the interaction between smoking and using antiplatelet agents in both additive and multiplicative scales.

Conclusions

Smoking was associated with higher rates of unfavorable clinical outcomes among VA patients taking antiplatelet agents. This suggested that VA patients, especially those using antiplatelet agents should quit smoking.

Demographic, Clinical, and Angiographic Characteristics of Atrial Fibrillation Patients Suffering From de novo Acute Myocardial Infarction: A Subgroup Analysis of the MINOCA-TR Study Population

BACKGROUND

Atrial fibrillation (AF) prevalence in patients with acute myocardial infarction (MI) ranges from 3% to 25%. However demographic, clinical, and angiographic characteristics of AF patients who admitted with de novo MI are unclear. The aim of this study was to investigate the prevalence of patients presenting with de novo MI with AF.

METHODS

The study was performed as a sub-study of the MINOCA-TR (Myocardial Infarction with Non-obstructive Coronary Arteries in Turkish Population) Registry, a multicenter, cross-sectional, observational, all-comer registry. MI patients without a known history of stable coronary artery disease and/or prior coronary revascularization were enrolled in the study. Patients were divided into AF and Non-AF groups according to presenting cardiac rhythm.

RESULTS

A total of 1793 patients were screened and 1626 were included in the study. The mean age was 61.5 (12.5) years. 70.7% of patients were men. The prevalence of AF was 3.1% (51 patients). AF patients were older [73.4 (9.4) vs. 61.0 (12.4) years, p<0.001] than non-AF patients. The proportion of women to men in the AF group was also higher than in the non-AF group (43.1% vs. 28.7%, p=0.027). Only 1 out of every 5 AF patients (10 patients, 19.6%) was using oral anticoagulants (OAC).

CONCLUSIONS

AF prevalence in patients presenting with de novo MI was lower than previous studies that issued on AF prevalence in MI cohorts. The majority of AF patients did not have any knowledge of their arrhythmia and were not undergoing OAC therapy at admission, emphasizing the vital role of successful diagnostic strategies, patient education, and implementations for guideline adaptation.

New-onset atrial fibrillation during COVID-19 infection predicts poor prognosis

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has led to a paradigm shift in healthcare worldwide. Little is known about the impact on the cardiovascular system, and the incidence and consequences of new onset of atrial fibrillation (AF) in infected patients remain unclear. The aim of this study was to analyze the cardiovascular outcomes of patients with newonset AF and coronavirus disease 2019 (COVID-19) infection.

METHODS

This observational study analyzed a sample of 160 consecutive patients hospitalized due to COVID-19. A group with new-onset AF (n = 12) was compared with a control group (total: n = 148, sinus rhythm: n = 118, previous AF: n = 30). New-onset AF patients were significantly older and hypertensive, as well as presenting more frequently with a history of acute coronary syndrome and renal dysfunction. This group showed a higher incidence of thromboembolic events (41.7% vs. 4.1%; p < 0.001), bleeding (33.3% vs. 4.7%, p = 0.005), a combined endpoint of thrombosis and death (58.3% vs. 19.6%, p = 0.006) and longer hospital stays (16.4 vs. 8.6 days, p < 0.001), with no differences in all-cause mortality.

RESULTS

In multivariate analysis, adjusted by potential confounding factors, new-onset AF demonstrated a 14.26 odds ratio for thromboembolism (95% confidence interval 2.86-71.10, p < 0.001).

CONCLUSIONS

New-onset AF in COVID-19 patients presumably has a notable impact on prognosis. The appearance of new-onset AF is related to worse cardiovascular outcomes, considering it as an independent predictor of embolic events. Further studies are needed to identify patients with COVID-19 at high risk of developing "de novo" AF, provide early anticoagulation and minimize the embolic risk of both entities.

Clopidogrel plus Aspirin Use is Associated with Worse Long-Term Outcomes, but Aspirin Use Alone is Safe in Patients with Vasospastic Angina: Results from the VA-Korea Registry, A Prospective Multi-Center Cohort

Anti-platelet agents are commonly used in vasospastic angina (VA) patients with comorbidity like coronary artery disease. However, long-term clinical outcomes in the use of aspirin, clopidogrel or the two agents together have rarely been investigated in VA patients. In a prospective study, we enrolled 2960 patients who received coronary angiography and ergonovine provocation test at 11 university hospitals in Korea. Among them, 1838 patients were diagnosed either with definite (n = 680) or intermediate (n = 1212) VA, using the criteria of chest pain, ECG changes and ergonovine provocation test results. They were analyzed according to their use of aspirin, clopidogrel or both, or no anti-platelet agent at all. The primary outcome was time to composite events of death from any cause, acute coronary syndrome (ACS) and symptomatic arrhythmia during a 3-year follow-up. A primary composite outcome was significantly more common in the aspirin plus clopidogrel group, at 10.8% (14/130), as compared with the non-antiplatelet group, at 4.4% (44/1011), (hazard ratio [HR] 2.41, 95% confidence interval [CI], 1.32–4.40, p = 0.004). With regard to the person-time event rate, similar results were shown, with the highest rate in the aspirin plus clopidogrel user at 4.72/1000 person months (95% CI, 2.79–7.96, log-rank test for primary outcome p = 0.016). The person-time event of the ACS rate was also highest in that group, at 2.81 (95% CI, 1.46–5.40, log-rank test for ACS p = 0.116). Kaplan-Meier survival analysis demonstrated poor prognosis in primary outcomes and ACS in aspirin plus clopidogrel users (log-rank test, p = 0.005 and p = 0.0392, respectively). Cox-proportional hazard regression analysis, adjusting for age, sex, history of coronary heart disease, hypertension, diabetes, presence or not of definite spasm, use of calcium channel blocker, demonstrated that the use of aspirin plus clopidogrel is an independent risk for the primary outcome (HR 2.01, CI: 1.07–3.81, p = 0.031). The aspirin-alone group had a similar primary and individual event rate compared to the no-antiplatelet agent group (HR 0.96, CI, 0.59–1.55, p = 0.872). Smokers using aspirin plus clopidogrel had poorer outcomes than non-smokers, with HR 6.36 (CI 2.31–17.54, p = 0.045 for interaction). In conclusion, among VA patients, aspirin plus clopidogrel use is associated with a poor clinical outcome at 3 years, especially in ACS. Aspirin alone appears to be safe for use in those patients.

Acute Left Ventricular Unloading Reduces Atrial Stretch and Inhibits Atrial Arrhythmias

BACKGROUND

Left atrium (LA) physiology is influenced by changes in left ventricular (LV) performance and load.

OBJECTIVES

The purpose of this study was to define the effect of acute changes in LV loading conditions on LA physiology in subacute myocardial infarction (MI).

METHODS

MI was percutaneously induced in 19 Yorkshire pigs. One to 2 weeks after MI, 14 pigs underwent acute LV unloading using a percutaneous LV assist device, Impella. The remaining 5 pigs underwent acute LV loading by percutaneous induction of aortic regurgitation. A pressure-volume catheter was inserted into the LA using a percutaneous transseptal approach, and LA pressure-volume loops were continuously monitored. Atrial arrhythmia inducibility was examined by burst-pacing of the right atrium. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) levels and ryanodine receptor phosphorylation were examined in LA tissues to study the potential effect of stretch-dependent oxidative stress.

RESULTS

MI resulted in reduced LV ejection fraction and increased LV end-diastolic pressure with concomitant increase in LA pressure and volumes. Acute LV unloading resulted in a reduction of LV end-diastolic pressure, which led to proportional decreases in mean LA pressure and maximum LA volume. LA pressure-volume loops exhibited a pump flow-dependent, left-downward shift. This was associated with reduced LA passive stiffness, suggesting the alleviation of the LA stretch that was present after MI. Prior to acute unloading of the LV, 71% of the pigs were arrhythmia-inducible; LV unloading reduced this to 29% (p = 0.02). Time to spontaneous termination of atrial arrhythmias was decreased from median 55 s (range 5 to 300 s) to 3 s (range 0 to 59 s). In contrast, acute LV loading with aortic regurgitation increased LA pressure without a significant effect on arrhythmogenicity. Molecular analysis of LA tissue revealed that NOX2 expression was increased after MI, whereas acute LV unloading reduced NOX2 levels and diminished ryanodine receptor phosphorylation.

CONCLUSIONS

Acute LV unloading relieves LA stretch and reduces atrial arrhythmogenicity in subacute MI.

Adverse Outcomes Associated with Pre-Existing and New-Onset Atrial Fibrillation in Patients with Acute Coronary Syndrome: A Retrospective Cohort Study

Introduction

Atrial fibrillation (AF) often occurs in patients with acute coronary syndrome (ACS). It remains unclear whether pre-existing or new-onset AF confers different risk in patients with ACS.

Methods

We conducted a retrospective cohort study using Taiwan’s National Health Insurance Research Database. Patients who were hospitalized with a primary diagnosis of ACS from 2005 to 2009 were studied. Major outcomes were mortality, heart failure, and combined ischemic stroke/systemic embolism (IS/SE). The date of the first ACS diagnosis was defined as the index date. Pre-existing AF was defined as AF occurring before the index date. New-onset AF was defined as AF that started after or at the same time as the ACS diagnosis.

Results

Among 6663 patients with ACS, 488 (7.3%) had pre-existing AF and 479 (7.2%) had new-onset AF. Compared to patients with pre-existing AF, those with new-onset AF were younger, less likely to have co-morbidities, and more likely to receive evidence-based therapy. The un-adjusted risks of adverse outcomes in both groups were similar. Compared to pre-existing AF, new-onset AF was significantly associated with a higher adjusted risk of death (hazard ratio 1.27, 95% confidence interval 1.06–1.52) and IS/SE (hazard ratio 1.49, 95% confidence interval 1.01–2.20). The significant associations between new-onset AF and adverse outcomes were more likely to be observed in elderly patients with ACS.

Conclusions

New-onset AF during ACS was associated with a significantly increased risk of adverse outcomes, especially in the elderly patients.

New-onset atrial fibrillation in patients with acute coronary syndrome may be associated with worse prognosis and future heart failure

BACKGROUND

The purpose of this study was to evaluate the prognostic value of atrial fibrillation (AF) in patients with acute coronary syndrome (ACS).

METHODS

A total 648 of consecutive ACS patients were divided into non-AF and all-AF groups. The all-AF group was further subdivided into new-onset AF and pre-existing AF groups. We compared prognosis among these groups using the Cox regression analysis.

RESULTS

The mean follow-up period was 1.4 ± 1.2 years. Overall patient numbers were 538 in non-AF and 110 in all-AF groups (67 in new-onset AF and 43 in pre-existing AF). Seventy-eight all-cause deaths and 42 cardiac deaths were observed. New-onset AF had a worse prognosis than the other groups in the Kaplan-Meier analysis (P = 0.025) after observation. Cox regression analysis indicated no significant difference for all-cause death among the three groups. The hazard ratio of congestive heart failure requiring hospitalization was significantly higher in the all-AF and new-onset AF group than in the non-AF group. Multivariate logistic regression analysis revealed that renal dysfunction, peripheral arterial disease, Killip classification ≥2, and left ventricular ejection fraction (LVEF) were independent predictors of all-cause death. The new-onset AF group had the highest prevalence of Killip classification ≥2 and the lowest LVEF.

CONCLUSION

In our study, AF was not an independent predictor of all-cause death, but new-onset AF may be associated with worse prognosis and future heart failure.

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.

Temporal trends and outcomes associated with atrial fibrillation observed during acute coronary syndrome: Real-world data from the Acute Coronary Syndrome Israeli Survey (ACSIS), 2000-2013

BACKGROUND

The past decade has brought major advances in therapy of patients presenting with acute coronary syndromes (ACS).

HYPOTHESIS

The outcomes of ACS patients with atrial fibrillation (AF) has improved over the years.

METHODS

We evaluated time-dependent changes in clinical characteristics, management strategies, and outcomes associated with AF observed during ACS hospitalization in patients enrolled in the biannual ACS Israeli Surveys (ACSIS) between 2000 and 2013. We divided the surveys into early (2000-2006) and late (2008-2013) time periods.

RESULTS

The study population comprised 13 297 ACS patients, of whom 755 (5.7%) either presented with or developed AF during the index hospitalization. The incidence of AF observed during ACS hospitalization was lower during the later period (6.2% vs 4.9%; P < 0.01). Kaplan-Meier survival analysis showed that 1-year mortality rates were significantly lower among ACS patients with and without AF who were enrolled during the later vs early survey period (log-rank P < 0.01 for the overall difference). However, AF observed among ACS patients was still associated with increased risk for in-hospital complications and 30-day and 1-year mortality during both the early and late survey periods (P < 0.05 for all comparisons).

CONCLUSIONS

In 10 years, rates of AF among ACS patients have declined significantly. Yet, despite improved overall 1-year survival for patients with AF, the development of AF in this population remains an independent predictor of mortality that has not changed appreciably over the years.

Global longitudinal strain predicts incident atrial fibrillation and stroke occurrence after acute myocardial infarction

Patients with acute myocardial infarction are at increased risk of developing atrial fibrillation. We aimed to evaluate whether speckle tracking echocardiography improves risk stratification for atrial fibrillation in these patients.The study comprised of 373 patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention. Patients had an echocardiogram performed at a median of 2 days after their STEMI. The echocardiograms consisted of conventional measurements and myocardial strain analysis by speckle tracking from 3 apical projections. The endpoint was a composite of new-onset atrial fibrillation and ischemic stroke. At a median follow-up time of 5.5 years (interquartile range 4.9, 6.1 years), 44 patients developed the endpoint (atrial fibrillation: n = 24, ischemic stroke: n = 24, both: n = 4). Patients who reached the endpoint had significantly reduced systolic function by the left ventricular ejection fraction (LVEF) (43% vs 46%; P = 0.042) and global longitudinal strain (10.9% vs 12.6%; P = 0.004), both being univariable predictors. However, only global longitudinal strain remained a significantly independent predictor (hazard ratio 1.12, 95% confidence interval 1.00; 1.25, P = 0.042, per 1% decrease) after multivariable adjustment for baseline predictors (age, sex, diabetes, hypertension, diastolic dysfunction, and LVEF) using Cox regression. Furthermore, global longitudinal strain resulted in significantly higher c-statistics for prediction of outcome compared with LVEF <45% (0.63 vs 0.52; P = 0.026). When stratified into tertiles of global longitudinal strain, it became evident that patients in the lowest tertile mediated this signal with a 2-fold increased risk compared with the highest tertile (hazard ratio 2.10, 95% confidence interval 1.04; 4.25).Global longitudinal strain predicts atrial fibrillation after STEMI and may add valuable information which can help facilitate arrhythmia detection in these patients.

High Killips Class as a Predictor of New-onset Atrial Fibrillation Following Acute Myocardial Infarction: Systematic Review and Meta-analysis

BACKGROUND

Recent observational studies have shown that patients with higher Killips score (>I) have higher risk of new-onset atrial fibrillation (NOAF) following acute myocardial infarction (AMI), while others drew a neutral conclusion. The ultimate predictive value of high Killips class on NOAF remained obscure.

METHODS

PubMed, Web of Science, China National Knowledge Infrastructure, and the Cochrane Controlled Trials Register Databases were searched until February 2015. Of the 3732 initially identified studies, 5 observational studies with 10,053 patients were analyzed.

RESULTS

The meta-analysis of these studies showed that higher Killips score on admission was associated with higher incidence of NOAF following AMI (odds ratio = 2.29, 95% confidence interval 1.96-2.67, P < 0.00001), while no significant differences exist among individual trials (P = 0.14 and I2 = 43%).

CONCLUSIONS

Killips class >I was associated with the higher opportunity of developing NOAF following AMI.

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.

Relation of contrast induced nephropathy to new onset atrial fibrillation in acute coronary syndrome

Chronic renal failure has been described as a risk factor for the development of atrial fibrillation (AF). The aim of this study was to examine the association between contrast-induced nephropathy (CIN) and new-onset AF in patients with acute coronary syndromes. A total of 1,520 consecutive patients (mean age 67.1 ± 12.7 years) with acute coronary syndromes (34.4% with ST-segment elevation myocardial infarctions) who underwent coronary angiography were studied. CIN was defined as an increase in serum creatinine of 0.5 mg/dl within 72 hours of contrast exposure. The independent effect of AF history (chronic or paroxysmal AF before catheterization) on the development of CIN, as well as the independent effect of CIN on the development of new-onset AF (after catheterization, during the in-hospital phase), were tested by using different logistic regression models. One hundred thirty-nine patients (9.1%) had histories of AF before catheterization (60 with paroxysmal and 79 with chronic AF), and 56 (4.1%) developed new-onset AF after catheterization. Eighty-seven patients (5.7%) had CIN. AF history was a predictor of CIN in univariate analysis (odds ratio 2.19, 95% confidence interval 1.22 to 3.95, p = 0.007) but not in multivariate analysis, after adjusting for confounding variables (odds ratio 1.69, 95% confidence interval 0.89 to 3.22, p = 0.111). In contrast, those with CIN had an increased prevalence of new-onset AF (15.3% vs 3.4%, p <0.001). After adjusting for those variables associated with new-onset AF in the univariate analysis, CIN continued to show a significant association with new-onset AF, with a twofold increased risk (odds ratio 2.45, 95% confidence interval 1.07 to 5.64, p = 0.035). In conclusion, the development of CIN is an independent predictor of new-onset AF in the context of acute coronary syndromes.

Mechanisms of new-onset atrial fibrillation complicating acute coronary syndrome

Atrial fibrillation (AF) is one of the most common arrhythmia complications of acute coronary syndrome (ACS). The incidence of new-onset AF is 2.3-37 %, and it is an important predictor of a patient's morbidity, mortality, and prolonged hospitalization. Various risk factors for the development of new-onset AF after ACS have been identified, including: old age, higher Killip class, relevant history (e.g., hypertension), and enlarged left atrium. Insights into the pathophysiological mechanisms of new-onset AF have been provided by both experimental and clinical investigations and show that new-onset AF is multifactorial, involving atrial ischemia and atrial stretch, inflammation, autonomic nervous system activity, and hormone activation. An understanding of the mechanisms underlying new-onset AF complicating ACS can provide new insight of therapeutic importance.