Dynamic high-sensitivity troponin elevations in atrial fibrillation patients might not be associated with significant coronary artery disease

Emergency medicine updates: Atrial fibrillation with rapid ventricular response

INTRODUCTION

Atrial fibrillation (AF) may lead to stroke, heart failure, and death. When AF occurs in the context of a rapid ventricular rate/response (RVR), this can lead to complications, including hypoperfusion and cardiac ischemia. Emergency physicians play a key role in the diagnosis and management of this dysrhythmia.

OBJECTIVE

This paper evaluates key evidence-based updates concerning AF with RVR for the emergency clinician.

DISCUSSION

Differentiating primary and secondary AF with RVR and evaluating hemodynamic stability are vital components of ED assessment and management. Troponin can assist in determining the risk of adverse outcomes, but universal troponin testing is not required in patients at low risk of acute coronary syndrome or coronary artery disease - especially patients with recurrent episodes of paroxysmal AF that are similar to their prior events. Emergent cardioversion is indicated in hemodynamically unstable patients. Rate or rhythm control should be pursued in hemodynamically stable patients. Elective cardioversion is a safe option for select patients and may reduce AF symptoms and risk of AF recurrence. Rate control using beta blockers or calcium channel blockers should be pursued in those with AF with RVR who do not undergo cardioversion. Anticoagulation is an important component of management, and several tools (e.g., CHA2DS2-VASc) are available to assist with this decision. Direct oral anticoagulants are the first-line medication class for anticoagulation. Disposition can be challenging, and several risk assessment tools (e.g., RED-AF, AFFORD, and the AFTER (complex, modified, and pragmatic) scores) are available to assist with disposition decisions.

CONCLUSION

An understanding of the recent updates in the literature concerning AF with RVR can assist emergency clinicians in the care of these patients.

The utility of delta troponin in diagnosing significant coronary artery disease in patients with symptomatic atrial fibrillation

BACKGROUND

Troponin I (cTnI) elevation is common in patients with atrial fibrillation (AF) but does not reliably indicate underlying coronary ischemia. We investigated whether dynamic changes in cTnI value (delta troponin) are useful in revealing significant coronary artery disease (sCAD) in patients presenting with symptomatic AF.

METHODS

We conducted a retrospective case-control study analyzing serial cTnI values in 231 patients presenting with symptomatic AF who had an objective assessment for underlying CAD within 6 months of the index admission. Diagnostic performance of an elevated cTnI (>0.04 μg/L) only, and elevated cTnI coupled with Youden Index derived cutoffs for absolute and relative changes in troponin, for distinguishing patients with sCAD, was evaluated.

RESULTS

A total of 107 patients had an elevated cTnI on serial measurements. In this group, the area under the receiver operating characteristic curve was 0.69 [95% confidence interval (CI), 0.56-0.81] for relative delta troponin and 0.71 (95% CI, 0.59-0.83) for absolute delta troponin. The optimal diagnostic cutoff for relative delta troponin was > -0.42, and > -0.055 μg/L for absolute delta troponin. The specificity of elevated troponin to diagnose sCAD increased from 56 to 77% when relative delta troponin was added, and to 88% with absolute delta troponin. Although the sensitivity of cTnI elevation (57.1%) decreased to 50% for relative and 35.7% for absolute delta troponin, the negative predictive values were high and similar at 86%.

CONCLUSION

When added to the troponin peak, delta troponin is a promising test for the diagnosis of significant coronary artery disease in patients presenting with symptomatic AF with elevated cTnI. This result requires prospective validation in a larger cohort of patients.

Diabetes mellitus is an independent predictor of obstructive coronary artery disease in patients presenting with atrial fibrillation and elevated troponin

Atrial fibrillation can present with symptoms of myocardial infarction and elevated troponin, even in the absence of obstructive coronary artery disease (CAD). We sought to determine the characteristics that predict underlying obstructive CAD. Obstructive CAD was far more likely in those with troponin elevation. In those with elevated troponin, diabetes mellitus was an independent predictor of obstructive CAD.

Predictive value of high-sensitivity troponin for significant coronary artery disease in new-onset atrial fibrillation with rapid ventricular response

BACKGROUND

High-sensitivity troponin-T (HS-cTnT) levels are often measured in patients presenting with atrial fibrillation (AF), with many subjected to unnecessary invasive assessments. The significance of a normal or mildly raised HS-cTnT in this context is poorly understood. This study aimed to determine the predictive value of HS-cTnT for significant coronary artery disease (CAD) in new AF with rapid ventricular response. We also compared the discriminative ability of HS-cTnT to suspected angina for significant CAD.

METHODS

We examined patients presenting with new AF to two tertiary Irish centers in a defined period. Those included had HS-cTnT taken at presentation and subsequent ischemic evaluation.

RESULTS

Of 5350 cases screened for inclusion, 281 were deemed eligible. Of these, 148 and 133 patients had a positive and negative index HS-cTnT, respectively. Of those with negative HS-cTnT, 13 (9.8%) had significant CAD versus 51 (34.5%) with positive HS-cTnT (P < 0.001). Positive Hs-cTnT status remained significant upon multivariate analysis (OR, 2.9; 95% CI, 1.37-6.14; P = 0.005). A similar model where HS-cTnT was replaced with suspected angina produced an OR of 1.64 (95% CI, 0.75-3.59; P = 0.213). A logistic model determined optimal cutoff value for HS-cTnT to be less than 30 ng/l, producing a negative predictive value of 91.8% and area under the receiver operative curve of 83.36.

CONCLUSION

HS-cTnT exhibits potential as an effective screening biomarker to predict nonsignificant CAD in new rapid AF, allowing more targeted and rationalized ischemic testing. HS-cTnT may also be a more accurate predictor of significant CAD than clinically suspected stable angina.Graphical abstract: http://links.lww.com/MCA/A540.

Association between high-sensitive cardiac troponin level and coronary artery disease: A systematic review and meta-analysis

Background and objectives

Previous studies suggest a link between high-sensitive cardiac troponin (hs-cTn) levels and coronary artery disease (CAD). However, the nature of this relationship is disputed. To address this, we conducted a study to gather and assess evidence on the association between hs-cTn and CAD prediction.

Data sources

Studies were systematically searched and collected from four databases and different types of gray literature to cover all available evidence. After the screening, the selected articles' quality and risk of bias assessment were evaluated.

Synthesis method

Meta-analysis calculated std. mean difference on the extracted data. Furthermore, heterogeneity, sensitivity, subgroups, and publication bias analyses were assessed.

Results

Twenty-two studies were included in this systematic review, with a total of 844 cases and 2101 control people. The results of the meta-analysis on nine studies showed a significant and positive association between hs-cTn levels and CAD (pooled std. mean difference = 0.44; 95% confidence interval = 0.14-0.73; p < 0.003), with no publication bias (p = 0.9170). Among subgroups, std. mean differences were notably different only when the data were stratified by region or risk of bias; however, subgroup analysis could not determine the source of heterogeneity.

Conclusions

Available prospective studies indicate a strong association of hs-cTn with the risk of CAD and significant improvements in CAD prediction. Further investigations in both molecular and clinical fields with proper methodology and more detailed information are needed to discover more evidence and underlying mechanisms to clear the interactive aspects of hs-cTn level in CAD patients.

Chest pain workup in the presence of atrial fibrillation: impacts on troponin testing, myocardial infarction diagnoses, and long-term prognosis

AIMS

Patients presenting to the emergency department (ED) with chest pain require evaluation for acute coronary syndrome (ACS). Atrial fibrillation (AF) can lead to troponin (cTn) elevation in the absence of ACS. There is limited evidence informing the impact of AF on the diagnostic performance of cTn testing for the diagnosis of Type 1 myocardial infarction (T1MI), or the association between AF and long-term outcomes in this context.

METHODS AND RESULTS

This study used the IMPACT and ADAPT study databases to compile a combined cohort of 3496 adults presenting to ED with chest pain between 2007 and 2014, with early cTn testing during ED workup. The mean age was 56.6 years, and 40.2% were female. Outcomes included adjudicated diagnoses for the index admission and mortality to 1-year after presentation. The specificity of initial cTn testing for T1MI diagnosis was lower for patients in AF compared with those not in AF (79.2% vs. 95.4%, P < 0.001), largely due to a relative increase in Type 2 myocardial infarction diagnoses. Sensitivity for T1MI did not differ between patients with or without AF (88.5% vs. 91.5%, P = 0.485). AF was associated with increased 1-year mortality (10.4% vs. 2.3%, P < 0.001), although this was not significant on multivariable analysis.

CONCLUSION

The specificity of serial cTn testing for the diagnosis of T1MI in patients presenting to ED with chest pain is reduced in the presence of AF. Further studies are needed to establish whether optimised cTn thresholds for patients with AF can improve workup and outcomes.

Atrial fibrillation following coronary artery bypass graft: Where do we stand?

Atrial fibrillation (AF) is the most common atrial arrhythmia following coronary artery bypass graft (CABG). Its prevalence is 15-45% and is associated with poor long-term prognosis. Risk factors can be patient-related, intraoperative, and/or postoperative. Therapeutic and preventive strategies have been developed to curtail AF burden. Cardioversion is recommended for unstable or symptomatic patients and rate control if asymptomatic. Anticoagulation is challenging with risk of thromboembolism and bleeding. However, patients should be anticoagulated after cardioversion or if AF persists >48 h and risk factors of stroke exist. A minimum of 4 weeks is recommended but longer duration should be considered in patients at high risk of stroke irrespective of recurrence of AF.

Cardiac Troponin Thresholds and Kinetics to Differentiate Myocardial Injury and Myocardial Infarction

BACKGROUND

Although the 99th percentile is the recommended diagnostic threshold for myocardial infarction, some guidelines also advocate the use of higher troponin thresholds to rule in myocardial infarction at presentation. It is unclear whether the magnitude or change in troponin concentration can differentiate causes of myocardial injury and infarction in practice.

METHODS

In a secondary analysis of a multicenter randomized controlled trial, we identified 46 092 consecutive patients presenting with suspected acute coronary syndrome without ST-segment-elevation myocardial infarction. High-sensitivity cardiac troponin I concentrations at presentation and on serial testing were compared between patients with myocardial injury and infarction. The positive predictive value and specificity were determined at the sex-specific 99th percentile upper reference limit and rule-in thresholds of 64 ng/L and 5-fold of the upper reference limit for a diagnosis of type 1 myocardial infarction.

RESULTS

Troponin was above the 99th percentile in 8188 patients (18%). The diagnosis was type 1 or type 2 myocardial infarction in 50% and 14% and acute or chronic myocardial injury in 20% and 16%, respectively. Troponin concentrations were similar at presentation in type 1 (median [25th-75th percentile] 91 [30-493] ng/L) and type 2 (50 [22-147] ng/L) myocardial infarction and in acute (50 [26-134] ng/L) and chronic (51 [31-130] ng/L) myocardial injury. The 99th percentile and rule-in thresholds of 64 ng/L and 5-fold upper reference limit gave a positive predictive value of 57% (95% CI, 56%-58%), 59% (58%-61%), and 62% (60%-64%) and a specificity of 96% (96%-96%), 96% (96%-96%), and 98% (97%-98%), respectively. The absolute, relative, and rate of change in troponin concentration were highest in patients with type 1 myocardial infarction (P<0.001 for all). Discrimination improved when troponin concentration and change in troponin were combined compared with troponin concentration at presentation alone (area under the curve, 0.661 [0.642-0.680] versus 0.613 [0.594-0.633]).

CONCLUSIONS

Although we observed important differences in the kinetics, cardiac troponin concentrations at presentation are insufficient to distinguish type 1 myocardial infarction from other causes of myocardial injury or infarction in practice and should not guide management decisions in isolation. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01852123.

Outcomes and Resource Utilization of Atrial Fibrillation Hospitalizations With Type 2 Myocardial Infarction

Scarce data exist on the prognostic impact of type 2 myocardial infarction (MI) in patients with AF. The Nationwide Readmission Database 2018 was queried for primary AF hospitalizations with and without type 2 MI. Complex samples multivariable logistic and linear regression models were used to determine the association between type 2 MI and outcomes (in-hospital mortality, index length of stay [LOS], hospital costs, discharge to nursing facility, and 30-day all-cause readmissions). Of 382,896 weighted primary AF hospitalizations included in this study, 7,375 (1.9%) had type 2 MI. AF with type 2 MI is associated with significantly higher in-hospital mortality (adjusted OR [aOR] 1.76; 95% CI 1.30 to 2.38), LOS (adjusted parameter estimate [aPE] 0.48; 95% CI 0.35 to 0.62), hospital costs (aPE 1307.75; 95% CI 986.05 to 1647.44), discharges to nursing facility (aOR 1.38; 95% CI 1.24 to 1.54), and 30-day all-cause readmissions (adjusted hazard ratio 1.17; 95% CI 1.07 to 1.27) compared to AF without type 2 MI. Heart failure, chronic kidney disease, neurologic disorders, and age (per year) were identified as independent predictors of mortality among AF patients with type 2 MI. In conclusion, type 2 MI in the setting of AF hospitalization is associated with high in-hospital mortality and increased resource utilization.

Low risk patients with acute atrial fibrillation and elevated high-sensitivity troponin do not have increased incidence of pathological stress tests

OBJECTIVES

Many patients with atrial fibrillation (AF) or atrial flutter (AFL) and rapid ventricular response (RVR) have elevated high-sensitivity troponin T (hsTnT) values. Elevated hsTnT is an independent risk marker for cardiovascular events and mortality. The aim was to examine if AF/AFL patients with RVR and elevated hsTnT have an increased incidence of pathological cardiac stress tests, indicating need of further evaluation for coronary artery disease (CAD). Design: We prospectively included 90 AF/AFL patients without known heart failure and CAD presenting with AF/AFL and RVR. Half of the patients had elevated hsTnT (cases) and half had levels below the 99th percentile (controls). All patients were discharged in sinus rhythm. After approximately one week in sinus rhythm a new hsTnT was analysed and the patients performed a bicycle exercise stress test within the 30 day follow-up. The primary endpoint was a pathological stress test confirmed by a pathological SPECT myocardial perfusion imaging or a coronary angiography. Results: None of the controls reached the primary endpoint. Two patients (4%) out of the 45 cases reached the primary endpoint (p = .49 vs controls), but only one was found to have significant CAD at subsequent coronary angiography. Conclusion: Patients with paroxysmal AF/AFL, without a history of CAD and heart failure, who present with a RVR and minor hsTnT elevations were not found to have an increased incidence of pathological stress tests compared to patients with hsTnT values below the 99th percentile.

Prognostic Value of Troponin in Patients with Atrial Fibrillation Admitted to an Emergency Department: Review and Meta-Analysis

Introduction

Elevated levels of cardiac troponin (cTn) indicate underlying heart disease and is known to predict adverse events in multiple conditions. Its role in atrial fibrillation (AF) in the acute setting is still not conclusive. We aimed to assess the prognostic value of c-Tn in patients with AF admitted to an emergency department (ED).

Methods

Systematic searches were conducted using PubMed and the Cochrane Library and the International Clinical Trials Registry Platform to identify studies from year 2009 to October 2019 reporting on the prognostic value of cTn on all-cause mortality or major adverse cardiac events (MACE) in adult patients with AF in the ED. We pooled hazard ratio (HR) and 95% confidence interval (CI) using fixed and random effects models according the heterogeneity. We planned to conduct a sensitivity and subgroup analyses.

Results

Five studies involving 5750 patients were identified. The mean follow-up ranged from 12 to 35 months. An increase in mortality was observed in the elevated cTn group compared to the controls, HR=2.7 (95% CI 1.55-4.72), P for effect<0.001, I2=80%). For MACE, the pooled HR was 2.17 (95%CI 1.60-2.94), P for effect<0.001, I2=0%). In the subgroup analysis we found no significant difference in type of troponin used and study design.

Conclusions

The elevation of cardiac troponin was significantly associated with higher mortality and major adverse cardiac events in patients with AF admitted to an ED. In this setting the use of c-Tn could provide prognostic information.

Myocardial Injury in the Era of High-Sensitivity Cardiac Troponin Assays: A Practical Approach for Clinicians

Importance

Traditionally, elevated troponin concentrations were synonymous with myocardial infarction. But with improvements in troponin assays, elevated concentrations without overt myocardial ischemia are now more common; this is referred to as myocardial injury. Physicians may be falsely reassured by the absence of myocardial ischemia; however, recent evidence suggests that myocardial injury is associated with even more detrimental outcomes. Accordingly, this article reviews the definition, epidemiology, differential diagnosis, diagnostic evaluation, and management of myocardial injury.

Observations

Current epidemiological evidence suggests that myocardial injury without overt ischemia represents about 60% of cases of abnormal troponin concentrations when obtained for clinical indications, and 1 in 8 patients presenting to the hospital will have evidence of myocardial injury. Myocardial injury is a concerning prognosis; the 5-year mortality rate is approximately 70%, with a major adverse cardiovascular event rate of 30% in the same period. The differential diagnosis is broad and can be divided into acute and chronic precipitants. The initial workup involves an assessment for myocardial ischemia. If infarction is ruled out, further evaluation includes a detailed history, physical examination, laboratory testing, a 12-lead electrocardiogram, and (if there is no known history of structural or valvular heart disease) an echocardiogram. Unfortunately, no consensus exists on routine management of patients with myocardial injury. Identifying and treating the underlying precipitant is the most practical approach.

Conclusion and Relevance

Myocardial injury is the most common cause of abnormal troponin results, and its incidence will likely increase with an aging population, increasing prevalence of cardiovascular comorbidities, and greater sensitivity of troponin assays. Myocardial injury represents a challenge to clinicians; however, given its serious prognosis, it warrants a thorough evaluation of its underlying precipitant. Future strategies to prevent and/or manage myocardial injury are needed.

Etiology of Minor Troponin Elevations in Patients with Atrial Fibrillation at Emergency Department-Tropo-AF Study

Patients with atrial fibrillation (AF) presenting to the emergency department (ED) often have elevated cardiac troponin T (TnT) levels without evidence of type 1 myocardial infarction. We sought to explore the causes and significance of minor TnT elevations in patients with AF at the ED. All patients with AF admitted to the ED of Turku University Hospital between 1 March, 2013 and 11 April, 2016, and at least two TnT measurements, were screened. Overall, 2911 patients with a maximum TnT of 100 ng/L during hospitalization were analyzed. TnT was between 15 and 100 ng/L in 2116 patients. The most common primary discharge diagnoses in this group were AF (18.1%), infection (18.3%), ischemic stroke/transient ischemic attack (10.7%), and heart failure (5.0%). Acute coronary syndrome (ACS) was equally uncommon both in patients with normal TnT and elevated TnT (4.4% vs. 4.5%). Age ≥75 years, low estimated glomerular filtration rate (eGFR), high C-reactive protein (CRP), and hemoglobin <10.0 g/dL, were the most important predictors of elevated TnT. Importantly, TnT elevation was a very frequent (>93%) finding in elderly (≥75 years) AF patients with either low eGFR or high CRP. In conclusion, minor TnT elevations carry limited diagnostic value in elderly AF patients with comorbidities.

[Association of Atrial Fibrillation with Coronary Lesion in Ischemic Heart Disease Patients]

AIM

to find out whether atrial fibrillation (AF) in patients with ischemic heart disease (IHD) is related to some definite localization or extent of coronary artery lesions or type of coronary circulation.

MATERIALS AND METHODS

We compared data of clinical, laboratory, and instrumental examination of 178 IHD patients from the Registry of coronary angiography of patients with AF (main group) and 331 patients (comparison group) selected according to propensity score matching with balancing by sex, age, body mass index, severity of chronic heart failure, frequency of myocardial infarctions, detection of arterial hypertension, and thyroid diseases.

RESULTS

The groups did not differ in terms of alcohol use, frequency of smoking, and detection of diabetes. Patients with AF compared with those without had higher mean heart rate (105±32 vs. 70±13 bpm, р&lt;0.001), lower level of triglycerides (1.74±1.08 vs. 1.94±1.17 mmol / l, р=0.019). AF patients more rarely had class III-IV effort angina (52.9 % vs. 66.5 %, р=0.041). Rate of detection of left ventricular (LV) dilatation and index of LV asynergy in both groups were similar, but absolute dimensions and indexes of LV, left atrium, right ventricle, LV myocardial mass were higher in the AF group. Hemodynamically significant mitral regurgitation and lowering of LV contractility were more often detected in patients with AF (49.1 % vs. 18.4 %, р&lt;0.001, and 56.2 % vs. 39.5 %, р&lt;0.001, in main and comparison groups, respectively). Analysis of coronary angiography data showed that patients with compared with those without AF more often had right type of coronary circulation (87.5 % vs. 80.4 %, р=0.043) as well as lesions of the right coronary artery (92.1 % vs. 85.8 %, р=0.037), and less often lesions of left coronary artery trunk (16.3 % vs. 24.8 %, р=0.027).

CONCLUSION

AF in patients with IHD is associated with right coronary artery lesions and right type of coronary circulation.

Biomarkers of Atrial Fibrillation: Which One Is a True Marker?

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmias and associated with the risk of stroke and death. Continuous development of the diagnostic tool and prognostic stratification may lead to optimal management of AF. The use of biomarkers in the management of AF has been grown as an interesting topic. However, the AF biomarkers are not yet well established in the major guidelines. Among these biomarkers, a lot of data show troponin and brain natriuretic peptides are promising for the prediction of future events. The troponin elevation in AF patients may not necessarily be diagnosed as myocardial infarction or significant coronary artery stenosis, and brain natriuretic peptide elevation may not necessarily confirm heart failure. Troponin T and troponin I may predict postoperative AF. Furthermore, troponin and brain natriuretic peptide gave better prognostic performance when compared with the risk score available today.

High sensitivity troponin in the management of tachyarrhythmias

BACKGROUND

The introduction of the highly sensitive troponin (hs-trop) assays into clinical practice has allowed for the more rapid diagnosis or exclusion of type 1 myocardial infarctions (T1MI) by clinicians, in addition type 2 myocardial infarctions (T2MI) are now more frequently detected. Tachyarrhythmias are one of the common causes of T2MI, the medium and long term outcome for this cohort of T2MI is yet to be clarified.

METHODS

Retrospective review of consecutive patients admitted with a diagnosis of either (a) non ST-elevation myocardial infarction (NSTEMI) or (b) tachyarrhythmia was performed. Data were collected on patient demographics and investigations. Patient mortality status was recorded through the Personal Demographics Service (PDS) via NHS Digital.

RESULTS

A total of 704 patients were eligible for inclusion to the study. 264 patients were included in the study with a final discharge diagnosis of NSTEMI and 440 patients with a final discharge diagnosis of tachyarrhythmia. There was a significantly higher peak troponin in NSTEMI patients compared to the tachyarrhythmia troponin positive group (4552ng/L vs 571ng/L, p<0.001). Mortality was significantly higher in the troponin positive tachyarrhythmia patients than the troponin negative patients (54 vs 34, 26.2% vs 14.5%, log rank p=0.003), furthermore, the mortality of NSTEMI and troponin positive tachyarrhythmia patients was similar (55 vs 54, 20.8% vs 26.2%, log rank p=0.416). Only one patient (0.14%) was given a formal diagnosis of T2MI.

CONCLUSIONS

These data suggest that troponin positive tachyarrhythmia is not a benign diagnosis, and has a mortality rate similar to NSTEMI. Formal labeling as T2MI is rare in real life practice. More investigation into the detection and management of T2MI and troponin positive arrhythmia patients is now warranted.