The Role of Troponin Testing in Patients with Supraventricular Tachycardia, Systematic Review and Meta-Analysis.

BACKGROUND: Supraventricular tachycardia (SVT) is commonly evaluated in the emergency department (ED). While troponin has been shown to be elevated in SVT, its usefulness for predicting coronary artery disease and future adverse cardiovascular outcomes has not been shown. OBJECTIVES: We aimed to evaluate the prognostic utility of troponin measurement as part of SVT management in the ED. METHODS: We performed a literature search in the PubMed and Scopus databases from inception to August 30, 2023, including all studies reporting troponin measurements in adult patients (age > 18 years) presenting to the ED with supraventricular tachycardia. The primary outcome of interest for this study was the prevalence of elevated troponin in patients with SVT. Secondary outcomes included the prevalence of major adverse cardiac events (MACE) and additional cardiac testing with significant findings. RESULTS: We included 7 studies (500 patients) in our analysis. Six studies reported the number of patients with SVT and elevated troponin, with a pooled prevalence of 46% (95% CI 27-66%, I2 93%). The pooled prevalence of all MACE in our study was 6% (95% CI 1-25%), while the prevalence for MACE among patients with elevated serum troponin levels was 11% (95% CI 4-27%). CONCLUSIONS: Troponin levels are frequently ordered for ED patients with SVT and are often elevated. However, this review suggests that they have low prognostic value in predicting MACE.

Percutaneous VDD leadless pacer implant post recent bioprosthetic tricuspid valve replacement for infective endocarditis.

In January 2020, the first Medtronic VDD leadless pacemaker Micra AV was approved by FDA to treat patients with advanced AV block, based on the encouraging results from the Micra Atrial tRacking using a Ventricular accELerometer 2 (MARVEL 2). There is reassuring data about safety and short-term outcomes of traditional leadless pacemaker implant after recent surgical tricuspid valve replacement, but only few cases are reported in literature. No data was found regarding AV Micra implant safety and outcomes in patients following bioprosthetic tricuspid valve replacement as of today. Our patient is a 44-year-old gentleman with history of IV drug use who recently underwent tricuspid replacement with bioprosthesis for infective endocarditis complicated by postsurgical heart block, acute kidney insufficiency requiring hemodialysis, persistent bacteremia and candidemia, and progressive failure of the epicardial pacing wires. Given the elevated infective risk, the decision of attempting leadless pacer implant through the bioprosthetic valve was taken and our patient underwent successful Micra AV implant on postoperative day 30. To our knowledge, this is the first AV Micra placement following bioprosthetic tricuspid valve replacement. The uneventful procedure and the encouraging short-term device follow-up results seem to confirm the relative safety of this device in treating advanced atrioventricular conduction disorders in patients at elevated infective risk.

Racial/Ethnic Disparities in Atrial Fibrillation Treatment and Outcomes among Dialysis Patients in the United States.

BACKGROUND: Because stroke prevention is a major goal in the management of ESKD hemodialysis patients with atrial fibrillation, investigating racial/ethnic disparities in stroke among such patients is important to those who could benefit from strategies to maximize preventive measures. METHODS: We used the United States Renal Data System to identify ESKD patients who initiated hemodialysis from 2006 to 2013 and then identified those with a subsequent atrial fibrillation diagnosis and Medicare Part A/B/D. Patients were followed for 1 year for all-cause stroke, mortality, prescription medications, and cardiovascular disease procedures. The survival mediational g-formula quantified the percentage of excess strokes attributable to lower use of atrial fibrillation treatments by race/ethnicity. RESULTS: The study included 56,587 ESKD hemodialysis patients with atrial fibrillation. Black, white, Hispanic, and Asian patients accounted for 19%, 69%, 8%, and 3% of the population, respectively. Compared with white patients, black, Hispanic, or Asian patients were more likely to experience stroke (13%, 15%, and 16%, respectively) but less likely to fill a warfarin prescription (10%, 17%, and 28%, respectively). Warfarin prescription was associated with decreased stroke rates. Analyses suggested that equalizing the warfarin distribution to that in the white population would prevent 7%, 10%, and 12% of excess strokes among black, Hispanic, and Asian patients, respectively. We found no racial/ethnic disparities in all-cause mortality or use of cardiovascular disease procedures. CONCLUSIONS: Racial/ethnic disparities in all-cause stroke among hemodialysis patients with atrial fibrillation are partially mediated by lower use of anticoagulants among black, Hispanic, and Asian patients. The reasons for these disparities are unknown, but strategies to maximize stroke prevention in minority hemodialysis populations should be further investigated.

Introduction: Early Diagnosis and Appropriate Treatment of Atrial Fibrillation.

Atrial fibrillation (AF), the most common sustained arrhythmia, represents a significant burden to patients and healthcare systems. Many patients with AF are asymptomatic and often undiagnosed. Improved detection methods and surveillance have resulted in recognition of asymptomatic and subclinical AF, providing earlier diagnosis. The recent EAST-AFNET 4 and Korean studies have demonstrated early rhythm control (ERC) with antiarrhythmic drugs (AADs) or ablation in patients with AF improves outcomes. The EARLY AF and STOP AF First studies have shown that ERC using ablation can slow AF progression. In the following videos, the authors discuss the evolving AF landscape, with an emphasis on the benefits of early diagnosis and treatment. Historic rate versus rhythm control studies and their limitations are reviewed, followed by recent studies that support the use of ERC alongside usual care including rate control. Discussion of ERC treatment includes the selection of appropriate AADs based on safety, when to choose ablation as first-line therapy, and the complementary use of ablation and AADs. The authors summarize the current guidelines for the use of AADs to treat AF, highlighting the importance of concordance with those guidelines. Patient cases are used to relate the contents of the videos to clinical practice and are supplemented with discussion of the importance of shared decision-making involving the patient in treatment decisions. It is anticipated that this digital publication will enable cardiologists and primary care providers to recognize when early treatment of AF will improve patient outcomes, and to empower them to initiate that treatment accordingly.

Chapter 3: Evidence for the Use of Early Rhythm Control to Prevent Atrial Fibrillation Progression.

This chapter reviews atrial fibrillation (AF) progression and its associated mechanisms, including comorbidities and AF as contributors to atrial myopathy, and atrial myopathy as a contributing factor to AF progression. In addition, the chapter discusses the concept of comorbidities and atrial myopathy as synergistic contributors to adverse outcomes, the notion of "AF begets AF," and the consequences of AF burden if left untreated. Clinical trials evaluating outcomes with antiarrhythmic drugs (AADs) compared with placebo have demonstrated efficacy, but also reveal a possible proarrhythmic and mortality risk if AAD selection is not appropriate and patients are not correctly identified based on risk factors and comorbidities. Data from ATHENA, the first and only trial to demonstrate that an AAD (dronedarone) can reduce cardiovascular (CV) hospitalizations in people with AF, are reviewed, along with studies reporting on the use of catheter ablation versus AADs for AF rhythm control. Finally, recent data showing a reduction in major adverse outcomes if rhythm control is initiated early are summarized, including results from the EAST-AFNET 4 trial, as well as confirmatory results from several large "real-world" trials. Chapter 3 is summarized as follows.

Chapter 4: Evidence for the Early Use of Ablation and AADs Post-Ablation.

Both catheter ablation and antiarrhythmic drugs (AADs) are effective treatments for atrial fibrillation (AF) and can be used individually or as complementary treatments. This chapter discusses the use of ablation for early rhythm control in AF, and the use of AADs post-ablation. Decisions on which therapeutic approach to pursue should be based on shared decision-making with the patient. The chapter reviews data from the CABANA trial, in which the intent-to-treat (ITT) analysis failed to show superiority for ablation versus AADs. Statistical significance was achieved, however, when using the pre-specified per-protocol and pre-treatment analyses. The discussion addresses the fact that data analysis was complicated by several factors: (1) not all members of the group assigned to ablation actually received ablation; (2) the AAD arm included rate control treatment without the use of AADs; (3) there were a large number of crossovers from the AAD arm to the ablation arm; and (4) many ablation-treated participants also used AADs. Results from the CABANA trial showed that ablation was better at preventing AF recurrence than AADs alone. Data from the STOP AF and EARLY AF trials that support the observation of ablation being superior to AADs alone for the reduction of recurrent AF are also reviewed. Many patients who undergo catheter ablation for AF either continue to use or need to restart AADs following ablation. This combination therapy is used by up to 40-50% of people at 1-year post ablation, as is clearly demonstrated by the results from the trials discussed above, in addition to those from the 5A trial, the POWDER AF trial, the AMIO-CAT trial, and a substantial meta-analysis. All these trials are reviewed in this chapter, noting that a variety of differences exist between the randomized clinical trials, including in ablation procedures, follow-up periods, physician experience, and AADs. Chapter 4 is summarized as follows.

Chapter 5: Guideline Recommendations: Which AAD and for Whom?

This chapter discusses the American College of Cardiology/American Heart Association/ Heart Rhythm Society (AHA/ACC/HRS) and European Society of Cardiology (ESC) guidelines for atrial fibrillation (AF) management with particular focus on antiarrhythmic drug (AAD) selection and the identification of individuals for whom AAD treatment is appropriate. Discussion includes AAD indications, when to start an AAD, choosing among AADs, how to minimize proarrhythmic risk, how to determine efficacy, and the use of adjuvant interventions. The indications for all AADs are based on safety; the current AHA/ACC/HRS and ESC guidelines state that the choice of AAD is based on the presence or absence of structural heart disease (SHD), coronary artery disease, or heart failure (HF), with further recommendations in the ESC guidelines based on HF type (e.g., HF with reduced ejection fraction [HFrEF] versus HF with preserved ejection fraction [HFpEF]). The chapter closes with a discussion of the lack of consistent use of guideline-directed care, with a review of supportive data from the recently reported AIM-AF survey-a multinational survey on AF management that involved both cardiologists and electrophysiologists. In AIM-AF, inappropriate drug selection in terms of suitable candidate selection and drug choice occurred with all types of drugs and in most patient groups. Most notable was the overuse of amiodarone in patients without SHD, and the widespread use of sotalol, including its use in patients with HFrEF. Chapter 5 is summarized as follows.

Chapter 6: AAD Use in Different Patient Populations, and a Patient-Centric Approach to Optimal Patient Management.

Associated with longer life expectancy, greater survival of patients with cardiovascular disorders, and increased use of wearable and insertable/implantable devices capable of detection, the frequency of atrial fibrillation (AF) diagnosis is increasing. This chapter describes two representative patient cases that were used to enable a discussion of the evaluation and management of AF in different scenarios. One patient is young and healthy with paroxysmal AF but no major comorbidities (though there is a family history of AF). The other is older with multiple complicating comorbidities. These cases sparked an active discussion among the panelists that demonstrated not only the multitude of considerations when choosing the optimal therapy for each individual, but also the individualistic differences in biases and styles that can exist between experts in the field. The results of these discussions revealed agreement that.

Chapter 1: The Evolving Atrial Fibrillation Landscape: Importance of Early Diagnosis and Treatment.

Chapter 1 begins with data that show the rising prevalence of atrial fibrillation (AF), which is increasing in tandem with the growing number of older adults, increased survival of people who have cardiovascular (CV) disorders, and the expanding use of wearable and insertable/implantable devices capable of detection. Together, these increases will result in healthcare providers seeing more patients with AF who present at earlier stages of the disease. The panel discussion covers information regarding symptoms that are common to patients with AF as well as information about the important adverse outcomes that may occur in patients with AF, including heart failure, hospitalization, thromboembolism, and death. Notably, these events may reflect either the comorbidities commonly underlying AF, AF itself, or a combination of these conditions. The chapter also introduces the four pillars of therapy-"upstream therapy," rate control, rhythm control, and embolic prevention-with an emphasis on early rhythm control as being optimal. Chapter 1 is summarized as follows.

Chapter 2: Rate Versus Rhythm Control.

Atrial fibrillation (AF) is a potentially serious health risk, both because of its symptoms and because of its association with an increased risk for heart failure, hospitalization, thromboembolism, and death. Chapter 2 discusses selection of appropriate treatments and when to initiate these therapies. Older trials focused on comparing rate versus rhythm control treatment options for AF. It is now recognized that both rate and rhythm control are important and can be used together. This chapter reviews the historical, pivotal rate versus rhythm control trials that failed to show any overall survival benefit of rhythm over rate control, as well as the trials' now-recognized limitations with respect to modern therapy. In addition, an in-depth discussion of the more recent trials of antiarrhythmic drugs (AAD) and ablation techniques (which have become available since the original rate versus rhythm trials were performed) is included. These updated trials show that when applied to patient- and disease-specific situations, rhythm control can reduce the risk for mortality and hospitalization. The chapter also reviews the guidelines that have been developed to achieve these goals. Chapter 2 is summarized as follows: (1) Rate control is needed (at rest and during exertion) to reduce rate-related symptoms when rhythm control is ineffective or incomplete and to prevent a tachycardia-induced cardiomyopathy. (2) Previous trials with pharmacological therapy alone comparing rate versus rhythm control using the AADs available at that time failed to show any overall survival benefit of rhythm control over rate control. (3) These earlier trials had many methodological limitations and enrolled participants who did not have access to modern therapies. (4) Newer therapies, including those for stroke prevention, dronedarone (the latest approved AAD), and AF ablation, have improved the safety and efficacy of rhythm control strategies.

Outcomes of Acute Conduction Abnormalities Following Transcatheter Aortic Valve Implantation With a Balloon Expandable Valve and Predictors of Delayed Conduction System Abnormalities in Follow-up.

Transcatheter aortic valve implantation (TAVI) is an acceptable treatment for severe aortic stenosis in high or intermediate risk patients. Conduction abnormalities are a known complication of TAVI. Most abnormalities occur perioperatively but can develop later. The predictors of delayed conduction abnormalities are unknown. Patients who underwent TAVI at our institution were reviewed. Patients with a pre-existing pacemaker were excluded. Baseline, in-hospital, and 30-day follow-up ECGs were reviewed. Patient and procedural characteristics were analyzed to look for predictors of acute and delayed abnormalities. Ninety-eight patients were included. All valves implanted were balloon expandable, most commonly SAPIEN S3 (78%). Thirty-seven (37.7%) patients developed abnormalities before discharge. Of these patients, 20 (57.1%) had complete resolution at 30-day follow-up. No patients with new conduction abnormalities during hospitalization had additional abnormalities at 30-day follow-up. Five (5.1%) patients developed new conduction abnormalities following discharge. Overall, 22 (22.4%) patients had conduction abnormalities at 30-day follow-up which were not present at baseline. Predilatation (p = 0.003), higher ratios of balloon (p = 0.03) or valve (p = 0.05) size to left ventricular outflow tract, and previous myocardial infarction (p = 0.034) were predictive of acute conduction abnormalities. Baseline right bundle branch block (p = 0.002), longer baseline (p <0.001) and discharge (p = 0.004) QRS duration, moderate, or severe aortic insufficiency (p = 0.002) and atrial fibrillation (p = 0.031) were predictors of new conduction abnormalities after discharge. In conclusion, most new in-hospital conduction abnormalities resolve by 30-day follow-up. In-hospital conduction abnormalities are related to technical aspects of TAVI while delayed conduction abnormalities are related to baseline conduction system disease.

Clozapine-induced myocarditis.

Approved in 1989 for the management of treatment-resistant schizophrenia, Clozapine is a last-line atypical antipsychotic drug used with increasing frequency. In addition to its well-known side effect of agranulocytosis, this drug also carries with it rare but serious adverse cardiovascular risk of myocarditis. We present a patient on Clozapine who was admitted to the cardiology service with chest pain, ST segment elevations and elevated troponin concerning for acute myocardial infarction. Evaluation with imaging revealed decreased left ventricular function, however, no coronary artery disease was present on catheterization; findings consistent with a diagnosis of myocarditis. Subsequent discontinuation of the patient's Clozapine and initiation of brief supportive medical therapy resulted in full recovery of systolic left ventricular function. Given the potential cardiovascular mortality risk, it is important for physicians on cardiology services caring for psychiatric patients to be aware of the presentation of symptoms, diagnostic findings and management of Clozapine induced myocarditis.

Percutaneous management of ostial stenosis of the left internal mammary artery graft.

A 61-year-old man, who had undergone coronary artery bypass surgery 10 years earlier, presented with a non-ST segment elevation myocardial infarction. He was treated with medical therapy and taken to the Cardiac Catheterization Laboratory. A left heart catheterization demonstrated an ostial stenosis in the left internal mammary artery graft, which was felt to be the culprit lesion. This was successfully repaired with a drug eluting stent. This case is presented as an unusual location for a de novo coronary stenosis. The pathophysiology of these lesions is not well understood.

Rate Versus Rhythm Control in Patients with Normal to Mild Left Atrial Enlargement: Insights from the AFFIRM Trial.

BACKGROUND: Atrial fibrillation is the most commonly encountered sustained arrhythmia and is associated with significant morbidity and mortality. Several trials have demonstrated that no mortality benefit exists when choosing a rhythm-control strategy over a rate-control strategy, with some trials suggesting an increase in mortality. Using the AFFIRM trial database we sought to determine the effect of rhythm control strategy in patients with normal or mild atrial enlargement. METHODS: AFFIRM Trial database was used to evaluate the effect of rhythm-control strategy compared to rate-control strategy in a subgroup of patients with normal to mild left atrial (LA) enlargement. The primary outcome measures of this study were all-cause mortality, cardiovascular mortality, non-cardiovascular mortality, and hospitalization/ED visit. RESULTS: We identified a subgroup of subjects from the AFFIRM trial with normal or mild LA enlargement (n=2022 of 4060 total subjects). Subjects in the rhythm-control group(n= 1022) had an increased risk of all-cause mortality by 34% (RR 1.34, 95% CI 1.08-1.67; P=0.007) and hospitalization/ED visits by 10% (RR 1.10, 95% CI 1.05-2.16; P=<0.001) compared to rate control group(n= 1000). CONCLUSION: This study demonstrated that rhythm-control strategy increases the risk of mortality and hospitalization in a subgroup of patients with normal to mild atrial enlargement compared to rate-control strategy. Amiodarone use in this subgroup of patients likely drove these findings.

The effect of angiotensin-converting enzyme inhibitors on clinical outcomes in patients with ischemic cardiomyopathy and midrange ejection fraction: a post hoc subgroup analysis from the PEACE trial.

BACKGROUND:: There have been significant advances in the treatment of patients with cardiomyopathy with reduced ejection fraction (EF < 40%). However, there is a dearth of information in the treatment of patients with cardiomyopathy and midrange EF (40-50%). Current guidelines state to treat these patients similarly to patients with cardiomyopathy and preserved EF. Data from the Prevention of Events with Angiotensin-Converting Enzyme Inhibition (PEACE) trial were used to elucidate whether angiotensin-converting enzyme (ACE) inhibitors improve clinical outcomes in patients with ischemic cardiomyopathy and midrange EF. METHODS:: A post hoc subgroup analysis of the PEACE trial was conducted to evaluate the effect of ACE inhibitors in a subgroup of patients with ischemic cardiomyopathy and midrange EF (40-50%). A Chi-square test and a Student's t-test were used to examine and compare the binary and continuous variables of baseline characteristics and outcomes between experimental and comparison groups. RESULTS:: We studied a subgroup of patients from the PEACE trial with ischemic cardiomyopathy and midrange EF ( n = 2512 of 8290 total patients). Patients were assigned to either the interventional group ( n = 1247) or the placebo group ( n = 1265). There were no significant differences in baseline demographic and health characteristics between the two groups. During a total of 7 years (mean 4.7 years) of follow up, the risk of composite outcomes [all-cause mortality, nonfatal myocardial infarction, and stroke; relative risk (RR) 0.79, 95% confidence interval (CI) 0.63-0.98; p = 0.03] and all-cause mortality (RR 0.85, 95% CI 0.73-0.99; p = 0.03) was reduced in patients treated with trandolapril. CONCLUSION:: This study revealed the benefit of ACE inhibitors among patients with ischemic cardiomyopathy and midrange EF.

Forest dynamics in Oregon landscapes: evaluation and application of an individual-based model.

The FORCLIM model of forest dynamics was tested against field survey data for its ability to simulate basal area and composition of old forests across broad climatic gradients in western Oregon, USA. The model was also tested for its ability to capture successional trends in ecoregions of the west Cascade Range. It was then applied to simulate present and future (1990-2050) forest landscape dynamics of a watershed in the west Cascades. Various regimes of climate change and harvesting in the watershed were considered in the landscape application. The model was able to capture much of the variation in forest basal area and composition in western Oregon even though temperature and precipitation were the only inputs that were varied among simulated sites. The measured decline in total basal area from tall coastal forests eastward to interior steppe was matched by simulations. Changes in simulated forest dominants also approximated those in the actual data. Simulated abundances of a few minor species did not match actual abundances, however. Subsequent projections of climate change and harvest effects in a west Cascades landscape indicated no change in forest dominance as of 2050. Yet, climate-driven shifts in the distributions of some species were projected. The simulation of both stand-replacing and partial-stand disturbances across western Oregon improved agreement between simulated and actual data. Simulations with fire as an agent of partial disturbance suggested that frequent fires of low severity can alter forest composition and structure as much or more than severe fires at historic frequencies.

The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study: approaches to control rate in atrial fibrillation.

OBJECTIVES: We sought to evaluate approaches used to control rate, the effectiveness of rate control, and switches from one drug class to another in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study. BACKGROUND: The AFFIRM study showed that atrial fibrillation (AF) can be treated effectively with rate control and anticoagulation, but drug efficacy to control rate remains uncertain. METHODS: Patients (n = 2,027) randomized to rate control in the AFFIRM study were given rate-controlling drugs by their treating physicians. Standardized rate-control efficacy criteria developed a priori included resting heart rate and 6-min walk tests and/or ambulatory electrocardiographic results. RESULTS: Average follow-up was 3.5 +/- 1.3 years. Initial treatment included a beta-adrenergic blocker (beta-blocker) alone in 24%, a calcium channel blocker alone in 17%, digoxin alone in 16%, a beta-blocker and digoxin in 14%, or a calcium channel blocker and digoxin in 14% of patients. Overall rate control was achieved in 70% of patients given beta-blockers as the first drug (with or without digoxin), 54% with calcium channel blockers (with or without digoxin), and 58% with digoxin alone. Adequate overall rate control was achieved in 58% of patients with the first drug or combination. Multivariate analysis revealed an association between first drug class and several clinical variables. There were more changes to beta-blockers than to the other two-drug classes (p < 0.0001). CONCLUSIONS: Rate control in AF is possible in the majority of patients with AF. Beta-blockers were the most effective drugs. To achieve the goal of adequate rate control in all patients, frequent medication changes and drug combinations were needed.

Relation of initial resting ventricular rate to the ability to achieve and maintain normal sinus rhythm in patients with atrial fibrillation.

Rate-control and rhythm-control strategies in the management of atrial fibrillation (AF) have been shown to have similar effects on morbidity and mortality. Data are lacking as to whether specific electrocardiographic features of AF affect the ability to achieve rate or rhythm control. This study evaluated the relation between initial resting ventricular rate (IRVR) during AF and the subsequent achievement of rate control and rhythm control in the AFFIRM Study. The independent relations between IRVR and the achievement of rate and rhythm control were assessed using multivariate Cox's proportional hazards modeling. In addition, we evaluated whether IRVR was associated with major cardiovascular end points. IRVR was analyzed in 4,059 patients. IRVR was higher in women, smokers, patients who had a first episode of AF, and in patients who had preserved left ventricular systolic function but lower in patients who had coronary artery disease, hypertension, left atrial enlargement, and a qualifying episode of AF that lasted >48 hours. A higher IRVR was independently associated with the achievement (p <0.0001) and maintenance (p = 0.0002) of sinus rhythm, whereas the ability to achieve adequate rate control was independent of IRVR. A higher IRVR was associated with an increased risk of cardiovascular hospitalization (p <0.0001). In the appropriate clinical setting, a rhythm-control strategy should be considered for patients who have a higher IRVR.