Carotid intima media thickness in multiple sclerosis: A CLSA study

BACKGROUND

People with multiple sclerosis (MS) have an increased incidence of atherosclerotic disease, including ischemic heart disease and stroke, compared to people without MS even after accounting for risk factors such as hypertension, dyslipidemia, diabetes and smoking. We compared carotid intima media thickness (CIMT), a surrogate of atherosclerosis, in people with MS and in two groups of people without MS (rheumatoid arthritis [RA]; all other participants).

METHODS

We used data from participants in the Canadian Longitudinal Study on Aging (CLSA) who did not have known vascular disease (ischemic heart disease, stroke, transient ischemic attack, peripheral vascular disease) and who underwent carotid ultrasound for assessment of CIMT. We selected participants with MS, RA and controls who did not have MS or RA. Using age and gender-stratified norms for average CIMT in the CLSA, we identified participants in each cohort with a CIMT ≥75th percentile (subclinical atherosclerosis). We also calculated ten-year level of cardiovascular risk using the Framingham Risk Score (FRS). We tested the association between cohort membership (MS, RA, controls) and atherosclerosis using logistic regression, adjusted for FRS, abdominal obesity, excess alcohol intake, education and elevated symptoms of depression. We adjusted all analyses for the stratified sampling design.

RESULTS

We included 78 participants with MS, 364 participants with RA and 13,891 controls. Overall, the average (SE) CIMT was 0.699 (0.002), and this did not differ between cohorts. Logistic regression analyses revealed that cohort membership was not associated with atherosclerosis based on the average CIMT in unadjusted or adjusted models. However, a 1-point higher FRS was associated with 1.032 (95 %CI: 1.021, 1.043) increased odds of atherosclerosis.

CONCLUSION

Average CIMT does not differ between people with MS, people with RA and people without these diseases. Subclinical atherosclerosis as defined by a CIMT ≥75 % is not observed in people with MS at an increased rate beyond what FRS would predict. Further evaluation is needed to determine what mechanisms underlie the increased rates of cardiovascular disease and stroke in MS.

Subclinical atherosclerosis in multiple sclerosis

Background

People with multiple sclerosis (MS) have an increased risk of ischemic heart disease as compared to people without MS after accounting for traditional vascular risk factors.

Objective

We assessed whether subclinical atherosclerosis, an inflammatory disease of arteries, occurs in persons with MS who do not have traditional vascular risk factors, and whether the Framingham Score (FRS) predicted carotid intima media thickness (CIMT) similarly in people with and without MS.

Methods

We recruited participants with and without MS who did not have vascular disease. Participants completed questionnaires, physical assessments, underwent an ultrasound (CIMT), and provided samples for HbA1c and lipid measurements. We defined subclinical atherosclerosis as an average CIMT ≥75th percentile, and tested the association between MS/not-MS, FRS, and atherosclerosis using logistic regression.

Results

We recruited 106 participants with MS 101 without MS. The average (SD) CIMT did not differ between the MS (0.60 [0.11]) and non-MS (0.61 [0.12]) cohorts (p = 0.69), nor did the proportion with atherosclerosis (MS: 11.3% vs. non-MS 13.4%, p = 0.58). On regression analysis a 1-point increase in the FRS was associated with 11% increased odds of having atherosclerosis (95%CI: 1.04, 1.19) but MS was not.

Conclusion

MS was not associated with subclinical atherosclerosis.

CT perfusion for Assessment of poor Neurological outcome in Comatose Cardiac Arrest Patients (CANCCAP): protocol for a prospective study

INTRODUCTION

Cardiac arrest remains one of the most common causes of death with the majority occurring outside of hospitals (out of hospital cardiac arrest). Despite advancements in resuscitation management, approximately 50% of comatose cardiac arrest patients (CCAP) will suffer a severe unsurvivable brain injury. To assess brain injury, a neurological examination is conducted, however, its reliability in predicting outcomes in the first days following cardiac arrest is limited. Non-contrast CT is the most employed scan to assess hypoxic changes, even though it is not sensitive to early hypoxic-ischaemic changes in the brain. CT perfusion (CTP) has shown high sensitivity and specificity in brain death patients, although its use in predicting poor neurological outcome in CCAP has not yet been explored. The purpose of this study is to validate CTP for predicting poor neurological outcome (modified Rankin scale, mRS≥4) at hospital discharge in CCAP.

METHODS AND ANALYSIS

The CT Perfusion for Assessment of poor Neurological outcome in Comatose Cardiac Arrest Patients study is a prospective cohort study funded by the Manitoba Medical Research Foundation. Newly admitted CCAP receiving standard Targeted Temperature Management are eligible. Patients undergo a CTP at the same time as the admission standard of care head CT. Admission CTP findings will be compared with the reference standard of an accepted bedside clinical assessment at the time of admission. Deferred consent will be used. The primary outcome is a binary outcome of good neurological status, defined as mRs<4 or poor neurological status (mRs≥4) at hospital discharge. A total of 90 patients will be enrolled.

ETHICS AND DISSEMINATION

This study has been approved by the University of Manitoba Health Research Ethics Board. The findings from our study will be disseminated through peer-reviewed journals and presentations at local rounds, national and international conferences. The public will be informed at the end of the study.

TRIAL REGISTRATION NUMBER

NCT04323020.

Disparities in management and outcomes of myocardial infarction in multiple sclerosis: A matched cohort study

Background:

Although multiple sclerosis (MS) confers an elevated risk of acute myocardial infarction (AMI), little is known about how it influences management of AMI.

Methods:

Using population-based administrative (health) data from two Canadian provinces, we conducted a retrospective matched cohort study. We identified people with MS who had an incident AMI, and up to five AMI controls without MS matched on age, sex, and region. We compared the likelihood of undergoing cardiac catheterization within 30 days of AMI, time to revascularization, use of recommended pharmacotherapy post-AMI, and mortality at 30 and 365 days post-AMI using multivariable regression models adjusting for potential confounders. We pooled findings across provinces using meta-analysis.

Results:

We identified 559 MS cases and 2523 matched controls. In the matched cohort, the MS cohort was less likely to undergo cardiac catheterization within 30 days of admission (odds ratio (OR) = 0.61; 95% confidence interval (CI) = 0.49–0.77), revascularization (hazard ratio (HR) = 0.78; 95% CI = 0.69–0.88), or to fill a prescription for recommended therapy. Mortality risk was higher in the MS cohort than in the matched cohort at 30 and 365 days post-AMI.

Conclusion:

Rates of diagnostic and therapeutic care, and survival after AMI were lower in the MS population than in a matched population.

Traditional risk factors may not explain increased incidence of myocardial infarction in MS

Objective

To compare the risk of incident acute myocardial infarction (AMI) in the multiple sclerosis (MS) population and a matched population without MS, controlling for traditional vascular risk factors.

Methods

We conducted a retrospective matched cohort study using population-based administrative (health claims) data in 2 Canadian provinces, British Columbia and Manitoba. We identified incident MS cases using a validated case definition. For each case, we identified up to 5 controls without MS matched on age, sex, and region. We compared the incidence of AMI between cohorts using incidence rate ratios (IRR). We used Cox proportional hazards regression to compare the hazard of AMI between cohorts adjusting for sociodemographic factors, diabetes, hypertension, and hyperlipidemia. We pooled the provincial findings using meta-analysis.

Results

We identified 14,565 persons with MS and 72,825 matched controls. The crude incidence of AMI per 100,000 population was 146.2 (95% confidence interval [CI] 129.0–163.5) in the MS population and 128.8 (95% CI 121.8–135.8) in the matched population. After age standardization, the incidence of AMI was higher in the MS population than in the matched population (IRR 1.18; 95% CI 1.03–1.36). After adjustment, the hazard of AMI was 60% higher in the MS population than in the matched population (hazard ratio 1.63; 95% CI 1.43–1.87).

Conclusion

The risk of AMI is elevated in MS, and this risk may not be accounted for by traditional vascular risk factors.

Impact of adjuvanted H1N1 vaccine on cell-mediated rejection in heart transplant recipients

During the H1N1 influenza virus pandemic, vaccination of high risk groups including solid-organ transplant recipients was advised. A retrospective case control study of 60 heart transplant patients, 15 having received the H1N1 virus antigen and ASO3 adjuvant vaccine (GlaxoSmithKline, Mississauga, ON, Canada) within 21 days and 45 having not been vaccinated, all undergoing routine surveillance endmyocardial biopsies, was performed. The overall rate of cellular rejection (all grades) was not statistically different between groups; however, acute cellular rejection, ≥grade 2 (1990 ISHLT criteria), was more frequent among those having recently vaccinated (control: 1/45 vs. 6/15, p = 0.001). On multivariate analysis, the only risk factor found to be associated with acute cellular rejection was recent H1N1 viral antigen and adjuvant vaccination (OR 26.5: 95% CI 02.59-270.5). Vaccine adjuvants increase host response to vaccine antigens by immune upregulation potentially increasing risk of rejection in solid-organ transplant recipients. The potential hazard of vaccination this study raises must be weighed with the clear benefit vaccination has proven to be.

A definition of initial, fatty streak, and intermediate lesions of atherosclerosis. A report from the Committee on Vascular Lesions of the Council on Arteriosclerosis, American Heart Association

The compositions of lesion types that precede and that may initiate the development of advanced atherosclerotic lesions are described and the possible mechanisms of their development are reviewed. While advanced lesions involve disorganization of the intima and deformity of the artery, such changes are absent or minimal in their precursors. Advanced lesions are either overtly clinical or they predispose to the complications that cause ischemic episodes; precursors are silent and do not lead directly to complications. The precursors are arranged in a temporal sequence of three characteristic lesion types. Types I and II are generally the only lesion types found in children, although they may also occur in adults. Type I lesions represent the very initial changes and are recognized as an increase in the number of intimal macrophages and the appearance of macrophages filled with lipid droplets (foam cells). Type II lesions include the fatty streak lesion, the first grossly visible lesion, and are characterized by layers of macrophage foam cells and lipid droplets within intimal smooth muscle cells and minimal coarse-grained particles and heterogeneous droplets of extracellular lipid. Type III (intermediate) lesions are the morphological and chemical bridge between type II and advanced lesions. Type III lesions appear in some adaptive intimal thickenings (progression-prone locations) in young adults and are characterized by pools of extracellular lipid in addition to all the components of type II lesions.

A definition of initial, fatty streak, and intermediate lesions of atherosclerosis. A report from the Committee on Vascular Lesions of the Council on Arteriosclerosis, American Heart Association

The compositions of lesion types that precede and that may initiate the development of advanced atherosclerotic lesions are described and the possible mechanisms of their development are reviewed. While advanced lesions involve disorganization of the intima and deformity of the artery, such changes are absent or minimal in their precursors. Advanced lesions are either overtly clinical or they predispose to the complications that cause ischemic episodes; precursors are silent and do not lead directly to complications. The precursors are arranged in a temporal sequence of three characteristic lesion types. Types I and II are generally the only lesion types found in children, although they may also occur in adults. Type I lesions represent the very initial changes and are recognized as an increase in the number of intimal macrophages and the appearance of macrophages filled with lipid droplets (foam cells). Type II lesions include the fatty streak lesion, the first grossly visible lesion, and are characterized by layers of macrophage foam cells and lipid droplets within intimal smooth muscle cells and minimal coarse-grained particles and heterogeneous droplets of extracellular lipid. Type III (intermediate) lesions are the morphological and chemical bridge between type II and advanced lesions. Type III lesions appear in some adaptive intimal thickenings (progression-prone locations) in young adults and are characterized by pools of extracellular lipid in addition to all the components of type II lesions.

CL 277,082: a novel inhibitor of ACAT-catalyzed cholesterol esterification and cholesterol absorption

CL 277,082 (I) was found to be a potent inhibitor of acyl CoA:cholesterol acyltransferase (ACAT, EC 2.3.1.26) in microsomes from a variety of tissues with IC50 values of 0.14 microM for intestinal mucosal microsomes, 0.74 microM for liver, and 1.18 microM for rat adrenal. I was also shown to inhibit ACAT in cultured smooth muscle cells (IC50 = 0.8 microM) and was found to be specific in inhibiting cholesterol esterification since it did not inhibit fatty acid incorporation into triglycerides or phospholipids. Also, other cholesterol esterifying enzymes such as lecithin:cholesterol acyltransferase (LCAT) and pancreatic cholesterol esterase were not inhibited by I, nor was esterification of retinol by acyl CoA:retinol acyltransferase (ARAT) from intestinal mucosal microsomes inhibited. I was a potent inhibitor of cholesterol absorption in cholesterol-fed rats by markedly inhibiting increases in liver and serum cholesterol concentration (ED50 = 5.2 mg/kg per day) while increasing the excretion of neutral 14C-labeled sterol in the feces.

Influence of the acyl-CoA: cholesterol O-acyltransferase inhibitor, CL 277082, on cholesteryl ester accumulation in rabbit macrophage-rich granulomas and hepatic tissue

The influence of the acyl-CoA: cholesterol O-acyltransferase (ACAT) inhibitor, CL 277082, on macrophage cholesteryl ester accumulation in a rabbit carrageenan granuloma macrophage-foam cell model was studied. Diets were supplemented with 0.3% cholesterol and 6% peanut oil with or without the inhibitor (0.25%) for 4 weeks prior to granuloma induction, and macrophage-rich granuloma tissue was harvested 14 days after carrageenan injection. Serum cholesterol was monitored biweekly, and plasma lipoproteins were isolated terminally. Total, free and esterified cholesterol contents were measured in hepatic and granuloma tissue. In hepatic tissue, administration of CL 277082 resulted in an 80% reduction in the content of total cholesterol, a 37% decrease in free cholesterol, and a 90% decrease in esterified cholesterol. Similarly, in macrophage-rich granuloma tissue, total cholesterol content was decreased by 44%, and esterified cholesterol content by 61%, with no change in free cholesterol. Additionally, CL 277082 was shown to inhibit granuloma tissue ACAT activity by 45%, VLDL mass was decreased slightly, LDL mass increased 3.4-fold and HDL mass was similar in both the inhibitor-treated and control animals. CL 277082 resulted in a 57% decrease in VLDL cholesteryl ester content and a 4.5-fold increase in triacylglycerol. Cholesteryl ester content in LDL was decreased by 31% and LDL triacylglycerol was increased 5.2-fold, while the only change in HDL composition was a 3.5-fold increase in triacylglycerol. The reductions in both hepatic tissue and macrophage-rich granuloma tissue esterified cholesterol accumulation are considered to be due largely to cellular ACAT inhibition, and the altered distribution and composition of the plasma lipoproteins.

Potential antiatherosclerotic agents. 2. (Aralkylamino)- and (alkylamino) benzoic acid analogues of cetaben

The syntheses of a series of (aralkylamino)- and (alkylamino)benzoic acids, as well as the corresponding esters and sodium salts, are described. The compounds were evaluated in vivo in rats for serum sterol and triglyceride lowering activity and in vitro for activity in inhibiting the principle cholesterol-esterifying enzyme of the arterial wall, fatty acyl-CoA:cholesterol acyltransferase (ACAT). Based on a combination of these two activities, cataben sodium (150) was selected for development as a hypolipidemic and potential antiatherosclerotic agent.