Impact of Electrode Type on Mapping of Scar-Related VT.

BACKGROUND: Substrate-based VT ablation is mostly based on maps acquired with ablation catheters. We hypothesized that multipolar mapping catheters are more effective for identification of scar and local abnormal ventricular activity (LAVA). METHODS AND RESULTS: Phase1: In a sheep infarction model (2 months postinfarction), substrate mapping and LAVA tagging (CARTO® 3) was performed, using a Navistar (NAV) versus a PentaRay (PR) catheter (Biosense Webster). Phase2: Consecutive VT ablation patients from a single center underwent NAV versus PR mapping. Point pairs were defined as a PR and a NAV point located within a 3D-distance of ≤3 mm. Agreement was defined as both points in a pair being manually tagged as normal or LAVA. Four sheep (4 years, 50 ± 4.8 kg) and 9 patients were included (53 ± 14 years, 8 male, 6 ischemic cardiomyopathy). Mapping density was higher within the scar with PR versus NAV (3.2 vs. 0.7 points/cm2 , P = 0.001) with larger bipolar scar area (68 ± 55 cm2 vs. 58 ± 48 cm2 , P = 0.001). In total, 818 point pairs were analyzed. Using PR, far-field voltages were smaller (PR vs. NAV; bipolar: 1.43 ± 1.84 mV vs. 1.64 ± 2.04 mV, P = 0.001; unipolar; 4.28 ± 3.02 mV vs. 4.59 ± 3.67 mV, P < 0.001). More LAVA were also detected with PR (PR vs. NAV; 126 ± 113 vs. 36 ± 29, P = 0.001). When agreement on LAVA was reached (overall: 72%; both LAVA, 40%; both normal, 82%) higher LAVA voltages were recorded on PR (0.48 ± 0.33 mV vs. 0.31 ± 0.21 mV, P = 0.0001). CONCLUSION: Multipolar mapping catheters with small electrodes provide more accurate and higher density maps, with a higher sensitivity to near-field signals. Agreement between PR and NAV is low.

The use of Impella 2.5 in severe refractory cardiogenic shock complicating an acute myocardial infarction.

OBJECTIVES: To investigate the outcome of patients with acute myocardial infarction (AMI) complicated by refractory cardiogenic shock (CS) who underwent mechanical circulatory support with Impella 2.5. BACKGROUND: AMI complicated by CS remains a highly fatal condition. A potent and minimally invasive left ventricular assist device might improve patient outcomes. METHODS: We analyzed the procedural characteristics and outcomes of 22 consecutive patients who underwent, between July 2008 and December 2012, a percutaneous coronary intervention and Impella 2.5 support for AMI complicated by CS refractory to first-line therapy with inotropes and/or Intra-aortic balloon pump. RESULTS: In this analysis, patients were relatively young with a mean age of 57.9 ± 11.6 year old and 59.1% were male. The majority of patients (77.3%) were admitted in CS and 40.9% sustained cardiac arrest prior to admission. Hemodynamics improved significantly upon initiation of support, end-organ and tissue perfusion improved subsequently demonstrated by a significant decrease in lactate levels from 6.37 ± 5.3 mmol/L to 2.41 ± 2.1 mmo/L, (P = 0.008) after 2 days of support. Thirteen (59.1%) patients were successfully weaned-off Impella 2.5 and 4 (18.2%) were transitioned to another device. We observed a functional recovery of the left ventricle when compared to baseline (43 ± 10% vs. 27 ± 9%, P < 0.0001). The survival rate at 6 months and 1 year was 59.1% and 54.5%, respectively. CONCLUSION: Impella 2.5 was initiated as a last resort therapy to support very sick patients with refractory CS after failed conventional therapy. The use of the device yielded favorable short and mid-term survival results with recovery being the most frequently observed outcome.

First report of a subacute stent thrombosis in a prasugrel resistant patient successfully managed with ticagrelor.

Prasugrel is a widely used antiplatelet agent in the setting of percutaneous coronary intervention. In case of resistance to this third-generation thienopyridine, choices of alternative drugs remain limited. Here, we describe a case of a 49-year-old man with stent thrombosis occurring 5 days after drug-eluting stent implantation despite a well-conducted antiplatelet therapy with aspirin and prasugrel. Evaluation of platelet functions by different tests revealed prasugrel resistance. Genotyping for various CYP single-nucleotide polymorphisms showed that the patient carried mutant alleles encoding enzymes CYP2B6 and CYP2C9 involved in prasugrel metabolic pathway. Strikingly, an adequate platelet response was rapidly obtained after switching from prasugrel to ticagrelor.

Management of life-threatening deformation of obstructive transcatheter mitral valve replacement bioprosthesis with balloon inflation in left ventricular outflow tract: a case report.

Background: Left ventricular outflow track (LVOT) obstruction (LVOTO) is a severe complication of transcatheter mitral valve replacement (TMVR) procedures, with an uncertain prognosis and only few strategies available to prevent its occurrence. TMVR is thus contraindicated in some patients because of a high risk of LVOTO onset. We demonstrate how LVOTO can be managed with a balloon inflation in the LVOT and a D-shaped deformation of the bioprosthetic valve. Case summary: A 64-year-old female presented with acute pulmonary oedema 2 weeks following aortic valve replacement and aorto-coronary bypass surgeries. A concomitant mitral stenosis, secondary to significant calcifications of the mitral annulus, was not treated during the procedure. After surgery, the mitral valvulopathy caused an acute heart failure and TMVR was performed by the heart team. The procedure was complicated by a cardiac arrest secondary to the onset of LVOTO which was managed by a balloon inflation in the LVOT and an alcohol septal ablation. Two-year follow-up shows a favourable outcome of the patient and good function of the prosthetic valve despite its deformation. Discussion: This case highlights the successful management of a LVOTO following valve-in-mitral annular calcification TMVR by balloon inflation in the LVOT. It is strongly recommended to place a 'rescue' guidewire in transaortic position during TMVR in order to manage the potential onset of acute LVOTO.

Transcatheter aortic valve implantation with the Evolut platform for bicuspid aortic valve stenosis: the international, multicentre, prospective BIVOLUTX registry.

BACKGROUND: Prospective data about transcatheter aortic valve implantation (TAVI) in bicuspid aortic valve (BAV) patients are limited. AIMS: We aimed to evaluate the clinical impact of the Evolut PRO and R (34 mm) self-expanding prostheses in BAV patients and explore the impact of different computed tomography (CT) sizing algorithms in a prospective registry. METHODS: A total of 149 bicuspid patients were treated in 14 countries. The primary endpoint was the intended valve performance at 30 days. Secondary endpoints were 30-day and 1-year mortality, severe patient-prosthesis mismatch (PPM) and the ellipticity index at 30 days. All study endpoints were adjudicated according to Valve Academic Research Consortium 3 criteria. RESULTS: The mean Society of Thoracic Surgeons score was 2.6% (1.7-4.2). Type I L-R BAV was observed in 72.5% of the patients. Evolut valve sizes 29 and 34 mm were utilised in 49.0% and 36.9% of the cases, respectively. The 30-day cardiac death rate was 2.6%; the 1-year cardiac death rate was 11.0%. Valve performance at 30 days was observed in 142/149 (95.3%) patients. The mean aortic valve area post-TAVI was 2.1 (1.8-2.6) cm2, and the mean aortic gradient was 7.2 (5.4-9.5) mmHg. No patient had more than moderate aortic regurgitation at 30 days. PPM was observed in 13/143 (9.1%) surviving patients and was severe in 2 patients (1.6%). Valve function was maintained at 1 year. The mean ellipticity index remained 1.3 (interquartile range 1.2-1.4). Overall, 30-day and 1-year clinical and echocardiography outcomes were similar between the two sizing strategies. CONCLUSIONS: BIVOLUTX demonstrated a favourable bioprosthetic valve performance and good clinical outcomes after TAVI with the Evolut platform in patients with bicuspid aortic stenosis. No impact from the sizing methodology could be identified.

Secreted frizzled-related protein-1 improves postinfarction scar formation through a modulation of inflammatory response.

OBJECTIVE: The inflammatory response after myocardial infarction plays a crucial role in the healing process. Lately, there is accumulating evidence that the Wnt/Frizzled pathway may play a distinct role in inflammation. We have shown that secreted frizzled-related protein-1 (sFRP-1) overexpression reduced postinfarction scar size, and we noticed a decrease in neutrophil infiltration in the ischemic tissue. We aimed to further elucidate the role of sFRP-1 in the postischemic inflammatory process. METHODS AND RESULTS: We found that in vitro, sFRP-1 was able to block leukocyte activation and cytokine production. We transplanted bone marrow cells (BMCs) from transgenic mice overexpressing sFRP-1 into wild-type recipient mice and compared myocardial healing with that of mice transplanted with wild-type BMCs. These results were compared with those obtained in transgenic mice overexpressing sFRP-1 specifically in endothelial cells or in cardiomyocytes to better understand the spatiotemporal mechanism of the sFRP-1 effect. Our findings indicate that when overexpressed in the BMCs, but not in endothelial cells or cardiomyocytes, sFRP-1 was able to reduce neutrophil infiltration after ischemia, by switching the balance of pro- and antiinflammatory cytokine expression, leading to a reduction in scar formation and better cardiac hemodynamic parameters. CONCLUSION: sFRP-1 impaired the loop of cytokine amplification and decreased neutrophil activation and recruitment into the scar, without altering the neutrophil properties. These data support the notion that sFRP-1 may be a novel antiinflammatory factor protecting the heart from damage after myocardial infarction.

Optimization of Impella 5.0 implantation using mini-sternotomy approach in postmyocardial infarction cardiogenic shock.

The Impella Recover LP 5.0® (Abiomed, Inc. Danvers, MA, USA) is an aortic transvalvular microaxial pump designed to unload the left ventricle and to ensure a systemic flow in severe left ventricular dysfunction. Surgical implantation using femoral or right subclavian approach may be difficult in certain circumstances, such as encountered in peripheral vascular disease, patients with small vessels or during substantial use of vasoactive drugs responsible for vasospasm. We propose a simple and effective technique for implantation of the Impella 5.0 LVAD by means of a mini-sternotomy in patients with postinfarction refractory cardiogenic shock.

Optical coherence tomography to guide percutaneous coronary intervention of the left main coronary artery: the LEMON study.

BACKGROUND: Intravascular ultrasound (IVUS)-guided PCI improves the prognosis of left main stem (LMS) PCI and is currently recommended by international guidelines. Although OCT resolution is greater than that of IVUS, this tool is not yet recommended in LMS angioplasty due to the absence of data. AIMS: This pilot study aimed to analyse the feasibility, safety and impact of OCT-guided LMS PCI. METHODS: This prospective, multicentre trial investigated whether patients might benefit from OCT-guided PCI for mid/distal LMS according to a pre-specified protocol. The primary endpoint was procedural success defined as follows: residual angiographic stenosis <50% + TIMI 3 flow in all branches + adequate OCT stent expansion (LEMON criteria). RESULTS: Seventy patients were included in the final analysis (median age: 72 [64-81] years, 73% male). The OCT pre-specified protocol was applied in all patients. The primary endpoint was achieved in 86% of subjects. Adequate stent expansion was observed in 86%, significant edge dissection in 30% and residual significant strut malapposition in 24% of the cases. OCT guidance modified the operators' strategy in 26% of the patients. The rate of one-year survival free from major adverse clinical events was 98.6% (97.2-100). CONCLUSIONS: This pilot study is the first to report the feasibility and performance of OCT-guided LMS PCI according to a pre-specified protocol.

Lethal Aorto-Right Ventricular Defect After Transcatheter Aortic Valve Implantation in a Patient With Radiation-Induced Porcelain Aorta: Notes of Caution.

A 47-year-old man with severe radiation-induced aortic stenosis was rejected for cardiac surgery because of porcelain aorta. We successfully implanted an Edwards SAPIEN valve (Edwards Lifesciences, Irvine, CA), but the patient was readmitted 3 weeks later for heart failure with a continuous murmur on auscultation. Echocardiography showed a small defect between the aorta and the infundibulum of the right ventricle, which was also confirmed with aortography and computed tomography. Medical therapy was optimized; however, he died unexpectedly a few weeks later. We concluded that irradiated tissues are particularly fragile and require specific attention during transcatheter aortic valve implantation. Furthermore, this case suggests that a more aggressive closure should have been applied.

Irrigated Needle Ablation Creates Larger and More Transmural Ventricular Lesions Compared With Standard Unipolar Ablation in an Ovine Model.

BACKGROUND: Ventricular tachycardia recurrence can occur after ventricular tachycardia ablation because of incomplete and nontransmural ventricular lesion formation. We sought to compare the lesions made by a novel irrigated needle catheter to conventional radiofrequency lesions. METHODS AND RESULTS: Thirteen female sheep (4.6±0.7 years, 54±8 kg) were studied. In 7 sheep, 60-s radiofrequency applications were performed using an irrigated needle catheter. In 6 sheep, conventional lesions were made using a 4-mm irrigated catheter. 1.5T in vivo and high-density magnetic resonance imaging (9.4T) were performed on explanted hearts from animals receiving needle radiofrequency. Conventional lesion volume was calculated as (1/6)×π×(A×B(2)+C×D(2)/2). Needle lesion volume was measured as Σ(π×r(2))/2 with a slice thickness of 1 mm. The dimensions of all lesions were also measured on gross pathology. Additional histological analysis of the needle lesions was performed. One hundred twenty endocardial left ventricular ablation lesions (conventional, n=60; needle, n=60) were created. At necropsy, more lesions were found using needle versus conventional radiofrequency (90% versus 75%; P<0.05). Comparing needle versus conventional radiofrequency: lesion volume was larger (1030±362 versus 488±384 mm(3); P<0.001), lesion depth was increased (9.9±2.7 versus 5±2.4 mm; P<0.001), and more transmural lesions were created (62.5% versus 17%; P<0.01). Pericardial contrast injection was observed in 4 apical attempts using needle radiofrequency, however, with no adverse effects. Steam pops occurred in 3 attempts using conventional radiofrequency. CONCLUSIONS: Irrigated needle ablation is associated with more frequent, larger, deeper, and more often transmural lesions compared with conventional irrigated ablation. This technology might be of value to treat intramural or epicardial ventricular tachycardia substrates resistant to conventional ablation.