Changes in estimated glomerular filtration rate before and after the first visit for atrial fibrillation.

BACKGROUND: Although the development of atrial fibrillation (AF) and the progression of chronic kidney disease are known to be interrelated, it remains unclear when and how renal function changes during the clinical course of AF. METHODS: This study retrospectively enrolled 131 patients who were able to collect data on estimated glomerular filtration rate (eGFR) at least five times during the 500 days before and 500 days after the first visit (baseline) of new-onset AF, respectively. To investigate the temporal relationship between the development of AF and the beginning of worsening renal function (WRF), a piecewise regression model was applied to the eGFR time series data. The time point at which the slopes of the two regression lines changed (inflection -point), the slope before and after the inflection-point (ß1 and ß2, respectively), and the difference in slope (Δß) were estimated. The presence of WRF was defined as having the inflection-point at which both Δß and ß2 were < - 0.0083 mL/min/1.73 m2/day (corresponding to 3.03 mL/min/1.73 m2/year), and the corresponding the inflection-point was defined as the beginning of WRF. RESULTS: WRF was detected in 54 (41.2%) patients. The beginning of WRF were distributed at various times, but most frequently (23 of 54 patients) within 100 days before and after baseline. The presence of WRF was not associated with age, heart failure, or baseline eGFR, but was associated with positive ß1 (odds ratio 30.5, 95% confidence interval 11.1-83.9, P < 0.01). CONCLUSION: In nearly half of AF patients with WRF, the beginning of WRF was observed within a few months before or after the first visit for AF. Patients with a positive eGFR slope before the onset of AF are more likely to develop WRF after the onset of AF, suggesting that potential kidney damage may be underlying.

A proposed interval for evaluation of renal function during anticoagulation therapy using direct oral anticoagulants in patients with atrial fibrillation.

BACKGROUND: Direct oral anticoagulants (DOACs) have been used to prevent cardiogenic embolism in patients with atrial fibrillation (AF). No evidence has been established for the follow-up renal function evaluation intervals. We hypothesized that a proposed follow-up interval of renal function can be estimated by patient's baseline characteristics including creatinine clearance (CCr). METHODS: We conducted a single-center retrospective study at Kindai University Hospital from May 2011 to December 2017. Patients were screened and they were enrolled if baseline CCr of ≥50 mL/min. To provide a periodical synchronization for measurements of CCr in all patients, these were evaluated at four different time points (approximately at 3, 6, 9, and 12 months). Primary endpoint was defined as a CCr value of <50 mL/min during the follow-up period. We analyzed associations between the cumulative risk for renal endpoint and baseline characteristics by the Kaplan-Meier method and the Cox proportional hazards model. RESULTS: Renal endpoint was associated with age (95% CI: 0.07 to 0.21, p<0.01), body weight (95% CI: -0.09 to -0.01, p<0.01), CCr (95% CI: -0.18 to -0.07, p<0.01), and CHA2DS2-VASc score (95% CI: 0.14 to 0.63, p<0.01). Combining baseline CCr of <60 mL/min and other risk factors, acceptable intervals for 5% risk levels were 78 days (age ≥75 years old), 100 days (CHA2DS2-VASc score of> 4 points), and 90 days (body weight <60kg), respectively. Under conditions of baseline CCr of <60 mL/min, age ≥75 years old, CHA2DS2-VASc score of> 4 points, or body weight <60 kg, an increased risk of renal endpoints is 4.85, 3.29, 1.24, 2.44 fold, respectively. CONCLUSIONS: We propose a risk-stratified follow-up interval for renal evaluation in patients with AF and DOACs therapy according to a combination of baseline CCr and other risk factors.

A novel method to demonstrate thrombus formation of the left atrial appendage in patients with persistent atrial fibrillation by cardiac computed tomography.

BACKGROUND: Transesophageal echocardiography (TEE) is currently the gold standard technique for diagnosing left atrial appendage (LAA) thrombi. Cardiac computed tomography (CT) has been expected to become an alternative method to TEE; however, a reliable quantitative evaluation method has not been established. METHODS AND RESULTS: We enrolled 177 patients with persistent atrial fibrillation who underwent both cardiac CT and TEE before catheter ablation. The patients were classified into two groups according to the TEE results: the thrombus group (13 patients) and non-thrombus group (164 patients). The Hounsfield unit (HU) density at the proximal LAA (LAAp) and distal LAA (LAAd) was measured on cardiac CT images. The LAAd/LAAp HU ratio and standard deviation of HU density (HU-SD) at the LAAd were evaluated. We created an algorithm by decision tree analysis to predict LAA thrombus formation using the HU ratio and HU-SD. Definite absence of LAA thrombus (Category-I) was diagnosed for 139 patients by combining the first and second branching of the decision tree (Category-Ia: HU ratio of ≥0.26, Category-Ib: HU ratio of <0.26, HD-SD of ≥26.94). Definite presence of LAA thrombus (Category-Ⅱ) was diagnosed for 3 patients using the third branching of the decision tree (Category-Ⅱ: HU ratio of <0.26 and HU-SD of <13.85). Highly possibility of LAA thrombus (Category-III), but not definite, was diagnosed for the remaining 35 patients; therefore, these patients required diagnostic TEE. The diagnostic accuracy of this algorithm was 0.95. CONCLUSION: We have proposed a reliable algorithm to diagnose LAA thrombus formation using the HU ratio and HU-SD.

Comparison of second appropriate defibrillator therapy occurrence in patients implanted for primary prevention and secondary prevention - Sub-analysis of the Nippon Storm Study.

BACKGROUND: Patients with implantable cardioverter defibrillator (ICD) use for primary prevention (primary prevention patients) of sudden cardiac death have lower incidence of appropriate ICD therapy (app-Tx) compared with those with ICD use for secondary prevention (secondary prevention patients). However, detail analysis of a second app-Tx after a first app-Tx is still lacking. OBJECTIVE: This study aimed to compare the incidence of a second app-Tx in primary vs secondary prevention patients. METHODS: We conducted sub-analysis of the Nippon Storm Study, which was a prospective, observational study involving 985 patients with structural heart disease (left ventricular ejection fraction ≤ 50%). Of these, we selected 251 patients (62 ± 14 years old, 82% men) who experienced at least one appropriate ICD therapy, and compared occurrence of a second app-Tx between primary (n = 116) and secondary (n = 135) prevention patients. RESULTS: There was no significant difference in the incidence of a second app-Tx between primary and secondary prevention patients (the cumulative incidence for a second app-Tx was 59% at 1 year and 79% at 3 years in primary prevention patients vs the cumulative incidence for the second app-Tx was 59% at 1 year and 75% at 3 years in secondary prevention patients).Additionally, we evaluated the incidence of a second app-Tx according to basal structural disease (ischemic and non-ischemic cardiomyopathy) and found no significant difference between primary and secondary prevention patients. CONCLUSION: Once app-Tx occurs, primary prevention patients acquire the high risk of subsequent ventricular arrhythmias because there is a comparable incidence of a second app-Tx in secondary prevention patients.