Florian Blachutzik

3D printing for sizing left atrial appendage closure device: head-to-head comparison with computed tomography and transoesophageal echocardiography

AIMS Device sizing for LAA closure using transoesophageal echocardiography (TEE) can be challenging due to complex LAA anatomy. We investigated whether the use of 3D-printed left atrial appendage (LAA) models based on preprocedural computed tomography (CT) permits accurate device sizing. METHODS AND RESULTS Twenty-two (22) patients (73±8 years, 55% male) with atrial fibrillation requiring anticoagulation at high bleeding risk underwent LAA closure (WATCHMAN device). Preprocedurally, LAA was sized by TEE and third-generation dual-source CT. Based on CT, 3D printing models of LAA anatomy were created for simulation of device implantation. Device compression was assessed in a CT scan of the 3D model with the implanted device. Implantation was successful in all patients. Mean LAA ostium diameter based on TEE was 22±4 mm and based on CT 25±3 mm (p=0.014). Predicted device size based on simulated implantation in the 3D model was equal to the device finally implanted in 21/22 patients (95%). TEE would have undersized the device in 10/22 patients (45%). Device compression determined in the 3D-CT model corresponded closely with compression upon implantation (16±3% vs. 18±5%, r=0.622, p=0.003). CONCLUSIONS Patient-specific CT-based 3D printing models may assist device selection and prediction of device compression in the context of interventional LAA closure.

A new novolimus-eluting bioresorbable coronary scaffold: Present status and future clinical perspectives.

The DESolve® scaffold (Elixir Medical Corporation, Sunnyvale, California, USA) is manufactured from a poly-l-lactide based polymer and elutes an anti-proliferative, anti-inflammatory drug, Novolimus from a poly-l-lactide based topcoat mixture. The strut thickness is 150μm and the scaffold has platinum-iridium radiopaque markers at both ends. Radial support is available during the early time period to prevent recoil. The scaffold biodegrades within 1year (>90% reduction in molecular weight) and then completely bioresorbs within 2years. The DESolve® scaffold permits a wide range of expansion with a consequently reduced risk for strut fracture. Lumen and scaffold enlargement is observed within 3-6months in both preclinical and clinical studies potentially allowing for the scaffolded region to respond to vasoactive stimuli. The device has a unique property of self-correction observed in bench top studies, which in clinical practice has the potential to eliminate minor malapposition following deployment.

A new novolimus-eluting bioresorbable scaffold for large coronary arteries: an OCT study of acute mechanical performance

AIMS To evaluate the acute performance of a novolimus-eluting bioresorbable scaffold (BRS) with a nominal diameter of 4.0mm (DESolve® XL) using optical coherence tomography (OCT) in terms of appropriate scaffold deployment. METHODS AND RESULTS Ten patients (55.6% male, mean age 60.0 y) undergoing OCT-guided scaffold implantation were enrolled consecutively in this retrospective study. Using data from the final pullback, the following indexes were calculated: mean and minimum area, residual area stenosis, incomplete strut apposition, tissue prolapse, eccentricity and symmetry indexes, strut fracture, and edge dissection. The clinical indication for the procedure was acute coronary syndrome in roughly half (55.5%) of the cases. All three main vessels were affected equally. The maximum post-dilatation balloon inflation pressure was 14.7±4.2atm. OCT analysis showed a lumen area of 11.4±1.9mm(2) and a scaffold area of 11.5±2.1mm(2). Mean residual area stenosis was 28.6%. No strut fractures or edge dissections were apparent. The mean eccentricity index was 0.65±0.16 and the mean symmetry index 0.39±0.25. CONCLUSION The size of large vessels does not adversely influence acute mechanical performance as assessed by the eccentricity and symmetry indexes. No adverse cardiac event occurred during the hospital stay or the 30-day follow-up. It is feasible to treat large vessels with the DESolve® XL BRS.

Predictors of Technical Failure in Transradial Coronary Angiography and Intervention

Transradial access for coronary angiography and intervention is preferred over the femoral approach but can be technically challenging. Identification of predictors of transradial access failure is important, especially in the context of acute coronary syndromes. We therefore retrospectively analyzed 13,095 consecutive patients (66 ± 12 years, 64% male) in whom transradial access was attempted for coronary angiography or intervention to identify predictors of transradial access failure. Angiograms and patient files were systematically reviewed to analyze patient characteristics associated with failure. Transradial access failure rate was 6.8% (909 of 13,095). Patients with transradial access failure were more frequently female (9.5% vs 5.5%; p <0.001), significantly older (68 ± 12 vs 66 ± 12 years, p <0.001), and had a smaller body surface area (1.89 ± 0.21 vs 1.94 ± 0.2 m2; p <0.001). Transradial failure was not significantly more frequent in ST-elevation myocardial infarction versus other patients (8.1% vs 6.9%, p = 0.195). After multivariable adjustment, only female sex (odds ratio [OR] 1.44, p <0.001), higher patient age (OR 1.01/year, p = 0.002), and lower height (OR 0.98/cm, p = 0.004) independently predicted transradial access failure. In conclusion, female sex, higher age, and smaller height independently predict transradial access failure in coronary angiography and intervention. Failure rate in ST-elevation myocardial infarction is not significantly increased.

Comparison of invasively measured FFR with FFR derived from coronary CT angiography for detection of lesion-specific ischemia: Results from a PC-based prototype algorithm

BACKGROUND We evaluated the diagnostic accuracy of a novel prototype for on-site determination of CT-based FFR (cFFR) on a standard personal computer (PC) compared to invasively measured FFR in patients with suspected coronary artery disease. METHODS A total of 91 vessels in 71 patients (mean age 65 ± 9 years) in whom coronary CT angiography had been performed due to suspicion of coronary artery disease, and who subsequently underwent invasive coronary angiography with FFR measurement were analyzed. For both cFFR and FFR, a threshold of ≤0.80 was used to indicate a hemodynamically relevant stenosis. The mean time needed to calculate cFFR was 12.4 ± 3.4 min. A very close correlation between cFFR and FFR could be shown (r = 0.85; p < 0.0001) with Bland-Altman analysis showing moderate agreement between FFR and cFFR with mild systematic overestimation of FFR values in CT (mean difference 0.0049, 95% limits of agreement ±2SD -0.007 to 0.008). Compared to FFR, the sensitivity of cFFR to detect hemodynamically significant lesions was 91% (19/21, 95% CI: 70%-99%), specificity was 96% (67/70, 95% CI: 88%-99%), positive predictive value 86% (95% CI: 65%-97%) and negative predictive value was 97% (95% CI: 90%-100%) with an accuracy of 93%. CONCLUSION cFFR obtained using an on-site algorithm implemented on a standard PC shows high diagnostic accuracy to detect lesions causing ischemia as compared to FFR. Importantly, the time needed for analysis is short which may be useful for improving clinical workflow.

Effect of non-compliant balloon postdilatation on magnesium-based bioresorbable vascular scaffolds

Optimal implantation results of bioresorbable scaffolds (BRS) are typically assumed to require postdilatation with non‐compliant (NC) balloons to achieve full scaffold apposition and minimize event rates. We systematically evaluated the mechanical effect of NC balloon postdilatation on magnesium‐based BRS (Magmaris®, Biotronik AG, Bülach, Switzerland) in vivo.

Percutaneous coronary intervention of unprotected left main stenoses – procedural data and outcome depending on SYNTAX I Score

BACKGROUND We hypothesized that SYNTAX I score is a predictor for procedure complexity in left main PCI. Procedure complexity, duration and contrast load may contribute to adverse outcome of complex left main percutaneous coronary intervention (PCI). METHODS In 105 consecutive patients who underwent PCI of unprotected left main coronary artery stenoses between 2014 and 2016, clinical parameters as well as PCI characteristics and follow-up data were analyzed. RESULTS The mean SYNTAX I score was 29 ± 12, with 66 patients having a SYNTAX I score ≤ 32 and 39 patients a SYNTAX I score > 32. In patients with high SYNTAX I score vs. low-to-intermediate SYNTAX I score, single stent techniques were performed significantly less frequently (18% vs. 68%; p < 0.001), while Crush (44% vs. 5%; p < 0.001) and Culotte techniques (20% vs. 5%; p = 0.003) were performed significantly more frequently. Procedural success was achieved in all 105 cases without periprocedural mortality. During follow up, repeat PCI was necessary significantly more frequently in patients with high compared to patients with low-to-intermediate SYNTAX I score (34% vs.13%; p = 0.003). Nevertheless, overall mortality did not differ between patients with high vs. low-to-intermediate SYNTAX I score (20% vs. 18%). CONCLUSIONS PCI strategies for the treatment of left main coronary artery stenoses get significantly more complex with increasing SYNTAX I scores. While this translates into a significantly longer procedure duration and contrast load, short-term outcome seems not to be influenced by the SYNTAX I score.

Major coronary evaginations following implantation of bioresorbable vascular scaffolds – Clinical and OCT characteristics

BACKGROUND Coronary evaginations can occur after implantation of bioresorbable vascular scaffolds (BRS) and may be associated with scaffold thrombosis. Aim of this study was to clarify the clinical manifestation, extent and time course of coronary artery remodeling in vessel segments that develop angiographically detectable evaginations following BRS implantation through optical coherence tomography (OCT) analysis. METHODS In 8 patients, 10 BRS (Absorb, Abbott Vascular, Santa Clara, CA, USA) which displayed coronary evaginations in clinically driven late invasive coronary angiograms were identified and findings were compared to 10 BRS in 8 patients without coronary evaginations. Vessel and device geometry was analyzed in serial OCT cross-sections at a spacing of 200 μm. Measured BRS dimensions were normalized to the reference vessel size at implantation. RESULTS In OCT, major evaginations on average affected 24 ± 19% of the scaffold length. Scaffolds with major evaginations had a significantly larger lumen area than scaffolds without evaginations (mean normalized lumen area 1.19 ± 0.58 vs. 0.77 ± 0.38; p < 0.001), and also displayed a significantly larger scaffold area (mean normalized scaffold area: 1.36 ± 0.6 vs. 1.13 ± 0.43; p < 0.001), and scaffold diameter (mean normalized scaffold diameter: 1.17 ± 0.33 vs.1.04 ± 0.19; p < 0.001). Lumen area (r = 0.47; p < 0.001), scaffold area (r = 0.52; p < 0.001), and scaffold diameter (r = 0.74; p < 0.001) in the evagination group were positively correlated to the time since scaffold implantation. CONCLUSION Coronary evaginations following BRS implantation are associated with an increased scaffold area, indicating that the scaffold follows the outward remodeling of the artery. The process affects the entire scaffold length and seems to be continuously progressing following implantation.