Faculty Bibliography

OBJECTIVES: This study sought to evaluate the safety and feasibility of a magnetic medical positioning system (MPS) to determine the three-dimensional (3D) position and orientation of intracoronary wires and catheters and to guide angiography and percutaneous coronary intervention (PCI). BACKGROUND: Coronary angiography relies on fluoroscopy for catheter navigation and often fails to accurately portray vessel tortuosity, overlap, and length because of complex anatomy and foreshortening of curved coronary segments. METHODS: Forty adult participants underwent coronary angiography and/or PCI with MPS guidance. Two interventional cardiologists independently scored (1-5) the accuracy of MPS catheter tracking projected on live fluoroscopy, recorded cine loops, and 3D vessel reconstructions. Measurements from MPS reconstructions were compared to conventional two-dimensional (2D) quantitative coronary angiography (QCA) measurements. Device procedural success was defined as the ability of the MPS-enabled catheter to reach the target vessel, perform the intended operations, and be retrieved without major adverse cardiac events. RESULTS: Diagnostic coronary angiography was performed in 19 (47.5%) and PCI in 21 patients (52.5%). MPS procedural success was achieved in 36 (90%) of the cases. MPS accuracy was highest with the MPS superimposed on live fluoroscopy (4.9 +/- 0.2/5) and the 3D vessel reconstruction (4.7 +/- 0.5/5). MPS length measurements were more accurate than conventional QCA. CONCLUSIONS: This study demonstrates the feasibility and safety of magnetic catheter tracking with 3D positional data during diagnostic angiography and PCI. Catheter position was accurately projected on real-time fluoroscopy, recorded cine loops, and 3D reconstructions. An MPS may serve as a platform for device navigation and positioning during PCI.

Studies have suggested that operator proficiency has a substantial effect on complication rates and procedural outcomes. Endovascular simulators have been used for training and have been proposed as an alternative to the conventional assessment of skills. The present study sought to validate simulation as an objective method for proficiency evaluation in carotid artery stenting. Interventional cardiologists classified as novice, intermediate, or experienced practitioners performed 3 simulated, interactive carotid stenting cases on an AngioMentor endovascular simulator. An automated algorithm scored the participants according to the technical performance, medical management, and angiographic results. A total of 33 interventional cardiologists (8 novices, 15 intermediates, and 10 experts) completed 82 simulated procedures. The composite scores for the case simulations varied significantly by operator experience, with better scores for the more experienced groups (p <0.0001). The metrics that discriminated between operator experience groups included fluoroscopy time, crossing the carotid lesion with devices other than a 0.014-in. wire before filter deployment, and incomplete coverage of the lesion by the stent. In conclusion, the results of the present study validate that a simulator with an automated scoring system is able to discriminate between levels of operator proficiency for carotid artery stenting. Simulator-based performance assessment could have a role in initial and ongoing proficiency evaluations and credentialing of interventional operators of high-risk endovascular procedures.

Complex catheter-based interventions and rising case volumes confer occupational risks to interventional cardiologists. Despite advances in technology, modern interventional procedures are performed in a manner remarkably similar to the techniques pioneered decades ago. Percutaneous interventions are associated with operator orthopedic injuries, exposures to blood borne pathogens, and the effects of chronic radiation exposure from fluoroscopy. This review highlights the occupational hazards of interventional procedures and provides a glimpse at the technologies and techniques that may reduce risks to operators in the catheterization laboratory.

Percutaneous coronary intervention (PCI) has seen steady technological progress over the past 3 decades. Despite improved patient safety and efficacy, modern interventionalists continue to face significant occupational hazards, including radiation exposure, cataracts, and orthopedic injuries. Robotic remote navigation systems have been developed to address risks and procedural challenges associated with conventional PCI. The first in-human experience using a modern robotic system for PCI yielded excellent results, with an overall technical success rate of 97.9 %. A larger multicenter prospective registry with this system is currently underway. Robotic PCI technology holds promise to reduce operator radiation exposure and musculoskeletal complaints. Postulated benefits to patients include more accurate lesion length calculations, precise stent placement, and reductions in radiation exposure and contrast-media delivery. The development of novel robotic remote control navigation systems represents the dawn of a new era of interventional cardiology.

Femoral arterial puncture is the most common access method for coronary angiography and percutaneous coronary interventions (PCIs). Access complications, although infrequent, affect morbidity, mortality, costs, and length of hospital stay. Vascular closure devices (VCDs) are used for rapid hemostasis and early ambulation, but there is no consensus on whether VCDs are superior to manual compression (MC). A retrospective review and nested case-control study of consecutive patients undergoing elective transfemoral coronary angiography and PCI over 3 years was performed. Hemostasis strategy was performed according to the operators' discretion. Vascular complications were defined as groin bleeding (hematoma, hemoglobin decrease >/=3 g/dl, transfusion, retroperitoneal bleeding, or arterial perforation), pseudoaneurysm, arteriovenous fistula formation, obstruction, or infection. Patients with postprocedure femoral vascular access complications were compared to randomly selected patients without complication. Data were available for 9,108 procedures, of which PCI was performed in 3,172 (34.8%). MC was performed in 2,581 (28.3%) and VCDs (4 different types) were deployed in 6,527 procedures (71.7%). Significant complications occurred in 74 procedures (0.81%), with 32 (1.24%) complications with MC and 42 (0.64%) with VCD (p = 0.004). VCD deployment failed in 80 procedures (1.23%), of which 8 (10%) had vascular complications. VCD use was a predictor of fewer complications (odds ratio 0.52, 95% confidence interval 0.33 to 0.83). In the case-control analysis, older age and use of large (7Fr to 8Fr) femoral sheaths were independent predictors of complications. In conclusion, the retrospective analysis of contemporary hemostasis strategies and outcomes in elective coronary procedures identified a low rate of complications (0.81%), with superior results after VCD deployment. Careful selection of hemostasis strategy and closure device may further decrease complication rates.

OBJECTIVE: The study aims to evaluate sex differences in extent and severity of coronary artery disease (CAD) and myocardial findings at autopsy among young people with fatal ischemic heart disease (IHD). BACKGROUND: Women with acute coronary syndrome are less likely than men to display obstructive CAD at angiography. This suggests unique mechanisms of acute coronary syndrome exist in women or may reflect prehospital death of women with the most severe CAD. METHODS: Reports of autopsies by the Office of the Chief Medical Examiner of New York City on people aged 21 to 54 years who died between January 1, 2006, and December 31, 2008, were reviewed. A total of 639 cases of death due to atherosclerotic or arteriosclerotic cardiovascular disease according to the medical examiner were analyzed. Significant CAD was defined as >/=75% cross-sectional area stenosis in an epicardial vessel or >/=50% left main. RESULTS: Women were less likely to have obstructive CAD (63% vs 77% of men, P = .002). There was pathologic evidence of myocardial infarction (MI) in 43% of cases, 17% of which had nonobstructive CAD. Frequency of MI did not vary by sex overall (38% of women vs 45% of men, P = .18) or among those without significant CAD (23% vs 29%, P = .45). CONCLUSIONS: Among young people determined at autopsy to have died of IHD, fewer women had obstructive CAD, consistent with angiographic data in other IHD syndromes. Pathologic evidence of MI may exist in the absence of obstructive CAD

Chromatin modifications are essential for directing transcription during embryonic development. Bromodomain-containing protein 2 (Brd2; also called RING3 and Fsrg1) is one of four BET (bromodomain and extra-terminal domain) family members known to selectively bind acetylated histones H3 and H4. Brd2 associates with multiple subunits of the transcriptional apparatus including the mediator, TFIID and Swi/Snf multiprotein complexes. While molecular interactions of Brd2 are known, the functions of Brd2 in mammalian embryogenesis remain unknown. In developing a mouse model deficient in Brd2, we find that Brd2 is required for the completion of embryogenesis and proper neural tube closure during development. Embryos lacking Brd2 expression survive up to embryonic day 13.5, soon after mid-gestation, and display fully penetrant neurulation defects that largely result in exencephaly of the developing hindbrain. In this study, we find that highest expression of Brd2 is detected in the developing neural tube, correlating with the neural tube defects found in Brd2-null embryos. Additionally, embryos lacking Brd2 expression display altered gene expression programs, including the mis-expression of multiple genes known to guide neuronal development. Together these results implicate essential roles for Brd2 as a critical integrator of chromatin structure and transcription during mammalian embryogenesis and neurogenesis.