Prediction of left atrial thrombi in patients with atrial tachyarrhythmias during warfarin administration: retrospective study in Hyogo College of Medicine

Percutaneous left atrial appendage closure in patients with hypertrophic cardiomyopathy and persistent atrial fibrillation: 3-year-followed case series

Hypertrophic cardiomyopathy (HCM) patients with atrial fibrillation (AF) are at high risk for stroke. Left atrial appendage closure (LAAC) is a promising alternative for stroke prevention in AF patients. We aimed to review the clinical outcomes of patients with AF and HCM at our center. We reviewed 673 patients who underwent LAAC implantation from 2014 to 2021 in a tertiary center, of whom 15 had HCM. AF Patients with HCM were compared with sex and age matched controls who also underwent LAAC. From 2014 to 2021, 673 AF patients received LAAC in a single center, of whom, 15 patients had HCM. LAAC devices were successfully implanted in 14 HCM patients and 59 patients in the control group. During the follow-up period (median 1151 days range: 132-2457 days), 2 HCM patient had ischemic strokes. There were another 2 HCM patients who had sudden cardiac death (SCD). Compared with the control, HCM patients had higher cumulative rate of combined death and stroke (26.67% vs 3.33%, P = .024). In our initial clinical experience, the cumulative stroke and death rate of the HCM patients was significantly higher than that of the non-HCM patients.

Construction of a Clinical Predictive Model of Left Atrial and Left Atrial Appendage Thrombi in Patients with Nonvalvular Atrial Fibrillation

Background. The purpose of this study was to investigate the risk factors of left atrial (LA) or left atrial appendage (LAA) thrombi in patients with nonvalvular atrial fibrillation (NVAF) and to establish and validate relevant predictive models. It might improve thromboembolic risk stratification in patients with NVAF. Methods. This study retrospectively included 1210 consecutive patients with NVAF undergoing transesophageal echocardiography (TEE), of whom 139 patients had thrombi in LA or in LAA. Through literature review and the ten events per variable (10EPV) principle, 13 variables were finally identified for inclusion in multivariate analysis. Models were constructed by multivariate logistic stepwise regression and least absolute shrinkage and selection operator (lasso) regression. Results. After logistic regression, five variables (AF type, age, B-type natriuretic peptide, E/e’ ratio, and left atrial diameter) were finally screened out as model 1. After Lasso regression, AF type, age, gender, B-type natriuretic peptide, E/e’ ratio, left atrial diameter, and left ventricular ejection fraction were finally screened as model 2. After comparing the two models, the simpler model 1 was finally selected. The area under the ROC curve (AUC) of the model 1 was 0.865 (95% CI: 0.838–0.892), the Hosmer–Lemeshow test = 0.898, and the AUC = 0.861 after internal validation. The clinical decision curve showed that the new clinical prediction model could achieve a net clinical benefit when the expected threshold was between 0 and 0.6. Conclusion. This study constructed a new clinical prediction model of LA or LAA thrombi, with a higher discriminative degree than the CHADS2 and CHA2DS2-VASc scoring systems (AUC: 0.865 vs. 0.643; AUC: 0.865 vs 0.652).

Management and outcomes of patients with left atrial appendage thrombus prior to percutaneous closure

Objective

Left atrial appendage (LAA) thrombus has heretofore been considered a contraindication to percutaneous LAA closure (LAAC). Data regarding its management are very limited. The aim of this study was to analyse the medical and invasive treatment of patients referred for LAAC in the presence of LAA thrombus.

Methods

This multicentre observational registry included 126 consecutive patients referred for LAAC with LAA thrombus on preprocedural imaging. Treatment strategies included intensification of antithrombotic therapy (IAT) or direct LAAC. The primary and secondary endpoints were a composite of bleeding, stroke and death at 18 months, and procedural success, respectively.

Results

IAT was the preferred strategy in 57.9% of patients, with total thrombus resolution observed in 60.3% and 75.3% after initial and subsequent IAT, respectively. Bleeding complications and stroke during IAT occurred in 9.6% and 2.9%, respectively, compared with 3.8% bleeding and no embolic events in the direct LAAC group before the procedure. Procedural success was 90.5% (96.2% vs 86.3% in direct LAAC and IAT group, respectively, p=0.072), without cases of in-hospital thromboembolic complications. The primary endpoint occurred in 29.3% and device-related thrombosis was found in 12.8%, without significant difference according to treatment strategy. Bleeding complications at 18 months occurred in 22.5% vs 10.5% in the IAT and direct LAAC group, respectively (p=0.102).

Conclusion

In the presence of LAA thrombus, IAT was the initial management strategy in half of our cohort, with initial thrombus resolution in 60% of these, but with a relatively high bleeding rate (~10%). Direct LAAC was feasible, with high procedural success and absence of periprocedural embolic complications. However, a high rate of device-related thrombosis was detected during follow-up.

Prevalence of Left Atrial Thrombus in Anticoagulated Patients With Atrial Fibrillation

BACKGROUND

The prevalence of left atrial (LA) thrombus in patients with atrial fibrillation (AF) or atrial flutter (AFL) on guideline-directed anticoagulation is not well known, yet this may inform transesophageal echocardiogram (TEE) use before cardioversion or catheter ablation.

OBJECTIVES

The purpose of this study was to quantify LA thrombus prevalence among patients with AF/AFL on guideline-directed anticoagulation and to identify high-risk subgroups.

METHODS

EMBASE, MEDLINE, and CENTRAL were systematically searched from inception to July 2020 for studies reporting on LA thrombus prevalence among patients with AF/AFL undergoing TEE following at least 3 weeks of continuous therapeutic oral anticoagulation with vitamin K antagonists (VKAs) or direct oral anticoagulants (DOACs). Meta-analysis was performed using random effects models.

RESULTS

Thirty-five studies describing 14,653 patients were identified. The mean-weighted LA thrombus prevalence was 2.73% (95% confidence interval [CI]: 1.95% to 3.80%). LA thrombus prevalence was similar for VKA- and DOAC-treated patients (2.80%; 95% CI: 1.86% to 4.21% vs. 3.12%; 95% CI: 1.92% to 5.03%; p = 0.674). Patients with nonparoxysmal AF/AFL had a 4-fold higher LA thrombus prevalence compared with paroxysmal patients (4.81%; 95% CI: 3.35% to 6.86% vs. 1.03%; 95% CI: 0.52% to 2.03%; p < 0.001). LA thrombus prevalence was higher among patients undergoing cardioversion versus ablation (5.55%; 95% CI: 3.15% to 9.58% vs. 1.65%; 95% CI: 1.07% to 2.53%; p < 0.001). Patients with CHA₂DS₂-VASc scores ≥3 had a higher LA thrombus prevalence compared with patients with scores ≤2 (6.31%; 95% CI: 3.72% to 10.49% vs. 1.06%; 95% CI: 0.45% to 2.49%; p < 0.001).

CONCLUSIONS

LA thrombus prevalence is high in subgroups of anticoagulated patients with AF/AFL, who may benefit from routine pre-procedural TEE use before cardioversion or catheter ablation.

Predictors of movable type left atrial appendage thrombi in patients with atrial fibrillation

Left atrial appendage thrombi (LAAT) are the main cause of thromboembolic events. Especially, movable type LAAT is high-risk for thromboembolic events. We aimed to investigate the predictors of the movable type LAAT in patients with atrial fibrillation (AF). We retrospectively studied 827 consecutive patients who underwent transthoracic echocardiography (TEE) prior to cardioversion or catheter ablation for AF. Sixty-nine patients who underwent cardiac surgery or significant valvular disease were excluded. The remaining 758 patients (age 67.6 ± 9.3, 535 males) were included in this study. Clinical data were evaluated at the time of TEE. The LAAT were classified into movable and fixed type LAAT by three independent observers who did not know clinical data. LAAT were detected in 57 (11 with movable and 46 with fixed type) of 758 patients (7.5%). Patients with movable type LAAT had an elevated E/e' ratio, lower left ventricular ejection fraction (LVEF), larger left atrial volume index, elevated C-reactive protein, higher prevalence of non-paroxysmal AF, patients taking warfarin (73% vs. 21%, P < 0.0001), and structural heart disease than control group (fixed type LAAT and without LAAT). On multivariate analysis, E/e' ratio, LVEF, and taking warfarin were significantly associated with movable type LAAT. The rate of movable type LAAT was the highest (7 of 49 patients, 14.3%) in patients with elevated E/e' ratio (> 12.7) and decrease LVEF (< 44%). E/e' ratio and LVEF could predict movable type LAAT in patients with AF. High-risk patients might need powerful antithrombotic therapy or taking early TEE.

Dabigatran vs. warfarin in relation to the presence of left ventricular hypertrophy in patients with atrial fibrillation- the Randomized Evaluation of Long-term anticoagulation therapY (RE-LY) study

Aim

We tested the hypothesis that left ventricular hypertrophy (LVH) interferes with the antithrombotic effects of dabigatran and warfarin in patients with atrial fibrillation (AF).

Methods and results

This is a post-hoc analysis of the Randomized Evaluation of Long-term anticoagulation therapY (RE-LY) Study. We defined LVH by electrocardiography (ECG) and included patients with AF on the ECG tracing at entry. Hazard ratios (HR) for each dabigatran dose vs. warfarin were calculated in relation to LVH. LVH was present in 2353 (22.7%) out of 10 372 patients. In patients without LVH, the rates of primary outcome were 1.59%/year with warfarin, 1.60% with dabigatran 110 mg (HR vs. warfarin 1.01, 95% confidence interval (CI) 0.75-1.36) and 1.08% with dabigatran 150 mg (HR vs. warfarin 0.68, 95% CI 0.49-0.95). In patients with LVH, the rates of primary outcome were 3.21%/year with warfarin, 1.69% with dabigatran 110 mg (HR vs. warfarin 0.52, 95% CI 0.32-0.84) and 1.55% with 150 mg (HR vs. warfarin 0.48, 95% CI 0.29-0.78). The interaction between LVH status and dabigatran 110 mg vs. warfarin was significant for the primary outcome (P = 0.021) and stroke (P = 0.016). LVH was associated with a higher event rate with warfarin, not with dabigatran. In the warfarin group, the time in therapeutic range was significantly lower in the presence than in the absence of LVH.

Conclusions

LVH was associated with a lower antithrombotic efficacy of warfarin, but not of dabigatran, in patients with AF. Consequently, the relative benefit of the lower dose of dabigatran compared to warfarin was enhanced in patients with LVH. The higher dose of dabigatran was superior to warfarin regardless of LVH status.

Clinical trial registration

http:www.clinicaltrials.gov. Unique identifier: NCT00262600.

Clinical background including anticoagulant therapy in patients with atrial fibrillation in a community-based survey: the Saitama AF Registry

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias, and carries an increased risk of cardiogenic embolism. Oral anticoagulants (OACs) including warfarin and/or non-vitamin K antagonists can prevent the majority of these events. The Saitama AF Registry was a community-based survey of patients with AF in Saitama City, which represents an urban community in Japan. A total of 75 institutions participated in the registry and attempted to enroll consecutive patients with AF from September 2014 to August 2015. The aim of the present study was to examine the clinical characteristics of patients with AF using data of the Saitama AF Registry. In addition, we investigated the difference in clinical characteristics of the patients between small-sized hospitals and large-sized hospitals. A total of 3591 patients were enrolled; 57.7% of all patients were enrolled from small-sized hospitals, whereas 42.3% were from large-sized hospitals. The patients from small-sized hospitals had higher CHADS₂ score than those from large-sized hospitals. Approximately, 80% of all patients were treated with OACs, and the prescription rate was higher in patients with CHADS₂ score ≥ 2 from both small-sized hospitals and large-sized hospitals. In conclusion, the present study demonstrated an appropriate use of OACs for high-risk patients with CHADS₂ score ≥2 in Saitama City regardless of hospital size.

Effects on bone metabolism markers and arterial stiffness by switching to rivaroxaban from warfarin in patients with atrial fibrillation

In recent years, direct oral anticoagulants (DOACs) of dabigatran, rivaroxaban, apixaban, edoxaban, which are all alternatives to warfarin, have been released. The use of DOACs is becoming more widespread in the clinical management of thrombotic stroke risk in patients with atrial fibrillation (AF). In large-scale clinical trials of each drug, DOACs were reported to inhibit intracranial hemorrhage, stroke, and death compared to warfarin. Warfarin is an endogenous vitamin K antagonist; therefore, patients who are taking warfarin must be prohibited from taking vitamin K. Vitamin K is an essential cofactor required for the ɤ-carboxylation of vitamin K-dependent proteins including coagulation factors, osteocalcin (OC), matrix Gla protein (MGP), and the growth arrest-specific 6 (GAS6). OC is a key factor for bone matrix formation. MGP is a local inhibitor of soft tissue calcification in the vessel wall. GAS6 prevents the apoptosis of vascular smooth muscle cells. Therefore, decrease of blood vitamin K levels may cause osteoporosis, vascular calcification, and the inhibition of vessels angiogenesis. This study aimed to evaluate the effects of changing from warfarin to rivaroxaban on bone mineral metabolism, vascular calcification, and vascular endothelial dysfunction. We studied 21 consecutive patients with persistent or chronic AF, who were treated with warfarin at least for 12 months. Warfarin administration was changed to rivaroxaban (10 or 15 mg/day) in all patients. Osteopontin (OPN), bone alkaline phosphatase (BAP), and under-carboxylated osteocalcin (ucOC) were measured. Pulse wave velocity (PWV) and augmentation index (AI) were also measured as atherosclerosis assessments. All measurements were done before and six months after the rivaroxaban treatment. There was a significant increase in serum level of BAP compared to baseline (12.5 ± 4.6 to 13.4 ± 4.1 U/L, P < 0.01). In contrast, there was a significant decrease in the serum level of ucOC (9.5 ± 5.0 to 2.7 ± 1.3 ng/ml, P < 0.01). Also, in the ucOC levels, there was a significant negative correlation between baseline values and baseline to 6-months changes in high ucOC group (r = -0.97, P < 0.01). The atherosclerosis- and osteoporosis-related biomarker, serum level of OPN were significantly decreased compared to baseline (268.3 ± 46.8 to 253.4 ± 47.1 ng/ml, P < 0.01). AI and PWV were significantly decreased after 6 months of treatment with rivaroxaban (33.9 ± 18.4 to 24.7 ± 18.4%, P = 0.04; 1638.8 ± 223.0 to 1613.0 ± 250.1 m/s, P = 0.03, respectively). Switching to rivaroxaban from warfarin in patients with atrial fibrillation was associated with an increase of bone formation markers and a decrease of bone resorption markers, and also improvements of PWV and AI.

The CHADS2 score predicts ischemic stroke in chronic heart failure patients without atrial fibrillation: comparison to other stroke risk scores

The CHADS₂ score is useful in stratifying the risk of ischemic stroke or transient ischemic attack (TIA) in patients with non-valvular atrial fibrillation (AF). However, it remains unclear whether the CHADS₂ score could predict stroke or TIA in chronic heart failure (CHF) patients without AF. Recently, the new stroke risk score was proposed from 2 contemporary heart failure trials. We evaluated the prognostic power of the CHADS₂ score for stroke or TIA in CHF patients without AF in comparison to the "stroke risk score". We retrospectively studied 127 CHF patients [left ventricular ejection fraction (LVEF) <40 %] without AF, who had been enrolled in our previous prospective cohort study. The primary endpoint was the incidence of stroke or TIA. The mean baseline CHADS₂ score was 2.1 ± 1.0. During the follow-up period of 8.4 ± 5.1 years, stroke or TIA occurred in 21 of 127 patients. At multivariate Cox analysis, CHADS₂ score (C-index 0.794), but not "stroke risk score" (C-index 0.625), was significantly and independently associated with stroke or TIA. The incidence of stroke or TIA appeared to increase in relation to the CHADS₂ score [low (=1), 0 per 100 person-years; intermediate (=2), 1.6 per 100 person-years; high (≥3), 4.7 per 100 person-years; p = 0.04]. CHADS₂ score could stratify the risk of ischemic stroke in CHF patients with the absence of AF, with greater prognostic power than the "stroke risk score".

Clinical Characteristics and Prognosis of End-stage Hypertrophic Cardiomyopathy

Background:

End-stage hypertrophic cardiomyopathy (HCM) is complicated by substantial adverse events. However, few studies have focused on electrocardiographic features and their prognostic values in HCM. This study aimed to evaluate the clinical manifestations and prognostic value of electrocardiography in patients with end-stage HCM.

Methods:

End-stage HCM patients were enrolled from a total of 1844 consecutive HCM patients from April 2002 to November 2013 at Fuwai Hospital. Clinical data, including medical history, electrocardiography, and echocardiography, were analyzed. Cox hazards regression analysis was used to assess the risk factors for cardiovascular mortality.

Results:

End-stage HCM was identified in 99 (5.4%) patients, averaged at 52 ± 16 years old at entry. Atrial fibrillation was observed in 53 patients and mural thrombus in 19 patients. During 3.9 ± 3.0 years of follow-up, embolic stroke, refractory heart failure, and death or transplantation were observed in 20, 39, and 51 patients, respectively. The incidence of annual mortality was 13.2%. Multivariate Cox hazards regression analysis identified New York Heart Association Class (NYHA) III/IV at entry (hazard ratio [HR]: 1.99; 95% confidence interval [CI]: 1.05–3.80; P = 0.036), left bundle branch block (LBBB) (HR: 2.80; 95% CI: 1.47–5.31; P = 0.002), and an abnormal Q wave (HR: 2.21; 95% CI: 1.16–4.23; P = 0.016) as independent predictors of cardiovascular death, in accordance with all-cause death and heart failure-related death.

Conclusions:

LBBB and an abnormal Q wave are risk factors of cardiovascular mortality in end-stage HCM and provide new evidence for early intervention. Susceptibility of end-stage HCM patients to mural thrombus and embolic events warrants further attention.

Prescription patterns of oral anticoagulants for patients with non-valvular atrial fibrillation: experience at a Japanese single institution

New oral anticoagulants (NOACs) are now clinically available. However, few studies have demonstrated which patients with non-valvular atrial fibrillation (NVAF) actually receive NOACs in a clinical setting. We analyzed 182 NVAF patients who received oral anticoagulants. Clinical backgrounds and the risk of stroke, systemic embolism, and bleeding associated with oral anticoagulants were investigated. Seventy-three (40 %) patients were treated with NOACs and 109 (60 %) patients were treated with warfarin. A significantly lower mean number of bleeding risk factors was observed among the patients treated with NOACs than among those treated with warfarin (P = 0.010). Of the bleeding risk factors, NOACs were significantly less frequently prescribed in patients with a bleeding history and elderly subjects (>65 years) than in those who received warfarin (P < 0.001 and P = 0.029). A multivariate logistic regression analysis revealed that CHF and bleeding history were independently and significantly associated with the administration of NOACs (P = 0.047 and P = 0.003). The rate of a history of intracranial hemorrhage was comparable between the patients treated with NOACs and those treated with warfarin (P = 1.000). Significantly lower rates of a history of gastrointestinal and other minor bleeding were observed in the patients who received NOACs versus those who received warfarin (P = 0.001 and P = 0.026). NOACs were less frequently prescribed in patients with a history of bleeding, especially those with a history of gastrointestinal bleeding in a clinical setting.

Influence of the concomitant use of heparin on the effects of warfarin during catheter ablation for atrial fibrillation

Warfarin is widely used to perform catheter ablation for atrial fibrillation (AF). Heparin is usually administered during this procedure to prevent thromboembolic events, while protamine is used to reduce the incidence of bleeding complications. The purpose of this study was to investigate the influence of heparin and protamine administration on the effects of warfarin and its safety. The subjects included 226 AF patients (206 males, 54.9 ± 9.1 years, paroxysmal/persistent AF: 118/108) undergoing AF ablation with the discontinuation of warfarin administration over 2 days. Heparin was administered to achieve an activated clotting time (ACT) above 300 s during the procedure. Several parameters of the coagulation status, including the prothrombin time international normalized ratio (PT-INR) and ACT values, measured immediately before and after protamine infusion were compared. The mean value of PT-INR prior to ablation was 1.9 ± 0.6. At the end of the procedure, the mean ACT and PT-INR values were 348.0 ± 52.9 and 2.9 ± 0.7, respectively. Following the infusion of 30 mg of protamine, both the ACT and PT-INR values significantly decreased, to 159.6 ± 31.0 (p < 0.0001) and 1.6 ± 0.3 (p < 0.0001), respectively. No cases of symptomatic cerebral infarction were observed, although femoral hematomas developed in 17 (7.5 %) of the patients without further consequence. The concomitant use of heparin augments the effect of warfarin. Meanwhile, protamine administration immediately reverses both the ACT and PT-INR, indicating the applicability of protamine for AF ablation in patients under the mixed administration of heparin and warfarin.