Left atrial appendage occlusion simulation based on three-dimensional printing: new insights into outcome and technique.

AIMS: The aim of this study was to assess the predictive value of simulation based on 3D-printed models before left atrial appendage occlusion (LAAO) for peri-device leaks (PDL) and the impact on procedural outcomes compared to conventional imaging. METHODS AND RESULTS: Seventy-six patients referred for LAAO with double disc device underwent construction of a 3D-printed LA model using flexible photopolymer resin. An implant simulation was performed retrospectively in Group 1 (55 patients), blinded to implanted device size, and prospectively in Group 2 (21 patients). In Group 1, an off-axis device position occurred in 14 patients (25%) and the incidence of PDL was 27% (15 patients); mismatch between model and device size was the best predictor (area under the curve 0.88, CI: 0.77-0.99). When using 3D simulation prospectively, mean prosthesis number per patient (1.05±0.21 vs. 1.20±0.52, p=0.04) and incidence of leaks (5% vs. 27%, p<0.01) were reduced compared to conventional imaging alone, as well as fluoroscopy time (19 mins [13.4-23] vs. 13.5 mins [11.1-15], p=0.012) and total fluoroscopy dose (7,291 [1,811-12,734] vs. 1,978 (1,548-4,800) mGy·cm2, p=0.029). CONCLUSIONS: 3D-printed patient-specific adaptive and flexible LA models improve LAAO double disc device sizing. This can potentially reduce procedure time and the number of prostheses employed per patient.

Predictive value for paravalvular regurgitation of 3-dimensional anatomic aortic annulus shape assessed by multidetector computed tomography post-transcatheter aortic valve replacement.

AIMS: Paravalvular regurgitation (PAR) remains a serious complication after trans-catheter aortic valve replacement (TAVR). Multidetector computed tomography (MDCT)-based measurements of the aortic basal virtual ring (BVR) are considered the gold standard for trans-catheter heart valve (THV) sizing. However, the real anatomic aortic annulus is a 3-dimensional structure. To compare measurement of 3D-anatomic annulus with BVR and secondly to assess independent predictive parameters that may impact on PAR > mild post-TAVR (PAR+). METHODS AND RESULTS: MDCT was performed in 92 patients before and after balloon or self-expandable TAVR. 3D-AA shape was obtained point by point following the semilunar attachment of aortic cusps (Osirix-MD 2.8.2). 3D-oversizing index (nominal THV area/3D-AA area - 1) × 100 was calculated as well as 2D-oversizing index using BVR area instead of 3D-AA area. PAR was quantified by planimetry of vena-contracta in transthoracic echocardiography short-axis view. Valvular calcium volume and annulus calcium area were measured using Hounsfield-intensity detection. ROC curves and logistic regression for PAR(+) were performed. BVR area overall underestimated 3D-AA area by 19 ± 9% (P< 0.001), significantly more in PAR(+) (26 ± 7%) vs. PAR(-) (17 ± 9%, P< 0.001). 3D-oversizing index had greater predictive value for PAR > mild (area under the curve, AUC = 0.88) with 88% sensibility (Se) and 82% specificity (Sp) than 2D-oversizing index (AUC = 0.68) with 84% Se, but only 41% Sp (P< 0.0001). Also, valvular calcium volume and annulus calcium area were less predictors for PAR > mild (AUC = 0.68, respectively, AUC = 0.75, P = 0.002). In a multivariate analysis, only 3D-oversizing index showed an independent value for PAR > mild (OR = 18.6, P< 0.001). CONCLUSION: Basal ring CT measurement significantly underestimated the real 3D-anatomic aortic annulus area. This may impact on THV sizing and PAR incidence. 3D-oversizing index is the most predictive factor for PAR > mild.

Modification of the Unipolar Atrial Electrogram as a Local Endpoint During Common Atrial Flutter Ablation.

INTRODUCTION: Complete elimination of the negative component of the unipolar atrial electrogram recently proved predictive of lesions transmurality. We prospectively assessed its relevance as a real-time local ablative endpoint for each individual lesion created across the cavotricuspid isthmus (CTI) in order to constitute a line of bidirectionnal block during common atrial flutter (AFL) ablation. METHODS AND RESULTS: Sixty-two consecutive patients underwent common AFL ablation following an electrophysiological approach guided by real-time electrogram modification analysis. In 31 patients (unipolar group), the local ablative endpoint was complete elimination of the negative component of the unipolar atrial electrogram, while the other 31 patients (control group) were treated following our standard approach based on the currently used local ablative endpoint defined by a ≥50% amplitude decrease of the bipolar atrial electrogram. Bidirectional block was achieved in all patients (mean age 67.9 ± 11.5 with 80.6% of men). Mean ablation time (164.3 ± 88.3 seconds vs 332.8 ± 151.5 seconds; P < 0.001) and mean energy delivery (7.5 ± 4.1 kJ vs 14.2 ± 6 kJ; P < 0.001) were significantly shorter in the unipolar group compared to the control group. No statistical differences were seen in procedure time (68.5 ± 22.6 min vs 77.5 ± 20.2 min; P = 0.10). CONCLUSION: Real-time unipolar electrogram modification is a relevant local endpoint during common AFL ablation and leads to a substantial reduction of ablation time and energy delivery compared to a standard ablative approach while displaying a similar short- and long-term success rate.

Unipolar signal modification as a guide for lesion creation during radiofrequency application in the left atrium: prospective study in humans in the setting of paroxysmal atrial fibrillation catheter ablation.

BACKGROUND: In patients treated for paroxysmal atrial fibrillation, the pulmonary vein (PV) reconnection rate is substantial and may be related to the lack of transmurality achievement while performing PV isolation (PVI). It has been experimentally demonstrated that positive unipolar atrial electrogram completion, when applying radiofrequency energy, was associated with transmural lesions. In this regard, we seek to determine whether the unipolar signal modification may be an appropriate end point for point-by-point radiofrequency application and find out whether it could improve the paroxysmal atrial fibrillation ablation results in humans. METHODS AND RESULTS: Fifty consecutive patients (61±8 years old, 41 men) with paroxysmal atrial fibrillation underwent PVI using Carto and Lasso. Each radiofrequency application lasted until development of a completely positive unipolar electrogram. Fifty patients (63±9 years old, 40 men), who previously underwent PVI following the standard approach of our institution, corresponded to the control group. All PVs were isolated in all patients of both groups. However, the procedural and ablation times were significantly lower in the unipolar group compared with those of the control group, whereas the PV reconnection rate, after 30 minutes of waiting time, was not significantly different. Overall, 21±4 months after 1 PVI session, the sinus rhythm maintenance rate without antiarrhythmic drugs was significantly higher (P=0.027) in the unipolar group (88%) compared with that of the control group (70%). CONCLUSIONS: Unipolar signal modification is a useful end point for radiofrequency energy delivery in patients with paroxysmal atrial fibrillation who undergo PVI and leads to a substantial midterm sinus rhythm maintenance rate.

Catheter ablation in selected patients with depressed left ventricular ejection fraction and persistent atrial fibrillation unresponsive to current cardioversion.

AIMS: In congestive heart failure (CHF) patients with persistent atrial fibrillation (AF), direct current cardioversion (DCC) may reveal participation of tachycardiamediated process to left ventricular (LV) dysfunction by restoring sinus rhythm (SR). However, if DCC fails to restore SR, patients' management remains challenging. The aim of the study was to assess the AF catheter ablation benefit in a selected group of CHF patients with LV ejection fraction (LVEF) <40% and persistent AF unresponsive to DCC, in whom a tachycardia-mediated process is thought to be predominant. METHODS AND RESULTS: Between January 2008 and September 2011, among 129 CHF patients with persistent AF referred to our institution, 34 (63.8 ± 9-year old, 24 men) presented AF refractory to DCC with an estimated high likelihood of tachycardia-mediated LV dysfunction according to a specific set of criteria. These 34 patients underwent stepwise AF ablation and were closely followed up. After a mean 1.9 AF ablation procedures per patient and 17.6 ± 7 months after the last procedure, all patients were in SR. The New York Heart Association class improved from 2.8 ± 0.3 to 1 ± 0.2 (P< 0.001) and the LVEF increased from 30.4 ± 6 to 54.6 ± 6% (P< 0.0001) after 3-6 months of SR, with a persistent benefit as long as the SR was maintained. CONCLUSION: Atrial fibrillation catheter ablation in selected CHF patients with persistent AF refractory to DCC and without any other evidence for secondary LV dysfunction leads to a substantial LVEF improvement in the majority of them. However, redo procedures are frequent in order to achieve mid-term SR maintenance.

Sinus rhythm restoration by catheter ablation in patients with long-lasting atrial fibrillation and congestive heart failure: impact of the left ventricular ejection fraction improvement on the implantable cardioverter defibrillator insertion indication.

AIMS: In the setting of congestive heart failure (CHF), atrial fibrillation (AF) ablation can improve clinical status and the left ventricular ejection fraction (LVEF) value. However, the impact of AF ablation on the implantable cardioverter defibrillator (ICD) indication has never been specifically addressed. METHODS AND RESULTS: Study subject were six CHF (mean age 61.1 +/- 6.9 years, mean LVEF 25.8 +/- 7.3%) patients refractory to conventional medical treatment with long-lasting AF unresponsive to external cardioversion. Five patients had an idiopathic dilated cardiomyopathy (DCM) and one had an ischaemic cardiomyopathy (ICM). Their New York Heart Association (NYHA) class was III-IV. Two patients had renal insufficiency. No patient had left ventricular delay. All patients underwent AF ablation. LVEF and NYHA class were dramatically improved in the five DCM patients. New York Heart Association class, but not the LVEF, was improved in the ICM patient. A redo ablative procedure was undertaken in four of five DCM patients and in the ICM patient due to arrhythmia recurrence. Left ventricular ejection fraction and NYHA were improved again in the DCM patients (56 +/- 4.4%, I-II, respectively) and led to ICD indication preclusion. The LVEF remained low in the ICM patient (30%) and led to ICD insertion. Sinus rhythm has been stable during the 18.1 +/- 5.7 months follow-up period. CONCLUSION: Atrial fibrillation ablation in CHF patients can improve both the clinical status of patients and their LVEF, especially among those affected by DCM. The LVEF improvement has the potential to preclude the indication for a primary prevention ICD insertion.