Comparison of Three Tracheal Intubation Techniques in Thyroid Tumor Patients with a Difficult Airway: A Randomized Controlled Trial

Objective

To investigate the effectiveness of the Shikani optical stylet (SOS) and GlideScope video laryngoscope (GVL) for tracheal intubation of thyroid tumor patients with a difficult airway.

Subjects and Methods

One hundred and twenty thyroid tumor patients with a difficult airway, who were undergoing elective surgery requiring general anesthesia, were enrolled in the study. They were randomly allocated to 3 groups (n = 40 each) who underwent direct laryngoscopy (DL), SOS or GVL. The outcomes recorded were time to intubation, first-attempt success rate, mean artery pressure (MAP), heart rate (HR) and incidence of complications.

Results

The mean time to intubation in the SOS group (group S; 42.4 ± 24.1 s) and the GLV group (group G; 29.8 ± 22.3 s) was significantly less than that in the DL group (group D) (68.8 ± 26.6 s). The first-attempt success rate in group S (90.0s%) and group G (97.5s%) was significantly higher than that in group D (75.0s%; all p < 0.05). The HR and MAP at 1 min after intubation were lowest in group S (76.4 ± 9.2 beats/min and 12.9 ± 1.1 kPa), followed by group G (79.9 ± 9.3 beats/min and 13.0 ± 0.9 kPa) and then group D (90.4 ± 8.1 beats/min and 16.6 ± 1.2 kPa). The difference was statistically significant (all p < 0.05). The incidence of lip or mucosal trauma was lowest in group S, followed by group G and then group D.

Conclusion

The SOS and the GLV had advantages over the DL in the management of thyroid tumor patients with a difficult airway in terms of a shorter time to intubation, a higher first-attempt success rate and a reduced incidence of complications. Thus, a rational choice of one of these techniques may be better for the perioperative safety of thyroid tumor patients with a difficult airway.Key Words: Tracheal intubation, Thyroid tumor, Direct laryngoscopy, Shikani optical stylet, GlideScope video laryngoscope     

Direct and Transdentinal (Indirect) Antibacterial Activity of Commercially Available Dental Gel Formulations against Streptococcus mutans

Objective

To evaluate the direct and transdentinal (indirect) agar diffusion antibacterial activity of different commercially available antibacterial dental gel formulations against Streptococcus mutans.

Materials and Methods

The commercially available dental gel formulations were Corsodyl® (COG, 1s% chlorhexidine), Cervitec® (CEG, 0.2s% chlorhexidine s+ 0.2s% sodium fluoride), Forever Bright® (FOB, aloe vera), Gengigel® (GEG, 0.2s% hyaluronic acid), 35s% phosphoric acid gel and distilled water (control). Direct agar diffusion was performed by isolating three wells from brain-heart infusion agar plates using sterile glass pipettes attached to a vacuum pump and adding 0.1 ml of the gels to each well. Transdentinal (indirect) agar diffusion was performed by applying gel to 0.2- and 0.5-mm-thick human dentin discs previously etched with phosphoric acid and rinsed with distilled water. Zones formed around the wells and the dentin discs were measured and analyzed using Kruskal-Wallis and Mann-Whitney U tests with Bonferroni correction (p < 0.01).

Results

Direct agar diffusion tests showed significant differences among all gel formulations (p < 0.01) except for COG and CEG (p > 0.01). COG and CEG exhibited higher antibacterial effects compared to FOB and GEG (p < 0.01) in both direct and transdentinal (indirect) testing procedures. GEG did not show any antimicrobial activity in transdentinal (indirect) testing.

Conclusion

Commercially available dental gels inhibited S. mutans, which may indicate their potential as cavity disinfectants.Key Words: Antibacterial dental gels, Streptococcus mutans, Cavity disinfectant, Chlorhexidine, Hyaluronic acid, Aloe vera     

Quality of Life of Children and Adolescents with Type 1 Diabetes in Kuwait

Objectives

To evaluate the health-related quality of life (HRQoL) of children and adolescents with type 1 diabetes (T1DM) in Kuwait using the Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scale and PedsQL 3.0 Diabetes Module, and to identify the risk factors associated with unsatisfactory QoL and their effects on metabolic control.

Subjects and Methods

A total of 436 patients (2–18 years) with T1DM (>6 months) and 389 healthy controls, with the parents of both groups, completed the Arabic Generic Core Scale. Those with T1DM also completed the Arabic Diabetes Module.

Results

The mean total score of the PedsQL Diabetes Module was 70.2 ± 9.8 reported by children and 59.9 ± 11.1 reported by parents (higher scores indicate better QoL). Young age and long duration of diabetes were associated with poor QoL (p < 0.001). Boys had better total scores than girls in most age groups (70.3 ± 9.3 vs. 52.3 ± 7.2, p < 0.001); however, girls did better than boys regarding treatment barriers and adherence (71.3 ± 7.8 vs. 68.1 ± 6.2, p < 0.005). Higher HbA1c values were associated with lower QoL scores (31.1 ± 5.1 at HbA1c of 15s% vs. 82.5 ± 6.1 at HbA1c of 6s%, p < 0.0001).

Conclusion

HRQoL of children and adolescents with T1DM was consistently poorer than controls. Parents consistently reported poorer QoL scores than their children. We recommend that more support should be provided for the care of children with diabetes in Kuwait.Key Words: Children, Adolescents, Quality of life, Childhood psychology, Pediatric Quality of Life Inventory     

Differences in carotid arterial morphology and composition between individuals with and without obstructive coronary artery disease: A cardiovascular magnetic resonance study

Objective

We sought to determine differences with cardiovascular magnetic resonance (CMR) in the morphology and composition of the carotid arteries between individuals with angiographically-defined obstructive coronary artery disease (CAD, ≥ 50% stenosis, cases) and those with angiographically normal coronaries (no lumen irregularities, controls).

Methods and results

191 participants (50.3% female; 50.8% CAD cases) were imaged with a multi-sequence, carotid CMR protocol at 1.5T. For each segment of the carotid, lumen area, wall area, total vessel area (lumen area + wall area), mean wall thickness and the presence or absence of calcification and lipid-rich necrotic core were recorded bilaterally. In male CAD cases compared to male controls, the distal bulb had a significantly smaller lumen area (60.0 ± 3.1 vs. 79.7 ± 3.2 mm², p < 0.001) and total vessel area (99.6 ± 4.0 vs. 119.8 ± 4.1 mm²; p < 0.001), and larger mean wall thickness (1.25 ± 0.03 vs. 1.11 ± 0.03 mm; p = 0.002). Similarly, the internal carotid had a smaller lumen area (37.5 ± 1.8 vs. 44.6 ± 1.8 mm²; p = 0.006) and smaller total vessel area (64.0 ± 2.3 vs. 70.9 ± 2.4 mm²; p = 0.04). These metrics were not significantly different between female groups in the distal bulb and internal carotid or for either gender in the common carotid. Male CAD cases had an increased prevalence of lipid-rich necrotic core (49.0% vs. 19.6%; p = 0.003), while calcification was more prevalent in both male (46.9% vs. 17.4%; p = 0.002) and female (33.3% vs. 14.6%; p = 0.031) CAD cases compared to controls.

Conclusion

Males with obstructive CAD compared to male controls had carotid bulbs and internal carotid arteries with smaller total vessel and lumen areas, and an increased prevalence of lipid-rich necrotic core. Carotid calcification was related to CAD status in both males and females. Carotid CMR identifies distinct morphological and compositional differences in the carotid arteries between individuals with and without angiographically-defined obstructive CAD.     

Uncomplicated obesity is associated with abnormal aortic function assessed by cardiovascular magnetic resonance

Aims

Obese subjects with insulin resistance and hypertension have abnormal aortic elastic function, which may predispose them to the development of left ventricular dysfunction. We hypothesised that obesity, uncomplicated by other cardiovascular risk factors, is independently associated with aortic function.

Methods and results

We used magnetic resonance imaging to measure aortic compliance, distensibility and stiffness index in 27 obese subjects (BMI 33 kg/m²) without insulin resistance and with normal cholesterol and blood pressure, and 12 controls (BMI 23 kg/m²). Obesity was associated with reduced aortic compliance (0.9 ± 0.1 vs. 1.5 ± 0.2 mm²/mmHg in controls, p < 0.02) and distensibility (3.3 ± 0.01 vs. 5.6 ± 0.01 mmHg^-1 × 10^-3, p < 0.02), as well as higher stiffness index (3.4 ± 0.3 vs. 2.1 ± 0.1, p < 0.02). Body mass index and fat mass were negatively correlated with aortic function. Leptin was higher in obesity (8.9 ± 0.6 vs. 4.7 ± 0.6 ng/ml, p < 0.001) and also correlated with aortic measures. In multiple regression models, fat mass, leptin and body mass index were independent predictors of aortic function.

Conclusion

Aortic elastic function is abnormal in obese subjects without other cardiovascular risk factors. These findings highlight the independent importance of obesity in the development of cardiovascular disease.     

Increased Skeletal Muscle Capillarization After Aerobic Exercise Training and Weight Loss Improves Insulin Sensitivity in Adults With IGT

OBJECTIVE

Transcapillary transport of insulin is one determinant of glucose uptake by skeletal muscle; thus, a reduction in capillary density (CD) may worsen insulin sensitivity. Skeletal muscle CD is lower in older adults with impaired glucose tolerance (IGT) compared with those with normal glucose tolerance and may be modifiable through aerobic exercise training and weight loss (AEX+WL). We tested the hypothesis that 6-month AEX+WL would increase CD to improve insulin sensitivity and glucose tolerance in older adults with IGT.

RESEARCH DESIGN AND METHODS

Sixteen sedentary, overweight-obese (BMI 27–35 kg/m²), older (63 ± 2 years) men and women with IGT underwent hyperinsulinemic-euglycemic clamps to measure insulin sensitivity, oral glucose tolerance tests, exercise and body composition testing, and vastus lateralis muscle biopsies to determine CD before and after 6-month AEX+WL.

RESULTS

Insulin sensitivity (M) and 120-min postprandial glucose (G₁₂₀) correlated with CD at baseline (r = 0.58 and r = −0.60, respectively, P < 0.05). AEX+WL increased maximal oxygen consumption (VO_2max) 18% (P = 0.02) and reduced weight and fat mass 8% (P < 0.02). CD increased 15% (264 ± 11 vs. 304 ± 14 capillaries/mm², P = 0.01), M increased 21% (42.4 ± 4.0 vs. 51.4 ± 4.3 µmol/kg FFM/min, P < 0.05), and G₁₂₀ decreased 16% (9.35 ± 0.5 vs. 7.85 ± 0.5 mmol/L, P = 0.008) after AEX+WL. Regression analyses showed that the AEX+WL-induced increase in CD independently predicted the increase in M (r = 0.74, P < 0.01) as well as the decrease in G₁₂₀ (r = −0.55, P < 0.05).

CONCLUSIONS

Six-month AEX+WL increases skeletal muscle CD in older adults with IGT. This represents one mechanism by which AEX+WL improves insulin sensitivity in older adults with IGT.     

Effect of rosiglitazone on progression of atherosclerosis: insights using 3D carotid cardiovascular magnetic resonance

Background

There is recent evidence suggesting that rosiglitazone increases death from cardiovascular causes. We investigated the direct effect of this drug on atheroma using 3D carotid cardiovascular magnetic resonance.

Results

A randomized, placebo-controlled, double-blind study was performed to evaluate the effect of rosiglitazone treatment on carotid atherosclerosis in subjects with type 2 diabetes and coexisting vascular disease or hypertension. The primary endpoint of the study was the change from baseline to 52 weeks of carotid arterial wall volume, reflecting plaque burden, as measured by carotid cardiovascular magnetic resonance. Rosiglitazone or placebo was allocated to 28 and 29 patients respectively. Patients were managed to have equivalent glycemic control over the study period, but in fact the rosiglitazone group lowered their HbA1c by 0.88% relative to placebo (P < 0.001). Most patients received a statin or fibrate as lipid control medication (rosiglitazone 78%, controls 83%). Data are presented as mean ± SD. At baseline, the carotid arterial wall volume in the placebo group was 1146 ± 550 mm³ and in the rosiglitazone group was 1354 ± 532 mm³. After 52 weeks, the respective volumes were 1134 ± 523 mm³ and 1348 ± 531 mm³. These changes (-12.1 mm³ and -5.7 mm³ in the placebo and rosiglitazone groups, respectively) were not statistically significant between groups (P = 0.57).

Conclusion

Treatment with rosiglitazone over 1 year had no effect on progression of carotid atheroma in patients with type 2 diabetes mellitus compared to placebo.     

Effects of Fixed and Removable Space Maintainers on Plaque Accumulation,Periodontal Health,Candidal and Enterococcus Faecalis Carriage

Objective

To evaluate the effects of space maintainers on plaque accumulation, periodontal health and oral microflora.

Subjects and Methods

The study participants comprised 38 patients aged 4-10 years requiring either fixed or removable space maintainers. Plaque index, gingival index, bleeding on probing index, candidal colonization and Enterococcus faecalis were recorded just before the application of space maintainers (T0) and during treatment at the 1st (T1), 3rd (T2) and 6th (T3) month.

Results

The gingival and bleeding on probing index scores increased significantly (gingival index from 0.20 ± 0254 to 0.54 ± 0417 and bleeding on probing index from 7.18 ± 9.946 to 18.07 ± 14.074) in the regions with fixed space maintainers at T3 (p < 0.01). The mean Candida counts also increased (for removable appliances from 1.90 ± 3.638 to 1.98 ± 3.318, p < 0.05, and for fixed appliances from 4.25 ± 4.587 to 4.52 ± 4.431, p < 0.001). The salivary E. faecalis counts at T3 also increased significantly with the use of fixed and removable appliances (for removable appliances from 5.93 ± 2.65 to 85.53 ± 34.1 and for fixed appliances from 4.95 ± 2.94 to 123.59 ± 29.51, p < 0.001). A positive correlation was found between the plaque (r = 0.67), gingival (r = 0.76) and bleeding on probing index scores (r = 0.76) and the candidal colonization for the fixed space maintainers (p < 0.01, p < 0.001).

Conclusions

In this study, both fixed and removable space maintainers led to an increase in the number of microorganisms in the oral cavity as well as to increases in the periodontal index scores. Patients should be informed that space maintainers may serve as a source of infection and that special attention must be given to their oral hygiene.Key Words: Space maintainers, Periodontal health, <italic>Candida</italic>, <italic>Enterococcus faecalis</italic>     

Intercentre reproducibility of cardiac apparent diffusion coefficient and fractional anisotropy in healthy volunteers

Background

Diffusion tensor cardiac magnetic resonance (DT-CMR) enables probing of the microarchitecture of the myocardium, but the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) reported in healthy volunteers have been inconsistent. The aim of this study was to validate a stimulated-echo diffusion sequence using phantoms, and to assess the intercentre reproducibility of in-vivo diffusion measures using the sequence.

Methods and results

A stimulated-echo, cardiac-gated DT-CMR sequence with a reduced-field-of-view, single-shot EPI readout was used at two centres with 3 T MRI scanners. Four alkane phantoms with known diffusivities were scanned at a single centre using a stimulated echo sequence and a spin-echo Stejskal-Tanner diffusion sequence. The median (maximum, minimum) difference between the DT-CMR sequence and Stejskal-Tanner sequence was 0.01 (0.04, 0.0006) × 10^-3 mm²/s (2%), and between the DT-CMR sequence and literature diffusivities was 0.02 (0.05, 0.006) × 10^-3 mm²/s (4%).The same ten healthy volunteers were scanned using the DT-CMR sequence at the two centres less than seven days apart. Average ADC and FA were calculated in a single mid-ventricular, short axis slice. Intercentre differences were tested for statistical significance at the p < 0.05 level using paired t-tests. The mean ADC ± standard deviation for all subjects averaged over both centres was 1.10 ± 0.06 × 10^-3 mm²/s in systole and 1.20 ± 0.09 × 10^-3 mm²/s in diastole; FA was 0.41 ± 0.04 in systole and 0.54 ± 0.03 in diastole. With similarly-drawn regions-of-interest, systolic ADC (difference 0.05 × 10^-3 mm²/s), systolic FA (difference 0.003) and diastolic FA (difference 0.01) were not statistically significantly different between centres (p > 0.05), and only the diastolic ADC showed a statistically significant, but numerically small, difference of 0.07 × 10^-3 mm²/s (p = 0.047). The intercentre, intrasubject coefficients of variance were: systolic ADC 7%, FA 6%; diastolic ADC 7%, FA 3%.

Conclusions

This is the first study to demonstrate the accuracy of a stimulated-echo DT-CMR sequence in phantoms, and demonstrates the feasibility of obtaining reproducible ADC and FA in healthy volunteers at separate centres with well-matched sequences and processing.     

Monomicrobial Necrotizing Fasciitis Caused by Aeromonas hydrophila and Klebsiella pneumoniae

Objective

To compare specific characteristics and clinical outcomes of monomicrobial necrotizing fasciitis caused by Aeromonas hydrophila and Klebsiella pneumoniae.

Material and Methods

Cases of monomicrobial necrotizing fasciitis caused by A. hydrophila (n = 11) and K. pneumoniae (n = 7) over an 8-year period were retrospectively reviewed. Differences in mortality, patient characteristics, clinical presentations, and laboratory data were compared between the A. hydrophila and the K. pneumoniae groups.

Results

The clinical signs and symptoms at the time of presentation did not differ significantly (p > 0.05) between the two groups. The A. hydrophila group had a significantly shorter interval between contact and admission (1.55 ± 0.52 vs. 5.14 ± 2.12 days, p < 0.001) and significant lower total white blood cell counts (10,245 ± 5,828 vs. 19,014 ± 11,370 cells/mm³, p < 0.045) than the K. pneumoniae group in the emergency room. Hepatic dysfunction was associated with mortality in patients with A. hydrophila infection, while diabetes mellitus was associated with mortality in patients with K. pneumoniae infection. Overall, 5 (45.5%) patients in the A. hydrophila group and 3 (42.8%) in the K. pneumoniae group died.

Conclusion

The initial clinical course of A. hydrophila monomicrobial necrotizing fasciitis was characterized by more rapidly progressive disease than that of the K. pneumoniae infection. Patients with hepatic dysfunction and necrotizing fasciitis should be suspected of having A. hydrophila infection, and diabetic patients with necrotizing fasciitis should be suspected of having K. pneumoniae infection initially.Key Words: Necrotizing fasciitis, Aeromonas hydrophila, Klebsiella pneumoniae     

Effects of pulmonary stretch reflex on lung injury in rabbits with acute respiratory distress syndrome

BACKGROUND:

Pulmonary stretch reflex plays an important role in regulation of respiratory movement. This study aimed to evaluate the effect of pulmonary stretch reflex on lung injury in rabbits with acute respiratory distress syndrome (ARDS).

METHODS:

ARDS rabbits were given intratracheal infusion of hydrochloric acid and ventilated with neurally adjusted ventilatory assistance (NAVA) with a tidal volume (V_T) of 6 mL/kg and the electrical activity of diaphragm (EAdi)-determined positive end expiratory pressure. After isolation of the bilateral vagus nerve trunk, the rabbits were randomized into two groups: sham operation (SHAM) group (n=5) and bilateral vagotomy (VAG) group (n=5). Gas exchange and respiratory mechanics were detected at baseline, after lung injury and 1, 2, and 3 hours after ventilation respectively. Pulmonary permeability index, pathological changes and inflammatory response were also measured.

RESULTS:

Compared with the SHAM group, PaO₂/FiO₂ in the VAG group decreased significantly 2 and 3 hours after ventilation (P<0.05). There was no significant difference in PaCO₂ between the SHAM and VAG groups (P>0.05), and the VAG group had a high V_T, peak pressure (Ppeak), and mean pressure (Pm) compared with the SHAM group 1, 2, 3 hours after ventilation (P<0.05). Compared to the SHAM group, dead space fraction (V_D/V_T) and respiratory system elastance (Ers) in the VAG group increased (P<0.05) and static pulmonary compliance (Cst) decreased markedly (P<0.05) after ventilation for 3 hours. Lung wet/dry weight ratio (W/D) (8.4±1.2 vs. 6.6±1.0), lung injury score (6.3±1.8 vs. 3.8±1.3), tumor necrosis factor-α (TNF-α) (779±372 pg/mL vs. 355±130 pg/mL) and interleukin-8 (IL-8) (169±21 pg/mL vs. 118±17 pg/mL) increased significantly in the VAG group compared with the SHAM group (P<0.05).

CONCLUSION:

Lung injury is aggravated after bilateral vagotomy, demonstrating that pulmonary stretch reflex may have protective effect on the lung.KEY WORDS: Pulmonary stretch reflex, Vagus nerve, Lung injury, Acute respiratory distress syndrome, Electrical activity of diaphragm, Mechanical ventilation     

Association between preterm birth and thoracic musculoskeletal static alterations in adolescents

OBJECTIVE:

To compare thoracic musculoskeletal static alterations in adolescents born prematurely with those born at term and investigate neonatal and post-neonatal variables associated with thoracic alterations.

METHOD:

This is a cross-sectional study with 57 adolescents aged 10-15 years born prematurely and 57 adolescents born at term paired by gender and age. Photographs of the head and thorax in the front, back, and right side views were studied using a computer program. The two groups were compared in regards to: elevation of clavicles, elevation of shoulders, protrusion of the head, and anteroposterior and mediolateral thoracic length. Factor associated with thoracic disorders were evaluated by linear regression analysis.

RESULTS:

The Preterm group had mean gestational age of 32.0±2.8 weeks and the birth weight was 1462±338 and 3342±430 g for the Preterm and Term adolescents, respectively. Preterm adolescents had higher elevation of the left shoulder (22.7±5.4^o vs. 20.6±5.3^o;sim, p=0.038) and the right shoulder (22.2±4.4^o vs. 18.5±5.7^o; p<0.001). Smaller protrusion of the head (27.8±6.1^o vs. 32.4±7.9^o; p=0.008), mediolateral thoracic length (22.9±2.3 cm vs. 25.1±3.1 cm; p<0.001) and anteroposterior thoracic length (19.7±2.2 cm vs. 21.1±3.4 cm; p<0.001) were found in preterm adolescents. By multiple regression analysis, factors associated with higher shoulder elevation were birth weight <1500 g (p<0.001) and mechanical ventilation during neonatal period >5 days (p=0.009).

CONCLUSION:

Adolescents born prematurely presented greater thoracic musculoskeletal static alterations compared to those born at term. Factors associated with these alterations were: very low birth weight and longer duration of mechanical ventilation in the neonatal unit.     

An Investigation of Tenascin-C Levels in Rheumatic Mitral Stenosis and Their Response to Percutaneous Mitral Balloon Valvuloplasty

Objective

The purpose of this study was to evaluate the tenascin-C levels in severe rheumatic mitral stenosis before and after percutaneous mitral balloon valvuloplasty (PMBV).

Subjects and Methods

Forty patients with severe mitral stenosis requiring PMBV and 20 age-matched healthy subjects were included in the study. The mitral valve areas, mitral gradients and systolic pulmonary artery pressure (sPAP) were measured by echocardiography. The sPAP values and mitral gradients were also measured by catheterization before and after PMBV. The blood tenascin-C levels were measured before PMBV and 1 month after the procedure.

Results

The echocardiographic mean mitral gradients had a significant decrease after PMBV (11.7 ± 2.8 vs. 5.6 ± 1.7 mm Hg; p < 0.001) and also those of catheterization (13.9 ± 4.4 vs. 4.0 ± 2.4 mm Hg; p < 0.001). Mitral valve areas increased significantly after PMBV (from 1.1 ± 0.1 to 1.8 ± 0.2 cm², p < 0.001). Tenascin-C levels decreased significantly in patients after PMBV (from 15.0 ± 3.8 to 10.9 ± 3.1 ng/ml; p < 0.001). Tenascin-C levels were higher in patients with mitral stenosis before PMBV than in healthy subjects (15.0 ± 3.8 and 9.4 ± 2.9 ng/ml; p < 0.001, respectively). There were no significant differences between patients with mitral stenosis after PMBV and healthy subjects (10.9 ± 3.1 and 9.4 ± 2.9 ng/ml; p = 0.09, respectively). There was a significant positive correlation between tenascin-C levels and sPAP (r = 0.508, p < 0.001). In multivariant analysis, tenascin-C predicted mitral stenosis (p = 0.004, OR: 2.31).

Conclusions

Tenascin-C was an independent predictor for rheumatic mitral stenosis.Key Words: Tenascin-C, Mitral stenosis, Percutaneous mitral balloon valvuloplasty, Pulmonary hypertension     

Association of Red Blood Cell Distribution Width Levels with Severity of Coronary Artery Disease in Patients with Non-ST Elevation Myocardial Infarction

Objectives

The aim of this study was to evaluate the association of the levels of red blood cell distribution width (RDW) with the severity of atherosclerosis and to determine whether or not the RDW level on admission is an independent predictor of all-cause mortality in patients with non-ST elevation myocardial infarction (NSTEMI).

Materials and Methods

A total of 335 consecutive patients with NSTEMI were enrolled in this study. The patients were divided into high (n = 105) and low (n = 230) SYNTAX groups. The high SYNTAX group was defined as patients with a value in the third tertile (SYNTAX score, SXscore ≥12), while the low SYNTAX group was defined as those with a value in the lower 2 tertiles (SXscore <12). The high RDW group (n = 152) was defined as patients with RDW >14.25s% and the low RDW group (n = 183) as those with RDW ≤14.25s%. All-cause mortality was followed up to 38 months.

Results

The mean follow-up period was 18 ± 11 months. The RDW levels of patients were significantly higher in the high SYNTAX group than in the low SYNTAX group (15.2 ± 1.8 vs. 14.2 ± 1.2, p < 0.001). Pearson''s coefficients were used to determine the degree of association between RDW levels and SXscore and also between RDW levels and high-sensitivity C-reactive protein. There was a significant correlation between RDW levels and SXscore (r = 0.460, p < 0.001). Also, there was a significant correlation between RDW levels and high-sensitivity C-reactive protein (r = 0.180, p = 0.001). All-cause mortality rate was not significantly different between the high and low RDW groups (log-rank, p = 0.621).

Conclusion

RDW levels were independently associated with high SXscore but were not associated with long-term mortality in NSTEMI patients.Key Words: Red blood cell distribution width, Non-ST elevation myocardial infarction, SYNTAX score, Coronary artery disease     

Post-conditioning with gradually increased reperfusion provides better cardioprotection in rats

BACKGROUND:

Rapid and complete reperfusion has been widely adopted in the treatment of patients with acute myocardial infarction (AMI), but this process sometimes can cause severe reperfusion injury. This study aimed to investigate different patterns of post-conditioning in acute myocardial ischemia-reperfusion injury, and to detect the role of mitogen activated protein kinase (MAPK) during the injury.

METHODS:

Rats were randomly divided into five groups: sham group, reperfusion injury (R/ I) group, gradually decreased reperfusion group (GDR group, 30/10-25/15-15/25-10/30 seconds of reperfusion/ischemia), equal reperfusion group (ER group, 20/20 seconds reperfusion/ischemia, 4 cycles), and gradually increased reperfusion group (GIR group, 10/30-15/25-25/15-30/10 seconds of reperfusion/ischemia). Acute myocardial infarction and ischemic post-conditioning models were established in the rats. Six hours after reperfusion, 3 rats from each group were sacrificed and myocardial tissues were taken to measure the expressions of phosphorylation of extracellular signal-regulated protein kinase (P-ERK), phosphorylated c-Jun N-terminal kinase (P-JNK), mitogen-activated protein kinase p38 (p38 MAPK), tumor necrosis factor-α (TNF-α), caspases-8 in the myocardial tissue, and cytochrome c in the cytosol using Western blot. Hemodynamics was measured at 24 hours after reperfusion, the blood was drawn for the determination of cardiac enzymes, and the heart tissue was collected for the measurement of apoptosis using TUNEL. One-way analysis of variance and the Q test were employed to determine differences in individual variables between the 5 groups.

RESULTS:

Three post-conditioning patterns were found to provide cardioprotection (P<0.05) compared with R/I without postconditioning. GIR provided the best cardioprotection effect, followed by ER and then GDR. Apoptotic index and serum marker levels were reduced more significantly in GIR than in ER (P<0.05). The enhanced cardioprotection provided by GIR was accompanied with significantly increased levels of P-ERK 1/2 (1.82±0.22 vs. 1.54±0.32, P<0.05), and lower levels of p-JNK, p38 MAPK, TNF-α, caspase-8, caspase-9 and cytochrome in the cytoplasm (P<0.05), compared with ER. The infarct size was smaller in the GIR group than in the ER group, but this difference was not significant (16.30%±5.22% vs. 20.57%±6.32%, P<0.05). All the measured variables were improved more significantly in the GIR group than in the GDR group (P<0.05).

CONCLUSION:

Gradually increased reperfusion in post-conditioning could attenuate reperfusion injury more significantly than routine method, thereby the MAPK pathway plays an important role in this process.KEY WORDS: Ischemia-reperfusion injury, Postconditioning, Apoptosis     

Cardiovascular magnetic resonance for the assessment of patients undergoing transcatheter aortic valve implantation: a pilot study

Background

Before trans-catheter aortic valve implantation (TAVI), assessment of cardiac function and accurate measurement of the aortic root are key to determine the correct size and type of the prosthesis. The aim of this study was to compare cardiovascular magnetic resonance (CMR) and trans-thoracic echocardiography (TTE) for the assessment of aortic valve measurements and left ventricular function in high-risk elderly patients submitted to TAVI.

Methods

Consecutive patients with severe aortic stenosis and contraindications for surgical aortic valve replacement were screened from April 2009 to January 2011 and imaged with TTE and CMR.

Results

Patients who underwent both TTE and CMR (n = 49) had a mean age of 80.8 ± 4.8 years and a mean logistic EuroSCORE of 14.9 ± 9.3%. There was a good correlation between TTE and CMR in terms of annulus size (R² = 0.48, p < 0.001), left ventricular outflow tract (LVOT) diameter (R² = 0.62, p < 0.001) and left ventricular ejection fraction (LVEF) (R² = 0.47, p < 0.001) and a moderate correlation in terms of aortic valve area (AVA) (R² = 0.24, p < 0.001). CMR generally tended to report larger values than TTE for all measurements. The Bland-Altman test indicated that the 95% limits of agreement between TTE and CMR ranged from -5.6 mm to + 1.0 mm for annulus size, from -0.45 mm to + 0.25 mm for LVOT, from -0.45 mm² to + 0.25 mm² for AVA and from -29.2% to 13.2% for LVEF.

Conclusions

In elderly patients candidates to TAVI, CMR represents a viable complement to transthoracic echocardiography.     

Susceptibility to ventilator induced lung injury is increased in senescent rats

Introduction

The principal mechanisms of ventilator induced lung injury (VILI) have been investigated in numerous animal studies. However, prospective data on the effect of old age on VILI are limited. Under the hypothesis that susceptibility to VILI is increased in old age, we investigated the pulmonary and extrapulmonary effects of mechanical ventilation with high tidal volume (VT) in old compared to young adult animals.

Interventions

Old (19.1 ± 3.0 months) and young adult (4.4 ± 1.3 months) male Wistar rats were anesthetized and mechanically ventilated (positive end-expiratory pressure 5 cmH2O, fraction of inspired oxygen 0.4, respiratory rate 40/minute) with a tidal volume (VT) of either 8, 16 or 24 ml/kg for four hours.Respiratory and hemodynamic variables, including cardiac output, and markers of systemic inflammation were recorded throughout the ventilation period. Lung histology and wet-to-dry weight ratio, injury markers in lung lavage and respiratory system pressure-volume curves were assessed post mortem. Basic pulmonary characteristics were assessed in non-ventilated animals.

Results

Compared to young adult animals, high VT (24 ml/kg body weight) caused more lung injury in old animals as indicated by decreased oxygenation (arterial oxygen tension (PaO2): 208 ± 3 vs. 131 ± 20 mmHg; P <0.05), increased lung wet-to-dry-weight ratio (5.61 ± 0.29 vs. 7.52 ± 0.27; P <0.05), lung lavage protein (206 ± 52 mg/l vs. 1,432 ± 101; P <0.05) and cytokine (IL-6: 856 ± 448 vs. 3,283 ± 943 pg/ml; P <0.05) concentration. In addition, old animals ventilated with high VT had more systemic inflammation than young animals (IL-1β: 149 ± 44 vs. 272 ± 36 pg/ml; P <0.05 - young vs. old, respectively).

Conclusions

Ventilation with unphysiologically large tidal volumes is associated with more lung injury in old compared to young rats. Aggravated pulmonary and systemic inflammation is a key finding in old animals developing VILI.     

Effect of captopril on uterine blood flow and prostaglandin E synthesis in the pregnant rabbit

Captopril, 5 mg/kg, administered to pregnant rabbits caused a reduction in mean arterial pressure (MAP) from 106±2 to 87±2 mmHg (P<0.01) without change in cardiac output or renal blood flow. Uterine blood flow fell from 31.9±2.5 to 21.3±3.4 ml/min (P<0.01) as uterine vein prostaglandin E series level (PGE) decreased from 127±23 ng/ml to 26±8 ng/ml (P<0.01). Saralasin also caused a reduction in MAP from 110±5 to 92±4.3 (P<0.01), a reduction in uterine blood flow from 28.8±1.6 to 21.8±1.7 ml/min (P<0.01) as uterine vein PGE decreased from 121.3±14.4 to 63.5±14.2 ng/ml (P<0.01). Plasma renin activity (PRA) was higher in the uterine vein, 11±3 ng/ml per h, than peripheral vein, 6±1.6 ng/ml per h, (P<0.05), before Captopril and rose in the uterine vein to 90±19 ng/ml per h (P<0.01) as peripheral vein PRA rose to 62±15 ng/ml per h (P<0.05) after Captopril. After saralasin uterine vein PRA rose from 4.6±1.5 to 14.8±6.3 ng/ml per h (P<0.05) and peripheral vein PRA rose from 3.7±1 to 6.5±2.1 (P<0.05).     

Iron overload in polytransfused patients without heart failure is associated with subclinical alterations of systolic left ventricular function using cardiovascular magnetic resonance tagging

Background

It remains incompletely understood whether patients with transfusion related cardiac iron overload without signs of heart failure exhibit already subclinical alterations of systolic left ventricular (LV) dysfunction. Therefore we performed a comprehensive evaluation of systolic and diastolic cardiac function in such patients using tagged and phase-contrast CMR.

Methods

19 patients requiring regular blood transfusions for chronic anemia and 8 healthy volunteers were investigated using cine, tagged, and phase-contrast and T2* CMR. LV ejection fraction, peak filling rate, end-systolic global midventricular systolic Eulerian radial thickening and shortening strains as well as left ventricular rotation and twist, mitral E and A wave velocity, and tissue e'' wave and E/e'' wave velocity ratio, as well as isovolumic relaxation time and E wave deceleration time were computed and compared to cardiac T2*.

Results

Patients without significant iron overload (T2* > 20 ms, n = 9) had similar parameters of systolic and diastolic function as normal controls, whereas patients with severe iron overload (T2* < 10 ms, n = 5), had significant reduction of LV ejection fraction (54 ± 2% vs. 62 ± 6% and 65 ± 6% respectively p < 0.05), of end-systolic radial thickening (+6 ± 4% vs. +11 ± 2 and +11 ± 4% respectively p < 0.05) and of rotational twist (1.6 ± 0.2 degrees vs. 3.0 ± 1.2 and 3.5 ± 0.7 degrees respectively, p < 0.05) than patients without iron overload (T2* > 20 ms) or normal controls. Patients with moderate iron overload (T2* 10-20 ms, n = 5), had preserved ejection fraction (59 ± 6%, p = NS vs. pts. with T2* > 20 ms and controls), but showed reduced maximal LV rotational twist (1.8 ± 0.4 degrees). The magnitude of reduction of LV twist (r = 0.64, p < 0.001), of LV ejection fraction (r = 0.44, p < 0.001), of peak radial thickening (r = 0.58, p < 0.001) and of systolic (r = 0.50, p < 0.05) and diastolic twist and untwist rate (r = -0.53, p < 0.001) in patients were directly correlated to the logarithm of cardiac T2*.

Conclusion

Multiple transfused patients with normal ejection fraction and without heart failure have subclinical alterations of systolic and diastolic LV function in direct relation to the severity of cardiac iron overload. Among all parameters, left ventricular twist is affected earliest, and has the highest correlation to log (T2*), suggesting that this parameter might be used to follow systolic left ventricular function in patients with iron overload.