N.M. Van Mieghem

Occurrence, fate and consequences of ventricular conduction abnormalities after transcatheter aortic valve implantation.

AIMS Transcatheter aortic valve implantation (TAVI) is frequently complicated by new left bundle branch block (LBBB). We investigated the development and persistence of LBBB during follow-up and its clinical consequences. METHODS AND RESULTS ECGs at baseline, within 24 hours, before discharge and at 12 months after TAVI were assessed in 476 patients without pre-existing LBBB and/or pacemaker before or after TAVI. TAVI-induced new LBBB was categorised based on the timing of the occurrence (within 24 hours [acute], after 24 hours but before discharge [subacute], and after discharge [late]), in addition to persistence (transient or persistent). A total of 175 patients (36.8%) developed new LBBB of which 85.7% occurred within 24 hours after TAVI, 12.0% before and 2.3% after hospital discharge, and was persistent in 111 patients (63.4%). Implantation of the Medtronic CoreValve System (MCS) more frequently led to new LBBB than the balloon-expandable Edwards SAPIEN valve (ES) (53.8% versus 21.7%) with less recovery during follow-up (39.0% versus 9.5%). Late new LBBB was only seen in four patients (0.8%). During a median follow-up of 915 (578-1,234) days, persistent LBBB was associated with a significant increase in mortality as compared to no LBBB and temporary LBBB combined (hazard ratio 1.49, 95% confidence interval, 1.10-2.03; p=0.01). CONCLUSIONS TAVI-induced new LBBB occurs in almost 40% of patients, almost all before hospital discharge. It occurs three times more frequently after MCS than after ES valve implantation and has a twofold lower tendency to resolve during follow-up. Persistent LBBB is associated with a higher mortality.

Are BVS suitable for ACS patients? Support from a large single center real live registry

OBJECTIVES To investigate one-year outcomes after implantation of a bioresorbable vascular scaffold (BVS) in patients presenting with acute coronary syndrome (ACS) compared to stable angina patients. BACKGROUND Robust data on the outcome of BVS in the setting of ACS is still scarce. METHODS Two investigator initiated, single-center, single-arm BVS registries have been pooled for the purpose of this study, namely the BVS Expand and BVS STEMI registries. RESULTS From September 2012-October 2014, 351 patients with a total of 428 lesions were enrolled. 255 (72.6%) were ACS patients and 99 (27.4%) presented with stable angina/silent ischemia. Mean number of scaffold/patient was 1.55±0.91 in ACS group versus 1.91±1.11 in non-ACS group (P=0.11). Pre- and post-dilatation were performed less frequent in ACS patients, 75.7% and 41.3% versus 89.0% and 62.0% respectively (P=0.05 and P=0.001). Interestingly, post-procedural acute lumen gain and percentage diameter stenosis were superior in ACS patients, 1.62±0.65mm (versus 1.22±0.49mm, P<0.001) and 15.51±8.47% (versus 18.46±9.54%, P=0.04). Major adverse cardiac events (MACE) rate at 12months was 5.5% in the ACS group (versus 5.3% in stable group, P=0.90). One-year definite scaffold thrombosis rate was comparable: 2.0% for ACS population versus 2.1% for stable population (P=0.94), however, early scaffold thromboses occurred only in ACS patients. CONCLUSIONS One-year clinical outcomes in ACS patients treated with BVS were similar to non-ACS patients. Acute angiographic outcomes were better in ACS than in non-ACS, yet the early thrombotic events require attention and further research.

Design and principle of operation of the HeartMate PHP (percutaneous heart pump)

The HeartMate PHP (percutaneous heart pump) is a second-generation transcatheter axial flow circulatory support system. The collapsible catheter pump is inserted through a 14 Fr sheath, deployed across the aortic valve expanding to 24 Fr and able to deliver up to 5 L/min blood flow at minimum haemolytic risk. As such, this device may be a valuable adjunct to percutaneous coronary intervention (PCI) of challenging lesions in high-risk patients or treatment of cardiogenic shock. This technical report discusses: (i) the HeartMate PHP concept, (ii) the implantation technique, (iii) the haemodynamic performance in an in vitro cardiovascular flow testing set-up, and (iv) preliminary clinical experience. An update on the device, produced by St. Jude Medical/Abbott Laboratories, can be found in the Appendix.

Everolimus-eluting bioresorbable vascular scaffolds for treatment of complex chronic total occlusions.

AIMS Bioresorbable vascular scaffolds (BVS) represent a novel therapeutic option for the treatment of coronary artery diseases. The objective of this study was to evaluate the feasibility of BVS implantation in complex chronic total occlusions (CTO). METHODS AND RESULTS The present report is a multicentre registry evaluating results after BVS deployment in challenging CTO lesions, defined as J-CTO score ≥2 (difficult or very difficult). A total of 105 patients were included in the present analysis. The mean J-CTO score was 2.61 (difficult 52.4%, very difficult 47.6%). Device success and procedural success rates were 98.1% and 97.1%, respectively. The retrograde approach was used in 25.7% of cases. After wire crossing, predilatation was performed in all cases with a mean predilatation balloon diameter of 2.73±0.43 mm. The mean scaffold length was 59.75±25.85 mm, with post-dilatation performed in 89.5% of the cases and a mean post-dilatation balloon diameter of 3.35±0.44 mm. Post-PCI minimal lumen diameter was 2.50±0.51 mm and percentage diameter stenosis 14.53±10.31%. At six-month follow-up, a total of three events were reported: one periprocedural myocardial infarction, one late scaffold thrombosis and one additional target lesion revascularisation. CONCLUSIONS The present report suggests the feasibility of BVS implantation in complex CTO lesions, given adequate lesion preparation and post-dilatation, with good acute angiographic results and midterm clinical outcomes.

Electrocardiographic imaging-based recognition of possible induced bundle branch blocks during transcatheter aortic valve implantations

AIMS Conventional electrocardiogram (ECG)-based diagnosis of left bundle branch block (LBBB) in patients with left ventricular hypertrophy (LVH) is ambiguous. Left ventricular hypertrophy is often seen in patients with severe aortic stenosis in which a transcatheter aortic valve implantation (TAVI) frequently results in a LBBB due to the mechanical interaction of the artificial valve and the conduction system. In this feasibility study, we propose and evaluate the sensitivity of a new electrocardiographic imaging tool; the cardiac isochrone positioning system (CIPS), visualizing the cardiac activation to detect interventricular conduction patterns pre- and post-TAVI. METHODS AND RESULTS The CIPS translates standard 12-lead ECG into ventricular isochrones, representing the activation sequence. It requires a patient-specific model integrating heart, lungs, and other thoracic structures derived from multi-slice computed tomography. The fastest route-based algorithm was used to estimate the activation isochrones and the results were compared with standard ECG analysis. In 10 patients the CIPS was used to analyse 20 ECGs, 10 pre- and 10 post-TAVI. In 11 cases the CIPS results were in agreement with the ECG-based diagnosis. In two cases there was partial agreement and in seven cases there was disagreement. In four of these cases, the clinical history of the patients favoured interpretation as assessed by CIPS, for the remaining three, it is unknown which method correctly classified the activation. CONCLUSION This feasibility study applying the CIPS shows promising results to classify conduction disorders originating from the left anterior or posterior ventricular wall, or the septum. The visualization of the activation isochrones as well as ventricular model-derived features might support TAVI procedures and the therapy selection afterwards.

Microsphere embolisation as an alternative for alcohol in percutaneous transluminal septal myocardial ablation.

BackgroundPercutaneous transluminal septal myocardial ablation using microsphere embolisation is a new interventional technique to treat patients with hypertrophic obstructive cardiomyopathy.Methods and resultsIn two patients, considered at high risk for myectomy, targeted septal perforators were occluded with microsphere embolisation instead of alcohol ablation to reduce left ventricular outflow gradient. In both cases the left ventricular outflow tract gradient was immediately reduced. No adverse events occurred.ConclusionThis is the first clinical experience with Embozene® Microspheres in the Netherlands as an alternative for alcohol septal ablation. In both cases it resulted in immediate improvement in the haemodynamics, without any adverse events.

Pulsatile iVAC 2L circulatory support in high-risk percutaneous coronary intervention

AIMS Our aim was to test the feasibility and safety of the transfemoral PulseCath iVAC 2L (PulseCath, Amsterdam, The Netherlands). METHODS AND RESULTS Circulatory support devices are helpful adjunctive tools to perform high-risk percutaneous coronary interventions (PCI). The PulseCath iVAC 2L is a novel pulsatile circulatory support system capable of generating output of up to 2 L/min. We performed a prospective clinical pilot study enrolling 14 patients who underwent high-risk PCI under protection with the iVAC 2L. Median age was 74 (56-84) years. Implantation of the iVAC 2L was successful in 13 (93%) patients. Median device flow was 1.4 (1.1-2.0) L/min. Total support time was 67 (23-149) minutes. The use of iVAC 2L support was associated with a better mean arterial pressure and cardiac output during the procedure. Angiographic success was 100%. There was one major procedural complication related to the 19 Fr access sheath. There were no major adverse events at three-month follow-up. CONCLUSIONS Circulatory support with the iVAC 2L device is feasible and safe in patients undergoing high-risk PCI.

The first human experience of a contact force sensing catheter for epicardial ablation of ventricular tachycardia

Contact force (CF) is one of the major determinants for sufficient lesion formation. CF-guided procedures are associated with enhanced lesion formation and procedural success. We report our initial experience in epicardial ventricular tachycardia (VT) ablation with a force-sensing catheter using a new approach with an angioplasty balloon. Two patients with arrhythmogenic right ventricular cardiomyopathy who underwent prior unsuccessful endocardial ablation were treated with epicardial VT ablation. CF data were used to titrate force, power and ablation time.

Non-invasive assessment of the collateral circulation in the hand: validation of the Nexfin system and relation to clinical outcome after transradial catheterisation

AIMS This study aims primarily to assess the extent of the collateral circulation of the hand in a combined population of healthy individuals and patients who underwent transradial catheterisation, using both the Nexfin system and laser Doppler perfusion imaging. METHODS AND RESULTS In total, 85 adults were included in the study (18 healthy volunteers; 67 patients who underwent transradial catheterisation). The perfusion of the thumb was assessed prior to and during complete radial artery compression using laser Doppler perfusion imaging (LDPI) and the Nexfin system. The palmar collateral flow index (PCFI) was compared between both devices and PCFINEXFIN was related to hand angiography and the upper limb function, using the QuickDASH questionnaire. Mean PCFILDPI was 0.77±0.15 and mean PCFINEXFIN was 0.88±0.08. Both were significantly related (Pearson correlation=0.49, 95% CI: 0.31-0.64, p<0.001, agreement -0.11±0.13). PCFINEXFIN correlated with the maximal diameter of the superficial palmar arch (R=0.49, p=0.04) and total minimal arch diameter (R=0.51, p<0.02). High PCFINEXFIN, measured at baseline, was correlated with a lower QuickDASH score for pain, activity and total at one month post transradial catheterisation (p=0.02, p<0.01, p<0.01), but not with discomfort or disability. CONCLUSIONS The Nexfin monitoring system is comparable with laser Doppler perfusion imaging in the quantification of the collateral perfusion in the hand. In patients, the Nexfin-derived collateral flow index measured at baseline is associated with clinical outcome at 30 days post transradial catheterisation.

Serial quantitative magnetic resonance angiography follow-up of renal artery dimensions following treatment by four different renal denervation systems

AIMS Renal sympathetic denervation (RDN) is being studied as a therapeutic option for patients with therapy-resistant hypertension. It remains unclear if the procedure affects the renal arteries in such a way that luminal narrowing might occur at the mid to longer term. The aim of the present study was to assess renal artery integrity accurately at the medium to long term using recently validated quantitative magnetic resonance angiography software in patients treated with four different RDN devices. METHODS AND RESULTS In a prospective cohort of 27 patients referred for RDN, quantitative magnetic resonance angiography (MRA) was used to assess 52 vessels at baseline, six, and 12 months post treatment with one of four different devices. No renal artery stenosis was seen at six or 12 months. The average mean lumen area was 26.6±7.3 mm2 at baseline versus 25.0±7.1 mm² and 25.0±6.1 mm² at six and 12 months, respectively, resulting in a late loss of 1.6 mm2 at six months and 1.9 mm2 at 12 months. No differences were observed in the arterial response to RDN with the four different systems used. There was no correlation between post-procedural dissections, oedema or thrombi as detected with invasive imaging, and luminal narrowing at follow-up. CONCLUSIONS Quantitative MRA of patients treated with RDN revealed no significant change in renal artery dimensions up to 12-month follow-up. The lack of a change in renal artery luminal dimensions was irrespective of the arterial response to the individual devices used.