Relationship Between the Degree of Carotid Stenosis and the Risk of Stroke in Patients Undergoing Cardiac Surgery

BACKGROUND

The impact of carotid stenosis (CS) in patients undergoing cardiac surgery remains controversial. The aim of this study was to evaluate the association between carotid stenosis and stroke and/or transient ischemic attack (TIA) in patients undergoing cardiac surgery on cardiopulmonary bypass.

METHODS

This is a retrospective cohort study including patients undergoing cardiac surgery on cardiopulmonary bypass between January 2006 and March 2018 at the Quebec Heart and Lung Institute. Data of patients' preoperative demographic characteristics, operative and postoperative variables were taken from a computerized database and patients' charts. Univariate and multivariate analyses were performed.

RESULTS

A total of 20,241 patients were included in the study. Among those who had received preoperative carotid ultrasound, 516 (2.6% of the total population) had unilateral or bilateral CS ≥50%. Categorized levels of carotid stenosis severity were identified as independent risk factors for post-operative stroke and/or transient ischemic attack occurrence. There was an almost three-fold increased risk of post-operative neurologic events in 80-99% CS vs. less severe 50-79% CS [OR 2.91; IC95% (1.30-6.54)] suggesting that the degree of severity of CS is potentially a strong independent predictor of post-operative neurologic events.

CONCLUSIONS

CS is an independent risk factor of post-operative stroke and/or TIA. This study suggests for the first time that the risk of stroke increases with the degree of severity of CS, with the greatest risk being for CS between 80-99%. The strength of this relationship and potential causality effect should be further explored in a prospective study focusing on this most at risk population.

Large Intramural Aortic Hematoma with Intimal Tear

A 72-year-old man presented with excruciating epigastric pain. A chest computed tomography angiography revealed an aortic intramural hematoma. A filling defect within the distal ascending aorta was noted. Images of an intramular hematoma and surgical details of an ascending aortic replacement under deep hypothermic circulatory arrest are provided.

Prediction of lung cancer risk at follow-up screening with low-dose CT: a training and validation study of a deep learning method

Background

Current lung cancer screening guidelines use mean diameter, volume or density of the largest lung nodule in the prior computed tomography (CT) or appearance of new nodule to determine the timing of the next CT. We aimed at developing a more accurate screening protocol by estimating the 3-year lung cancer risk after two screening CTs using deep machine learning (ML) of radiologist CT reading and other universally available clinical information.

Methods

A deep machine learning (ML) algorithm was developed from 25,097 participants who had received at least two CT screenings up to two years apart in the National Lung Screening Trial. Double-blinded validation was performed using 2,294 participants from the Pan-Canadian Early Detection of Lung Cancer Study (PanCan). Performance of ML score to inform lung cancer incidence was compared with Lung-RADS and volume doubling time using time-dependent ROC analysis. Exploratory analysis was performed to identify individuals with aggressive cancers and higher mortality rates.

Findings

In the PanCan validation cohort, ML showed excellent discrimination with a 1-, 2- and 3-year time-dependent AUC values for cancer diagnosis of 0·968±0·013, 0·946±0·013 and 0·899±0·017. Although high ML score cohort included only 10% of the PanCan sample, it identified 94%, 85%, and 71% of incident and interval lung cancers diagnosed within 1, 2, and 3 years, respectively, after the second screening CT. Furthermore, individuals with high ML score had significantly higher mortality rates (HR=16·07, p<0·001) compared to those with lower risk.

Interpretation

ML tool that recognizes patterns in both temporal and spatial changes as well as synergy among changes in nodule and non-nodule features may be used to accurately guide clinical management after the next scheduled repeat screening CT.

Predicting Malignancy Risk of Screen-Detected Lung Nodules-Mean Diameter or Volume

OBJECTIVE

In lung cancer screening practice low-dose computed tomography, diameter, and volumetric measurement have been used in the management of screen-detected lung nodules. The aim of this study was to compare the performance of nodule malignancy risk prediction tools using diameter or volume and between computer-aided detection (CAD) and radiologist measurements.

METHODS

Multivariable logistic regression models were prepared by using data from two multicenter lung cancer screening trials. For model development and validation, baseline low-dose computed tomography scans from the Pan-Canadian Early Detection of Lung Cancer Study and a subset of National Lung Screening Trial (NLST) scans with lung nodules 3 mm or more in mean diameter were analyzed by using the CIRRUS Lung Screening Workstation (Radboud University Medical Center, Nijmegen, the Netherlands). In the NLST sample, nodules with cancer had been matched on the basis of size to nodules without cancer.

RESULTS

Both CAD-based mean diameter and volume models showed excellent discrimination and calibration, with similar areas under the receiver operating characteristic curves of 0.947. The two CAD models had predictive performance similar to that of the radiologist-based model. In the NLST validation data, the CAD mean diameter and volume models also demonstrated excellent discrimination: areas under the curve of 0.810 and 0.821, respectively. These performance statistics are similar to those of the Pan-Canadian Early Detection of Lung Cancer Study malignancy probability model with use of these data and radiologist-measured maximum diameter.

CONCLUSION

Either CAD-based nodule diameter or volume can be used to assist in predicting a nodule's malignancy risk.

Participant selection for lung cancer screening by risk modelling (the Pan-Canadian Early Detection of Lung Cancer [PanCan] study): a single-arm, prospective study

BACKGROUND

Results from retrospective studies indicate that selecting individuals for low-dose CT lung cancer screening on the basis of a highly predictive risk model is superior to using criteria similar to those used in the National Lung Screening Trial (NLST; age, pack-year, and smoking quit-time). We designed the Pan-Canadian Early Detection of Lung Cancer (PanCan) study to assess the efficacy of a risk prediction model to select candidates for lung cancer screening, with the aim of determining whether this approach could better detect patients with early, potentially curable, lung cancer.

METHODS

We did this single-arm, prospective study in eight centres across Canada. We recruited participants aged 50-75 years, who had smoked at some point in their life (ever-smokers), and who did not have a self-reported history of lung cancer. Participants had at least a 2% 6-year risk of lung cancer as estimated by the PanCan model, a precursor to the validated PLCOm2012 model. Risk variables in the model were age, smoking duration, pack-years, family history of lung cancer, education level, body-mass index, chest x-ray in the past 3 years, and history of chronic obstructive pulmonary disease. Individuals were screened with low-dose CT at baseline (T0), and at 1 (T1) and 4 (T4) years post-baseline. The primary outcome of the study was incidence of lung cancer. This study is registered with ClinicalTrials.gov, number NCT00751660.

FINDINGS

7059 queries came into the study coordinating centre and were screened for PanCan risk. 15 were duplicates, so 7044 participants were considered for enrolment. Between Sept 24, 2008, and Dec 17, 2010, we recruited and enrolled 2537 eligible ever-smokers. After a median follow-up of 5·5 years (IQR 3·2-6·1), 172 lung cancers were diagnosed in 164 individuals (cumulative incidence 0·065 [95% CI 0·055-0·075], incidence rate 138·1 per 10 000 person-years [117·8-160·9]). There were ten interval lung cancers (6% of lung cancers and 6% of individuals with cancer): one diagnosed between T0 and T1, and nine between T1 and T4. Cumulative incidence was significantly higher than that observed in NLST (4·0%; p<0·0001). Compared with 593 (57%) of 1040 lung cancers observed in NLST, 133 (77%) of 172 lung cancers in the PanCan Study were early stage (I or II; p<0·0001).

INTERPRETATION

The PanCan model was effective in identifying individuals who were subsequently diagnosed with early, potentially curable, lung cancer. The incidence of cancers detected and the proportion of early stage cancers in the screened population was higher than observed in previous studies. This approach should be considered for adoption in lung cancer screening programmes.

FUNDING

Terry Fox Research Institute and Canadian Partnership Against Cancer.

Plasma pro-surfactant protein B and lung function decline in smokers

Plasma pro-surfactant protein B (pro-SFTPB) levels have recently been shown to predict the development of lung cancer in current and ex-smokers, but the ability of pro-SFTPB to predict measures of chronic obstructive pulmonary disease (COPD) severity is unknown. We evaluated the performance characteristics of pro-SFTPB as a biomarker of lung function decline in a population of current and ex-smokers. Plasma pro-SFTPB levels were measured in 2503 current and ex-smokers enrolled in the Pan-Canadian Early Detection of Lung Cancer Study. Linear regression was performed to determine the relationship of pro-SFTPB levels to changes in forced expiratory volume in 1 s (FEV1) over a 2-year period as well as to baseline FEV1 and the burden of emphysema observed in computed tomography (CT) scans. Plasma pro-SFTPB levels were inversely related to both FEV1 % predicted (p=0.024) and FEV1/forced vital capacity (FVC) (p<0.001), and were positively related to the burden of emphysema on CT scans (p<0.001). Higher plasma pro-SFTPB levels were also associated with a more rapid decline in FEV1 at 1 year (p=0.024) and over 2 years of follow-up (p=0.004). Higher plasma pro-SFTPB levels are associated with increased severity of airflow limitation and accelerated decline in lung function. Pro-SFTPB is a promising biomarker for COPD severity and progression.

Probability of cancer in pulmonary nodules detected on first screening CT

BACKGROUND

Major issues in the implementation of screening for lung cancer by means of low-dose computed tomography (CT) are the definition of a positive result and the management of lung nodules detected on the scans. We conducted a population-based prospective study to determine factors predicting the probability that lung nodules detected on the first screening low-dose CT scans are malignant or will be found to be malignant on follow-up.

METHODS

We analyzed data from two cohorts of participants undergoing low-dose CT screening. The development data set included participants in the Pan-Canadian Early Detection of Lung Cancer Study (PanCan). The validation data set included participants involved in chemoprevention trials at the British Columbia Cancer Agency (BCCA), sponsored by the U.S. National Cancer Institute. The final outcomes of all nodules of any size that were detected on baseline low-dose CT scans were tracked. Parsimonious and fuller multivariable logistic-regression models were prepared to estimate the probability of lung cancer.

RESULTS

In the PanCan data set, 1871 persons had 7008 nodules, of which 102 were malignant, and in the BCCA data set, 1090 persons had 5021 nodules, of which 42 were malignant. Among persons with nodules, the rates of cancer in the two data sets were 5.5% and 3.7%, respectively. Predictors of cancer in the model included older age, female sex, family history of lung cancer, emphysema, larger nodule size, location of the nodule in the upper lobe, part-solid nodule type, lower nodule count, and spiculation. Our final parsimonious and full models showed excellent discrimination and calibration, with areas under the receiver-operating-characteristic curve of more than 0.90, even for nodules that were 10 mm or smaller in the validation set.

CONCLUSIONS

Predictive tools based on patient and nodule characteristics can be used to accurately estimate the probability that lung nodules detected on baseline screening low-dose CT scans are malignant. (Funded by the Terry Fox Research Institute and others; ClinicalTrials.gov number, NCT00751660.).

Transcatheter aortic valve implantation for the treatment of surgical valve dysfunction ("valve-in-valve"): assessing the risk of coronary obstruction

Acute coronary obstruction is one of the most feared complications associated with transcatheter aortic valve-in-valve implantation. Strategies for assessing the risk of coronary occlusion during these procedures as well as preventive measures are discussed.

Magnetic Properties of Hitperm (Fe,Co)88Zr7B4Cu1 Nanocrystalline Magnets (Invited)

Alloys consisting of Fe-Co-M-B-Cu (with M = Zr, Hf, Nb), called HITPERM alloys, have been developed. Synchrotron X-radiation studies have been used to show that the ferromagnetic phase in an equiatomic FeCo-based alloy is the α'-FeCo phase. Since both the α'-FeCo phase and the FeCo-based amorphous phase of the nanocrystalline alloy have high Curie temperatures, a high magnetization persists up to the α -> γ structural phase transformation temperature of 980°C. Room temperature AC permeability measurements have shown that the alloys maintain a high permeability of ∼2000 up to a frequency of 20 kHz. The room temperature core loss has also been shown to be competitive with commercial high temperature magnetic alloys with a value of 1 W/g at Bs = 10 kG andf= 10 kHz. Analysis of extended X-ray absorption fine structure (EXAFS) data is consistent with a two-phase mixture of nanocrystalline body centered cubic derivative FeCo structure and an amorphous Zr-rich phase. A differential scanning calorimetry study of the primary crystallization reaction shows an activation energy of 323.3 kJ/mol. As a preliminary study of phase and grain stability, broadening of X-ray diffraction peaks indicates little grain growth after annealing at 600 °C for 3072 hours.

Deflazacort treatment of Duchenne muscular dystrophy

OBJECTIVE

We report the long-term effects on muscle strength and side effects with deflazacort in Duchenne muscular dystrophy (DMD).

STUDY DESIGN

Boys with DMD between the ages of 7 and 15 years were reviewed retrospectively; 30 had been treated with deflazacort, and 24 had not. Muscle function, pulmonary function, and side effects were compared.

RESULTS

The boys not treated with deflazacort stopped walking at 9.8 +/-1.8 years. Seven of 30 treated boys had stopped walking at 12.3+/-2.7 years (P<.05), and of the 23 boys who were still walking, 21 were older than 10 years. Pulmonary function (percent predicted functional vital capacity) was significantly greater in treated boys at 15 years (88% +/- 18%) than in boys not treated (39%+/-20%) (P<.001). Between 9 and 15 years, treated boys were shorter. Between 9 and 13 years, treated boys weighed less. After 13 years the treated boys maintained their weight, whereas boys not treated lost weight. Asymptomatic cataracts developed in 10 of 30 boys who received deflazacort. Other potential side effects of deflazacort such as hypertension, glucosuria, acne, infection, or bruising were not more common.

CONCLUSIONS

We conclude that deflazacort can preserve gross motor and pulmonary function in boys with DMD with limited side effects.

Evidence of mdx mouse skeletal muscle fragility in vivo by eccentric running exercise

Duchenne muscular dystrophy is an X-linked devastating disease due to the lack of expression of a functional dystrophin. Unfortunately, the dystrophin-deficient mdx mouse model does not present clinical signs of dystrophy before the age of 18 months, and the role of dystrophin in fiber integrity is not fully understood. The fragility of the skeletal muscle fibers was investigated in transgenic mice expressing beta-galactosidase under the control of a muscle specific promoter. Adult mdx/beta-galactosidase (dystrophin-negative) and normal/beta-galactosidase (dystrophin-positive) mice were submitted to one short session of eccentric, downhill running exercise. The leakage of muscle enzymes creatine kinase and beta-galactosidase was investigated before, 1 h after, and 3 days after the running session. A significant and transient rise in the level of these enzymes was noted in the serum of mdx mice following the exercise session. Thus, the lack of dystrophin in the mdx model led to local microdamages to the exercised muscle allowing leakage of proteins from the fibers. The peak leakage was transient, suggesting that muscle fiber lesions were rapidly repaired following this short, noninvasive eccentric running session.

Immunosuppression with monoclonal antibodies and CTLA4-Ig after myoblast transplantation in mice

Various combinations of monoclonal antibodies specific for lymphocyte cell surface antigens and a recombinant molecule (CTLA4-Ig) were used to immunosuppress mice after transplantation of MHC-incompatible myoblasts. To assess the effectiveness of the immunosuppression, the donor myoblasts were obtained from a transgenic mouse (TnI LacZ1/29) containing a beta-galactosidase (beta-gal) reporter gene under the control of a muscle-specific promoter. No muscle fibers expressing beta-gal were observed 1 month after the myoblast transplantation, when the animals were not immunosuppressed or were treated with CTLA4-Ig alone. Approximately 50% of the muscle fibers expressed the beta-gal reporter gene 1 month after transplantation in mice treated with CTLA4-Ig combined with an anti-CD4 monoclonal antibody and in mice treated with a combination of anti-CD4, anti-CD8, and anti-lymphocyte function-associated antigen-1. The percentage of beta-gal-labeled muscle fibers increased to 94% when this combination of the three monoclonal antibodies was administrated weekly for 3 weeks. Although excellent graft survival rates were obtained 1 month after transplantation, reflecting an effective immunosuppression by these three treatments, no beta-gal-positive fibers were found 2 months after the transplantation, indicating the inability of these immunosuppressive agents to maintain long-term graft survival and induce tolerance to the myoblasts and muscle fibers of donor origin.

Prevention of immune reactions triggered by first-generation adenoviral vectors by monoclonal antibodies and CTLA4Ig

The therapeutic potential of adenovirus-mediated gene transfer using first-generation vectors is severely limited by the fact that only transient expression is achievable in immunocompetent animals. The loss in transgene expression can be attributed at least in part to the appearance of detrimental immune responses directed toward vector and/or transgene-encoded determinants. FK506 and cyclosporin A both reduced these immune responses. These immunosuppressants, however, may induce many severe side effects during prolonged use. An alternative strategy has been developed to overcome these problems following in vivo transfection of muscles of adult immunocompetent mice with a delta E1/E3a adenoviral vector encoding a beta-galactosidase (beta-Gal) expression cassette. YTS 177 (an anti-CD4 monoclonal antibody) as well as CTLA4Ig, a recombinant protein, partially controlled the immune responses. They were indeed able to reduce the muscle infiltration by CD4+ and CD8+ cells but they failed to repress the humoral response. Co-administration of YTS 191 (an anti-CD4), YTS 169 (an anti-CD8), and TIB 213 (an anti-CD11a) was, however, very efficient in blocking both cellular and humoral immune reactions. This combination of monoclonal antibodies allowed strong and stable transgene expression over 1 month. These data underline the potential of monoclonal antibodies as immunosuppressive adjunct treatment for adenovirus-mediated gene transfer.

Overproduction of three genes leads to camphor resistance and chromosome condensation in Escherichia coli

We isolated and characterized three genes, crcA, cspE and crcB, which when present in high copy confer camphor resistance on a cell and suppress mutations in the chromosomal partition gene mukB. Both phenotypes require the same genes. Unlike chromosomal camphor resistant mutants, high copy number crcA, cspE and crcB do not result in an increase in the ploidy of the cells. The cspE gene has been previously identified as a cold shock-like protein with homologues in all organisms tested. We also demonstrate that camphor causes the nucleoids to decondense in vivo and when the three genes are present in high copy, the chromosomes do not decondense. Our results implicate camphor and mukB mutations as interfering with chromosome condensation and high copy crcA, cspE and crcB as promoting or protecting chromosome folding.

Increased interferon-gamma mRNA expression following alloincompatible myoblast transplantation is inhibited by FK506

Myoblasts from C57BL/10SnJ+/+ were transplanted in major histocompatibility complex (MHC)-compatible mice (i.e., C57BL10SnJ+/+ and C57BL/10SnSc mdx/mdx) and in MHC-noncompatible (BALB/c+/+) mice. The recipients were killed 1-21 days after transplantation. C57BL10SnJ+/+ myoblasts were also transplanted in a few BALB/c+/+ mice treated with FK506 and killed 7 days thereafter. Our results showed that after MHC-noncompatible transplantation, interferon-gamma (IFN-gamma) mRNA expression is increased from day 5 to day 21, indicating the presence of a cellular immune reaction. Short-term immunosuppressive treatment with FK506 inhibited the transcription of IFN-gamma mRNA compared with that in untreated mice. Myoblast-specific antibodies were also detected 2 and 3 weeks after MHC-incompatible transplantation, indicating that the cellular immune reaction, revealed by the increase in IFN-gamma, was followed by a humoral reaction.

Marital enrichment: the contribution of sixteen process variables to the effectiveness of a program

A marital enrichment program, based on Sager's contractual model of couple functioning, was analyzed to see which of its components were linked to good and/or improved marital adjustment, communication and problem-solving skills. Nineteen couples underwent the eight-week program, and were pre- and posttested on the Dyadic Adjustment Scale, the Marital Communication Inventory, and the Marital Interaction Coding System. A factor analysis of 16 process variables within the program confirmed the relationship between components of the program and the therapeutic goals based on Sager's model. When the factors thus derived and the variables themselves were used as predictors of the outcome variables within stepwise multiple regression equations, a positive awareness of one's expectations and of the marital relationship seemed to be particularly important to couple functioning. The role of communication skills and of negotiation training were not as clear. One trend that emerged was that negotiation skills seemed more useful for seriously dysfunctional couples.

Short- and long-term effects of a marital enrichment program upon couple functioning

Short- and long-term effects of a new marital enrichment program (MEP), based upon Sager's contractual model of couple functioning, were evaluated using both self-inventories (DAS, MCI) and behavioral scales (MICS). Couples were randomly assigned to either no-treatment control conditions or the 20-hour long MEP. Evaluations of marital functioning of both groups were repeatedly done during the experimentation, at pretest, midtest, posttest and follow-up 1 (two months after completion of the program). A second follow-up on the experimental couples was done a year after the end of MEP. Significant results were obtained for five of the seven criterion variables (marital adjustment and communication and certain aspects of problem-solving behavior). Positive gains shown by the experimental couples in the subjective measures were maintained for an entire year following MEP. It was concluded that the program succeeded in meeting both its short- and long-term goals, thus representing a most promising preventative strategy to modern couple living.

Surgical treatment of tennis elbow

Nine patients with eleven cases of tennis elbow, recalcitrant to conservative therapy, underwent surgical reconstruction as described by Gardner in 1970. The average duration of symptoms preoperatively was 49 weeks. There were seven females and two males. Ages ranged from 30 to 54 years. Follow-up ranged from 1.3 to 4.25 years. Patients were evaluated regarding pain, activity, grip strength and satisfaction with the surgical result. Preoperatively, pain was described as moderate in eight, and severe in three. All patients described limitation of activity and decreased grip strength. Postoperatively, mild pain occurred in three, and none in eight. All patients reported no limitation of activity, normal grip strengths, and were satisfied with their surgical result. Lack of full elbow extension initially present in all cases resolved in three to twelve months. Surgical reconstruction of the elbow as described by Gardner is an effective means of treating unresponsive tennis elbow.