Usefulness of a Combination of Interatrial Block and a High CHADS2 Score to Predict New Onset Atrial Fibrillation.

Interatrial block (IAB) is associated with an increased risk of atrial fibrillation (AF). The aim of this retrospective study was to investigate the association of a combination of IAB and the CHADS2 score, an AF-related risk score for ischemic stroke, with new onset AF in patients in sinus rhythm. A total of 1,571 patients (803 males, 768 females; mean age: 58 ± 16 years) were included in this study. IAB was defined as a P-wave duration > 120 ms in the 12-lead electrocardiogram, and a high CHADS2 score as ≥ 2 points. During the mean follow-up period of 4.8 ± 0.7 years, new onset AF occurred in 122 patients (16.1 per 1,000 patient-years). The incidence of new onset AF was 4.0 per 1,000 patient-years in patients with no IAB and a low CHADS2 score, and 44.0 per 1,000 patient-years in patients with IAB and a high CHADS2 score. In multivariate Cox regression analysis, the hazard ratio for IAB and a high CHADS2 score compared with no IAB and a low CHADS2 score was 12.18 (95% confidence interval: 6.22-23.87, P < 0.001), after adjustment for age, sex, coronary artery disease, valvular heart disease, smoking, medications, and echocardiographic parameters. In conclusion, IAB and a high CHADS2 score independently and synergistically predict new onset AF in patients in sinus rhythm, indicating an approximately 12-fold higher risk in patients with both IAB and a high CHADS2 score. Patients meeting these criteria should have more aggressive early intervention to prevent AF.

Advanced interatrial block predicts clinical recurrence of atrial fibrillation after catheter ablation.

BACKGROUND: It has been demonstrated that advanced interatrial block (IAB) is associated with an increased risk of atrial fibrillation (AF); however, the impact of advanced IAB on recurrence of paroxysmal AF after catheter ablation is not clear. METHODS: 204 consecutive patients with paroxysmal AF who underwent index circumferential pulmonary vein (PV) isolation were prospectively enrolled. In all patients, a resting electrocardiogram in sinus rhythm was evaluated for the presence of advanced IAB, defined as a P-wave duration >120ms and biphasic (±) morphology in the inferior leads. Advanced IAB was detected in 20.1% of patients. AF recurrence was defined as the occurrence of confirmed atrial tachyarrhythmia lasting more than 30s beyond 3 months after the catheter ablation in the absence of any antiarrhythmic treatment. RESULTS: During the mean follow-up period of 13.9±6.2 months (range, 3-27 months), 62 patients (30.4%) developed recurrence of AF. The recurrence rate was higher in patients with advanced IAB than those without advanced IAB (46.3% vs. 26.4%, p=0.006). Cox regression analysis with adjustment for age, P-wave duration, CHADS2 score, and PV isolation identified advanced IAB (hazard ratio, 2.111; 95% confidence interval, 1.034-4.308; p=0.040) and left atrial diameter (hazard ratio, 1.051; 95% confidence interval, 1.004-1.100; p=0.034) as two independent predictors of recurrence of AF. CONCLUSIONS: Patients with advanced IAB were at an increased risk of AF recurrence after catheter ablation.

Efficacy of catheter ablation for atrial fibrillation in patients with a permanent pacemaker for atrioventricular block.

Catheter ablation has been established to be an effective therapy for drug-refractory paroxysmal AF and is recommended as the treatment of choice for many patients, including those with a permanent pacemaker (PM). However, the clinical efficacy of catheter ablation of paroxysmal AF in patients with a permanent PM for atrioventricular block (AVB) is not clear. Twenty-nine patients with a permanent PM for AVB (AVB + PM group), and 145 age- and gender-matched control patients (on a 1:5 basis) without AVB and without a permanent PM (no-AVB + no-PM group), were included in this study. Atrial fibrillation (AF) recurrence was defined as the occurrence of confirmed atrial tachyarrhythmia lasting more than 30 seconds beyond 3 months after catheter ablation in the absence of any antiarrhythmic treatment. During a mean follow-up period of 14.2 ± 8.6 months (range, 3-30 months), 54 patients (31.0%) developed recurrence of AF. The recurrence rate was higher in the AVB + PM group than in the no-AVB + no-PM group (48.3% versus 27.6%, P = 0.005). Cox regression analysis with adjustment for age, valvular heart disease, AVB and a PM together, left atrial (LA) diameter and PV isolation identified LA diameter (hazard ratio 1.054, 95% confidence interval 1.001-1.110, P = 0.047) and AVB and a PM together (hazard ratio 2.095, 95% confidence interval 1.109-3.960, P = 0.023) as two independent predictors of recurrence of AF. Patients with a permanent PM for AVB were at an increased risk of recurrence of AF after catheter ablation.

Effects of thyroid dysfunction on the severity of coronary artery lesions and its prognosis.

BACKGROUND: Abnormal thyroid hormone metabolism influences the occurrence and progress of coronary heart disease (CHD). The aim of the present study was to analyze the severity of coronary artery lesions and the prognosis of thyroid dysfunction patients admitted for coronary angiography (CAG). METHODS: From July 2011 to July 2012, 605 consecutive patients with suspected coronary heart disease admitted for CAG were selected. The patients were divided into three groups, based on their thyroid function prior to CAG: euthyroid group (n=455 patients), low T3 syndrome group (n=96 patients), and hypothyroidism group (n=54 patients). All patients underwent CAG. Then the severity of coronary artery lesions was assessed by Gensini scores. All patients were followed up for major adverse cardiac events. RESULTS: The prevalence of CHD in low T3 syndrome group and hypothyroidism group was significantly higher than that in the euthyroid group (p<0.001 and p=0.004, respectively). Moreover, the severity of coronary artery lesions in low T3 syndrome group and hypothyroidism group was significantly greater than that in the euthyroid group (all p<0.001). Multinomial logistic regression analysis demonstrated that low T3 syndrome was an independent risk factor of coronary artery moderate [odds ratio (OR)=4.268, 95% CI: 3.294-7.450, p=0.016] and severe (OR=4.294, 95% CI: 2.259-9.703, p<0.001) lesions. The mean duration of follow-up was 15.3±3.8 months; patients with thyroid dysfunction had a significantly worse prognosis as compared to those in the euthyroid group for the composite end-point (p<0.01). Moreover, the incidence of the composite end-point (all-cause death, non-fatal myocardial infarction, and coronary revascularization) was significantly higher in low T3 syndrome group and hypothyroidism group compared with that of in the euthyroid group (all p<0.001). CONCLUSIONS: The patients with hypothyroidism and low T3 syndrome had a high prevalence of CHD, increased severity of coronary artery lesions and poor prognosis.