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Few studies are available on magnetic navigation system (MNS) for coronary artery disease. The present investigation was conducted to evaluate the feasibility and safety of guidewire navigation with a MNS in diseased coronary arteries.Between February 2004 and August 2005, a total of 59 patients (68 target vessels) underwent magnetic-assisted guidewire navigation in coronary arteries with stenoses amenable to coronary intervention. Patients were excluded if any of the following conditions applied: pacemakers or cardioverter defibrillator implanted; acute myocardial infarction; thrombotic lesions; chronic total occlusion; claustrophobia; and renal dysfunction with serum creatinine2.5mg/dl. Procedural success was defined as successful guidewire passage distal to the stenoses with no procedural events, defined as either perforation or dissection. Magnetic guidewires successfully crossed 60 (88%) lesions. Only 1 patient experienced a minor dissection of vessel wall in a circumflex lesion and was treated with a coronary stent. There was no other complication related to the magnetic guidewire. Nineteen (27.3%) coronary interventions were performed with magnetic guidewires. In 4 complex lesions (a lesion located in saphenous vein graft with proximal severe tortuosity; 3 approaches to stent-jailed side branch), where conventional wires failed to cross the culprit lesions, magnetic navigation achieved successful guidewire passage.Guidewire navigation using a MNS was feasible and safe. In the four complex cases, magnetic navigation enabled crossing of lesions in which conventional attempts failed. Further studies are needed to better evaluate the efficacy of MNS compared with conventional manual navigation.

Aims To describe the contemporary approach of chronic total occlusion (CTO) treatment of patients at the Thoraxcenter, Rotterdam, The Netherlands. Additionally, to make a critical appraisal of the performance of state-of-the-art CTO dedicated guidewires and devices in a prospective registry of patients. Methods and results During 20 months, a total of 160 consecutive patients (165 CTOs) were enrolled. The mean age was 61.5+/-11.1 years and 83.6% were male. In 91.5% of the patients this was the first attempt to open the CTO and 93.8% were de novo. The overall success rate was 60.6%. A median of 1 guiding catheter was used per case (Range: 1 to 9) and a median of 4 guidewires (Range: 1 to 11; 13 different types). 74.5% patients required more than one guidewire/device for the treatment of the CTO. The guidewires that most frequently crossed the CTO were the following: PT Graphix intermediate 33.0%, Miracle 3 g 27.4% and Crosswire NT 25.5%. The only device tested as a first option for the treatment of the CTOs was the CROSSER. Overall, the CROSSER system was used in 23 (13.9%) patients with a success rate of 60.9%. The Point 9(R) X-80 Laser catheter was used in 10 (6.1%) patients with a success rate of 60%. Another 3 patients were treated with the Point 7(R) laser catheter. Both were used either to facilitate the crossing of the balloon, or to treat primarily in-stent restenosis occlusions. The SafeCross(R) System was used in 15 (9.1%) patients and the success rate in these patients was 46.7%. The most common strategy used in this registry was the use of an over-the-wire balloon in 81.5% of the cases. The parallel wire technique was used in 27.3% of the cases and in 12.7% was converted into a "see-saw" technique. When a large false lumen was created, re-entry into the true lumen was attempted in 21.2% of the cases, by means of IVUS guided approach and/or the use of stiffer guidewires, such as a Confianza guidewire. Retrograde recanalisation was attempted in 10 cases (6.1%), in three cases a graft was used; the remaining cases were treated either via collaterals or the septal branches. Conclusions The treatment of CTOs requires the use of a high number of guiding catheters and guidewires, as well as the use of sophisticated devices. The procedure must be carefully planned in advance as far as possible, as well as considering a prompt change in approach during the performance of the procedure to prevent complications derived from long procedures by using specific techniques such as parallel wire, see-saw, anchoring balloon, etc.

Virtual histology (VH) uses intravascular ultrasound (IVUS) radiofrequency spectral analysis to locally identify the morphology and composition of atherosclerotic plaques. We sought to explore in vivo the relation between IVUS-derived thin cap fibro-atheroma (IDTCFA) and remodelling index in patients with acute coronary syndromes using IVUS-VH.Twenty-one patients (63 vessels) were enrolled. When compared to cross sectional areas (CSAs) without necrotic core in contact with the lumen (NCCL), CSAs with NCCL had a larger plaque burden 42.8+/-11.5% vs. 32.8+/-11.5%, p0.001; higher overall necrotic core content [13.8+/-10.7% vs. 2.3+/-7.9% (p0.001)] and calcified tissue [4.7+/-6.5 vs. 0.66+/-2.1% (p0.001)]. On average there were 2 IVUS-derived thin cap fibro-atheroma (IDTCFA) per patient. Nearly half of the IDTCFAs had positive remodelling.CSAs with NCCL had worse morphological profiles than those with no NCCL. The simultaneous and more detailed assessment of IDTCFA and remodelling index identifies a reduced number of allegedly high-risk plaques. The findings of this study may have important clinical implications, since they shed light into a possible method of identiying potentially high-risk plaques suitable for pharmacological and/or local treatment.

To validate a novel 3-D QCA system (CardiOp-B) and compare the 2-D (CAAS II) and 3-D systems in in vivo experimental settings. The phantom lumen diameters were also assessed ex vivo by optical coherence tomography (OCT). The accuracy of the 3-D system has not been appreciated.Precision-drilled plexiglass phantoms with 5 different luminal diameters that ranged from 0.5 to 1.9 mm were percutaneously inserted into the coronary arteries in four Yorkshire pigs. Twenty-two angiographic images of the artificial phantom coronary artery stenoses in the pigs were acquired as an in vivo validation test. Quantitative assessments of the minimum and mean lumen diameters were performed using both QCA systems. Ex vivo images of the same phantom lumens were also taken and measured using OCT.Both of the 2-D and 3-D QCA systems significantly underestimated the actual phantom lumen diameters with the exception of measurements taken in the lateral projection at isocenter using the 2-D QCA systems. This underestimation was more significant in the 3-D system (accuracy of 0.19 at isocenter; 0.23 by catheter calibration). There was good agreement between the two QCA systems. OCT measured the ex vivo lumen diameter of plexiglass phantoms precisely.The accuracy of the luminal diameter measurements with the current 2-D system was still superior to the 3-D system. Further development and validation studies under various conditions are warranted. The excellent results achieved by OCT with the ex vivo images indicate its potential as an intravascular quantitative imaging tool for future clinical practice.

AIMS This study was performed to assess the differences in culprit plaque composition between patients with and without pre-infarction angina (PA) by using spectral analysis of intravascular ultrasound (IVUS) radiofrequency (RF) data. METHODS AND RESULTS Of 57 patients consecutively admitted to our institution with acute myocardial infarction, pre-intervention IVUS RF data of culprit plaques were obtained and analysed in 35 patients after percutaneous aspiration thrombectomy. Among the 35 patients, 21 patients had PA. Culprit plaques of patients without PA consisted of a higher percentage of the necrotic core component than those with PA (minimum lumen area [MLA]) site, 21.2+/-8.9% versus 9.9+/-9.8%, p=0.0015; entire culprit lesion, 18.9+/-6.3% versus 12.0+/-9.6%, p=0.023). In contrast, culprit plaques of patients with PA contained a higher percentage of the fibrofatty component than those without PA (MLA site, 21.0+/-12.0% versus 11.5+/-7.6%, p=0.013; entire culprit lesion, 16.8+/-7.9% versus 12.1+/-5.5%, p=0.062). There was no significant difference in quantitative parameters between the patients with and without PA. CONCLUSIONS Culprit plaques of patients with PA were different from those without PA. Plaque composition may play an important role in the occurrence of PA.