Clinical Significance of B-Type Natriuretic Peptide Levels at 3 Months after Atrial Fibrillation Ablation.

The role of B-type natriuretic peptide (BNP) levels as a predictor of arrhythmia recurrence (AR) after atrial fibrillation (AF) ablation remains unclear. In this study, we investigated the association of BNP levels before and 3 months after ablation with the risk of AR. A total of 234 patients undergoing their first session of AF ablation were included (68% male, mean age of 69 years). The cut-off value for discriminating AR was determined based on the maximum value of the area under the receiver operating characteristic (ROC) curve. The impact of BNP levels on AR was evaluated using Cox regression analysis. ROC curve analysis showed that the area under the curve for BNP at 3 months after the procedure was larger (0.714) compared to BNP levels before ablation (0.593). Elevated levels of BNP 3 months after the procedure (>40.5 pg/mL, n = 96) was associated with a higher risk of AR compared to those without elevated levels (34.4% vs. 10.9%, p < 0.01). Multivariate Cox regression analysis revealed that elevated BNP levels were associated with an increased risk of AR (hazard ratio 2.43; p = 0.014). Elevated BNP levels 3 months after AF ablation were a significant prognostic factor in AR, while baseline BNP levels were not.

Usefulness of electron microscopy in the diagnosis of wild-type transthyretin cardiac amyloidosis.

Wild-type transthyretin cardiac amyloidosis (ATTRwt) has been recognized as an important cause of heart failure with preserved ejection fraction; thus, its accurate diagnosis is crucial. Herein, we describe the case of a 76-year-old man who presented with dyspnea and palpitation. On observing the laboratory evaluations and clinical course, we suspected cardiac amyloidosis. However, optical microscopic analysis by Congo-red and direct fast scarlet staining revealed no amyloid deposits in the biopsy samples. Therefore, a more thorough investigation was pursued by examining the myocardial tissue under electron microscopy. We could recognize amyloid deposits between the myocardial fibers using electron microscopy. We submitted all the pathological specimens to a specialized facility for genetic testing to ensure the accurate diagnosis of the amyloidosis disease type. As a result, a biopsy sample from the minor salivary gland was stained with the Congo red stain. Anti-transthyretin antibody detected using immunohistochemical analysis of amyloidosis supported the presence of transthyretin form of amyloid proteins. Genetic testing revealed the absence of TTR gene mutations. The final diagnosis was ATTRwt. We believe that this case suggests the usefulness of electron microscopy in the diagnosis of ATTRwt and other related disorders. Further study is warranted to validate our findings.

A cavotricuspid isthmus pouch revealed to be a breakout site for gap conduction of recurrent common atrial flutter.

A cavotricuspid isthmus pouch can be a breakout site for gap conduction of cavotricuspid isthmus block line. If the previous block line is electrically silent, high-density 3-D mapping and pouchgraphy are useful to find the pouch and ablate within it.

Pseudoblock of cavotricuspid isthmus via detouring gap conduction.

To detect detouring gap conduction, as demonstrated in this case, 3-D mapping is useful in addition to conventional methods.

Disappearance of an anticoagulation-resistant left atrial appendage thrombus after administration of low-dose pimobendan.

Anticoagulation therapy is essential for preventing thrombus formation in the left atrial appendage (LAA) and subsequent ischemic strokes in patients with atrial fibrillation (AF). The complete disappearance of any existing LAA thrombi is crucial before AF ablation. Currently, warfarin and direct oral anticoagulants are widely used for this purpose. However, treatment strategies for anticoagulation-resistant LAA thrombi are not well established. Here, we present a case of an 85-year-old male who was scheduled to undergo AF ablation. He developed an LAA thrombus that was resistant to 300 mg/day of dabigatran. Low-dose pimobendan was prescribed in addition to dabigatran; three months later, the thrombus was dissolved successfully. This case demonstrates the potential efficacy of a low-dose oral inotrope for treating an anticoagulation-resistant LAA thrombus. .

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".

Usefulness of Cardiac MetaIodobenzylguanidine Imaging to Improve Prognostic Power of the Model for End-Stage Liver Disease Scoring System in Patients With Mild-to-Moderate Chronic Heart Failure.

Liver dysfunction has a prognostic impact on the outcomes of patients with advanced heart failure (HF). The model for end-stage liver disease (MELD) score is a robust system for rating liver dysfunction, and a high score has been shown to be associated with a poor prognosis in ambulatory patients with HF. In addition, cardiac metaiodobenzylguanidine (MIBG) imaging provides prognostic information in patients with chronic HF (CHF). However, the long-term predictive value of combining the MELD score and cardiac MIBG imaging in patients with CHF has not been elucidated. To prospectively investigate whether cardiac MIBG imaging provides additional prognostic value to the MELD score in patients with mild-to-moderate CHF, we studied 109 CHF outpatients (New York Heart Association: 2.0 ± 0.6) with left ventricular ejection fraction <40%. At enrollment, an MELD score was obtained, and the heart-to-mediastinal ratio on delayed imaging and MIBG washout rate (WR) were measured using cardiac MIBG scintigraphy. During a follow-up period of 7.5 ± 4.2 years, 36 of 109 patients experienced cardiac death (CD). On multivariate Cox analysis, MELD score and WR were significantly independently associated with CD, although heart-to-mediastinal ratio showed an association with CD only on univariate Cox analysis. Patients with abnormal WR (>27%) had a significantly greater risk of CD than those with normal WR in both those with high MELD scores (≥10; hazard ratio 4.0 [1.2 to 13.6]) and with low MELD scores (<10; hazard ratio 6.4 [1.7 to 23.2]). In conclusion, cardiac MIBG imaging would provide additional prognostic information to the MELD score in patients with mild-to-moderate CHF.

Usefulness of cardiac meta-iodobenzylguanidine imaging to identify patients with chronic heart failure and left ventricular ejection fraction <35% at low risk for sudden cardiac death.

Patients with chronic heart failure (CHF) at risk of sudden cardiac death (SCD) are often treated with implantable cardiac defibrillators (ICDs). However, current criteria for device use that is based largely on left ventricular ejection fraction (LVEF) lead to many patients receiving ICDs that never deliver therapy. It is of clinical significance to identify patients who do not require ICDs. Although cardiac I-123 meta-iodobenzylguanidine (MIBG) imaging provides prognostic information about CHF, whether it can identify patients with CHF who do not require an ICD remains unclear. We studied 81 patients with CHF and LVEF <35%, assessed by cardiac MIBG imaging at enrollment. The heart-to-mediastinal ratio (H/M) in delayed images and washout rates were divided into 6 grades from 0 to 5, according to the degree of deviation from control values. The study patients were classified into 3 groups: low (1 to 4), intermediate (5 to 7), and high (8 to 10), according to the MIBG scores defined as the sum of the H/M and washout rate scores. Sixteen patients died of SCD during a follow-up period. Patients with low MIBG score had a significantly lower risk of SCD than those with intermediate and high scores (low [n = 19], 0%; intermediate [n = 37], 19%; high [n = 25], 36%; p = 0.001). The positive predictive value of low MIBG score for identifying patients without SCD was 100%. In conclusion, the MIBG score can identify patients with CHF and LVEF <35% who have low risk of developing SCD.

Risk stratification of patients with chronic heart failure using cardiac iodine-123 metaiodobenzylguanidine imaging: incremental prognostic value over right ventricular ejection fraction.

AIMS: Right ventricular (RV) systolic dysfunction has been shown to be an independent predictor of clinical outcome in patients with chronic heart failure (CHF), and cardiac metaiodobenzylguanidine (MIBG) imaging also provides prognostic information. We aimed to evaluate the long-term predictive value of combining RV systolic dysfunction and abnormal findings of cardiac MIBG imaging on outcome in CHF patients. METHODS AND RESULTS: We enrolled 63 CHF outpatients with left ventricular ejection fraction (EF) <40% in a prospective cohort study. At entry, RVEF was measured by radionuclide angiography. Furthermore, cardiac MIBG imaging was performed, and the cardiac MIBG washout rate (WR) was calculated. Reduced RVEF was defined as ≤37%, and abnormal WR was defined as >27%. The study endpoint was unplanned hospitalization for worsening heart failure (WHF) and cardiac death. During a follow-up period of 8.9 ± 4.3 years, 19 of 63 patients had unplanned hospitalization for WHF, and 19 of 63 patients had cardiac death. In multivariate analysis, both WR and RVEF were independent predictors of unplanned WHF hospitalization, while WR was also an independent predictor of cardiac death. A risk-stratification model based on independent predictors of unplanned WHF hospitalization separated the patients into those with low (absence of the predictors), intermediate (one of the predictors), and high (two or more of the predictors) risk of unplanned WHF hospitalization (P < 0.0001) or cardiac death (P = 0.0113). CONCLUSIONS: Cardiac MIBG imaging provides incremental value when it is used along with RV systolic dysfunction to predict clinical outcome in patients with CHF.