Decreased device related thrombus and enhanced neo-endocardial tissue maturation with a new generation left atrial appendage closure (LAAC) device. An anticoagulation and antiplatelet free canin study

Introduction

Device related thrombus (DRT) has been reported in up to 7% of patients post LAAC even while on anticoagulation. Clinical predictors of DRT are poorly understood and may be related to patient, procedural and device factors. A next generation WATCHMAN LAAC device (NG) is identical in shape and geometry to the current WATCHMAN FLX device (CW) but has a device coating designed to make it hemocompatible and less thrombogenic.

Objective

To evaluate the incidence and burden of WM surface thrombus formation as detected longitudinally by TEE and at necropsy in a canine model implanted with the NG device.

Methods

The study included 12 canine (6 implanted with CW and 6 implanted with NG) that underwent serial TEE follow up at 14, 28 and 45 days to evaluate surface thrombus on WM face. This was a challenged canine model designed to induce thrombus with no anticoagulation or antiplatelet use throughout the study. D-dimer levels were measured at 7 days and 45 days and compared to baseline measurements.

Results

All devices were successfully implanted. TEE follow up at 14 days showed noticeably reduced thrombus burden on the NG device compared to CW (fig.1) with even further diminution by 28 days in the NG (6/6) as compared to only in 1/6 in the CW group (fig.2). After 45 days in-life, the post-fixation trim en-face images show a smooth, glistening neoendocardial covering (absence of acute thrombus material) in all (6/6) NG compared to only 2/6 in the CW (fig.3). The CW had 3/6 devices with exuberant, bulging calcified thrombus mass one of which was considered to be a mobile DRT. D Dimer levels at 7 and 45 days were significantly lower relative to baseline in the NG compared to CW.

Conclusion

The NG device compared to the CW device was associated with markedly less thrombus formation at 14 days and no thrombus formation at 28 days post implant on no anticoagulant and no antiplatelet therapy along with a more mature uniform tissue coverage at 45 days. The WATCHMAN FLX Pro device coating is a promising step to reduce DRT even without the use of anticoagulation and antiplatelets and merits further investigation in human studies.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boston Scientific

Impact of pacing-related differences on clinical and echocardiographic outcomes after TAVR with SAPIEN-3 valve

Background

Data regarding the impact of pacing on outcomes after transcatheter aortic valve replacement (TAVR) is evolving especially with regards to pre-existing PPM. We examined the impact of new and prior PPM on clinical and hemodynamic outcomes after SAPIEN-3 (S3) TAVR.

Methods

Consecutive patients who underwent transfemoral-TAVR using S3 valve between April 2015 and December 2018 at our Clinic were included.

Results

Among 1028 patients, 10.2% required new PPM within 30 days, while 14% had pre-existing PPM. The presence of either prior or new PPM had no impact on 3-year mortality (log-rank p=0.6), or 1-year major adverse cardiac and cerebrovascular event (MACCE) (log-rank p=0.65). New PPM was associated with lower left ventricular ejection fraction (LVEF) at both 30 days (54.4±11.3% vs. 58.4±10.1%; p=0.001), and 1 year (54.2±12% vs. 59.1±9.9%; p=0.009) compared to no PPM. Similarly, prior PPM was associated with worse LVEF at 30 days (53.6±12.3%; p<0.001) and 1 year (55.5±12.1%; p=0.006) compared to no PPM. Interestingly, new PPM was associated with lower 1-year mean gradient (11.4±3.8 vs. 12.6±5.6 mmHg; p=0.04), and peak gradient (21.3±6.5 vs. 24.1±10.4 mmHg; p=0.01) despite no baseline differences. Prior PPM was also associated with lower 1-year mean gradient (10.3±4.4 mmHg; p=0.001), and peak gradient (19.4±8 mmHg; p<0.001), and higher doppler velocity index (0.51±0.12 vs. 0.47±0.13; p=0.039). Moreover, 1-year LV end-systolic volume (LVESVi) was higher with new (23.2±16.1 vs. 20±10.8 ml/m2; p=0.038), and prior PPM (24.5±19.7; p=0.038) compared to no PPM. Prior PPM was associated with higher moderate-to-severe tricuspid regurgitation (35.3% vs. 17.7%; p<0.001). There were no differences with regards to the rest of the studied echocardiographic outcomes at 1 year.

Conclusion

In this S3 cohort, new and prior PPM did not affect 3-year mortality or 1-year MACCE, however they were associated with worse LVEF, higher LVESVi and lower mean and peak gradients on follow-up compared to no PPM.

Funding Acknowledgement

Type of funding sources: None. Figure 1. All-cause Survival

C reactive protein concentration and recurrence of atrial fibrillation after electrical cardioversion

BACKGROUND

To test the hypothesis that a high C reactive protein (CRP) concentration would predict recurrence of atrial fibrillation (AF) after cardioversion in patients taking antiarrhythmic drugs.

METHODS

111 patients who underwent direct current cardioversion for symptomatic AF were enrolled. Blood was drawn for CRP determination before cardioversion on the same day. All patients were taking antiarrhythmic drugs before and after electrical cardioversion.

RESULTS

After a mean follow up of 76 days, 75 patients had recurrence of AF. In univariate analysis, the median CRP concentration was significantly higher in patients with AF recurrence (3.95 mg/l v 1.81 mg/l, p = 0.002). Among the 55 patients with CRP in the upper 50th centile, 44 (80%) experienced recurrence of AF over a total follow up of 8.98 patient years, whereas among the 56 patients with CRP in the lower 50th centile, 31 (55%) experienced recurrence of AF over a total follow up of 14.3 patient years (p < 0.001). The adjusted hazard ratio comparing the upper 50th centile of CRP with the lower 50th centile of CRP was 2.0 (95% confidence interval 1.2 to 3.2, p = 0.007).

CONCLUSIONS

CRP is independently associated with recurrence of AF after electrical cardioversion among patients taking antiarrhythmic drugs. These results suggest that inflammation may have a role in the pathogenesis of AF resistant to antiarrhythmic drugs.

C-reactive protein elevation in patients with atrial arrhythmias: inflammatory mechanisms and persistence of atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) may persist due to structural changes in the atria that are promoted by inflammation. C-reactive protein (CRP), a marker of systemic inflammation, predicts cardiovascular events and stroke, a common sequela of AF. We hypothesized that CRP is elevated in patients with atrial arrhythmias.

METHODS AND RESULTS

Using a case-control study design, CRP in 131 patients with atrial arrhythmias was compared with CRP in 71 control patients. Among arrhythmia patients, 6 had frequent atrial ectopy or tachycardia, 86 had paroxysmal AF, 39 had persistent AF lasting >30 days, and 70 had lone arrhythmias. CRP was higher in arrhythmia than in control patients (median, 0.21 versus 0.096 mg/dL; P<0.001). Arrhythmia patients in AF within 24 hours before sampling had higher CRP than those in sinus rhythm (0.30 versus 0.15 mg/dL; P<0.001). CRP in controls was not different than in patients with atrial ectopy or tachycardia. Lone arrhythmia patients had a CRP of 0.21 mg/dL, which was not significantly lower than arrhythmia patients with structural heart disease (CRP, 0.23 mg/dL) but higher than controls (P=0.002). Persistent AF patients had a higher CRP (0.34 mg/dL) than paroxysmal AF patients (0.18 mg/dL; P=0.008); both groups had higher CRP levels than controls (P</=0.005).

CONCLUSIONS

CRP is elevated in AF patients. This study is the first to document elevated CRP in non-postoperative arrhythmia patients. These findings are reinforced by stepwise CRP elevation with higher AF burden. Although the cause of elevated CRP levels in AF patients remains unknown, elevated CRP may reflect an inflammatory state that promotes the persistence of AF.