Wen, S

Abstract Background Catheter ablation for atrial fibrillation (AF) improves quality of life and lowers cardiovascular adverse events. However, AF recurrence rates remain high - thus the need for better or improved predictors of AF recurrence. The role of left atrial (LA) stiffness remains unclear, as prior findings were controversial. Purpose To explore the relationship between a noninvasive LA stiffness index (LAstiffn) and AF recurrence after catheter ablation. Methods We analyzed a prospectively recruited cohort of patients who underwent catheter ablation for AF, were in sinus rhythm at 3 months post-ablation, had no significant (< moderate) valvular disease, and had LA volumes and LA diastolic function prospectively measured. LAStiffn was calculated as (E/e’)/LA emptying fraction (LAEF) ratio (abnormal defined as >15/45≈0.3). Outcome endpoint was the first documented AF/atrial flutter episode, lasting >30s, beyond 3 months post ablation (end of blanking period). Results A total of 589 patients were studied (mean age 60±10 years; 75% men; 50% with persistent AF; Table 1). At 3 months post-ablation, mean LAVI(Left atrial volume index) was 36±10 mL/m2 and LAstiffn 0.32±0.22. LAstiffn tended to be higher in older patients, in females, and patients with persistent AF and comorbidities (hypertension, congestive heart failure, coronary artery disease, CHA2DS2-VASc score ≥2, etc). At multivariable regression analysis, LAstiffn correlated with LV size and mass, degree of mitral/tricuspid regurgitation, and right ventricular systolic pressure. At 1 year, 3 years, and 8 years follow up, AF recurred in 118, 191, and 347 patients, respectively. At univariate Cox proportional hazards regression analysis, LAstiffn index >0.3 was significantly associated with AF recurrence at 1 year (log-rank P=.0005), 3 years (P=.0002), and 8 years follow up (P<.0001; Figure). In multivariate analysis including all clinical and laboratory factors with P<.10 in univariate analysis, LAstiffn >0.3 remained an independent factor for AF recurrence only at 3-years (adjusted HR 1.40 [1.03-1.91], P=.03) and 8 years follow up (adjusted HR 1.65 [1.29-2.13], P<.0001) after adjustment for age, sex, type of AF (persistent/paroxysmal), LA volume index (LAVi), obstructive sleep apnea, and prior pacemaker/ICD implantation (best independent factors); P=.14 at 1 year follow up. In ROC analysis, LAstiffn (AUC 0.61, P=.001) performed slightly better than LA deformation LAEF (AUC 0.59, P=.002) or E/e’ (AUC 0.58, P=.03), though with modest sensitivity/specificity (58%/62%). Conclusions LAstiffn may reflect LA myopathy that is likely due to the cumulative effects of comorbidities, diastolic dysfunction, and intrinsic LA tissue remodeling. LA stiffening may be a substrate facilitating redevelopment of AF, thus patients with increased LAstiffn may need more frequent monitoring to prevent/treat AF recurrence earlier.

Abstract Background Atrial fibrillation (AF) occurs more frequently in men, but women suffer more AF recurrence; mechanisms are not completely understood. Purpose To explore whether sex related differences in LA stiffness (LAstiffn) in patients with AF ablation could potentially explain differences in AF recurrence. Methods We screened patients with catheter ablation for AF, in sinus rhythm at 3 months post-ablation, with no significant mitral valve disease (< moderate), and with prospectively measured LA volumes [maximum (LAVI) and minimum volume index] by echocardiography. LAStiffn index was estimated as (E/e’)/LA emptying fraction. Outcome endpoint was AF recurrence up to 14 years post ablation. Results A total of 591 patients with AF ablation were studied (mean age 60±10 years; 25% women; Table1). At 3 months post-ablation, LAVI was 36±10 mL/m2 and LAstiffn was 0.31±0.21 1/%. Compared to males, female patients were slightly older, had more frequently hypertension, congestive heart failure, prior stroke/TIA, higher CHA2DS2-VASc score; they less often had persistent AF, coronary artery disease, or dilated cardiomyopathy. Women also had higher LAstiffn (0.37±0.24 vs. 0.29±0.19, P <.0001, Figure 1), despite similar indexed LA volumes (Table1). Rates of AF recurrence at follow-up (median 7.5 years; 347 patients with events) were higher in women vs. men (Figure 2, left; log-rank P<.001) and persisted after adjustment for age, type and duration of AF, body mass index, cardiovascular risk factors and comorbidities, CHA2DS2-VASc score ≥2, LV ejection fraction, and LAVI (adjusted HR 1.58 [1.20-2.08], P=.001). Overall, LA volumes and LAstiffn were higher in patients with older age and more comorbidities (hypertension, congestive heart failure, coronary artery disease, persistent AF, CHA2DS2-VASc score ≥2, etc; P<.01 for all). At multivariable regression analysis, LAVI and LAstiffn correlated with E/e’, LV size and mass, degree of mitral/tricuspid regurgitation, and LV stroke volume index (only LAVI). In addition, LAstiffn was higher in patients with elevated right ventricular systolic pressure (RVSP) >35 mmHg and increase in RVSP more than 10 mmHg from pre-ablation (P<.0001) (correlation R=0.44, P<.0001). At follow-up, after adjusting for age and LAVI, higher LAstiffn remained associated with AF recurrence in women (P=.02, HR 2.82 per unit change, 95% CI, 1.08-6.72; Figure 2, right), but not in men (P=.30). Conclusions LAStiffn is higher in women vs. men and correlates with burden of comorbidities, aging, diastolic dysfunction and pulmonary hypertension, possibly reflecting more extensive LA myopathy, and potentially contributing to sex differences in AF recurrence.Figure 1Table 1

Abstract Background Increased left ventricular (LV) stiffness (LVStiffn) was shown to be associated with mortality in patients with severe aortic stenosis (AS), despite aortic valve replacement (AVR), and may contribute to future heart failure (HF) symptoms. The aim was to assess whether preoperative LVStiffn is a risk factor of HF in these patients. Methods A retrospective analysis was done in patients with severe AS who underwent AVR (93% surgical). LV end-diastolic pressure-volume relations (P=aVb) were reconstructed from LV end-diastolic volumes and estimated end-diastolic pressures (from E/e'); LVStiffn at 30 mmHg (CS30) and capacitance (V30) were then derived. Primary endpoint was development of symptomatic HF at >1 month post AVR. Results 1,837 patients were studied (age 76±10 years, 62% males, LVEF 61±12%; Table). Mean CS30 was 2.2±1.3 mmHg/mL and V30 64±17 mL/m2. Patients with higher CS30 ≥3 mmHg/mL were older, more frequently female, and had more comorbidities. During a median follow-up of 5.0 [3.0–7.9] years, 607 (33%) patients developed HF. A higher CS30 (≥3 mmHg/mL), but not V30 (P=0.32), was associated with higher risk of HF events (HR 1.86 [95% CI 1.52–2.27], P<0.0001), along with other clinical and echo predictors (Table). In multivariate analysis, adjusting for age, sex, comorbidities, advanced NYHA class III–IV, creatinine >1.5 mg/dL, medication use, severity of AS, reduced LVEF <50%, diastolic dysfunction grade ≥2, right ventricular size and pulmonary hypertension, a higher CS30 ≥3 mmHg/mL remained independently associated with HF events (adjusted HR 1.61 [1.29–2.01], P<0.0001; Figure). Conclusion Increased LVStiffn in patients with severe AS undergoing AVR is associated with HF at follow-up, despite the benefits brought by AVR, and can help identify patients with poorer outcomes who may need closer monitoring/more intensive treatment of comorbidities Funding Acknowledgement Type of funding sources: None.

Abstract Background Atrial fibrillation (Afib) leads to beat-to-beat variability in cycle length; however, whether there is associated beat-to-beat variability in the tricuspid annulus (TA) dimensions or variability in the time in cardiac cycle when TA reaches maximal size is unknown. Purpose We aim to assess the beat-to-beat variability in the TA dimensions in Afib compared with sinus rhythm (SR). Methods Images were obtained from 58 patients (29 in Afib, 29 in SR) undergoing either 3D TTE or TEE examination. We measured TA in 3–6 cardiac cycles per patient using commercially available software (TomTec 4MV). Results Median absolute difference in maximal TA area over 3–6 cardiac cycles was 1.60 cm2 (range 0.35 cm2 to 4.08 cm2) in Afib vs. 1.17 cm2 (range 0.32 cm2 to 2.19 cm2) in SR, p=0.0063. Median absolute difference in the maximal circumference was 0.79 cm (range 0.09 cm to 2.2 cm) in Afib vs 0.54 cm (range 0.12 cm to 1.43 cm) in SR, p=0.0175. A total of 118 cardiac cycles were analyzed in patients in SR and 147 in Afib. Timing of maximal TA area was most commonly recorded at end-diastole (80–100% of the R-R interval) in 62% of cycles in SR; however, it was distributed over a broad range in Afib, p<0.0001, [Figure]. Conclusion Afib leads to significant beat-to-beat variability in the maximal TA area, minimal TA area, maximal TA circumference, and in the time of maximal TA area. These findings suggest that accurate assessment of TA dimensions should be based on continuous tracking of the TA over several cardiac cycles, especially in patients with Afib. These observations have significant implications for device sizing in percutaneous tricuspid valve interventions. Timing of Maximal TA Area Funding Acknowledgement Type of funding source: None