18F-Fludeoxyglucose PET/CT in the evaluation of large-vessel vasculitis

British Journal of Radiology (2012) 85, e188-e194 

¹⁸F-Fludeoxyglucose PET/CT in the evaluation of large-vessel vasculitis: diagnostic performance and correlation with clinical and laboratory parameters  N D Papathanasiou Correspondence: Dr Jamshed Bomanji, Institute of Nuclear Medicine, University College Hospital, 235 Euston Road, London NW1 2BU, UK. E-mail: jamshed.bomanji@uclh.nhs.uk

Abstract

Objective: To investigate the diagnostic performance of ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/CT in patients with suspected large-vessel vasculitis and its potential to evaluate the extent and activity of disease.

Methods: 78 consecutive patients (mean age 63 years; 53 females) with suspected large-vessel vasculitis were evaluated with ¹⁸F-FDG PET/CT. ¹⁸F-FDG uptake in the aorta and major branches was visually graded using a four-point scale and quantified with standardised uptake values (SUV_max). According to clinical diagnosis, patients were classified into three groups: (a) steroid-naïve, large-vessel vasculitis (16 patients), (b) vasculitis on steroid treatment (18 patients) and (c) no evidence of vasculitis (44 patients). Analysis of variance and linear regression were used to investigate the association of ¹⁸F-FDG uptake with clinical diagnosis and inflammatory markers.

Results: ¹⁸F-FDG PET/CT was positive (visual uptake ≥2; equal to or greater than liver) in all patients with steroid-naïve, large-vessel vasculitis. The thoracic aorta, the carotid and the subclavian arteries were most frequently involved. 

Conclusion: ¹⁸F-FDG PET/CT can detect the extent and activity of large-vessel vasculitis in untreated patients and is unreliable in diagnosing vasculitis in patients on steroids.

Metallo Beta lactamase producing pseudomonas aeruginosa and its association with diabetic foot.

Diabetic foot infections are common and there is increasing possibility that they are getting resistant to all antibiotics available due to inadequate or inappropriate use of them. Infection with multi drug resistance organisms (MDROs) is common in diabetic foot ulcers and is associated with inadequate glycemic control and increased requirement for surgical treatment.

Pseudomonas aeruginosa strains that produce metallo beta lactamases (MBLs) are becoming increasingly prevalent in wound infections

Indian J Surg. 2011 Aug;73(4):291-4. Epub 2011 May 3.

Residents vs attending surgeons

Coronary Artery Bypass Graft Patency: Residents Versus Attending Surgeons

Faisal G. Bakaeen, MD, Gulshan Sethi, MD, Todd H. Wagner, PhD,
Rosemary Kelly, MD, Kelvin Lee, PhD, Anjali Upadhyay, MS, Hoang Thai, MD,
Elizabeth Juneman, MD, Steven Goldman, MD, and William L. Holman, MD
Michael E. DeBakey Veterans Affairs Medical Center and Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas; Division of Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, Houston, Texas; Department of Cardiothoracic Surgery, University of Arizona Health Science Center, Tucson, Arizona; Veterans Affairs Palo Alto Health Care System, Palo Alto, California; Department of Cardiovascular Surgery, University
of Minnesota Hospital, Minneapolis, Minnesota; Southern Arizona Veterans Affairs Health Care System and University of Arizona, Tucson, Arizona; and Division of Cardiothoracic Surgery, University of Alabama, Birmingham, Alabama 

Background. Data are limited regarding the patency of coronary artery bypass grafts performed by residents versus attending surgeons.
 

Methods. We analyzed data from a multicenter, randomized Veterans Affairs Cooperative Study in which the left internal mammary artery was used preferentially to graft the left anterior descending coronary artery, and the best remaining coronary vessel received (per random assignment) either a radial artery or a saphenous vein graft. The study vessel’s 1-year graft patency was the primary outcome measure. Secondary outcomes included operative times, operative morbidity, mortality, repeat revascularization, cost, angina symptoms, and quality of life. Multivariate analyses were used to compare patient outcomes for residents versus attendings. 

Results. Residents were designated as primary surgeons in 23% of cases (167 of 725). Among the 531 patients who had a 1-year angiogram, study graft patency rates for resident cases (n 122) and attending cases (n 409) were not significantly different (86% versus 90%, p 0.22). Residents’ cases had longer perfusion time (119 versus 105 minutes, p < 0.0001) and cross-clamp time (84 versus 68 minutes, p < 0.0001). After risk adjustment, all outcome measures did not differ between the two groups, and there was no apparent interaction effect between resident/ attending designation and radial artery versus saphenous
vein use or on-pump versus off-pump approach.

Conclusions. Surgeons in training perform coronary artery bypass surgery without compromising graft patency or patient outcomes. Ongoing evaluation of residents’ performance and surgical outcomes is needed, given the major changes that are occurring in residency training.

(Ann Thorac Surg 2012;94:482– 8) © 2012 by The Society of Thoracic Surgeons

Low-density lipoprotein lowering does not improve calf muscle perfusion, energetics, or exercise performance in peripheral arterial disease.

J Am Coll Cardiol. 2011 Aug 30;58(10):1068-76.

West AM, Anderson JD, Epstein FH, Meyer CH, Wang H, Hagspiel KD, Berr SS, Harthun NL, Weltman AL, Dimaria JM, Hunter JR, Christopher JM, Kramer CM.

Source

Department of Medicine, University of Virginia Health System, University of Virginia, Charlottesville, Virginia.

Abstract

OBJECTIVES:

We hypothesized that low-density lipoprotein (LDL) reduction regardless of mechanism would improve calf muscle perfusion, energetics, or walking performance in peripheral arterial disease (PAD) as measured by magnetic resonance imaging and magnetic resonance spectroscopy.

BACKGROUND:

Statins improve cardiovascular outcome in PAD, and some studies suggest improved walking performance.

METHODS:

Sixty-eight patients with mild to moderate symptomatic PAD (age 65 ± 11 years; ankle-brachial index [ABI] 0.69 ± 0.14) were studied at baseline and annually for 2 years after beginning simvastatin 40 mg (n = 20) or simvastatin 40 mg/ezetimibe 10 mg (n = 18) if statin naïve, or ezetimibe 10 mg (n = 30) if taking a statin. Phosphocreatine recovery time was measured by (31)P magnetic resonance spectroscopy immediately after symptom-limited calf exercise on a 1.5-T scanner. Calf perfusion was measured using first-pass contrast-enhanced magnetic resonance imaging with 0.1 mM/kg gadolinium at peak exercise. Gadolinium-enhanced magnetic resonance angiography was graded. A 6-min walk and a standardized graded Skinner-Gardner exercise treadmill test with peak Vo(2) were performed. A repeated-measures model compared changes over time.

RESULTS:

LDL reduction from baseline to year 2 was greater in the simvastatin 40 mg/ezetimibe 10 mg group (116 ± 42 mg/dl to 56 ± 21 mg/dl) than in the simvastatin 40 mg group (129 ± 40 mg/dl to 90 ± 30 mg/dl, p < 0.01). LDL also decreased in the ezetimibe 10 mg group (102 ± 28 mg/dl to 79 ± 27 mg/dl, p < 0.01). Despite this, there was no difference in perfusion, metabolism, or exercise parameters between groups or over time. Resting ABI did improve over time in the ezetimibe 10 mg group and the entire study group of patients.

CONCLUSIONS:

Despite effective LDL reduction in PAD, neither tissue perfusion, metabolism, nor exercise parameters improved, although rest ABI did. Thus, LDL lowering does not improve calf muscle physiology or functional capacity in PAD. (Comprehensive Magnetic Resonance of Peripheral Arterial Disease; NCT00587678).

Statins and Peripheral Arterial Disease

Based on the Heart Protection Study, persons with PAD should be treated with statins regardless of age, gender, or initial serum lipids levels. 

In addition to that  - Three double-blind, randomized, placebo-controlled studies have also demonstrated that statins improve walking performance in persons with PAD.

In a study of 69 persons, mean age 75 years, with intermittent claudication, a mean ABI of 0.63, and a serum LDL cholesterol of 125 mg/dl or higher, 3 of 34 persons (9%) treated with simvastatin and 6 of 35 persons (17%) treated with placebo died before the 1-year study was completed . Compared with placebo, simvastatin significantly increased treadmill exercise time until the onset of intermittent claudication by 24% at 6 months and by 42% at 1 year after therapy. 

In a study of 354 persons, mean age 68 years, with intermittent claudication and hypercholesterolemia, at 1-year follow-up, compared with placebo, atorvastatin 80 mg daily significantly improved pain-free treadmill walking distance by 40% and significantly improved community-based physical activity. 

In a study of 86 persons, mean age 67 years, with intermittent claudication and hypercholesterolemia, at 6-month follow-up, compared with placebo, simvastatin 40 mg daily significantly improved pain-free walking distance and total walking distance on a treadmill, significantly improved the mean ABI at rest and after exercise, and significantly improved symptoms of claudication.

It is also interesting to note that Statin use is also associated with superior leg functioning independent of cholesterol levels and other potential confounders. The data suggest that non-cholesterol-lowering properties of statins may influence functioning in persons with and without PAD.

1. Aronow WS, Nayak D, Woodworth S, Ahn C. Effect of simvastatin versus placebo on treadmill exercise time until the onset of intermittent claudication in older patients with peripheral arterial disease at 6 months and at 1 year after treatment. Am J Cardiol. 2003;92:711–2. 

2. Mohler ER, III, Hiatt WR, Creager MA., the Study Investigators Cholesterol reduction with atorvastatin improves walking distance in patients with peripheral arterial disease. Circulation. 2003;108:1481–6.

3. Mondillo S, Ballo P, Barbati R, et al. Effects of simvastatin on walking performance and symptoms of intermittent claudication in hypercholesterolemic patients with peripheral vascular disease. Am J Med. 2003;114:359–64.

Lancet. 2002 Jul 6;360(9326):7-22. 

MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20,536 high-risk individuals: a randomised placebo-controlled trial.

Heart Protection Study Collaborative Group.

Abstract  : Throughout the usual LDL cholesterol range in Western populations, lower blood concentrations are associated with lower cardiovascular disease risk. In such populations, therefore, reducing LDL cholesterol may reduce the development of vascular disease, largely irrespective of initial cholesterol concentrations.

METHODS: 20,536 UK adults (aged 40-80 years) with coronary disease, other occlusive arterial disease, or diabetes were randomly allocated to receive 40 mg simvastatin daily (average compliance: 85%) or matching placebo (average non-study statin use: 17%). Analyses are of the first occurrence of particular events, and compare all simvastatin-allocated versus all placebo-allocated participants. These "intention-to-treat" comparisons assess the effects of about two-thirds (85% minus 17%) taking a statin during the scheduled 5-year treatment period, which yielded an average difference in LDL cholesterol of 1.0 mmol/L (about two-thirds of the effect of actual use of 40 mg simvastatin daily). Primary outcomes were mortality (for overall analyses) and fatal or non-fatal vascular events (for subcategory analyses), with subsidiary assessments of cancer and of other major morbidity.

FINDINGS: All-cause mortality was significantly reduced (1328 [12.9%] deaths among 10,269 allocated simvastatin versus 1507 [14.7%] among 10,267 allocated placebo; p=0.0003), due to a highly significant 18% (SE 5) proportional reduction in the coronary death rate (587 [5.7%] vs 707 [6.9%]; p=0.0005), a marginally significant reduction in other vascular deaths (194 [1.9%] vs 230 [2.2%]; p=0.07), and a non-significant reduction in non-vascular deaths (547 [5.3%] vs 570 [5.6%]; p=0.4).  

The proportional reduction in the event rate was similar (and significant) in each subcategory of participant studied, including: those without diagnosed coronary disease who had cerebrovascular disease, or had peripheral artery disease, or had diabetes; men and, separately, women; those aged either under or over 70 years at entry; and--most notably--even those who presented with LDL cholesterol below 3.0 mmol/L (116 mg/dL), or total cholesterol below 5.0 mmol/L (193 mg/dL). The benefits of simvastatin were additional to those of other cardioprotective treatments. The annual excess risk of myopathy with this regimen was about 0.01%. There were no significant adverse effects on cancer incidence or on hospitalisation for any other non-vascular cause.

 

INTERPRETATION: Adding simvastatin to existing treatments safely produces substantial additional benefits for a wide range of high-risk patients, irrespective of their initial cholesterol concentrations. Allocation to 40 mg simvastatin daily reduced the rates of myocardial infarction, of stroke, and of revascularisation by about one-quarter. After making allowance for non-compliance, actual use of this regimen would probably reduce these rates by about one-third. Hence, among the many types of high-risk individual studied, 5 years of simvastatin would prevent about 70-100 people per 1000 from suffering at least one of these major vascular events (and longer treatment should produce further benefit). The size of the 5-year benefit depends chiefly on such individuals' overall risk of major vascular events, rather than on their blood lipid concentrations alone.

Vascular malformations in the forearm subcutaneous tissues can be completely excised. This video shows the excision of the Lymphovenous malformation on the lateral aspect of the upper and middle 1/3rd of the forearm in the cephalic vein zone.

Age related differences in Endothelial response to smoke?

Buerger's disease in young men who started smoking in teen age!

In few countries Buerger's disease affecting the small blood vessels in the leg disappeared, but in the other countries it is still a problem. This disease is more often noted in the rural population or societies where childhood or teenage smoking is a problem. It gives us the suspicion that the endothelium may be responding in different ways depending on the age, but that fact was not tested and published till now. Here is one paper trying the test that hypothesis in rats.

Cigarette smoke causes oxidative stress in the lung resulting in injury and disease. The purpose of this study was to determine if there were age-related differences in cigarette smoke extract (CSE)-induced production of reactive species in single and co-cultures of alveolar epithelial type I (AT I) cells and microvascular endothelial cells harvested from the lungs (MVECLs) of neonatal, young and old male Fischer 344 rats.

Cultures of AT I cells and MVECLs grown separately (single culture) and together (co-culture) were exposed to CSE (1, 10, 50, 100%). Cultures were assayed for the production of intracellular reactive oxygen species (ROS), hydroxyl radical (OH), peroxynitrite (ONOO(-)), nitric oxide (NO) and extracellular hydrogen peroxide (H(2)O(2)). Single and co-cultures of AT I cells and MVECLs from all three ages produced minimal intracellular ROS in response to CSE. All ages of MVECLs produced H(2)O(2) in response to CSE, but young MVECLs produced significantly less H(2)O(2) compared to neonatal and old MVECLs. Interestingly, when grown as a co-culture with age-matched AT I cells, neonatal and old MVECLs demonstrated ~50% reduction in H(2)O(2) production in response to CSE. However, H(2)O(2) production in young MVECLs grown as a co-culture with young AT I cells did not change with CSE exposure. 

To begin investigating for a potential mechanism to explain the reduction in H(2)O(2) production in the co-cultures, we evaluated single and co-cultures for extracellular total antioxidant capacity. We also performed gene expression profiling specific to oxidant and anti-oxidant pathways. The total antioxidant capacity of the AT I cell supernatant was ~5 times greater than that of the MVECLs, and when grown as a co-culture and exposed to CSE (≥ 10%), the total antioxidant capacity of the supernatant was reduced by ~50%. There were no age-related differences in total antioxidant capacity of the cell supernatants. Gene expression profiling found eight genes to be significantly up-regulated or down-regulated. This is the first study to describe age-related differences in MVECLs exposed to CSE.

Microvasc Res. 2011 Nov;82(3):311-7. Epub 2011 Oct 6.