Left atrial hypertension and the risk of early incident heart failure after atrial fibrillation ablation

Prevalence, Associated Factors, and Echocardiographic Estimation of Left Atrial Hypertension in Patients With Atrial Fibrillation

Background Elevated left atrial (LA) pressure predisposes individuals to the initiation and persistence of atrial fibrillation (AF), and LA hypertension is associated with AF recurrence after catheter ablation (CA). However, the exact frequency and factors associated with LA hypertension are unknown, and its noninvasive estimation is challenging. This study aimed to investigate the prevalence and determinants of LA hypertension in patients with AF who underwent first CA. Methods and Results We examined 183 patients with AF who underwent conventional and speckle-tracking echocardiography before CA to assess LA size, reservoir strain, and stiffness. Direct LA pressure was measured at the time of CA, and LA hypertension was defined as mean LA pressure >15 mm Hg. Thirty-three (18.0%) patients exhibited LA hypertension. Patients with LA hypertension had a significantly larger LA volume index (40.2 [28.4-52.1] versus 34.1 [26.9-42.4] mL/m2, P=0.025), reduced LA reservoir strain (15.1 [10.4-21.7] versus 22.7 [14.4-32.3] %, P=0.002) and increased LA stiffness (0.69 [0.34-0.99] versus 0.36 [0.24-0.54], P<0.001). Multivariable analyses showed that waist circumference, C-reactive protein level, LA reservoir strain, and LA stiffness were independently associated with LA hypertension (all P<0.05), while LA volume and E/e' ratio were not. Among echocardiographic parameters, receiver operating characteristic curve analysis identified LA stiffness as the best predictor of LA hypertension. Conclusions Approximately 20% of patients with AF who underwent CA had LA hypertension. Central obesity and inflammation might be involved in the pathophysiological mechanisms of LA hypertension, and echocardiography-derived LA stiffness may have clinical utility for the detection of LA hypertension before CA.

Heart Rate Decrease After Atrial Fibrillation Catheter Ablation Predicts Decompensated Heart Failure After the Procedure

Background: Decompensated heart failure (DHF) can complicate catheter ablation for atrial fibrillation (AF). We investigated the association between heart rate and DHF in AF patients undergoing catheter ablation. Methods and Results: In all, 1,004 consecutive patients who underwent initial ablation for AF (mean [±SD] age 68±10 years; 34% female; persistent AF n=513 [51%]) were enrolled in the study. Heart rate was assessed before and after ablation. DHF was defined as heart failure requiring medical therapy within 2 days after the procedure. The incidence of DHF was 2% (22 of 1,004 patients). Patients with DHF had a higher prevalence of a history of symptomatic heart failure (11/22 [50%] vs. 160/982 [16%]; P<0.0001) and a greater degree of heart rate decrease after the procedure (-21±29 vs. 2±21 beats/min; P=0.001) than those without DHF. On multivariate analysis, heart rate decrease was a significant independent predictor of DHF (hazard ratio 0.8; 95% confidence interval 0.7-0.9; P=0.004; 10 beats/min-increment). Conclusions: In patients undergoing AF ablation, a decrease in heart rate after the procedure was an independent predictor of DHF.

Post-ablation P wave characteristics correlate with recurrent atrial fibrillation in the ABCD-AF cohort

PURPOSE

Atrial fibrillation (AF) ablation is a common procedure to reduce cardiovascular morbidity but is limited by recurrence. The objective of this study was to determine if post-ablation acute surface P wave morphology and other electrocardiographic parameters correlate with AF recurrence.

METHODS

The Avoiding Bladder Catheters During AF ablation (ABCD-AF) trial was a randomized, prospective trial in 160 subjects undergoing AF ablation. The present study examined correlation between AF recurrence in follow-up and acute post-ablation electrocardiographic P wave parameters.

RESULTS

Median follow-up was 255 (188, 306) days. The ABCD-AF cohort had a mean age of 62.7 ± 12.8 with 32.1% being females. Rate of recurrent AF was 35.8%, with a median time to AF of 135 (109, 182) days. There was no baseline demographic associated with AF recurrence. There was more AF recurrence in those with longer follow-up (p = 0.001). Lead 2 PR interval, lead 2 P wave duration/PR (Pdur/PR), lead V1 PR interval, and lead V1 Pdur/PR were all significantly associated with recurrent AF (p = 0.03, 0.02, 0.01, 0.01). Longer PR and shorter Pdur/PR predicted AF recurrence. In a multivariable model, lead V1 Pdur/PR provided the best predictor of AF recurrence, with an odds ratio of 0.018 (p = 0.016) per standard deviation change.

CONCLUSIONS

Shorter P wave duration combined with longer AV node delay, as measured by proportion of the PR that the P wave occupies, was the best predictor of AF recurrence post-ablation.