Mechanical Dyssynchrony Combined with Septal Scarring Reliably Identifies Responders to Cardiac Resynchronization Therapy

Background and aim: The presence of mechanical dyssynchrony on echocardiography is associated with reverse remodelling and decreased mortality after cardiac resynchronization therapy (CRT). Contrarily, myocardial scar reduces the effect of CRT. This study investigated how well a combined assessment of different markers of mechanical dyssynchrony and scarring identifies CRT responders. Methods: In a prospective multicentre study of 170 CRT recipients, septal flash (SF), apical rocking (ApRock), systolic stretch index (SSI), and lateral-to-septal (LW-S) work differences were assessed using echocardiography. Myocardial scarring was quantified using cardiac magnetic resonance imaging (CMR) or excluded based on a coronary angiogram and clinical history. The primary endpoint was a CRT response, defined as a ≥15% reduction in LV end-systolic volume 12 months after implantation. The secondary endpoint was time-to-death. Results: The combined assessment of mechanical dyssynchrony and septal scarring showed AUCs ranging between 0.81 (95%CI: 0.74-0.88) and 0.86 (95%CI: 0.79-0.91) for predicting a CRT response, without significant differences between the markers, but significantly higher than mechanical dyssynchrony alone. QRS morphology, QRS duration, and LV ejection fraction were not superior in their prediction. Predictive power was similar in the subgroups of patients with ischemic cardiomyopathy. The combined assessments significantly predicted all-cause mortality at 44 ± 13 months after CRT with a hazard ratio ranging from 0.28 (95%CI: 0.12-0.67) to 0.20 (95%CI: 0.08-0.49). Conclusions: The combined assessment of mechanical dyssynchrony and septal scarring identified CRT responders with high predictive power. Both visual and quantitative markers were highly feasible and demonstrated similar results. This work demonstrates the value of imaging LV mechanics and scarring in CRT candidates, which can already be achieved in a clinical routine.

Reintroducing dyssynchrony significantly increases myocardial stiffness at mitral valve closure

Background

Cardiac shear wave elastography (SWE) allows for the non-invasive assessment of myocardial stiffness via the detection of shear waves. Shear waves are mechanical waves that travel through the heart after for example mitral valve closure (MVC). The propagation speed of these waves is directly dependent on myocardial stiffness, where a higher shear wave speed correlates with a higher stiffness. However, the effect of a left bundle branch block (LBBB) and a dyssynchronous contraction pattern on shear wave speed is currently unknown.

Purpose

To investigate the effect of a dyssynchronous contraction pattern caused by LBBB on shear wave speed.

Methods

We included 29 non-ischemic heart failure patients with an LBBB (68±15y; 52% males) and 9 age-matched healthy volunteers (68±4y; 55% males) as controls. All LBBB patients were implanted with a CRT device and dyssynchrony was reintroduced by turning biventricular (BiV) pacing off to allow native ventricular conduction. Echocardiographic images were taken during BiV pacing on and BiV pacing off, with a conventional ultrasound machine and an experimental high frame rate ultrasound scanner. Shear waves were visualized in M-modes of the septum, colour coded for tissue acceleration. The slope of the shear waves in the M-mode represents their propagation speed. Further, longitudinal strain at MVC and the time difference between onset of septal contraction and MVC were measured (negative time values indicate that MVC occurs before onset of septal contraction).

Results

There was no significant difference in shear wave speed between healthy controls and LBBB patients during BiV pacing on (4.5±1.1 m/s vs 4.9±1.2 m/s; p=0.365; Figure A). However, shear wave speed was significantly higher in LBBB patients during BiV pacing off compared to healthy controls (4.5±1.1 m/s vs 5.6±1.1 m/s; p=0.041; Figure A). Turning BiV pacing off lead to a significant increase in shear wave speed in LBBB patients (4.9±1.2 m/s vs 5.6±1.1 m/s; p=0.003; Figure A), indicating that the reintroduction of LBBB increases septal myocardial stiffness. MVC occurred significantly later after the onset of septal contraction during BiV pacing off (−9±57 ms vs 40±26 ms; p=0.001) and strain values at MVC were more negative (−0.3±0.6% vs −2.0±1.5%; p<0.001). Therefore we hypothesize that during BiV pacing off, the septal wall was further into the contraction phase at the time of MVC, leading to an increased myocardial stiffness, and thus increased shear wave speed (Figure B). Our interpretation was further strengthened by a strong correlation between the change in shear wave speed and the change in septal longitudinal strain at MVC when BiV pacing is turned off (r=0.81; p<0.001; Figure C).

Conclusion

Reintroducing dyssynchrony in LBBB patients significantly increases shear wave speed at MVC. Our results suggest that the earlier contraction of the septum during dyssynchrony is an explanation for the higher septal stiffness at MVC.

Funding Acknowledgement

Type of funding sources: None.

Cardiac shear wave elastography can detect the presence of a septal scar in patients with LBBB

Background

In patients with heart failure and a left bundle branch block (LBBB), cardiac resynchronization therapy (CRT) is an established treatment. However, the rate of non-response to this costly therapy remains high. So far, CRT has proven to be less effective in patients with a septal scar. Detection of a septal scar before CRT implantation could therefore help to improve response rate to CRT. The gold standard to detect septal scarring, LGE MRI, is quite costly and not suited or available for all patients. Cardiac shear wave elastography (SWE) may be an alternative. It allows for the non-invasive assessment of myocardial stiffness based on the detection of shear waves, after for example mitral valve closure (MVC). SWE has shown to be capable to detect myocardial scar, however this has never been demonstrated in the presence of LBBB.

Purpose

To determine whether SWE is able to detect the presence of a septal scar in patients with LBBB.

Methods

To investigate this, 39 CRT patients with a LBBB were included with ischemic (n=10; age: 73±6 y; 70% males) or non-ischemic (n=29; 68±14 y; 52% males) cardiomyopathy and 9 age-matched healthy volunteers (68±4 y; 55% males) served as controls. In order to obtain native ventricular conduction biventricular (BiV) pacing was turned off. All ischemic patients had septal scar only, proven by MRI or scintigraphy. For SWE, left ventricular parasternal long-axis views were acquired with an experimental high frame rate ultrasound scanner (frame rate: 932±32 fps). Shear waves were visualized in M-modes of the septum, colour coded for tissue acceleration. The slope of the shear waves in the M-mode represents their propagation speed (Figure 1A).

Results

Patients characteristics and echocardiographic parameters are shown in Table 1. Shear wave speed after MVC was significantly higher in LBBB patients with and without a septal scar compared to healthy controls (7.8±1.2 m/s vs 4.5±1.1 m/s; p<0.001; 5.6±1.1 m/s vs 4.5±1.1 m/s; p=0.041; Figure 1B), indicating that the presence of LBBB increases myocardial stiffness. However, more importantly, shear wave speed was significantly higher in LBBB patients with a septal scar compared to LBBB patients without a septal scar (7.8±1.2 m/s vs 5.6±1.1 m/s; p<0.001; Figure 1B). This implies that the presence of a septal scar increases shear wave speed even more than LBBB alone. A ROC-curve analysis further showed that SWE is capable of distinguishing scarred from non-scarred septum in LBBB patients (AUC: 0.92; p<0.001; Figure 1C). A cut-off of 7.1 m/s could identify LBBB patients with a septal scar with a sensitivity of 80% and specificity of 93%.

Conclusion

Septal scarring results in a significant increase in myocardial stiffness, so that it reaches a clear pathological range. SWE seems therefore capable of detecting the presence of a septal scar in LBBB patients and could potentially be used as a novel approach for the assessment of septal scarring in CRT candidates.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Research foundation Flanders (FWO)

Dyssynchrony significantly increases myocardial stiffness at mitral valve closure

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): FWO: Fonds Wetenschappelijk Onderzoek (fund for Scientific Research Flanders)

Background

Recently, shear wave elastography (SWE) has emerged as a promising, non-invasive technique to determine myocardial tissue stiffness. SWE is based on the detection of shear waves, for example induced by mitral valve closure (MVC), that propagate through the myocardium. The propagation speed of these shear waves is directly dependent on myocardial stiffness. However, the effect of a dyssynchronous contraction pattern – as it occurs in left bundle branch block (LBBB) – on shear wave speed is currently unknown.

Purpose

To investigate the effect of the dyssynchronous contraction pattern caused by LBBB on shear wave speed.

Methods

We included 25 non-ischemic heart failure patients with LBBB (age: 68 ± 15y; 52% males), all implanted with a CRT device. Dyssynchrony was reintroduced by turning biventricular (BiV) pacing off to allow native ventricular conduction. Echocardiographic images were taken during BiV pacing on and BiV pacing off, both with a conventional ultrasound machine and an experimental high frame rate ultrasound scanner (frame rate: 932 ± 32 fps). For SWE, left ventricular parasternal long-axis views were acquired. Shear waves were visualized in M-modes of the septum, colour coded for tissue acceleration. The slope of the shear waves in the M-mode represents their propagation speed. Speckle tracking of the four-chamber apical view was used to asses longitudinal strain of the mid-septal segment. To further investigate how dyssynchrony affects shear wave speed, the following time points were measured: onset of QRS, MVC and onset of septal contraction.

Results

Acutely switching BiV pacing on and off did not significantly affect left ventricular ejection fraction, nor end-diastolic or end-systolic volumes (all p > 0.05). Shear wave speed was significantly higher during BiV pacing off compared to BiV pacing on (5.6 ± 1.2 m/s vs 4.9 ± 1.3 m/s; p = 0.003; figure A). Furthermore, the onset of septal contraction was significantly earlier during BiV off (11 ± 15 ms vs 105 ± 57 ms; p < 0.0001). As a result, during BiV pacing off, the septal wall was further into the contraction phase at the time of MVC, leading to an increased myocardial stiffness, and thus increased shear wave speed (figure B). Our interpretation that increased shear wave speed could be attributed to an earlier onset of contraction of the septum was further strengthened by a strong correlation between the change in shear wave speed and the change in septal longitudinal strain at MVC when BiV pacing is turned off (r = 0.83; p < 0.001; figure C).

Conclusion

A dyssynchronous contraction caused by LBBB significantly increases shear wave propagation speed at MVC. This could be attributed to the early-systolic contraction of the septum during dyssynchrony. These results indicate that changes in contraction pattern caused by LBBB significantly influence myocardial stiffness at MVC. Abstract Figure.

Can cardiac shear wave elastography detect the presence of septal scar in patients with left bundle branch block?

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): FWO: Fonds Wetenschappelijk Onderzoek (fund for scientific research Flanders)

Background

Cardiac resynchronization therapy (CRT) is an established treatment for heart failure patients with left bundle branch block (LBBB). Regardless, CRT has proven to be less effective in patients with ischemic cardiomyopathy, in particular when the septum is affected. The detection of septal scar prior to CRT implantation could therefore help to improve response rate. However, magnetic resonance imaging (MRI), the gold standard to assess myocardial scar, cannot be used in every patient due to already implanted devices or impaired renal function. Cardiac shear wave elastography (SWE) allows for the non-invasive assessment of myocardial stiffness via the detection of shear waves, for example induced by mitral valve closure (MVC), that travel through the myocardium. Shear wave speed is directly related to tissue stiffness. Recently, SWE has shown to be capable to detect myocardial scar, however this has never been demonstrated in the presence of LBBB.

Purpose

To evaluate whether SWE is able to detect the presence of septal scar in patients with LBBB.

Methods

We included 34 heart failure patients with LBBB (age: 69 ± 13 y; 56% males) and with ischemic (n = 9) or non-ischemic (n = 25) cardiomyopathy and 9 age-matched healthy volunteers (age: 68 ± 4 y; 66% males) as controls. In order to obtain native ventricular conduction biventricular (BiV) pacing was turned off. All ischemic patients had septal scar only, proven by MRI or scintigraphy. For SWE, left ventricular parasternal long-axis views were acquired with an experimental high frame rate ultrasound scanner (frame rate: 932 ± 32 fps). Shear waves were visualized in M-modes of the septum, colour coded for tissue acceleration. The slope of the shear waves in the M-mode represents their propagation speed (Figure A).

Results

Patient characteristics including echocardiographic parameters are shown in Table 1. Shear wave speed after MVC was significantly higher in patients with LBBB with or without septal scar compared to healthy controls (7.9 ± 1.2 m/s vs 4.5 ± 1.1 m/s; p = 0.044; 5.6 ± 1.2 m/s vs 4.5 ± 1.1 m/s: p < 0.001; figure B). This implies that the presence of LBBB alone increases myocardial stiffness. Most importantly, however, shear wave speed was significantly higher in LBBB patients with a septal scar compared to LBBB patients without a septal scar (7.9 ± 1.2 m/s vs 5.6 ± 1.2 m/s; p < 0.001; figure B), indicating that the presence of scar increases myocardial stiffness even more than LBBB alone.

Conclusions

LBBB causes a mild but significant increase in shear wave propagation speed in non-ischemic patients compared to controls. The presence of septal scarring leads to an additional and more significant increase. This indicates that SWE is capable of detecting stiffer scarred myocardium even in the presence of LBBB. Therefore, SWE could potentially be used as a novel method to detect septal scarring in LBBB patients before CRT implantation. Abstract Figure.  Abstract Figure.

Cardiac shear wave elastography can distinguish healthy and scarred myocardium in patients with conduction delays

Background

Cardiac resynchronization therapy (CRT) is an established therapy for patients suffering from heart failure and left bundle branch block (LBBB) conduction delays. Despite its proven beneficial effects, CRT is associated with a high percentage of non-response. Since CRT has shown to be less effective in patients with ischemic cardiomyopathy, determining the presence of myocardial scar before implantation could help to improve the response-rate. However, the gold standard to assess myocardial scar, magnetic resonance imaging (MRI), cannot be used in every patient, due to already implanted devices and/or reduced renal function. Recently introduced shear wave elastography (SWE) allows the non-invasive assessment of myocardial stiffness. Natural shear waves are excited by mitral valve closure (MVC) and travel through the heart with a speed directly related to tissue stiffness. SWE has previously been proven to be able to detect myocardial scar, however this has never been shown in the presence LBBB.

Purpose

The aim of this study was to evaluate the capability of SWE as a novel method to determine myocardial scar in patients with conduction delays.

Methods

We included 24 heart failure patients (age: 68±10; 50% males) with ischemic (n=8) and non-ischemic (n=16) cardiomyopathy. The CRT device was set to AAI mode in order to obtain native ventricular conduction. For patients with ischemic cardiomyopathy, the presence and location of scar was determined by MRI or scintigraphy. All ischemic patients had septal scar only. For SWE, left ventricular parasternal long-axis views were acquired with an experimental high frame rate ultrasound scanner (average frame rate: ±1200 Hz). Shear waves were visualized in M-modes of the septum, colour coded for tissue acceleration. The slope of the shear waves in the M-mode represents their propagation speed (Figure A).

Results

There was no significant difference between the ischemic and non-ischemic patients in QRS width after CRT (149±31 ms vs 144±26 ms), systolic blood pressure blood pressure (135±11 mmHg vs 135±23 mmHg), diastolic blood pressure (74±9 mmHg vs 70±11 mmHg) and heart rate (58±4 bpm vs 63±9 bpm) (all p>0.05). Ejection fraction (33±8% vs 45±10%), end-diastolic volume (196±34 ml vs 129±64 ml) and global longitudinal strain (−9.8±3.1% vs −14.1±4.1%) differed significantly between the groups (all p<0.05). Shear wave speed after MVC was significantly higher in patients with septal scar compared to non-ischemic patients (8.2±1.9 m/s vs 5.5±1.2 m/s; p<0.01) (Figure B).

Conclusion

In the presence of scar, we found markedly elevated shear wave propagation speed compared to non-ischemic patients. These results indicate that SWE is able to identify scarred myocardium even in patients with LBBB. We therefore believe that SWE could be a novel easy and non-invasive method to evaluate septal myocardial scarring in patients before CRT implantation.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): FWO - Research Foundation Flanders

Discrepancies Between BMI and Classic Cardiovascular Risk Factors

BACKGROUND

Obesity is related to increased cardiovascular risk. It is unknown whether increasing levels of obesity also increase levels of cardiovascular risk factors and systemic inflammation. This study describes the relationship between classic cardiovascular risk factors and inflammatory markers with BMI in a group of obese and non-obese subjects.

MATERIALS AND METHODS

Obese subjects (BMI ≥ 30 kg/m²; n = 576; mean ± SD BMI 43.8 ± 7.58 kg/m²) scheduled for bariatric surgery were included. The reference population consisted of non-obese volunteers (BMI < 30 kg/m²; n = 377, BMI 25.0 ± 2.81 kg/m²). The relationship between BMI quintiles and the levels of cardiovascular risk factors was analyzed. Adipose tissue volumetry was performed in 42 obese subjects using abdominal CT scans.

RESULTS

The obese group included more women and subjects with type 2 diabetes mellitus, hypertension, and current smoking behavior. In obese subjects, HDL-C and triglycerides decreased with increasing BMI. Systolic and diastolic blood pressure, total cholesterol, LDL-C, and apoB were not related to BMI in the obese group, in contrast to the non-obese group. Inflammatory markers CRP, leukocyte count, and serum complement C3 increased with increasing BMI in the obese group, while these relations were less clear in the non-obese group. The subcutaneous adipose tissue surface was positively correlated to BMI, while no correlation was observed between BMI and visceral adipose tissue.

CONCLUSIONS

Markers of inflammation are strongest related to BMI in obese subjects, most likely due to increased adipose tissue mass, while cardiovascular risk factors do not seem to deteriorate above a certain BMI level. Limited expansion capacity of visceral adipose tissue may explain these findings.

Effect of a treat-to-target intervention of cardiovascular risk factors on subclinical and clinical atherosclerosis in rheumatoid arthritis: a randomised clinical trial

BACKGROUND

Patients with rheumatoid arthritis (RA) have an increased risk for cardiovascular disease (CVD). No long-term intervention trials on CVD risk factors have been published, and a debate on the efficacy of controlling traditional risk factors in RA is ongoing. We aimed to evaluate a treat-to-target approach versus usual care regarding traditional CVD risk factors in patients with RA.

METHODS

In this open-label, randomised controlled trial, patients with RA aged <70 years without prior CVD or diabetes mellitus were randomised 1:1 to either a treat-to-target approach or usual care of traditional CVD risk factors. The primary outcome was defined as change in carotid intima media thickness (cIMT) over 5 years, and the secondary outcome was a composite of first occurrence of fatal and non-fatal cardiovascular events.

RESULTS

A total of 320 patients (mean age 52.4 years; 69.7% female) with RA underwent randomisation and 219 patients (68.4%) completed 5 years of follow-up. The mean cIMT progression was significantly reduced in the treat-to-target group compared with usual care (0.023 [95% CI 0.011 to 0.036] mm vs 0.045 [95% CI 0.030 to 0.059] mm; p=0.028). Cardiovascular events occurred in 2 (1.3%) of the patients in the treat-to-target group vs 7 (4.7%) in those receiving usual care (p=0.048 by log-rank test).

CONCLUSION

This study provides evidence on the benefit of a treat-to-target approach of traditional CVD risk factors for primary prevention in patients with well-treated RA.

TRIAL REGISTRATION NUMBER

NTR3873.

Risk of misclassification with a non-fasting lipid profile in secondary cardiovascular prevention

AIMS

Routinely fasting is not necessary for measuring the lipid profile according to the latest European consensus. However, LDL-C tends to be lower in the non-fasting state with risk of misclassification. The extent of misclassification in secondary cardiovascular prevention with a non-fasting lipid profile was investigated.

METHODS AND RESULTS

329 patients on lipid lowering therapy for secondary cardiovascular prevention measured a fasting and non-fasting lipid profile. Cut-off values for LDL-C, non-HDL-C and apolipoprotein B were set at <1.8mmol/l, <2.6mmol/l and <0.8g/l, respectively. Study outcomes were net misclassification with non-fasting LDL-C (calculated using the Friedewald formula), direct LDL-C, non-HDL-C and apolipoprotein B. Net misclassification <10% was considered clinically irrelevant. Mean age was 68.3±8.5years and the majority were men (79%). Non-fasting measurements resulted in lower LDL-C (-0.2±0.4mmol/l, P<0.001), direct LDL-C (-0.1±0.2mmol/l, P=0.001), non-HDL-C (-0.1±0.4mmol/l, P=0.004) and apolipoprotein B (-0.02±0.10g/l, P=0.004). 36.0% of the patients reached a fasting LDL-C target of <1.8mmol/l with a significant net misclassification of 10.7% (95% CI 6.4-15.0%) in the non-fasting state. In the non-fasting state net misclassification with direct LDL-C was 5.7% (95% CI 2.1-9.2%), 4.0% (95% CI 1.0-7.4%) with non-HDL-C and 4.1% (95% CI 1.1-9.1%) with apolipoprotein B.

CONCLUSION

Use of non-fasting LDL-C as treatment target in secondary cardiovascular prevention resulted in significant misclassification with subsequent risk of undertreatment, whereas non-fasting direct LDL-C, non-HDL-C and apolipoprotein B are reliable parameters.

Erythrocyte-bound apolipoprotein B in atherosclerosis and mortality

BACKGROUND

The binding of apolipoprotein (apo) B-containing lipoproteins to circulating erythrocytes (ery-apoB) is associated with a decreased prevalence of atherosclerosis. In this study, we evaluated ery-apoB as a possible prognostic factor in cardiovascular events and all-cause mortality, in a prospective cohort study.

MATERIALS AND METHODS

Ery-apoB was measured by flow cytometry in subjects with and without cardiovascular disease (CVD). The primary endpoint was the cardiovascular event rate. Secondary endpoints were all-cause mortality and the combined endpoint of all-cause mortality and cardiovascular events (any event rate). A Cox regression analysis with univariate and multivariate analyses and Kaplan-Meier survival analysis was performed.

RESULTS

Follow-up data were available of 384 subjects. Subjects were divided according to high (> 2·0 au, n = 60), intermediate (0·2-2·0 au, n = 274) or low (< 0·2 au, n = 50) ery-apoB. Median follow-up was 1767 days (IQR 1564-2001). In univariate analysis, low ery-apoB was associated with increased all-cause mortality [HR 9·9 (1·2-79·0), P = 0·031] and any event rate [HR 3·4 (95% CI 1·3-8·7), P = 0·012]. In a Cox regression analysis, only a history of CVD was significantly associated with any event rate [HR 3·6 (1·6-8·0), P = 0·002], while low ery-apoB showed a trend [HR 2·4 (0·9-6·4), P = 0·07]. In a subgroup analysis, in subjects with a history of CVD, ery-apoB was significantly associated with all-cause mortality (log rank P = 0·021) and any event rate (log rank P = 0·009).

CONCLUSIONS

Low ery-apoB is associated with increased mortality and cardiovascular risk, especially in patients with a prior history of CVD. These subjects may benefit from more aggressive secondary prevention treatment.

Effect of a Single Dose of Vitamin D3 on Postprandial Arterial Stiffness and Inflammation in Vitamin D-Deficient Women

CONTEXT

Cholecalciferol (vitamin D3) improves vascular function and inflammation, potentially providing an explanation for the proposed cardiovascular protection of vitamin D.

OBJECTIVE

We investigated whether cholecalciferol supplementation reduces postprandial arterial dysfunction and inflammation.

DESIGN

Randomized, 1:1, double-blind trial.

SETTING

Diabetes and Vascular Center, Franciscus Gasthuis, Rotterdam, The Netherlands.

PATIENTS

Twenty-four healthy, premenopausal, overweight or obese, vitamin D-deficient women.

INTERVENTIONS

A single high (300,000 IU) or low dose (75,000 IU) of cholecalciferol.

MAIN OUTCOME MEASURES

The effect of low- and high-dose cholecalciferol on postprandial leukocyte activation markers, pulse wave velocity (PWV), and augmentation index (AIx) during an oral fat loading test, expressed as area under the curve (AUC).

RESULTS

High- and low-dose supplementation increased vitamin D by 163% ± 134% (P < 0.001) and 66% ± 59% (P < 0.001), respectively. Monocyte CD11b-AUC slightly increased after low but not high dose (6% ± 2%, P = 0.012, and 4% ± 1%, P = 0.339, respectively). There were no significant effects on postprandial PWV or AIx by high- or low-dose vitamin D. Fasting complement component 3 (C3) levels decreased by 5.9% (P = 0.004) in the high-dose group and by 4.0% (P = 0.018) in the low-dose group.

CONCLUSION

A single dose of vitamin D does not seem to reduce arterial stiffness and leukocyte activation in overweight, vitamin D-deficient women. Vitamin D may decrease fasting C3. Possibly, higher vitamin D concentrations may be needed to decrease inflammation and improve vascular function in overweight or obese vitamin D-deficient women.

Leucocyte-bound apolipoprotein B in the circulation is inversely associated with the presence of clinical and subclinical atherosclerosis

BACKGROUND

Atherosclerosis is a pro-inflammatory condition, in which leucocyte activation plays an important role. The interaction between circulating leucocytes and apolipoprotein (apo) B-containing lipoproteins results in pro-inflammatory changes of these cells. We aimed to evaluate the relationship between apo B bound to circulating leucocytes and atherosclerosis.

METHODS

Apo B on circulating leucocytes was measured by flow cytometry in subjects with and without cardiovascular disease (CVD), expressed as mean fluorescent intensity in arbitrary units (au). Carotid intima-media thickness (cIMT) was measured using B-mode ultrasound. Data are given as median (interquartile range).

RESULTS

A total of 396 subjects were included, of whom 183 had a history of CVD. Compared to subjects without CVD, patients with CVD had lower apo B bound to neutrophils (12·7 au (9·8-16·2) and 14·2 au (10·1-17·5), respectively, P = 0·038) and to monocytes (2·5 au (1·7-3·1) and 2·7 (1·9-3·6) au, respectively, P = 0·025). No differences were found for lymphocyte-bound apo B. Neutrophil- and monocyte-bound apo B were inversely correlated with cIMT (Spearman's rho: -0·123, P = 0·017 and -0·108, P = 0·035, respectively). Both monocyte- and neutrophil-bound apo B were inversely associated with different factors related to the metabolic syndrome, such as body mass index, triglycerides and complement C3. There was a positive association between erythrocyte-bound apo B and apo B bound to each of the leucocyte classes, possibly reflecting a similar mechanism. Discontinuation of statins in 54 subjects did not influence leucocyte-bound apo B.

CONCLUSION

Unexpectedly, the presence of noninternalized apo B-containing lipoproteins on circulating neutrophil and monocyte membranes may represent a protective mechanism against atherosclerosis.

Marked underdiagnosis and undertreatment of hypertension and hypercholesterolaemia in rheumatoid arthritis

OBJECTIVE

To investigate the prevalence of underdiagnosis and undertreatment of traditional cardiovascular risk factors in RA patients.

METHODS

RA patients ⩽70 years of age without cardiovascular disease (CVD) or diabetes mellitus were included. Systolic blood pressure and a fasting lipid profile were measured. The 10-year CVD risk was estimated using the Dutch Cardiovascular Risk Management (CVRM) guideline and EULAR modifications of the Systemic Coronary Risk Evaluation tables.

RESULTS

A total of 327 patients were included (female gender: 68%). The mean age was 53 (11) years [mean (s.d.)]. The median disease duration was 7 years (inter quartile range: 2-14 years). According to the CVRM guideline, 52% of the patients had a CVD risk ⩾20% and according to the EULAR guidelines, 18% of the patients had a CVD risk ≥ 20%. Low-density lipoprotein cholesterol (LDL-C) >2.5 mmol/l was found in >80% of the patients with a CVD risk ⩾10% as estimated by both the CVRM and EULAR guidelines, and 32-42% of the patients with a CVD risk ⩾10% had a systolic blood pressure >140 mmHg, depending on the risk model used. Statins were used in 6% and antihypertensives in 23-25%, and 50-86% of these patients did not reach the recommended treatment targets.

CONCLUSION

Regardless of the adapted risk assessment model used, untreated hypertension and hypercholesterolaemia were frequently found in RA patients with increased CVD risk. Treatment of these cardiovascular risk factors deserves more attention in RA.

TRIAL REGISTRATION

The Dutch Trial Register, www.trialregister.nl, NTR3873.

In vivo evidence for chylomicrons as mediators of postprandial inflammation

BACKGROUND AND AIMS

The postprandial situation is a pro-inflammatory condition most likely linked to the development of atherosclerosis. We evaluated the relationship between apolipoprotein (apo) B48 and fasting and postprandial leukocyte activation markers.

METHODS

Leukocyte activation markers and apo B48 were determined in 80 subjects with and without coronary artery disease (CAD). Twelve healthy subjects underwent an oral fat loading test (up to 8 h).

RESULTS

Fasting apo B48 was significantly higher in patients with CAD (n = 47, 8.1 ± 5.2 mg/L) than in subjects without CAD (n = 33, 5.9 ± 3.9 mg/L, p = 0.022). Fasting apo B48 and triglycerides correlated positively with fasting monocyte CD11b and neutrophil CD66b expression. Plasma apo B48 and leukocyte activation markers increased after an oral fat load. No correlations were found between fasting or postprandial triglycerides and postprandial leukocyte activation markers. We observed no correlations between postprandial apo B48 and postprandial neutrophil CD11b or CD66b expression.

CONCLUSION

This study suggests that chylomicron remnants may be responsible for postprandial leukocyte activation in the circulation. The postprandial chylomicron response may be a stronger mediator of postprandial inflammation than postprandial triglyceridemia.

Association of Cardiovascular Risk Factors with Carotid Intima Media Thickness in Patients with Rheumatoid Arthritis with Low Disease Activity Compared to Controls: A Cross-Sectional Study

Objectives

Rheumatoid arthritis (RA) has been identified as an independent cardiovascular risk factor. The importance of risk factors such as hypertension and hyperlipidemia in the generation of atherosclerosis in RA patients is unclear. This study analyzed clinical parameters associated with carotid intima media thickness (cIMT) in patients with RA.

Methods

Subjects with RA and healthy controls without RA, both without known cardiovascular disease, were included. Participants underwent a standard physical examination and laboratory measurements including a lipid profile. cIMT was measured semi-automatically by ultrasound.

Results

In total 243 RA patients and 117 controls were included. The median RA disease duration was 7 years (IQR 2–14 years). The median DAS28 was 2.4 (IQR 1.6–3.2) and 114 (50.4%) of the RA patients were in remission. The presence of RA and cIMT were not associated (univariate analysis). Multivariable regression analysis showed that cIMT in RA patients was associated with age (B = 0.006, P<0.001) and systolic blood pressure (B = 0.003, P = 0.003). In controls, cIMT was associated with age (B = 0.006, P<0.001) and smoking (B = 0.097, P = 0.001).

Conclusion

cIMT values were similar between RA patients and controls. Hypertension was strongly associated with cIMT in RA patients. After adjustment, no association between cIMT and specific RA disease characteristics was found in this well treated RA cohort.

Adherence to cardiovascular prevention strategies in patients with rheumatoid arthritis

OBJECTIVES

Patients with rheumatoid arthritis (RA) have a high risk of cardiovascular disease (CVD). Recent national and international guidelines suggest strict treatment of CVD risk factors in RA. The aim of this study was to evaluate the self-reported adherence to CV prevention strategies in patients with RA.

METHOD

RA patients visiting an outpatient clinic for strict CVD risk management received a validated questionnaire to evaluate adherence to CV prevention strategies. Strict treatment targets were defined and lifestyle recommendations were given following a prespecified protocol. CVD risk was assessed using the SCORE algorithm.

RESULTS

In total, 111 questionnaires were returned (response rate of 82%). A high 10-year CVD risk (≥ 20%) was present in 53%, but only 3% thought they had an increased CVD risk. A total of 53% of patients reported that they 'follow the doctors' suggestions exactly' and 75% reported finding it 'easy to follow the suggestions'. Of the 69% of patients who were prescribed lipid- and/or blood pressure-lowering drugs, 90% reported taking all prescribed tablets. The advice to follow a diet was given to 42%, of whom 68% said they followed the advised diet. Physical exercise was advised to 67%, of whom 62% said they performed specific physical exercise on at least 3 days a week. The adherence to lifestyle recommendations was not significantly different across the CVD risk groups.

CONCLUSIONS

RA patients tend to underestimate their CVD risk. The self-reported adherence of RA patients to CVD risk management was high concerning pharmaceutical interventions and moderate in the case of lifestyle interventions.

Glucose-dependent leukocyte activation in patients with type 2 diabetes mellitus, familial combined hyperlipidemia and healthy controls

BACKGROUND

Leukocyte activation has been associated with vascular complications in type 2 diabetes mellitus (T2DM). Hyperglycemia may be involved in this leukocyte activation. Our aim was to investigate the role of elevated glucose concentrations on leukocyte activation in patients with a wide range of insulin sensitivity.

METHODS

Leukocyte activation was determined after ingestion of 75 gram glucose in subjects with T2DM, familial combined hyperlipidemia (FCH) and healthy controls. Leukocyte activation markers were measured by flow cytometry. Postprandial changes were calculated as the area under the curve (AUC), and the incremental area under the curve corrected for baseline values (dAUC).

RESULTS

51 Subjects (20 T2DM, 17 FCH and 14 controls) were included. Fasting neutrophil CD66b expression and CD66b-AUC were respectively 36% and 39% higher in T2DM patients than in controls (p=0.004 and p=0.003). Fasting neutrophil CD66b expression correlated positively with glucose-AUC (Spearman's rho 0.481, p<0.001) and HbA1c (rho 0.433, p=0.002). Although fasting monocyte CD11b expression was not significantly different between subjects, monocyte CD11b-AUC was 26% higher in T2DM than in controls (p=0.006). Similar trends were observed for FCH patients. Monocyte CD11b-dAUC correlated positively with glucose-AUC (rho 0.322, p=0.022) and HbA1c (rho 0.319, p=0.023).

CONCLUSIONS

These data suggest that both acute and chronic hyperglycemia, associated with insulin resistance as seen in T2DM and FCH, are involved in the increased fasting and postprandial leukocyte activation observed in these conditions.

Differential complement activation pathways promote C3b deposition on native and acetylated LDL thereby inducing lipoprotein binding to the complement receptor 1

Lipoproteins can induce complement activation resulting in opsonization and binding of these complexes to complement receptors. We investigated the binding of opsonized native LDL and acetylated LDL (acLDL) to the complement receptor 1 (CR1). Binding of complement factors C3b, IgM, C1q, mannose-binding lectin (MBL), and properdin to LDL and acLDL were investigated by ELISA. Subsequent binding of opsonized LDL and acLDL to CR1 on CR1-transfected Chinese Hamster Ovarian cells (CHO-CR1) was tested by flow cytometry. Both native LDL and acLDL induced complement activation with subsequent C3b opsonization upon incubation with normal human serum. Opsonized LDL and acLDL bound to CR1. Binding to CHO-CR1 was reduced by EDTA, whereas MgEGTA only reduced the binding of opsonized LDL, but not of acLDL suggesting involvement of the alternative pathway in the binding of acLDL to CR1. In vitro incubations showed that LDL bound C1q, whereas acLDL bound to C1q, IgM, and properdin. MBL did neither bind to LDL nor to acLDL. The relevance of these findings was demonstrated by the fact that ex vivo up-regulation of CR1 on leukocytes was accompanied by a concomitant increased binding of apolipoprotein B-containing lipoproteins to leukocytes without changes in LDL-receptor expression. In conclusion, CR1 is able to bind opsonized native LDL and acLDL. Binding of LDL to CR1 is mediated via the classical pathway, whereas binding of acLDL is mediated via both the classical and alternative pathways. Binding of lipoproteins to CR1 may be of clinical relevance due to the ubiquitous cellular distribution of CR1.

Glucose-dependent leukocyte activation in patients with type 2 diabetes mellitus, familial combined hyperlipidemia and healthy controls

BACKGROUND

Leukocyte activation has been associated with vascular complications in type 2 diabetes mellitus (T2DM). Hyperglycemia may be involved in this leukocyte activation. Our aim was to investigate the role of elevated glucose concentrations on leukocyte activation in patients with a wide range of insulin sensitivity.

METHODS

Leukocyte activation was determined after ingestion of 75 gram glucose in subjects with T2DM, familial combined hyperlipidemia (FCH) and healthy controls. Leukocyte activation markers were measured by flow cytometry. Postprandial changes were calculated as the area under the curve (AUC), and the incremental area under the curve corrected for baseline values (dAUC).

RESULTS

51 Subjects (20 T2DM, 17 FCH and 14 controls) were included. Fasting neutrophil CD66b expression and CD66b-AUC were respectively 36% and 39% higher in T2DM patients than in controls (p=0.004 and p=0.003). Fasting neutrophil CD66b expression correlated positively with glucose-AUC (Spearman's rho 0.481, p<0.001) and HbA1c (rho 0.433, p=0.002). Although fasting monocyte CD11b expression was not significantly different between subjects, monocyte CD11b-AUC was 26% higher in T2DM than in controls (p=0.006). Similar trends were observed for FCH patients. Monocyte CD11b-dAUC correlated positively with glucose-AUC (rho 0.322, p=0.022) and HbA1c (rho 0.319, p=0.023).

CONCLUSIONS

These data suggest that both acute and chronic hyperglycemia, associated with insulin resistance as seen in T2DM and FCH, are involved in the increased fasting and postprandial leukocyte activation observed in these conditions.

Automated screening for myelodysplastic syndromes through analysis of complete blood count and cell population data parameters

The diagnosis of myelodysplastic syndromes (MDS) requires a high clinical index of suspicion to prompt bone marrow studies as well as subjective assessment of dysplastic morphology. We sought to determine if data collected by automated hematology analyzers during complete blood count (CBC) analysis might help to identify MDS in a routine clinical setting. We collected CBC parameters (including those for research use only and cell population data) and demographic information in a large (>5,000), unselected sequential cohort of outpatients. The cohort was divided into independent training and test groups to develop and validate a random forest classifier that identifies MDS. The classifier effectively identified MDS and had a receiver operating characteristic area under the curve (AUC) of 0.942. Platelet distribution width and the standard deviation of red blood cell distribution width were the most discriminating variables within the classifier. Additionally, a similar classifier was validated with an additional, independent set of >200 patients from a second institution with an AUC of 0.93. This retrospective study demonstrates the feasibility of identifying MDS in an unselected outpatient population using data routinely collected during CBC analysis with a classifier that has been validated using two independent data sets from different institutions.

Closure of midline laparotomies by means of small stitches: practical aspects of a new technique

Randomized studies support the closure of midline incisions with a suture length to wound length ratio (SL:WL) of more than 4, accomplished with small tissue bites and short stitch intervals to decrease the risk of incisional hernia and wound infection. We investigated practical aspects of this technique possibly hampering the introduction of this technique. Patient data, operative variables and SL:WL ratio were collected at two hospitals: Sundsvall Hospital (SH) and Erasmus University Medical Center (EMC). A structured implementation of the technique had been performed at SH but not at EMC. Personnel were interviewed by questionnaire. At each hospital, 18 closures were analyzed. Closure time was significantly longer (p = 0.023) at SH (median 18 minutes, range: 9-59) than at EMC (median 13 minutes, range: 5-23). An SL:WL ratio of more than 4 was achieved in 8 of 18 cases at EMC and in all 18 cases at SH. We conclude that calculation of an SL:WL ratio is easily performed. Suturing with the small bite-short stitch interval technique of SH required 5 minutes extra, outweighing the morbidity of incisional hernia. Without a structured implementation to suture with an SL:WL ratio of more than 4, a lower ratio is often achieved.

Alcohol and plasma triglycerides

PURPOSE OF REVIEW

This study reviews recent developments concerning the effects of alcohol on plasma triglycerides. The focus will be on population, intervention and metabolic studies with respect to alcohol and plasma triglycerides.

RECENT FINDINGS

Alcohol consumption and fat ingestion are closely associated and stimulated by each other via hypothalamic signals and by an elevated cephalic response. A J-shaped relationship between alcohol intake and plasma triglycerides has been described. A normal body weight, polyphenols in red wine and specific polymorphisms of the apolipoprotein A-V and apolipoprotein C-III genes may protect against alcohol-associated hypertriglyceridemia. In contrast, obesity exaggerates alcohol-associated hypertriglyceridemia and therefore the risk of pancreatitis.

SUMMARY

High alcohol intake remains harmful since it is associated with elevated plasma triglycerides, but also with cardiovascular disease, alcoholic fatty liver disease and the development of pancreatitis. Alcohol-induced hypertriglyceridemia is due to increased very-low-density lipoprotein secretion, impaired lipolysis and increased free fatty acid fluxes from adipose tissue to the liver. However, light to moderate alcohol consumption may be associated with decreased plasma triglycerides, probably determined by the type of alcoholic beverage consumed, genetic polymorphisms and lifestyle factors. Nevertheless, patients should be advised to reduce or stop alcohol consumption in case of hypertriglyceridemia.

Leukocyte cell population data (volume conductivity scatter) in postprandial leukocyte activation

INTRODUCTION

Changes in leukocyte cell population data have been reported in various infectious diseases, but little is known in other inflammatory conditions such as the postprandial state. We investigated whether leukocyte cell population data change during postprandial leukocyte activation.

METHODS

Healthy volunteers underwent a standardized oral fat loading test (OFLT). Flowcytometric quantitation of leukocyte activation markers CD11b, CD66b, CD35, and CD36, together with leukocyte cell population data from LH750 hematology analyzers were measured fasting and at 4 and 8 h postprandially.

RESULTS

Twelve volunteers were included. Postprandial leukocyte activation was confirmed by increased expression of CD11b by monocytes (+11.7%) and neutrophils (+15.0%) and by increased expression of CD66b (+14.7%) and CD35 (+16.6%) by neutrophils at T = 4 h. The mean scatter from neutrophils, reflecting granularity, significantly decreased at T = 4 h (P < 0.05) and returned to baseline at T = 8 h (P-anova 0.048). The mean volume of monocytes increased significantly at T = 4 h (P < 0.001) and returned to baseline at T = 8 h (P-anova 0.0008). At T = 4 h, CD11b expression on neutrophils was associated with a reduction in mean scatter of neutrophils (Pearson's r: -0.677, P = 0.016).

CONCLUSION

Postprandial leukocyte activation is accompanied by temporary changes in leukocyte cell population data, similar to changes observed during various infections, but to a lesser extent.

A physician's guide for the management of hypertriglyceridemia: the etiology of hypertriglyceridemia determines treatment strategy

Hypertriglyceridemia is a common lipid disorder associated to different, highly prevalent metabolic derangements like diabetes mellitus, the metabolic syndrome and obesity. The choice of treatment depends on the underlying pathogenesis and the consequences for atherosclerosis or pancreatitis. A family history, physical examination and analysis of the lipid profile including measurement of apolipoprotein B or non-HDL-C are necessary to establish the underlying primary or secondary cause. Due to physiological diurnal variations of triglycerides (TG), the time of measurement (fasting or postprandial) should be taken into account when evaluating TG values. Increased awareness arises concerning the impact of postprandial hypertriglyceridemia on the development of atherosclerosis. Hypertriglyceridemia is strongly associated to postprandial hyperlipidemia, remnant accumulation, increased small dense LDL concentrations, low HDL-C, increased oxidative stress, endothelial dysfunction, leukocyte activation and insulin resistance. All these factors are strongly linked to the development of atherosclerosis. Treatment should be aimed at reducing the secretion of triglyceride-rich lipoproteins, increasing intravascular lipolysis and reducing the number of circulating remnants. The main intervention is a change of lifestyle with decreased alcohol consumption, increased physical activity, dietary changes and, if applicable, adaptation of used medication. Fibrates, fish oil and nicotinic acid are the first choice of treatment in sporadic and familial hypertriglyceridemia to reduce the risk of pancreatitis, whereas high dose statins, sometimes in combination with fibrates, nicotinic acid, or fish oil capsules, are indicated for familial combined hyperlipidemia. Statins are necessary to reach low LDL-C concentrations in patients with type 2 diabetes mellitus and statin dosage should be increased when hypertriglyceridemia is present to reach secondary treatment targets for apolipoprotein B or non-HDL-C. Finally, family screening is mandatory to detect familial lipid disorders for early intervention in other family members.

Erythrocyte-associated apolipoprotein B and its relationship with clinical and subclinical atherosclerosis

BACKGROUND

Apolipoprotein (apo) B-containing lipoproteins are closely linked to atherogenesis. These lipoproteins are transported in plasma and are also associated with blood leucocytes. Our aim was to investigate whether apoB-containing lipoproteins are also present on the surface of erythrocytes and investigate the relationship with the presence of atherosclerosis in a cross-sectional study.

MATERIALS AND METHODS

Erythrocyte-bound apoB (ery-apoB) was measured by flowcytometry in subjects with (CAD+) and without coronary artery disease (CAD-), based on coronary angiography or on a history of cardiovascular disease. Intima media thickness (IMT) measurements were carried out using B-mode ultrasound. The relationship between ery-apoB and clinical and subclinical atherosclerosis was evaluated with binary logistic regression.

RESULTS

A total of 166 subjects were included (40 CAD+ and 126 CAD-). ApoB was detected on freshly isolated erythrocytes (range: 0·1-5·5 au; mean ± SEM 0·86 ± 0·09 au) in all but nine subjects (four CAD+ and five CAD-). Ery-apoB was lower in CAD+ (0·62 ± 0·09 au) compared to CAD- (1·18 ± 0·10 au; P < 0·001). Higher ery-apoB was associated with a lower risk of CAD (adjusted OR: 0·003 (95% CI: 0·001-0·08; P < 0·001), but the protective effect was diminished with increasing age (adjusted OR: 1·10 (95% CI: 1·04-1·16; P < 0·001). IMT was increased in CAD+ subjects (0·77 ± 0·13 mm) compared to CAD- (0·57 ± 0·14 mm; P < 0·001). A significant negative association was found between ery-apoB and IMT (β = -0·214: 95% CI -0·284 to -0·145; P < 0·001). There was no association between ery-apoB and plasma apoB (Pearson's r = -0·45; P = 0·57).

CONCLUSIONS

Human erythrocytes carry apoB-containing lipoproteins. Subjects with atherosclerosis have lower ery-apoB. High ery-apoB may be protective against atherosclerosis and may reflect an alternative blood cell-mediated lipoprotein transport system in the circulation, in which these lipoproteins less likely interact with the endothelium.

Daytime triglyceride variability in men and women with different levels of triglyceridemia

BACKGROUND

Triglyceride (TG) levels measured in either the fasting or non-fasting state predict the risk of cardiovascular disease (CVD). Since CVD risk assessment is affected by variability in TG, the aim of the study was to investigate intra-individual variability of non-fasting TG.

METHODS

Capillary triglyceride (cTG) levels were measured in 246 free-living individuals at six time-points during the day on three separate occasions. Intra-individual variability in cTG was assessed by calculating the standard deviation of three measures at each time-point. Subjects were analyzed by gender and by fasting TG level.

RESULTS

In the fasting state, intra-individual variability was similar in males and females (0.28 and 0.35 mmol/l, respectively), but increased significantly in male but not in female subjects during the day, i.e., 0.28 to 0.69, and 0.35 to 0.36 mmol/l, resp. Subjects with higher fasting TG levels had greater absolute variability in both fasting and non-fasting TG.

CONCLUSIONS

The variability in non-fasting TG is greater in males and in individuals with higher levels of TG. Since greatest variability in non-fasting TG occurs very late in the day, it is unlikely to affect the assessment of CVD risk, which is based on a blood sample taken during daylight hours.

[Cholesterol homeostasis and enterohepatic connection: new insights in cholesterol absorption]

The intestines have been proposed as the 'new player' in the field of atherosclerosis as a result of recent discoveries on intestinal cholesterol absorption and excretion. 'Niemann-Pick C1-like 1' is one of the most important transport proteins in the process of intestinal and biliary cholesterol absorption. Cholesterol is not only excreted via the hepato-biliary route but is also excreted directly into the intestinal lumen; this transintestinal cholesterol excretion is particularly important in mice. Other cholesterol transporters have also been identified, including the ABC transporters, which have been linked to rare disorders such as sitosterolemia. Inhibition of intestinal cholesterol absorption increases the hepatic synthesis of cholesterol and vis versa; several different genes and hormones play an important role in this process. When the effect of statins is insufficient or they cause too many side-effects, additional inhibition of intestinal cholesterol absorption is indicated.