Factors associated with silent cerebral events during catheter ablation for atrial fibrillation in the era of uninterrupted oral anticoagulation therapy

Background

A silent cerebral event (SCE), detected by brain magnetic resonance imaging (MRI), is defined as an acute new brain lesion without clinically apparent neurological deficit, and is frequently observed after catheter ablation in atrial fibrillation (AF) patients. Although the small number of SCEs does not cause neurocognitive dysfunction, the greater volume and/or larger number of SCE lesions are reportedly related to neuropsychological decline; SCE incidence may be a surrogate marker for the potential thromboembolic risk. Thus, strategies to reduce SCEs would be beneficial. Uninterrupted oral anticoagulation strategy for peri-procedural period reportedly reduced the risk of SCEs, but the incidence hovers at 10% to 30%. We sought factors associated with SCEs during catheter ablation for AF in patients with peri-procedural uninterrupted oral anticoagulation (OAC) therapy.

Methods

AF patients undergoing catheter ablation were eligible (n=255). All patients took non-vitamin K antagonist oral anticoagulants (NOACs) or vitamin K antagonist (VKA) for peri-procedural OAC (>4 weeks) without interruption during the procedure. Brain MRI was performed within 2 days after the procedure to detect SCEs. Clinical characteristics and procedure-related parameters were compared between patients with and without SCEs.

Results

SCEs were detected in 59 patients (23%, SCE[+]) but not in 196 patients (77%, SCE[-]). Average age was higher in SCE[+] than SCE[-] (66±10 years vs. 62±12 years, p<0.05). Persistent AF prevalence, CHADS2/CHA2DS2-VASc scores, and serum NT-ProBNP levels increased in SCE[+] vs. SCE[-]. In transthoracic/transesophageal echocardiography, left-atrial dimension (LAD) was larger and AF rhythm/spontaneous echo contrast were more frequently observed in SCE[+] than SCE[-]. SCE[+] had lower initial activated clotting time (ACT) before unfractionated heparin (UFH) injection and longer time to reach optimal ACT (>300 sec) before trans-septal puncture than SCE [-]. In multivariate analysis, LAD, initial ACT before UFH injection, and time to reach optimal ACT were predictors for SCEs.

Conclusions

LAD and intra-procedural ACT kinetics affect SCEs during the procedure in patients with uninterrupted OAC for AF ablation. Shortening time to achieve optimal ACT during the procedure may reduce the risk of SCEs.

Funding Acknowledgement

Type of funding source: None

P1901Use of direct thrombin inhibitor on the day of atrial fibrillation ablation decreases incidence of silent cerebral ischemia detected by magnetic resonance imaging

Background

There is increasing evidence to use direct oral anticoagulants (DOACs) in atrial fibrillation (AF) ablation. Uninterrupted use of DOACs is recommended for peri-procedural anticoagulation; the ways of choosing and/or using DOACs depend on physicians' decisions and preferences. Uninterrupted dabigatran (DAB), a direct thrombin inhibitor, reportedly decreased the risk of major bleeding (MB) in AF ablation, compared to uninterrupted warfarin (NEJM 2017; 376:1627). Among DOACs, only regular-dose of DAB (150 mg b.i.d.), showed superiority to warfarin for preventing ischemic thromboembolism (TE) in patients with non-valvular AF, implicating the powerful anti-thrombotic agent. DAB may decrease the potential risk of procedure-related TE.

Purpose

To evaluate whether use of DAB on the day of AF ablation decreases the prevalence of silent cerebral ischemia (SCI) detected by magnetic resonance imaging (MRI).

Methods

414 AF patients on DOACs were enrolled and admitted on the day before AF ablation. Among 354 patients on factor Xa inhibitors (rivaroxaban, apixaban, and edoxaban), the original DOACs were switched to DAB (150 mg b.i.d.) on the day of the procedure in 172 patients (Group D); the treatment remained unchanged in 182 patients (Group non-D). In both groups, DOACs were continuously used throughout the procedure. After propensity-score matching, procedure-related parameters/events and the incidence of MRI-detected SCI were compared between Group D (n=134) and Group non-D (n=134). These parameters in patients originally taking DAB, used without interruption during the procedure (uninterrupted DAB, n=55), were also compared to Group D (n=55) after propensity-score matching.

Results

Baseline activated clotting time (ACT) before initial heparin injection was increased in Group D vs. Group-non-D (179±25* vs. 146±23 sec, *p<0.05 vs. Group non-D). The time to achieve optimal ACT (>300 sec) was shorter in Group D (34±29* vs. 43±32 min). The amounts of heparin needed to achieve optimal ACT and the total amount of heparin used during the procedure were unchanged between Group D and Group non-D. The incidence of SCI decreased in Group D (13.1%* vs. 21.9%), suggesting the potential anti-thrombotic efficacy of DAB. No MB or symptomatic TE events were observed in either group. Baseline ACT, the time to achieve ACT >300 sec, and the incidence of SCI in Group D were comparable to those in uninterrupted DAB (183±38 vs. 181±32 sec, 39±31 vs. 42±28 min, and 14.5% vs. 16.4%, respectively). No MB or symptomatic TE events were observed either in Group D or uninterrupted DAB.

Conclusions

Temporarily switching to DAB from the other DOACs and using it on the day of procedure enable us to achieve optimal ACT quickly and decrease the incidence of SCI, showing similar potential anti-thrombotic efficacy to uninterrupted DAB. Use of DAB on the day of AF ablation also benefits from the availability of its antidote in the case of MB during the procedure.

P1809Impact of mitral regurgitation on clinical outcome in patients with cardiac sarcoidosis

Background

Mitral regurgitation (MR) is sometimes observed in cardiac sarcoidosis (CS), and might be related to worsening heart failure. However, mechanism and clinical significance of MR associated with CS remains undetermined.

Methods

We retrospectively analyzed consecutive 51 CS patients, and identified 16 patients with moderate to severe MR evaluated by quantitative echocardiography. According to the assessment of coaptation point and tenting height, main mechanisms of the 16 patients with MR were classified into prolapse (P) in 5, and tethering in 11 (T). Prednisolone was started from 30 mg/day, gradually tapered over a period of 6 months to a maintenance dose of 5 to 10 mg/day and continued a lifetime.

Results

At the first visit, patients with MR showed higher incidence of NYHA class IV heart failure as compared to those without MR (56 vs. 9%, p<0.001). Abnormal uptake of fluorine-18 fluorodeoxyglucose in the papillary muscle was more frequent in patients with MR than those without MR (63% vs. 23%, p<0.05). Patients with tethering MR showed higher incidence of complete atrioventricular block (T: 74% vs. P: 40% vs. without MR: 31%, p<0.05), significantly reduced left ventricular (LV) ejection fraction (T: 33±7% vs. P: 52±9% vs. without MR: 52±16%, p<0.001) and increased LV end-diastolic volume index (T: 100±52ml/m2 vs. P: 66±23ml vs. without MR: 62±21ml, p<0.001). During the mean follow-up of 108 months, cardiac-event free survival was significantly worse in patients with tethering MR as compared to the other patients (log-rank; 11.7, p<0.001). Six of the 11 patients with tethering MR received cardiac resynchronization therapy, and then did not experience further hospitalization due to decompensated heart failure for at least 2 years. Multivariate analysis identified tethering MR as an independent predictor of cardiac event (HR: 6.7, p<0.05).

Conclusions

MR associated with CS has variety of mechanisms including prolapse, tethering and inflammation of the LV papillary muscle, and may be related to ventricular remodeling and poor clinical outcome.

Intraglomerular metastasis from pancreatic cancer

Few case reports have shown the presence of metastatic tumor cells in renal glomeruli. We report one case with intraglomerular metastasis proved at renal biopsy. A 60-year-old man suffered from weight loss and fever of unknown origin. Urinalysis revealed proteinuria with cellular and granular casts. Because vasculitis was suspected, renal biopsy was performed. Presence of tumor cells occupying the glomerular capillary lumina was shown by means of light microscopy and electron microscopy. Laboratory findings revealed elevated leukocyte count (28.9 x 10(3)/mm(3)), serum granulocyte colony-stimulating factor (G-CSF) (77 pg/mL), and serum CA 19-9 (21,885 U/mL). The patient soon developed disseminated intravascular coagulation and died. Autopsy findings revealed pancreatic cancer showing positive staining for G-CSF and CA 19-9. Tumor cells in the glomerular capillary lumina showed positive staining for CA 19-9 and proliferating cell nuclear antigen (PCNA). These results suggest that the pancreatic tumor cells producing G-CSF were entrapped in the glomerular capillary lumina where they proliferated. This may have been the first step in renal metastasis.

Outbreak of Chinese herb nephropathy in Japan: are there any differences from Belgium?

OBJECTIVE

The purpose of this article was to study and clarify the features of Chinese herb nephropathy (CHN) in Japan.

PATIENTS AND METHODS

The subjects consisted of patients diagnosed as having CHN in Saiseikai Nakatsu Hospital and of those reported in the literature in Japan. We investigated the clinical and histological features of CHN patients in Japan and compared them with the Belgian cases.

RESULTS

The remarkable differences were as follows: (1) high prevalence in males compared with Belgian cases, (2) Fanconi syndrome was found in most cases, (3) no patients had malignant tumors in the urinary tract. In addition, the ascribed Chinese medicines in Japan were divided into three groups: 'Tenshin-toki-shigyaku-ka-gosyuyu-syokyo-to', 'Boui-ougi-to', and others.

CONCLUSION

CHN in Japan has some characteristics distinguished from Belgian nephropathy. One hypothesis is a susceptibility to aristolochic acids (AAs), which is considered to be a causative agent, may be different among races. Another is that there could be some other toxic substances affecting the clinical findings although they are not identified at present. Further studies must be undertaken to clarify these differences.

C4d and C4bp deposition along the glomerular capillary walls in a patient with preeclampsia

Complement (C) 4d and cofactor C4b binding protein (C4bp) are detected in the glomerular capillary walls of a patient with preeclampsia. A 32-year-old nullipara had proteinuria of 1.2 g/d and edema at the 33rd week of pregnancy. Gradually the urinary protein excretion increased, reaching 5.1 g/d at the 37th week. The patient also showed hypertension at this stage. After normal mature delivery, the level of the urinary protein excretion remained at 3 to 4 g/d. Renal biopsy performed by means of light and electron microscopy, 15 days after delivery, showed almost normal glomeruli and modest subendothelial widening. Immunohistochemistry indicated that immunoglobulin (Ig) A, IgG, C1q, C3c, and C4c were not deposited in the glomeruli, whereas weakly positive IgM and fibrin-related antigen (FRA) were observed. Conversely, C4d, C3d, and C4bp were strongly deposited. Protein S (PS) also was observed, with a similar distribution pattern to that of C4bp. Immunoelectron microscopy showed the deposition of C4d along the capillary walls and of C4bp in the subendothelium. These findings suggest that the C4 activation process as well as the regulation process of C system and of the inflammatory coagulation axis by C4bp and PS may play an important role in the pathophysiology of preeclampsia, so-called glomerular capillary endotheliosis (GCE).

Osteoblast maturation suppressed osteoclastogenesis in coculture with bone marrow cells

The analysis of co-culture system using osteoblast and bone marrow indicated that the mineralized osteoblast decreased osteoclast formation. This finding was an incentive to better investigate the relation of osteoblast development and osteoclastogenesis. The expression of osteoclast differentiation factor (ODF/RANKL) mRNA and protein dramatically decreased. Alternatively, macropharge colony stimulation factor (M-CSF/CSF-1) transcription and protein secreted in media slightly decreased as the development of osteoblast. On the other hands, mRNA expression and the secretion to the culture medium of osteoclastogenesis inhibitory factor (OPG/OCIF) didn't significantly change depending on osteoblast differentiation. We conclude that osteoblast development might suppress osteoclastogenesis especially with the decrease of ODF/RANKL.

[Emergency aortic valve replacement in active infective endocarditis in a chronically hemodialyzed patient]

A 36-year-old housewife, who had been treated with hemodialysis for 15 years is reported. She had suffered from active infective endocarditis of the aortic valve caused by blood access infection for several weeks. She rapidly fell into severe cardiac failure. Five days after the onset of the cardiac failure she was transferred to our hospital. The aortic valve was replaced using #21 Björk-Shiley aortic valve prosthesis shortly after the arrival to the hospital. Postoperatively she was treated with vigorous antibiotics and was anticoagulated. Seven months after the surgery, patient is back to an active life with hemodialysis 3 times a week.