Atrial fibrillation and cardiac resynchronization therapy

Cardiac resynchronization therapy in the presence of total atrioventricular block reduces long‐lasting atrial fibrillation episodes

Background

There is an ongoing debate on how cardiac resynchronization therapy (CRT) in the presence of total AV block affects atrial fibrillation (AF) episodes and symptoms in patients with AF.

Methods

Seventy‐five patients with symptomatic, drug and ablation refractory AF received, irrespective of their left ventricular ejection fraction (EF), either a CRT device and underwent subsequent atrioventricular node (AVN) ablation or already had a total AV block and underwent CRT upgrade. Long‐lasting AF episodes (>48 h), left ventricular ejection fraction (LVEF), left ventricular end‐diastolic diameter (LVEDD), left atrial diameter (LAD), NTproBNP levels, EHRA score, and NYHA class had been monitored on the follow‐up.

Results

The number of patients experiencing long‐lasting AF episodes (>48 h) and symptoms decreased significantly within 24 months after CRT implantation in the presence of total AV block (p < .001) from 57 (76%) to 25 (33.3%). Mean LAD decreased from 52 mm (IQR 48.0–56.0) to 48 mm (IQR 42.0–52.0, p < .001) and LVEDD from 54 mm (IQR 49.0–58.0) to 51 mm (IQR 46.5–54.0, p < .001).

Conclusion

A combination of total AVN block and biventricular pacing markedly reduces long‐lasting AF episodes, symptoms, left atrial diameter, and left ventricular end‐diastolic diameter.

A prognostic nomogram for event-free survival in patients with atrial fibrillation before cardiac resynchronization therapy

Background

Atrial fibrillation (AF), one of the most common comorbidities of heart failure (HF), is associated with worse long-term prognosis in HF patients receiving cardiac resynchronization therapy (CRT). However, there is still no convenient tool to identify CRT candidates with AF who are at high risk of mortality and hospitalization due to HF.

Methods

We included 152 consecutive patients with AF for CRT in our hospital from January 2009 to July 2019. Multiple imputation was used for missing values. With imputed datasets, a multivariate Cox regression model was performed for variable selection using the backward stepwise method to predict all-cause mortality and HF readmissions. A nomogram and nomogram-based scoring system were constructed from the selected predictors. Then, internal validation and calibration were achieved by the bootstrap method, deriving the corrected concordance index and calibration curves. Sensitivity analysis was also performed to validate our selected predictors.

Results

Five predictors were incorporated in the nomogram, including N-terminal pro brain natriuretic protein (NT-proBNP) > 1745 pg/mL, history of syncope, previous pulmonary hypertension, moderate or severe tricuspid regurgitation, thyroid-stimulating hormone (TSH) > 4 mIU/L. The concordance index (0.70, 95% CI 0.62–0.77), corrected concordance index (0.67, 95% CI 0.59–0.74) and calibration curve showed optimal discrimination and calibration of the established nomogram. A significant difference in overall event-free survival was recognized by the nomogram-derived scores for patients with high risk (> 50 points), intermediate risk (21–50 points) and low risk (0–20 points) before CRT.

Conclusion

Our internally validated nomogram may be an applicable tool for the early risk stratification of CRT candidates with AF.