Randomized prospective evaluation of same-day discharge after cryoballoon ablation of atrial fibrillation: results of the EASY PVI study

BACKGROUND

With advancements in technology and ablation techniques, catheter ablation for the treatment of atrial fibrillation (AF) has become safer with time. In the past, standard-of-care recommended overnight stay for outpatient procedures. As safety has improved and procedure times have shortened, some centers have allowed for same-day discharge. We report the results of a multi-center, randomized clinical trial investigating the safety of same-day discharge post-cryoballoon ablation.

METHODS

Patients with paroxysmal atrial fibrillation underwent pulmonary vein isolation (PVI) with the Medtronic Arctic Advance cryoballoon at 3 US centers. Six hours after the procedure, patients were randomized to either stay overnight or be discharged same day.

RESULTS

A total of 49 patients were enrolled. Two patients were withdrawn prior to randomization. One patient chose to withdraw after randomization. Of the 22 patients randomized to same-day discharge and the 23 patients randomized the overnight stay, no significant adverse outcomes were reported in either group. Occurrence of adverse events did not differ significantly between the two groups. Procedure time and fluoroscopy time did not significantly differ between groups.

CONCLUSIONS

This is the first randomized trial examining the safety of same-day discharge post-cryoballoon ablation. Based on our results, same-day discharge following cryoballoon ablation for paroxysmal AF is a safe option following uncomplicated ablation for PVI. Operators should use their discretion in selecting patients for same-day discharge.

Achieving regioselective materials binding using multidomain peptides

The ability to integrate two disparate materials-binding domains into a single ligand to achieve regiospecific binding would be powerful to direct material assembly; however, this has proven challenging to achieve due to cross-materials binding. Accomplishing this goal might be achieved by harnessing the precision of biology to exploit the recognition between peptides and specific nanomaterials. Here, a designed bifunctional molecule termed Biomolecular Exfoliant and Assembly Motifs (BEAM) is introduced, featuring two different materials-binding peptide domains, one for graphene and one for hexagonal boron nitride (h-BN), at each end of the molecule, separated by a fatty acid spacer. The BEAM is demonstrated to bind strongly to both graphene and h-BN surfaces, and in each case the materials-binding peptide domain is shown to preferentially bind its target material. Critically, the two materials-binding domains exhibited limited cross-domain interaction. The BEAM design concept shows substantial potential to eventually guide self-organization of a range of materials in aqueous media.

Clinical evaluation of a novel 12-hole irrigated tip catheter ablation system for the treatment of typical atrial flutter-results from the Duo FLAIR clinical study

INTRODUCTION

Higher current density at the proximal end of a six-hole catheter is not irrigated and thus could lead to uneven heating and possibly coagulum and charring. This study tested a novel 12-hole irrigated catheter with six additional holes at the proximal end that provides more uniform cooling during atrial flutter (AFL) ablation.

METHODS

A total of 188 patients (28 females, 66 ± 11 years) were treated for typical AFL at 22 sites in the USA and Canada using Cool Path Duo at 50 W and 45 °C at an irrigation rate of 13 ml/min. The results were compared to historical data from an AFL study which used a six-hole catheter with similar design.

RESULTS

A total of 2,725 RF lesions were applied in 188 patients with a mean RF duration of 18.2 ± 11.7 min per procedure. Procedural success was achieved in 96.3 % (181 of 188) acutely and 98.3 % (173 of 176) patients at 3 months. Steam pops occurred in 0.6 % of lesions (15 of 2,725) without coagulum or charring… Compared to the six-hole irrigated tip catheter, the Cool Path Duo catheter delivered more power (33.8 ± 5.9 vs. 29.7 ± 5.2 W, p < 0.0001) at a lower average tip temperature (34.7 ± 1.5 vs. 37.2 ± 2.1 °C, p < 0.0001) with no statistical differences in either 3-month AFL recurrence or complications.

CONCLUSION

Cool Path Duo™ irrigated tip catheter is safe and effective in treating typical AFL. When compared to a six-hole irrigated tip catheter, the Cool Path Duo catheter delivers more power at a lower temperature.

Comparison of pulmonary uptake with transient cavity dilation after exercise thallium-201 perfusion imaging

OBJECTIVES

The purpose of the study was to evaluate the relationship between elevated lung/heart ratio (LHR) and transient ischemic dilation (TID) after stress thallium-201 myocardial perfusion imaging and to provide further insight into the mechanism of cavity dilation.

BACKGROUND

Because both LHR and TID have been identified as adjunctive markers of severe coronary disease they should be found in the same patients. Although the mechanism of LHR has been defined, that of transient dilation has not.

METHODS

We identified 4,618 consecutive patients undergoing maximal exercise perfusion imaging with thallium-201. Lung/heart ratio and a dilation index were derived and compared to each other and to relevant clinical parameters.

RESULTS

There was a very weak relationship between the LHR and dilation index (r = 0.15, p < 0.001). Defining a dilation index > or =1.10 and LHR > or =50% as abnormal revealed that 322 of the patients (7%) had TID only, 351 (7.8%) had LHR only and 40 (0.9%) had both. When compared to patients without these findings both TID and LHR had higher thallium stress defect and redistribution scores. When comparing subjects who had elevated LHR uptake to those who had TID, it was found that those with LHR were more likely to have had prior myocardial infarction (MI) (29% vs. 9%), coronary artery bypass grafting (22% vs. 8%), lower ejection fraction (34+/-17% vs. 55+/-11%) and had more evidence of ischemia based on thallium stress defect and redistribution scores. However, patients with cavity dilation had a higher frequency of positive electrocardiographic response (31% vs. 19%) despite lower scintigraphic markers.

CONCLUSIONS

Although pulmonary uptake and transient cavity dilation have both been associated with severe coronary disease, they have a very weak correlation, which, in combination with the different clinical parameters associated with each, suggests that they represent different pathophysiologic responses to exercise-induced ischemia. Our data support the hypothesis that TID represents transient subendocardial ischemia rather than physical dilation from increased end-diastolic pressure.