A lightweight, inexpensive robotic system for insect vision.

Designing hardware for miniaturized robotics which mimics the capabilities of flying insects is of interest, because they share similar constraints (i.e. small size, low weight, and low energy consumption). Research in this area aims to enable robots with similarly efficient flight and cognitive abilities. Visual processing is important to flying insects' impressive flight capabilities, but currently, embodiment of insect-like visual systems is limited by the hardware systems available. Suitable hardware is either prohibitively expensive, difficult to reproduce, cannot accurately simulate insect vision characteristics, and/or is too heavy for small robotic platforms. These limitations hamper the development of platforms for embodiment which in turn hampers the progress on understanding of how biological systems fundamentally work. To address this gap, this paper proposes an inexpensive, lightweight robotic system for modelling insect vision. The system is mounted and tested on a robotic platform for mobile applications, and then the camera and insect vision models are evaluated. We analyse the potential of the system for use in embodiment of higher-level visual processes (i.e. motion detection) and also for development of navigation based on vision for robotics in general. Optic flow from sample camera data is calculated and compared to a perfect, simulated bee world showing an excellent resemblance.

Impact of new-onset persistent left bundle branch block on late clinical outcomes in patients undergoing transcatheter aortic valve implantation with a balloon-expandable valve.

OBJECTIVES: The aim of this study was to determine the impact of new-onset persistent left bundle branch block (NOP-LBBB) on late outcomes after transcatheter aortic valve implantation (TAVI). BACKGROUND: The impact of NOP-LBBB after TAVI remains controversial. METHODS: A total of 668 consecutive patients who underwent TAVI with a balloon-expandable valve without pre-existing LBBB or permanent pacemaker implantation (PPI) were included. Electrocardiograms were obtained at baseline, immediately after the procedure, and daily until hospital discharge. Patients were followed at 1, 6, and 12 months and yearly thereafter. RESULTS: New-onset LBBB occurred in 128 patients (19.2%) immediately after TAVI and persisted at hospital discharge in 79 patients (11.8%). At a median follow-up of 13 months (range 3 to 27 months), there were no differences in mortality rate between the NOP-LBBB and no NOP-LBBB groups (27.8% vs. 28.4%; adjusted-hazard ratio: 0.87 [95% confidence interval (CI): 0.55 to 1.37]; p = 0.54). There were no differences between groups regarding cardiovascular mortality (p = 0.82), sudden death (p = 0.87), rehospitalizations for all causes (p = 0.11), or heart failure (p = 0.55). NOP-LBBB was the only factor associated with an increased rate of PPI during the follow-up period (13.9% vs. 3.0%; hazard ratio: 4.29 [95% CI: 2.03 to 9.07], p < 0.001. NOP-LBBB was also associated with a lack of left ventricular ejection fraction improvement and poorer New York Heart Association functional class at follow-up (p < 0.02 for both). CONCLUSIONS: NOP-LBBB occurred in ∼1 of 10 patients who had undergone TAVI with a balloon-expandable valve. NOP-LBBB was associated with a higher rate of PPI, a lack of improvement in left ventricular ejection fraction, and a poorer functional status, but did not increase the risk of global or cardiovascular mortality or rehospitalizations at 1-year follow-up.

RNA polymerase II mutations conferring defects in poly(A) site cleavage and termination in Saccharomyces cerevisiae.

Transcription termination by RNA polymerase (Pol) II is an essential but poorly understood process. In eukaryotic nuclei, the 3' ends of mRNAs are generated by cleavage and polyadenylation, and the same sequence elements that specify that process are required for downstream release of the polymerase from the DNA. Although Pol II is known to bind proteins required for both events, few studies have focused on Pol II mutations as a means to uncover the mechanisms that couple polyadenylation and termination. We performed a genetic screen in the yeast Saccharomyces cerevisiae to isolate mutations in the N-terminal half of Rpb2, the second largest Pol II subunit, that conferred either a decreased or increased response to a well-characterized poly(A) site. Most of the mutant alleles encoded substitutions affecting either surface residues or conserved active site amino acids at positions important for termination by other RNA polymerases. Reverse transcription polymerase chain reaction experiments revealed that transcript cleavage at the poly(A) site was impaired in both classes of increased readthrough mutants. Transcription into downstream sequences beyond where termination normally occurs was also probed. Although most of the tested readthrough mutants showed a reduction in termination concomitant with the reduced poly(A) usage, these processes were uncoupled in at least one mutant strain. Several rpb2 alleles were found to be similar or identical to published mutants associated with defective TFIIF function. Tests of these and additional mutations known to impair Rpb2-TFIIF interactions revealed similar decreased readthrough phenotypes, suggesting that TFIIF may have a role in 3' end formation and termination.

Angiographic and clinical outcomes after implantation of drug eluting stents in bifurcation lesions with crush or kissing stent technique.

BACKGROUND: Long-term outcome after bifurcation stenting with drug-eluting stents (DES) for obstructive coronary artery disease is poorly understood. In this study, we report 6-9-month angiographic follow-up and long-term clinical outcomes after implantation of drug-eluting stents by crush and kissing stent technique for coronary bifurcation lesions. METHODS: Consecutive patients undergoing bifurcation stenting with DES by crush or kissing stent technique were enrolled in a prospective registry. Angiographic follow-up was obtained at 6-9 months and clinical follow-up completed for a median of 38 months. RESULTS: A total of 86 patients participated in the study. Bifurcation stenting by crush technique was performed in 73 (85%) and by kissing stent in 13 (15%) patients. Stenting of left main bifurcation was applied in 24 (28%) patients. Angiographic follow-up was completed in 75 (87%) patients and showed restenosis in the main for 8 (11%) and side branch for 20 (27%) patients. Clinical follow-up was available for a median duration of 38 months. During follow-up, 2 (2%) patients died, 4 (5%) experienced myocardial infarction (MI), and 11 (13%) underwent target vessel revascularization (TVR) with an overall major adverse cardiac event (MACE) rate of 16%. In left main cohort, angiographic restenosis occurred in 9 (37%) patients, and 3 (12%) patients required TVR. There were no deaths or stent thrombosis. A comparison of crush and kissing stent technique showed significantly higher angiographic restenosis with crush (26% vs 13% in kissing stent patients, P = 0.046) and 95% of restenosis in crush group involved ostium of the side branch. There was no difference in clinical outcomes between the crush and kissing stent groups. Final kissing balloon dilatation (FKB) was successful in 65 (89%) patients in the crush group and associated with a significant reduction in MACE (8% in FKB successful vs 37% in FKB unsuccessful, P = 0.04) during follow-up. CONCLUSION: Bifurcation stenting with crush or kissing stent technique is safe and associated with a low rate of TLR and MACE on long-term follow-up. Crush stenting is associated with a significantly higher rate of side branch restenosis compared to kissing stent technique. FKB is associated with significant reduction in MACE during follow-up.

Long-term outcomes after transcatheter aortic valve implantation: insights on prognostic factors and valve durability from the Canadian multicenter experience.

OBJECTIVES: This study sought to evaluate the long-term outcomes after transcatheter aortic valve implantation (TAVI) in the Multicenter Canadian Experience study, with special focus on the causes and predictors of late mortality and valve durability. BACKGROUND: Very few data exist on the long-term outcomes associated with TAVI. METHODS: This was a multicenter study including 339 patients considered to be nonoperable or at very high surgical risk (mean age: 81 ± 8 years; Society of Thoracic Surgeons score: 9.8 ± 6.4%) who underwent TAVI with a balloon-expandable Edwards valve (transfemoral: 48%, transapical: 52%). Follow-up was available in 99% of the patients, and serial echocardiographic exams were evaluated in a central echocardiography core laboratory. RESULTS: At a mean follow-up of 42 ± 15 months 188 patients (55.5%) had died. The causes of late death (152 patients) were noncardiac (59.2%), cardiac (23.0%), and unknown (17.8%). The predictors of late mortality were chronic obstructive pulmonary disease (hazard ratio [HR]: 2.18, 95% confidence interval [CI]: 1.53 to 3.11), chronic kidney disease (HR: 1.08 for each decrease of 10 ml/min in estimated glomerular filtration rate, 95% CI: 1.01 to 1.19), chronic atrial fibrillation (HR: 1.44, 95% CI: 1.02 to 2.03), and frailty (HR: 1.52, 95% CI: 1.07 to 2.17). A mild nonclinically significant decrease in valve area occurred at 2-year follow-up (p < 0.01), but no further reduction in valve area was observed up to 4-year follow-up. No changes in residual aortic regurgitation and no cases of structural valve failure were observed during the follow-up period. CONCLUSIONS: Approximately one-half of the patients who underwent TAVI because of a high or prohibitive surgical risk profile had died at a mean follow-up of 3.5 years. Late mortality was due to noncardiac comorbidities in more than one-half of patients. No clinically significant deterioration in valve function was observed throughout the follow-up period.

Acetylation of the SUN protein Mps3 by Eco1 regulates its function in nuclear organization.

The Saccharomyces cerevisiae SUN-domain protein Mps3 is required for duplication of the yeast centrosome-equivalent organelle, the spindle pole body (SPB), and it is involved in multiple aspects of nuclear organization, including telomere tethering and gene silencing at the nuclear membrane, establishment of sister chromatid cohesion, and repair of certain types of persistent DNA double-stranded breaks. How these diverse SUN protein functions are regulated is unknown. Here we show that the Mps3 N-terminus is a substrate for the acetyltransferase Eco1/Ctf7 in vitro and in vivo and map the sites of acetylation to three lysine residues adjacent to the Mps3 transmembrane domain. Mutation of these residues shows that acetylation is not essential for growth, SPB duplication, or distribution in the nuclear membrane. However, analysis of nonacetylatable mps3 mutants shows that this modification is required for accurate sister chromatid cohesion and for chromosome recruitment to the nuclear membrane. Acetylation of Mps3 by Eco1 is one of the few regulatory mechanisms known to control nuclear organization.

Collagenase Total Occlusion-1 (CTO-1) trial: a phase I, dose-escalation, safety study.

BACKGROUND: Percutaneous interventions for chronic total occlusions have low success rates, primarily because of failure of guide wire crossing. Collagen-rich matrix constitutes the main barrier to chronic total occlusion crossing. In preclinical studies, local delivery of a bacterial collagenase formulation improved guide wire crossing. The Collagenase Total Occlusion-1 (CTO-1) Trial is a phase I, dose-escalation trial to assess the safety and efficacy of collagenase therapy to facilitate guide wire crossing in coronary artery chronic occlusions. METHODS AND RESULTS: Twenty subjects with ≥1 previous failure of chronic total occlusion guide wire crossing were enrolled at 2 sites. Subjects were treated in 4 distinct cohorts of 5 patients, with escalation of collagenase dose in each cohort from 300 to 1200 µg. Collagenase was locally delivered into the occlusions with either an over-the-wire balloon system (n=8) or a fine-cross microcatheter (n=12) for a period of 30 minutes. Subjects were brought back to the catheterization laboratory for guide wire crossing and angioplasty the next day. Guide wire crossing was successfully achieved in 15 subjects (75%). A soft-tip guide wire (Whisper, Pilot-50, Fielder XT) was either the sole or predominant guide wire used in 75% of successful crossings. Non-ST-segment-elevation myocardial infarctions occurred in 3 patients as a result of side-branch ischemia during stenting. Computed tomographic angiography at 3 months showed no late complications and patent stents in successfully treated chronic total occlusion. Anginal improvement occurred with a reduction in Canadian Cardiovascular Society class from baseline to 3 months (2.5±0.6 versus 0.9±0.9; P<0.001). CONCLUSION: Local delivery of collagenase into coronary chronic total occlusion is feasible and safe with encouraging guide wire crossing results in previously failed cases. Larger clinical trials are required to determine efficacy. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01271335.

Characterization of clopidogrel hypersensitivity reactions and management with oral steroids without clopidogrel discontinuation.

OBJECTIVES: The purpose of this study was to characterize clopidogrel hypersensitivity and describe its successful management with oral steroids without clopidogrel discontinuation. BACKGROUND: Hypersensitivity reactions to clopidogrel are poorly understood and present difficulty in management. METHODS: Patients diagnosed with clopidogrel hypersensitivity after percutaneous coronary intervention underwent evaluation and received oral prednisone without clopidogrel discontinuation. Cutaneous testing was performed after completion of clopidogrel therapy for diagnosis and assessment of cross-reactivity. RESULTS: Sixty-two patients representing 1.6% of the percutaneous coronary intervention population developed clopidogrel hypersensitivity during the study period. The mean age was 62 ± 11 years, 71% of patients were male, and 35% reported prior adverse drug reaction. Clopidogrel hypersensitivity manifested as generalized exanthema in 79%, localized skin reaction in 16%, and angioedema or urticaria in 5% of patients. Biopsy of affected areas demonstrated a lymphocyte-mediated delayed hypersensitivity reaction. Complete resolution of hypersensitivity reaction was observed in 61 patients (98%) with a short course of oral prednisone. Cutaneous testing confirmed delayed hypersensitivity reaction to clopidogrel in 34 (81%) and immediate hypersensitivity in 3 of 42 patients (7%) tested. Allergenic cross-reactivity was observed for ticlopidine in 10 (24%), prasugrel in 7 (17%), and both ticlopidine and prasugrel in 3 patients (7%). Histological examination showed lymphocyte-mediated hypersensitivity in abnormal patch test areas. CONCLUSIONS: Clopidogrel hypersensitivity is manifested as generalized exanthema and is caused by a lymphocyte-mediated delayed hypersensitivity in most patients. This can be managed with oral steroids without clopidogrel discontinuation. Allergenic cross-reactivity with ticlopidine, prasugrel, or both is present in a significant number of patients with clopidogrel hypersensitivity.

Characterization of operator learning curve for transradial coronary interventions.

BACKGROUND: Transradial percutaneous coronary intervention (TR-PCI) improves clinical outcomes compared to the transfemoral (TF) approach. However, inadequate training and experience has limited widespread adoption by interventional cardiologists. METHODS AND RESULTS: Clinical and procedural characteristics for TR-PCI were prospectively collected from 1999 to 2008. To identify minimum case volume for optimum clinical benefit, single-vessel TR-PCI cases were chronologically ranked and stratified into 1 to 50, 51 to 100, 101 to 150 and 151 to 300 case volume groups for operators starting the TR approach at the study institution. Cases by operators with a >300 TR-PCI case volume comprised the control group. TR-PCI failure rates, contrast use, guide usage, and fluoroscopy time were compared among groups. A total of 1672 patients underwent TR-PCI by 28 operators. TR-PCI failure occurred in 4% and was higher in the 1 to 50 case volume group compared to the 51 to 100 (P=0.007) and control (P=0.01) groups. Contrast use was greater in the 1 to 50 group (180±79 mL) compared to the 151 to 300 (157±75 mL, P=0.02) and control (168±79 mL, P=0.05) groups. Fluoroscopy time was higher in the 1 to 50 group (15±10 minutes) compared to the 101 to 150 (13±10 minutes, P=0.04) and control (12±9 minutes, P=0.02) groups. Reasons for TR-PCI failure included spasm (38%), subclavian tortuousity (16%), poor guide support (16%), failed access (10%), and radial loop (7%). Case volume was significantly correlated with TR-PCI failure (ß=-0.0076, P=0.0028), and odds of failure was reduced by 32% for each 50 increments in case volume. CONCLUSIONS: TR-PCI success depends on operator experience, and a case volume of ≥50 cases is required to achieve outcomes comparable to experienced operators. These findings have implications both for PCI operators looking to expand their skills and for defining standards for training.

Comparison of abciximab and eptifibatide on angiographic and clinical outcomes in rescue percutaneous coronary intervention for failed fibrinolytic therapy.

BACKGROUND: Adjunctive administration of the glycoprotein IIb/IIIa platelet receptor antagonist (GPA), abciximab, improves outcomes in patients undergoing rescue percutaneous coronary intervention (PCI). However, it is unknown if other GPAs provide a similar benefit in this setting. OBJECTIVE: We sought to compare angiographic and clinical outcomes of patients receiving abciximab or eptifibatide as an adjunct to rescue PCI. METHODS: In this prospective, nonrandomized study, consecutive patients who underwent rescue PCI and received adjunctive preprocedural GPA comprised the study population. Thrombolysis in myocardial infarction (TIMI) flow, corrected TIMI frame count (CTFC) and myocardial blush grade (MBG) were determined before and immediately after rescue PCI. Residual ST-segment elevation at 90-120 minutes and peak creatine kinase (CK) values for 48 hours after PCI were recorded. Major adverse cardiac events (MACE) including death, reinfarction and target vessel revascularization (TVR) were determined at discharge, 1 and 6 months. RESULTS: A total of 241 patients were included in the study. 162 patients received abciximab and 79 received eptifibatide. There were no differences in baseline clinical and angiographic characteristics between groups. Post-PCI TIMI flow was similar but post-PCI CTFC was significantly lower (17 +/- 10 vs. 22 +/- 18; p = 0.01) and post-PCI MBG significantly higher (2.8 +/- 0.5 vs. 2.6 +/- 0.6; p = 0.01) in the abciximab group. Patients in the abciximab group had less ST-segment elevation (1.0 +/- 0.9 vs. 1.5 +/- 1.0 mm; p = 0.003) and lower peak CK (2,484 +/- 2,176 vs. 2,650 +/- 2,798 U/L; p = 0.001) after PCI. On multivariate analyses, abciximab administration (OR = 0.50, CI = 0.26, 0.96; p = 0.03), pre-PCI TIMI 3 flow (OR = 0.22, CI = 0.05, 0.99; p = 0.04) and female gender (OR = 0.24, CI = 0.08, 0.66; p = 0.006) were positive and cardiogenic shock (OR = 2.76, CI = 1.16, 6.58; p = 0.02) was a negative predictor of normal epicardial perfusion post PCI. Abciximab administration (OR = 0.46, CI = 0.24, 0.87; p = 0.02) and pre-PCI CTFC < 25 (OR = 0.09, CI = 0.02, 0.31, 0.0001) were positive predictors and cardiogenic shock (OR = 3.96, CI = 1.55, 10.12; p = 0.004) was a negative predictor of normal myocardial perfusion post-PCI as determined by CTFC. Abciximab administration (OR = 0.31, CI = 0.15, 0.63; p = 0.001) and pre-PCI MBG 3 (OR = 0.07, CI = 0.02, 0.23; p < 0.0001) were positive predictors of normal myocardial perfusion post-PCI as determined by MBG. In-hospital, 1- and 6-month clinical events and MACE rates did not differ between groups. CONCLUSIONS: In the setting of rescue PCI, adjunctive administration of abciximab resulted in greater improvement in angiographic and electrical estimates of myocardial perfusion and smaller infarct size compared to eptifibatide. These findings suggest that all GPA may not provide equal benefit in rescue PCI.

Visible angiographic complications predict short and long-term outcomes in patients with post-procedural creatine-phosphokinase elevation.

OBJECTIVES: To assess whether visible angiographic complication is related to outcome in patients with elevated creatine phosphokinase (CK-MB) following percutaneous coronary intervention (PCI). BACKGROUND: Elevated biomarkers following PCI are associated with increased incidence of adverse events but the absolute risk of such events is low. A more specific marker of risk is needed. METHODS: Consecutive patients with elevated post-PCI CK-MB were divided into two groups according to presence (n = 115, 43%) or absence (n = 150, 57%) of an angiographic complication. A control group (n = 250) was randomly chosen from 2,403 patients undergoing PCI during the same period without CK-MB elevation. Major adverse cardiac events (MACE) were assessed at 30 days and 1 year. RESULTS: Patients with an identifiable angiographic complication and elevated postprocedural CK-MB had significantly worse outcomes at 30 days and 1 year compared with biomarker positive patients without an identifiable complication and control patients (30 day MACE rate: 8% vs 0% vs 0.4%, respectively, p < 0.001; 1 year MACE rate: 26% vs 11% vs 11%, respectively, p = 0.002, all p-values for angiographic complication vs no angiographic complication and for angiographic complication vs control). Biomarker positive patients without identifiable angiographic complication had an excellent short and long term outcome, which was no different from biomarker negative patients (1 year MACE rate: 11% vs 11%, p = 0.53). CONCLUSION: Post-PCI patients without visible angiographic complications have an excellent short and long term outcome. These findings call into question the need for routine CK-MB monitoring after PCI in the absence of clinical symptoms or angiographic complication.

Transcatheter aortic valve implantation for the treatment of severe symptomatic aortic stenosis in patients at very high or prohibitive surgical risk: acute and late outcomes of the multicenter Canadian experience.

OBJECTIVES: The aim of this study was: 1) to evaluate the acute and late outcomes of a transcatheter aortic valve implantation (TAVI) program including both the transfemoral (TF) and transapical (TA) approaches; and 2) to determine the results of TAVI in patients deemed inoperable because of either porcelain aorta or frailty. BACKGROUND: Very few data exist on the results of a comprehensive TAVI program including both TA and TF approaches for the treatment of severe aortic stenosis in patients at very high or prohibitive surgical risk. METHODS: Consecutive patients who underwent TAVI with the Edwards valve (Edwards Lifesciences, Inc., Irvine, California) between January 2005 and June 2009 in 6 Canadian centers were included. RESULTS: A total of 345 procedures (TF: 168, TA: 177) were performed in 339 patients. The predicted surgical mortality (Society of Thoracic Surgeons risk score) was 9.8 +/- 6.4%. The procedural success rate was 93.3%, and 30-day mortality was 10.4% (TF: 9.5%, TA: 11.3%). After a median follow-up of 8 months (25th to 75th interquartile range: 3 to 14 months) the mortality rate was 22.1%. The predictors of cumulative late mortality were peri-procedural sepsis (hazard ratio [HR]: 3.49, 95% confidence interval [CI]: 1.48 to 8.28) or need for hemodynamic support (HR: 2.58, 95% CI: 1.11 to 6), pulmonary hypertension (PH) (HR: 1.88, 95% CI: 1.17 to 3), chronic kidney disease (CKD) (HR: 2.30, 95% CI: 1.38 to 3.84), and chronic obstructive pulmonary disease (COPD) (HR: 1.75, 95% CI: 1.09 to 2.83). Patients with either porcelain aorta (18%) or frailty (25%) exhibited acute outcomes similar to the rest of the study population, and porcelain aorta patients tended to have a better survival rate at 1-year follow-up. CONCLUSIONS: A TAVI program including both TF and TA approaches was associated with comparable mortality as predicted by surgical risk calculators for the treatment of patients at very high or prohibitive surgical risk, including porcelain aorta and frail patients. Baseline (PH, COPD, CKD) and peri-procedural (hemodynamic support, sepsis) factors but not the approach determined worse outcomes.

Mechanism and predictors of failed transradial approach for percutaneous coronary interventions.

OBJECTIVES: The study aimed to determine the mechanism and predictors of procedural failure in patients undergoing percutaneous coronary intervention (PCI) from the transradial approach (TR). BACKGROUND: Transradial approach PCI reduces vascular complications compared with a transfemoral approach (TF). However, the mechanism and predictors of TR-PCI failure have not been well-characterized. METHODS: The study population consisted of patients undergoing TR-PCI by low-to-intermediate volume operators with traditional TF guide catheters. Baseline characteristics, procedure details, and clinical outcomes were prospectively collected. Univariate and multivariate analyses were performed to determine independent predictors of TR-PCI failure. RESULTS: A total of 2,100 patients underwent TR-PCI and represented 38% of PCI volume. Mean age was 64 +/- 12 years, and 17% were female. Vascular complications occurred in 22 (1%), and TR-PCI failure was observed in 98 (4.7%) patients. The mechanism of TR-PCI failure included inability to advance guide catheter to ascending aorta in 50 (51%), inadequate guide catheter support in 35 (36%), and unsuccessful radial artery puncture in 13 (13%) patients. The PCI was successful in 94 (96%) patients with TR-PCI failure by switching to TF. On multivariate analysis, age >75 years (odds ratio [OR]: 3.86; 95% confidence interval [CI]: 2.33 to 6.40, p = 0.0006), prior coronary artery bypass graft surgery (OR: 7.47; 95% CI: 3.45 to 16.19, p = 0.0002), and height (OR: 0.97; 95% CI: 0.95 to 0.99, p = 0.02) were independent predictors of TR-PCI failure. CONCLUSIONS: Transradial approach PCI can be performed by low-to-intermediate volume operators with standard equipment with a low failure rate. Age >75 years, prior coronary artery bypass graft surgery, and short stature are independent predictors of TR-PCI failure. Appropriate patient selection and careful risk assessment are needed to maximize benefits offered by TR-PCI.

Post-traumatic ventricular septal defects--review of the literature and a novel technique for percutaneous closure.

Post-traumatic ventricular septal defect (VSD) is infrequent, with clinical sequelae ranging from imminent death to complete spontaneous resolution. The most appropriate management strategy is unclear. Careful observation has been advocated in the management of these patients. We demonstrate this concept by reporting two different approaches in two patients with traumatic injuries to the chest and review the English-language literature of both spontaneous and percutaneous closure of these lesions. In our case of percutaneous closure, we report a novel technique involving a transseptal approach that does not require exteriorization and formation of an arteriovenous loop, thus avoiding loop-related complications.

An unusual case of chronic coronary artery dissection: did cisplatin play a role?

Spontaneous coronary artery dissection is an unusual cause of acute myocardial ischemia. The natural history of spontaneous coronary artery dissection that persists on angiography after the acute event has not been well characterized. A case of a 36-year-old man who presented with monomorphic ventricular tachycardia 12 years following a myocardial infarction that occurred during his last course of bleomycin-etoposide-cisplatin therapy for testicular cancer is reported. On further investigation, coronary angiography revealed a long chronic dissection of the right coronary artery. The patient was successfully treated with medical management and insertion of an implantable cardioverter defibrillator. The case also highlights the increased cardiovascular morbidity in testicular cancer survivors and evokes the possibility of mechanisms of myocardial ischemia other than atherosclerotic disease in these young patients.

Complete occlusion of the proximal subclavian artery post-CABG: presentation and treatment.

Atherosclerotic disease of the proximal left subclavian artery is an uncommon cause of angina in the post-coronary artery bypass graft patient, and is termed coronary-subclavian steal syndrome. Typical manifestations include cardiac symptoms of angina and noncardiac symptoms of lightheadedness, left arm numbness or weakness, and a difference in blood pressure of more than 20 mmHg between both arms. A case of complete proximal occlusion of the subclavian artery is reported. The clinical picture, investigations and treatment are described. Historical treatments of occlusive disease include surgical bypass graft and, more recently, percutaneous transluminal angioplasty. The patient underwent percutaneous transluminal angioplasty with stenting by a retrograde approach, with an excellent short-term response, but ultimately required a carotid subclavian bypass due to restenosis.

Intraluminal filling defects on coronary angiography: more than meets the eye.

Intraluminal filling defects are occasionally encountered on coronary angiography and often related with coronary thrombi. However, other conditions affecting the coronary arteries may present with similar angiographic findings causing diagnostic uncertainty. Accurate characterization of the angiographic filling defect is critical, particularly in patients planned for a percutaneous coronary intervention (PCI), as diagnosis of a coronary thrombus not only increases the risk of post procedural adverse events but also requires a specific therapeutic approach. In this paper, we report three patients in whom coronary angiography revealed intraluminal filling defects mimicking coronary thrombi. When further investigated with intravascular ultrasound (IVUS) as a part of the planned PCI, the thrombus was excluded and alternate etiology of the filling defect was confirmed in all patients. The angiographic "pseudothrombi" were produced by coronary dissection in one and by heavy calcification within the atherosclerotic plaque in two patients. The use of IVUS allowed accurate characterization of the angiographic filling defect and provided important information to guide management and optimize therapeutic approach.

Bleeding complications in patients with acute coronary syndrome undergoing early invasive management can be reduced with radial access, smaller sheath sizes, and timely sheath removal.

OBJECTIVES: Our objective was to analyze the impact of arterial access site, sheath size, timing of sheath removal, and use of access site closure devices on high-risk patients with acute coronary syndromes (ACS). BACKGROUND: In the SYNERGY trial, 9,978 patients with ACS were randomly assigned to receive enoxaparin or unfractionated heparin. METHODS: This analysis includes 9,404 patients for whom sheath access information was obtained for the first PCI procedure or diagnostic catheterization. Comparisons of baseline, angiographic, and procedural characteristics were carried out according to access site and sheath size. RESULTS: Overall, 9,404 (94%) patients underwent angiography at a median of 21 hr (25th and 75th percentiles: 5, 42) and 4,687 (50%) underwent PCI at a median of 23 hr (6,49) of enrollment. The access site was femoral for 94.9% of cases, radial for 4.4%, and brachial for 0.7%. Radial access was associated with fewer transfusions than femoral access (0.9% vs. 4.8%, P=0.007). For femoral access, the rates of noncoronary artery bypass grafting (CABG)-related TIMI major bleeding by sheath size was 1.5% for 4 or 5 French (Fr), 1.6% for 6 Fr, 3.3% for 7 Fr, and 3.8% for >or=8 Fr (P<0.0001). After adjustment for baseline characteristics, femoral access site, larger sheath size, and delayed sheath removal were independent predictors of need for transfusion. CONCLUSIONS: Smaller sheaths, radial access, and timely sheath removal may mitigate the bleeding risk associated with potent antithrombotic/platelet therapy and early catheterization.

Comparison of radial versus femoral approach for percutaneous coronary interventions in octogenarians.

BACKGROUND: The safety and efficacy of a radial approach for percutaneous coronary intervention (PCI) in octogenarians is not well established. METHODS: To evaluate the benefits of a radial approach for preventing vascular complications after PCI, clinical, procedural, and outcome data were prospectively collected and compared for 228 octogenarians undergoing elective PCI either through a radial or a femoral approach. RESULTS: Radial approach was associated with longer cannulation (3.1 +/- 2.9 vs. 2.0 +/- 2.0 min, P < 0.001) and fluoroscopy times (19.3 +/- 16.1 vs. 16.1 +/- 11.8 min, P = 0.04), greater utilization of contrast media (224 +/- 46 vs. 182 +/- 20 ml, P < 0.001) and higher crossover rate (11 vs 4%, P = 0.03) to alternate access site compared with the femoral approach. However, ambulation time (5.2 +/- 3.1 vs. 11.6 +/- 6.3 hr, P < 0.001), access site bleeding (4 vs. 14%, P = 0.007), hematoma (1 vs. 11%, P = 0.001) or any vascular complication (5 vs 26%, P = 0.001) were significantly reduced with a radial approach. Procedural success rates were equivalent with both approaches. Multivariate regression analysis identified radial approach (OR = 0.23; CI = 0.08, 0.65) as an independent negative predictor of postprocedural vascular complications. CONCLUSION: Radial approach for PCI in octogenarians is technically challenging for the operator and exposes patients to greater volume of nephrotoxic contrast media. However, it results in early ambulation and significantly reduces vascular complications in this high risk population. These findings support a strategy of preprocedural risk assessment and use of radial approach for PCI in a select group of octogenarians to maximize benefits offered by this technique.