A nationwide analysis of the outcomes in hospitalized patients with atrial fibrillation and temperature-related illnesses.

OBJECTIVES: The authors evaluated mortality and indices of cost of care among inpatients with Atrial Fibrillation (AF) and a diagnosis of a Temperature-Related Illness (TRI). The authors also assessed trends in the prevalence of TRIs among AF hospitalizations. METHODS: In this cross-sectional study, the authors used discharge data from the Nationwide Inpatient Sample (NIS) collected between January 2005 and September 2015 to identify patients with a diagnosis of AF and TRI. Outcomes of interest included in-hospital mortality, invasive mechanical ventilation, hospital length of stay, and cost of hospitalization. RESULTS: A total of 37,933 encounters were included. The median age was 79 years. Males were slightly overrepresented relative to females (54.2% vs. 45.8%, respectively). Although Blacks were only 6.6% of the cohort, they represented 12.2% of the TRI cases. Compared to non-TRI-related hospitalizations, a diagnosis of a TRI was associated with an increased likelihood of invasive mechanical ventilation (16.5% vs. 4.1%, p < 0.001), longer length-of-stay (5 vs. 4 days, p < 0.001), higher cost of care (10,082 vs. 8,607, in US dollars p < 0.001), and increased mortality (18.6% vs. 5.1%, p < 0.001). Compared to non-TRI, cold-related illness portends higher odds of mortality 4.68, 95% Confidence Interval (4.35-5.04), p < 0.001, and heat-related illness was associated with less odds of mortality, but this was not statistically significant 0.77 (0.57-1.03), p = 0.88. CONCLUSION: The occurrence of TRI among hospitalized AF patients is small but there is an increasing trend in the prevalence, which more than doubled over the decade in this study. Individuals with AF who are admitted with a TRI face significantly poorer outcomes than those admitted without a TRI including higher mortality. Cold-related illness is associated with higher odds of mortality. Further research is required to elucidate the pathogenic mechanisms underlying these findings and identify strategies to prevent TRIs in AF patients.

Effect of atrial fibrillation on mortality in SARS-CoV-2 patients: A propensity score-matched analysis of nationwide hospitalizations in the United States.

Background: Atrial fibrillation (AF) is one of the most common arrhythmias encountered in patients with SARS-CoV-2 infection. There are racial disparities in the incidence of AF and COVID-19. Several studies have reported an association between AF and mortality. However, it remains to be determined if AF represents an independent risk factor for COVID-19-related mortality. Methods: A propensity score-matched (PSM) analysis was performed using data from the National Inpatient Sample to assess the risk of mortality among patients hospitalized with SARS-CoV-2 infection and incident AF from March 2020 through December 2020. Results: AF was less common among patients who tested positive for SARS-CoV-2 as compared to those who tested negative (6.8% vs 7.4%, p < 0.001). White individuals with the virus had an increased incidence of AF but had lower mortality rates relative to Black and Hispanic patients. After PSM analysis, AF retained a significantly increased odds of mortality among patients with SARS-CoV-2 (OR: 1.35, CI: 1.29-1.41, p < 0.001). Conclusion: This PSM analysis shows that AF is an independent risk factor for inpatient mortality in those with SARS-CoV-2 infection and that White patients, while having a higher burden of SARS-CoV-2 and AF, demonstrate a significantly lower mortality rate as compared to their Black and Hispanic counterparts.

A nationwide analysis of the outcomes in hospitalized patients with atrial fibrillation and temperature-related illnesses

Abstract Objectives The authors evaluated mortality and indices of cost of care among inpatients with Atrial Fibrillation (AF) and a diagnosis of a Temperature-Related Illness (TRI). The authors also assessed trends in the prevalence of TRIs among AF hospitalizations. Methods In this cross-sectional study, the authors used discharge data from the Nationwide Inpatient Sample (NIS) collected between January 2005 and September 2015 to identify patients with a diagnosis of AF and TRI. Outcomes of interest included in-hospital mortality, invasive mechanical ventilation, hospital length of stay, and cost of hospitalization. Results A total of 37,933 encounters were included. The median age was 79 years. Males were slightly overrepresented relative to females (54.2% vs. 45.8%, respectively). Although Blacks were only 6.6% of the cohort, they represented 12.2% of the TRI cases. Compared to non-TRI-related hospitalizations, a diagnosis of a TRI was associated with an increased likelihood of invasive mechanical ventilation (16.5% vs. 4.1%, p< 0.001), longer length-of-stay (5 vs. 4 days, p <0.001), higher cost of care (10,082 vs. 8,607, in US dollars p <0.001), and increased mortality (18.6% vs. 5.1%, p <0.001). Compared to non-TRI, cold-related illness portends higher odds of mortality 4.68, 95% Confidence Interval (4.35-5.04), p <0.001, and heat-related illness was associated with less odds of mortality, but this was not statistically significant 0.77 (0.57-1.03), p= 0.88. Conclusion The occurrence of TRI among hospitalized AF patients is small but there is an increasing trend in the prevalence, which more than doubled over the decade in this study. Individuals with AF who are admitted with a TRI face significantly poorer outcomes than those admitted without a TRI including higher mortality. Cold-related illness is associated with higher odds of mortality. Further research is required to elucidate the pathogenic mechanisms underlying these findings and identify strategies to prevent TRIs in AF patients.

Association between Empagliflozin Use and Electrocardiographic Changes.

Empagliflozin, a sodium-glucose transporter 2 inhibitor, has been shown to bind to late sodium channels in mice cardiomyocytes. We sought to investigate the electrocardiographic (ECG) features associated with empagliflozin use in patients with diabetes mellitus. We compared ECG features of 101 patients before and after initiation of empagliflozin and found that empagliflozin was associated with a significant increase in QRS duration among diabetes patients with heart failure.

Association between electrocardiographic features and mortality in COVID-19 patients.

BACKGROUND: Cardiovascular events have been reported in the setting of coronavirus disease-19 (COVID-19). It has been hypothesized that systemic inflammation may aggravate arrhythmias or trigger new-onset conduction abnormalities. However, the specific type and distribution of electrocardiographic disturbances in COVID-19 as well as their influence on mortality remain to be fully characterized. METHODS: Electrocardiograms (ECGs) were obtained from 186 COVID-19-positive patients at a large tertiary care hospital in Northern Nevada. The following arrhythmias were identified by cardiologists: sinus bradycardia, sinus tachycardia, atrial fibrillation (A-Fib), atrial flutter, multifocal atrial tachycardia (MAT), premature atrial contraction (PAC), premature ventricular contraction (PVC), atrioventricular block (AVB), and right bundle branch block (RBBB). The mean PR interval, QRS duration, and corrected QT interval were documented. Fisher's exact test was used to compare the ECG features of patients who died during the hospitalization with those who survived. The influence of ECG features on mortality was assessed with multivariable logistic regression analysis. RESULTS: A-Fib, atrial flutter, and ST-segment depression were predictive of mortality. In addition, the mean ventricular rate was higher among patients who died as compared to those who survived. The use of therapeutic anticoagulation was associated with reduced odds of death; however, this association did not reach statistical significance. CONCLUSION: The underlying pathogenesis of COVID-19-associated arrhythmias remains to be established, but we postulate that systemic inflammation and/or hypoxia may induce potentially lethal conduction abnormalities in affected individuals. Longitudinal studies are warranted to evaluate the risk factors, pathogenesis, and management of COVID-19-associated cardiac arrhythmias.

Ethnic differences in atrial fibrillation identified using implanted cardiac devices.

INTRODUCTION: Atrial fibrillation (AF) is suggested to be less common among black and Asian individuals, which could reflect bias in symptom reporting and access to care. In the Asymptomatic AF and Stroke Evaluation in Pacemaker Patients and the AF Reduction Atrial Pacing Trial (ASSERT), patients with hypertension but no history of AF had AF recorded via an implanted pacemaker or defibrillator, thus allowing both symptomatic and asymptomatic AF incidence to be determined without ascertainment bias. METHODS AND RESULTS: The ASSERT enrolled 2,580 patients in 23 countries in North America, Europe, and Asia. AF was defined as device-recorded AF episodes >190/min, lasting either for >6 minutes or >6 hours in duration. All ethnic groups with >50 patients were enrolled. Ethnic groups studied include Europeans (n = 1900), black Africans (n = 73), Chinese (n = 89), and Japanese (n = 105) patients. Compared to Europeans, black Africans had more risk factors for AF such as heart failure (27.8 vs 14.6%) and diabetes (41.7 vs 26.3%). At 2.5 years follow-up, all 3 non-European races had a lower incidence of AF (8.3%, 10.1%, and 9.5% vs 18.0%, respectively, for AF>6 minutes, P < 0.006). When adjusted for baseline difference, Chinese had a lower incidence of AF > 6 minutes (P < 0.007), and Japanese and black Africans had a lower incidence of AF > 6 hours (P < 0.04 and P = 0.057, respectively). CONCLUSIONS: Black Africans, Chinese, and Japanese had lower incidence of AF compared to Europeans. In the case of black Africans, this is despite an increased prevalence of AF risk factors.

Differential impact of race and risk factors on incidence of atrial fibrillation.

Despite some common risk factors for atrial fibrillation (AF) being more prevalent among blacks, African Americans are increasingly being reported with lower prevalence and incidence of AF compared with whites. Contemporary studies have not provided a complete explanation for this apparent AF paradox in African Americans. Although many traditional and novel risk factors for AF have been identified, the role of ethnic-specific risk factors has not been examined. Whereas hypertension has been the most common risk factor associated with AF, coronary artery disease also plays an important role in AF pathophysiology in whites. Thereby, elucidating the role of ethnic-specific risk factors for AF may provide important insight into why African Americans are protected from AF or why whites are more prone to develop the arrhythmia. The link between AF susceptibility and genetic processes has only been recently uncovered. Polymorphisms in renin-angiotensin system genes have been characterized as predisposing to AF under certain environmental conditions. Several ion channel genes, signaling molecules, and several genetic loci have been linked with AF. Thereby, studies investigating genetic variants contributing to the differential AF risk in individuals of African American versus European ancestry may also provide important insight into the etiology of the AF paradox in blacks.

Calmodulin inhibitor W-7 unmasks a novel electrocardiographic parameter that predicts initiation of torsade de pointes.

BACKGROUND: We have shown that the calmodulin inhibitor W-7 suppresses torsade de pointes (TdP) without shortening the QT interval, which is consistent with other findings that QT prolongation, per se, is insufficient to generate TdP. ECGs were analyzed from a well-characterized animal model of TdP to identify more reliable predictors of this life-threatening ventricular arrhythmia. METHODS AND RESULTS: TdP was induced using methoxamine and clofilium in 12 of 14 rabbits pretreated with vehicle control, whereas pretreatment with W-7 (50 micromol/kg), an inhibitor of the intracellular Ca2+-binding protein calmodulin, significantly suppressed TdP induction (1 of 11 rabbits with TdP, P<0.001). W-7 did not affect heart rate, increases in QT intervals, or dispersion compared with measurements in vehicle-treated control animals. However, a progressive and significant increase in the ratio of U-wave to T-wave amplitude (UTA) occurred before TdP onset in control animals, and this was prevented by W-7. CONCLUSIONS: Selective suppression of TdP inducibility by W-7, without shortening the duration of cardiac repolarization, allowed identification of the UTA ratio as a new electrocardiographic index for predicting TdP onset. These findings are consistent with the idea that prolonged repolarization is not the proximate cause of arrhythmia initiation, and they suggest that an increased UTA ratio reflects activation of intracellular Ca2+/calmodulin-dependent processes that are required for triggering TdP in this model.