Characteristics and Outcomes of Atrial Fibrillation in Patients With Thyroid Disease (from the ARISTOTLE Trial)

Serum protein profiling reveals mechanism of activated thrombus formation in patients with stroke and atrial fibrillation

Stroke is an acute cerebrovascular disease in which blood flow to the brain is suddenly disrupted, causing damage to nerve cells. It involves complex and diverse pathophysiological processes and the treatment strategies are also diverse. The treatment for patients with stroke and atrial fibrillation (AF) is aimed at suppressing thrombus formation and migration. However, information regarding the protein networking involved in different thrombus formation pathways in patients with AF and stroke is insufficient. We performed protein profiling of patients with ischemic stroke with and without AF to investigate the mechanisms of thrombus formation and its pathophysiological association while providing helpful information for treating and managing patients with AF. These two groups were compared to identify the protein networks related to thrombus formation in AF. We observed that patients with ischemic stroke and AF had activated inflammatory responses induced by C-reactive protein, lipopolysaccharide-binding protein, and alpha-1-acid glycoprotein 1. In contrast, thyroid hormones were increased due to a decrease in transthyretin and retinol-binding protein 4 levels. The mechanism underlying enhanced cardiac activity, vasodilation, and the resulting thrombosis pathway were confirmed in AF. These findings will play an essential role in improving the prevention and treatment of AF-related stroke.

Reversible acute heart failure induced by thyrotoxic cardiomyopathy: A case report

RATIONALE

Thyrotoxic cardiomyopathy is a rare but severe complication of thyrotoxicosis, leading to episodes of acute heart failure. This case report highlights a rare presentation of thyrotoxic cardiomyopathy with low-output heart failure, emphasizing the importance of early diagnosis and comprehensive management. The report aims to increase awareness among clinicians about the potential reversibility of this condition and the effective strategies for managing such complex cases.

PATIENT CONCERNS

This patient presented with dyspnea and chest constriction, without any antecedent predisposing factors. Subsequently, the patient abruptly manifested symptoms indicative of acute heart failure during outpatient consultation. Electrocardiography revealed rapid atrial fibrillation with type A preexcitation syndrome, whereas cardiac ultrasonography demonstrated global cardiac enlargement with a diminished ejection fraction (EF).

DIAGNOSES

After a comprehensive evaluation, the patient was diagnosed with thyrotoxic cardiomyopathy, acute heart failure, and atrial fibrillation with preexcitation syndrome.

INTERVENTIONS

Immediate interventions comprised diuretic administration, oxygen therapy, and antiarrhythmic agents, addressing acute heart failure concomitant with preexcitation syndrome. Following a fortnight of comprehensive therapeutic measures, the patient was discharged with a prescription for oral medications, notably methimazole.

OUTCOMES

Following the intervention, the patient showed significant improvement with the resolution of heart failure symptoms and dyspnea, restoration of sinus rhythm, improved left ventricular ejection fraction (LVEF improved from 36% to 45%), and normalization of thyroid function. These outcomes underscore the efficacy of the intervention strategy and offer a hopeful prognosis for similar cases.

LESSONS

Thyrotoxicosis may cause cardiomyopathy in patients with heart failure that manifests as dilated cardiac chambers. Clinicians should carefully screen patients for this reversible condition. Diagnosis requires a comprehensive assessment of various tests, and the therapeutic goal is to restore normal thyroid function.

Epidemiology, prognosis, and challenges in the management of hyperthyroidism-related atrial fibrillation

Atrial fibrillation (AF) is a common condition with a global estimated prevalence of 60 million cases, and the most common cardiac complication of hyperthyroidism, occurring in 5-15% of overtly hyperthyroid patients. Additionally, subclinical hyperthyroidism and high-normal free T4 have been associated with an increased risk in the development of AF. Hyperthyroidism-related AF is a reversible cause of AF, and the majority of patients spontaneously revert to sinus rhythm in 4-6 months during or after restoration of euthyroidism. Therefore, restoring thyroid function is an indispensable element in hyperthyroidism-related AF management. Rate control with beta-blockers consists another first-line therapy, reserving rhythm control in cases of persistent hyperthyroidism-related AF. It is still controversial whether hyperthyroidism is an independent risk factor of stroke in nonvalvular AF. As a result, initiating anticoagulation should be guided by the clinical thromboembolic risk score CHA2DS2-VASc score in the same way it is applied in patients with non-hyperthyroidism-related AF. Treatment with the novel direct oral anticoagulants appears to be as beneficial and may be safer than warfarin in patients with hyperthyroidism-related AF. In this review, we address the epidemiology, prognosis, and diagnosis of hyperthyroidism-related AF, and we discuss the management strategies and controversies in patients with hyperthyroidism-related AF.

Prognostic implications of thyroid disease in patients with atrial fibrillation

Atrial fibrillation (AF) is often accompanied by thyroid disease (THD). This study aimed to explore the relationship between THD and the occurrence of significant clinical outcomes in patients with AF. This post hoc analysis utilized data from the MISOAC-AF trial (NCT02941978), which enrolled hospitalized patients with AF. Patients were categorized based on their THD history into hyperthyroidism, hypothyroidism, or euthyroidism. Cox regression models were employed to calculate unadjusted and adjusted hazard ratios (aHRs). The primary outcomes of interest included all-cause mortality, cardiovascular death, and hospitalizations during the follow-up period. The study included 496 AF patients (mean age 73.09 ± 11.10 years) with available THD data, who were followed-up for a median duration of 31 months. Among them, 16 patients (3.2%) had hyperthyroidism, 141 (28.4%) had hypothyroidism, and 339 (68.4%) had no thyroid disease. Patients with hypothyroidism exhibited higher rates of hospitalization during follow-up (aHR: 1.57, 95% CI 1.12 to 2.20, p = 0.025) compared to the euthyroid group. Elevated levels of thyroid-stimulating hormone (TSH) were correlated with an increased risk of cardiovascular mortality (aHR: 1.03, 95% CI 1.01 to 1.05, p = 0.007) and hospitalizations (aHR: 1.06, 95% CI 1.01 to 1.12, p = 0.03). Conversely, lower levels of triiodothyronine (T3) were associated with higher risks of all-cause mortality (aHR: 0.51, 95% CI 0.31 to 0.82, p = 0.006) and cardiovascular mortality (aHR: 0.42, 95% CI 0.23 to 0.77, p = 0.005). Among patients with AF, hypothyroidism was associated with increased hospitalizations. Furthermore, elevated TSH levels and decreased T3 levels were linked to higher cardiovascular and all-cause mortality risks, respectively.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Thyroid Disorders and Peripheral Arterial Disease

Hypothyroidism and hyperthyroidism, both overt and subclinical, are associated with increased risk of cardiovascular morbidity and mortality. The association between thyroid-stimulating hormone levels and cardiovascular risk has been demonstrated in large epidemiological studies and meta-analyses and is now considered a U-shaped curve. Several pathophysiological mechanisms linking thyroid and cardiovascular disease are known; however, specific clinical complications of peripheral arterial disease as endpoints of clinical trials have not been adequately investigated. The potential mechanisms linking hypothyroidism and peripheral arterial disease are endothelial dysfunction, blood pressure changes, dyslipidemia, and low-grade systemic inflammation. The potential mechanisms linking hyperthyroidism and peripheral arterial disease are hyperdynamic circulation, elevated systolic blood pressure, hypercoagulability, and possibly increased arterial inflammation.

A Nomogram to Predict the Risk for MACCE within 1 Year after Discharge of Patients with NVAF and HFpEF: A Multicenter Retrospective Study

Background

To develop and validate a nomogram prediction model for assessing the risk of major adverse cardiovascular and cerebrovascular events (MACCE) in patients with nonvalvular atrial fibrillation (NVAF) and heart failure with preserved ejection fraction (HFpEF) within one year of discharge.

Methods

We enrolled 828 patients with NVAF and HFpEF from May 2017 to March 2022 in Zhongda Hospital as the training cohort, and 564 patients with NVAF and HFpEF in Taizhou People's Hospital between August 2018 and March 2022 as the validation cohort. A total of 35 clinical features, including baseline characteristics, past medical records, and detection index, were used to create a prediction model for MACCE risk. The optimized model was verified in the validation cohort. Calibration plots, the Hosmer-Lemeshow test, and decision curve analyses (DCA) were utilized to assess the accuracy and clinical efficacy of the nomogram.

Results

MACCE occurred in 23.1% of all patients within one year of discharge. The nomogram identified several independent risk factors for MACCE, including atrial fibrillation duration ≥ 6 years, poor medication compliance, serum creatinine level, hyperthyroidism, serum N-terminal pro-brain natriuretic peptide level, and circumferential end-diastolic stress. The DCA demonstrated the excellent efficacy of the prediction model for the MACCE end-point, with a wide range of high-risk threshold probabilities in both cohorts. The Hosmer-Lemeshow test confirmed that momogram predictions fit for both the training (p = 0.573) and validation (p = 0.628) cohorts.

Conclusions

This nomogram prediction model may offer a quantitative tool for estimating the risk of MACCE in patients with NVAF and HFpEF within one year of discharge.

Mechanisms and Management of Thyroid Disease and Atrial Fibrillation: Impact of Atrial Electrical Remodeling and Cardiac Fibrosis

Atrial fibrillation (AF) is the most common cardiac arrhythmia associated with increased cardiovascular morbidity and mortality. The pathophysiology of AF is characterized by electrical and structural remodeling occurring in the atrial myocardium. As a source of production of various hormones such as angiotensin-2, calcitonin, and atrial natriuretic peptide, the atria are a target for endocrine regulation. Studies have shown that disorders associated with endocrine dysregulation are potential underlying causes of AF. The thyroid gland is an endocrine organ that secretes three hormones: triiodothyronine (T3), thyroxine (T4) and calcitonin. Thyroid dysregulation affects the cardiovascular system. Although there is a well-established relationship between thyroid disease (especially hyperthyroidism) and AF, the underlying biochemical mechanisms leading to atrial fibrosis and atrial arrhythmias are poorly understood in thyrotoxicosis. Various animal models and cellular studies demonstrated that thyroid hormones are involved in promoting AF substrate. This review explores the recent clinical and experimental evidence of the association between thyroid disease and AF. We highlight the current knowledge on the potential mechanisms underlying the pathophysiological impact of thyroid hormones T3 and T4 dysregulation, in the development of the atrial arrhythmogenic substrate. Finally, we review the available therapeutic strategies to treat AF in the context of thyroid disease.

Thyroid storm complicated by corpus callosum infarction in a young patient: A case report and literature review

RATIONALE

Thyroid storm (TS) is a rare life-threatening hypermetabolic thyrotoxicosis with an incidence of 0.57-0.76/100,000. The coexistence of TS and acute cerebral infarction is rare. Previous studies have shown that hyperthyroidism complicated by cerebral infarction mainly occurs in the intracranial basal ganglia; however, there are no reports of corpus callosum infarction. We report a case of TS complicated by cerebral infarction of the corpus callosum at our hospital.

PATIENT CONCERNS

A 31-year-old male patient with a history of hyperthyroidism was admitted to the hospital because of fatigue, palpitations, fever, and profuse sweating accompanied by a mild decrease in the muscle strength of the left limb. Diagnosis of a TS was confirmed by the laboratory test results. The patient's clinical symptoms gradually improved after treatment. However, his left limb muscle strength progressively decreased, and the bilateral pathological signs were positive at the same time. Magnetic resonance imaging (MRI) of the head revealed acute cerebral infarction of the corpus callosum and pons.

DIAGNOSIS

The diagnosis was thyroid strom with acute cerebral infarction of the corpus callosum and pons and severe stenosis or occlusion of the basilar artery.

INTERVENTIONS

The patient was given 300 mg hydrocortisone intravenously per day, propylthiouracil tablets of 200 mg 3 times a day by nasal feeding, and 20 mg propranolol three times a day by nasal feeding. Aspirin and clopidogrel were administered to prevent platelet aggregation, and atorvastatin calcium was administered to lower lipid levels to stabilize plaques.

OUTCOMES

The patient's left limb muscle strength recovered to grade 4+, and he could walk beside the bed with support. Simultaneously, thyroid function was better than before.

LESSONS

Careful physical examination should be performed in patients with thyroid storm, and head imaging examination should be improved for the early detection of cerebral infarction.

The bidirectional relationship of thyroid disease and atrial fibrillation: Established knowledge and future considerations

Atrial fibrillation (AF) tends to occur frequently in patients with thyroid disease, primarily hyperthyroidism. In hyperthyroidism, increased levels of thyroid hormones, via intra- and extranuclear mechanisms, have profound effects on cardiac electrophysiology. Hypothyroidism carries a lower risk for AF and is mainly associated with the overtreatment of hypothyroid patients. New-onset AF is frequently the only manifestation of thyroid disease, which renders screening for thyroid dysfunction in that scenario clinically useful. Managing thyroid disease and comorbid AF is essential. This includes thyroid hormones control along with conventional AF therapy. However, there are several open issues with this comorbid duo. The optimal management of thyroid disease and its impact on AF burden remains obscure. There is scanty information on clear-cut benefits for therapy of subclinical thyroid disease and screening of asymptomatic patients. Furthermore, the immunogenetic overlap between the autoantibodies in Graves' disease and AF genesis may lead to novel therapeutic implications. The objective of this review is to summarize the up-to-date epidemiology, pathogenesis, pathophysiology and management of interacting thyroid disease and AF.

Efficacy and safety of anticoagulation in thyrotoxic atrial fibrillation: a systematic review and meta-analysis

Background

Evidence on the efficacy and safety of anticoagulation in preventing stroke and thromboembolic events in people with thyrotoxic atrial fibrillation is scarce.

Objective

We evaluated the efficacy and safety of anticoagulation in people with thyrotoxic atrial fibrillation.

Methods

Our study protocol was published in the International Prospective Register of Systematic Reviews (registration no. CRD42020222782). Four databases and two systematic review registers were searched through 25 November 2020 for interventional and observational studies comparing anticoagulation therapy with active comparators, placebo, or no treatment in people with thyrotoxic atrial fibrillation. Random-effects meta-analysis and sensitivity analysis were performed. Quality of evidence was described using the GRADE framework.

Results

In the study, 23,145 records were retrieved. One randomized controlled trial and eight cohort studies were ultimately included. Effect estimates on the efficacy and safety of anticoagulation were extracted. Meta-analysis using the inverse variance and random-effects methods was conducted on four cohort studies with 3443 participants and 277 events. Anticoagulation in people with thyrotoxic atrial fibrillation reduced the risk of ischemic stroke and systemic thromboembolism by 3% (95% CI: 1-6%). Warfarin may prevent ischemic stroke in people with thyrotoxic atrial fibrillation if the CHA2DS2-VASc score exceeds 1 and when atrial fibrillation persists beyond 7 days. Direct oral anticoagulants may be associated with fewer bleeding events than warfarin.

Conclusions

Anticoagulation prevents ischemic stroke and systemic thromboembolism in people with thyrotoxic atrial fibrillation. Direct oral anticoagulants may be associated with fewer bleeding events.

Thyroid dysfunction on the heart: clinical effects, prognostic impact and management strategies

Thyroid hormones have a considerable influence on cardiac function and structure. There are direct and indirect effects of thyroid hormone on the cardiovascular system, which are prominent in both hypothyroidism and hyperthyroidism. In this review, we discuss how thyroid dysfunction impacts cardiovascular pathophysiology and the underlying molecular mechanisms.

Yearly Incidence of Stroke and Bleeding in Atrial Fibrillation with Concomitant Hyperthyroidism: A National Discharge Database Study

Background: Hyperthyroidism is associated with atrial fibrillation (AF), and the latter is a major risk factor for stroke. Aim: We aimed to investigate the yearly incidence of stroke and bleeding in AF patients with and without concomitant hyperthyroidism from the French National Hospital Discharge Database. Methods: Admissions with AF between January 2010 and December 2019 were retrospectively identified and retrieved from the French national database. Incidence rates of ischaemic stroke and bleeding were compared in AF patients with and without concomitant hyperthyroidism. The associations of risk factors with ischaemic stroke were assessed by Cox regression. Results: Overall 2,421,087 AF patients, among whom 32,400 had concomitant hyperthyroidism were included in the study. During the follow-up (mean: 2.0 years, standard deviation SD: 2.2 years), the yearly incidence of ischaemic stroke was noted to be 2.6 (95% confidence interval CI: 2.5−2.8) in AF patients with concomitant hyperthyroidism, and 2.3 (95%CI: 2.3−2.4) in non-thyroid AF patients. Hyperthyroidism was noted as an independent risk factor for ischaemic stroke (adjusted hazard ratio aHR: 1.133, 95%CI: 1.080−1.189) overall, particularly within the first year of hyperthyroidism diagnosis (aHR 1.203, 95%CI 1.120−1.291), however, the association became non-significant in subsequent years (aHR 1.047, 95%CI 0.980−1.118). Major bleeding incidence was lower in the hyperthyroid AF group in comparison to the non-thyroid AF group (incidence ratio: 5.1 vs. 5.4%/year, p < 0.001). The predictive value of CHA2DS2VASc and HAS-BLED scores for ischaemic stroke and bleeding events, respectively, did not differ significantly between AF patients with or without concomitant hyperthyroidism. Conclusions: Hyperthyroidism seems to be an independent risk factor of ischaemic stroke in AF patients, particularly within the first year of hyperthyroidism diagnosis.

Association Between Thyroid Dysfunction and Incidence of Atrial Fibrillation in Patients With Hypertrophic Obstructive Cardiomyopathy

OBJECTIVE

To explore the correlation between the incidence of atrial fibrillation (AF) and thyroid dysfunction in patients with hypertrophic obstructive cardiomyopathy (HOCM).

METHODS

Thyroid function testing in 755 consecutive patients with HOCM were examined at the National Center for Cardiovascular Diseases (China) from October 2009 to December 2013. Patients were divided into four groups according to the TSH levels: TSH<0.55 mIU/L(n=37)、0.55~2.49 mIU/L (n=490)、2.50~9.9 mIU/L (n=211) and >10.00mIU/L(n=17).

RESULTS

A total of 107 patients were diagnosed with AF (14%).(1) Compared to HOCM patients without AF,HOCM patients with AF have older age (P<0.001), higher NT-proBNP (P=0.002), higher Cr (P=0.005), larger left atrial diameter(P=0.001), lower FT3 (P=0.046), higher FT4 (P=0.004).(2) In the four groups according to the TSH levels: TSH<0.55 mIU/L, 0.55~2.49mIU/L, 2.50~9.9mIU/L and ≥10.00mIU/L, the incidence of AF was 27.02%(10/37),10.20%(50/490), 19.43%(41/211), and 35.29%(6/17), respectively. Both high and low TSH levels were associated with an increased incidence of AF. After adjusting for the common risk factor (age, NT-proBNP, and so on), stepwise multiple logistic regression analysis revealed that TSH levels were significantly related to AF incidence.Compared to patients with TSH 0.55~2.49 mlU/L, the adjusted odds ratio of AF for TSH<0.55, 2.50~9.99, ≥10.00 mIU/L were 1.481 (95% CI 0.485~4.518,P=0.490), 1.977 (95%CI 1.115~3.506, p=0.02), 4.301 (95%CI 1.059~17.476, P=0.041), respectively.

CONCLUSION

Our results suggested that thyroid dysfunction was associated with an increased risk of AF in patients with HOCM.

Impact of thyroid disease in patients with atrial fibrillation: Analysis from the JoFib registry

Background

Thyroid disease is a well-established risk factor for atrial fibrillation (AF). However, only a handful of studies examined its impact on treatment. This study aims to report the prevalence rate of thyroid disease in patients with AF and to demonstrate the effect of thyroid disease on AF treatment.

Materials and methods

We retrospectively analyzed the Jordanian Atrial Fibrillation Study (JoFib). Among Jordan and Palestine, patients with AF were evaluated for their sociodemographic, clinical, and pharmacological characteristics.

Results

A total of 2000 patients with AF (53.3% males, mean age 67.6 ± 13.1 years) were enrolled in the JoFib registry from May 2019 to November 2020. Thyroid disease was present in 210 (10.5%) patients. Hypertension, diabetes mellitus, and dyslipidemia were the most common comorbidities among patients with thyroid history (75.2%, 51.0%, and 45.7%, respectively). Diabetes mellitus (p = .04), pulmonary hypertension (p = .01), and chronic kidney disease (p = .01) were significantly higher in this particular subgroup. Patients with thyroid disease demonstrated significantly higher usage of anticoagulants (p = .02).

Conclusion

Despite having similar stroke and bleeding risks, patients with thyroid disease demonstrated meaningful differences in their baseline characteristics. Prospective studies are required to assess the influence of thyroid hormone fluctuations on the progression of AF.

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Thyroid disease doesn't appear to impact bleeding risk in atrial fibrillation.

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Patients with thyroid disease are more likely to consume more anticoagulants.

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Thyroid disease in atrial fibrillation maybe linked with pulmonary hypertension.

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Assessment tools of stork or bleeding may be underestimated in Arab Jordanians.

New-onset arrhythmia associated with patients hospitalized for thyroid dysfunction

BACKGROUND

Thyroid dysfunction has been associated with cardiovascular dysfunction in the literature. However, the frequency of new-onset arrhythmias associated with thyroid disease hospitalization is unknown. Hence, we analyzed frequency, in-hospital outcomes, and resource utilization of new-onset arrhythmias associated with thyroid dysfunction hospitalizations.

METHODS

The patients who were admitted with the primary reason of thyroid dysfunction were included using appropriate international classification of disease, ninth revision, clinical modification (ICD-9-CM) codes. We then identified new-onset arrhythmias using appropriate ICD-9-CM codes. We utilized the "present on admission" variable to exclude arrhythmias that were present on admission.

RESULTS

Among the eligible patients with thyroid dysfunction, only 3% (n=12,111) developed a new-onset arrhythmia. Atrioventricular block (1.49%) is the most frequent followed by atrial fibrillation (0.92%), ventricular tachycardia (0.47%), atrial flutter (0.23%), supraventricular tachycardia (0.1%) and ventricular fibrillation (0.07%). Patients with new-onset arrhythmias were older (mean age 76.7±12.5 years), more predominantly white (n=9008, 74.4%), higher females (n= 7632, 63%), and had a higher frequency of comorbidities. In-hospital mortality occurred in 827 (6.8%) patients with new-onset arrhythmias and 8632 (2.2%) patients without new-onset arrhythmias (P-value <0.001). The medical length of stay and cost of hospitalization was also higher in these patients.

CONCLUSION

Thyroid dysfunction is not associated with significantly higher rates of new-onset arrhythmias while inpatient. However, when developed, these arrhythmias are associated with higher mortality and resource utilization. The patients admitted to the hospital should have thyroid function checked when found to have an arrhythmia.

Direct Oral Anticoagulants in Atrial Fibrillation Patients With Concomitant Hyperthyroidism

OBJECTIVE

Patients with hyperthyroidism were excluded from the randomized clinical trials of direct oral anticoagulants (DOACs) for stroke prevention in patients with nonvalvular atrial fibrillation (NVAF).

METHODS

We performed a nationwide retrospective cohort study using data from the Taiwan National Health Insurance Research Database. We enrolled 3213 and 1181 NVAF patients with hyperthyroidism who were taking DOACs and warfarin, respectively, from June 1, 2012 to December 31, 2017. We also enrolled 53 591 and 16 564 NVAF patients without hyperthyroidism, taking DOACs and warfarin, respectively. We used propensity score stabilized weights (PSSWs) to balance covariates across the study groups. We also used 1:4 matching on both taking DOACs, with (n = 3213) and without hyperthyroidism (n = 12 852); and both taking warfarin, with (n = 1181) and without hyperthyroidism (n = 4724).

RESULTS

After PSSW, DOAC had a comparable risk of ischemic stroke/systemic embolism (IS/SE) and a lower risk of major bleeding (hazard ratio [HR] 0.65; 95% confidential interval [CI], 0.44-0.96; P = 0.0295) than warfarin among patients with hyperthyroidism. There were comparable risks of IS/SE and major bleeding between those patients with and without hyperthyroidism. However, among patients taking warfarin, those with hyperthyroidism had a lower risk of IS/SE than those without hyperthyroidism (HR 0.61; 95% CI, 0.43-0.86; P = 0.0050).

CONCLUSION

Among NVAF Asian patients with concomitant hyperthyroidism, DOACs may be an effective and safer alternative to warfarin. Thromboprophylaxis with DOACs may be considered for such patients, and it is important to validate this finding in further prospective study.

The Perfect Storm: A Case of Ischemic Stroke in the Setting of Thyroid Storm

Mortality in thyroid storm, without appropriate treatment, can rise as high as 100%. Thyroid storm coexisting with ischemic stroke is a rare presentation that further increases the risk of mortality. Early recognition and appropriate management are critical to the prevention of mortality and morbidity. Here, we review the case of a 63-year-old male presenting with new neurological deficits who was found to have thyroid storm; appropriate management of the co-existing conditions are also reviewed.