Aortic valve implantation-induced conduction block as a framework towards a uniform electrocardiographic definition of left bundle branch block

Introduction

New-onset left bundle branch block (LBBB) following transcatheter or surgical aortic valve replacement (LBBB_AVI) implies a proximal pathogenesis of LBBB. This study compares electrocardiographic characteristics and concordance with LBBB definitions between LBBB_AVI and non-procedure-induced LBBB controls (LBBB_control).

Methods

All LBBB_AVI patients at Ghent University Hospital between 2013 and 2019 were enrolled in the study. LBBB_AVI patients were matched for age, sex, ischaemic heart disease and ejection fraction to LBBB_control patients in a 1:2 ratio. For inclusion, a non-strict LBBB definition was used (QRS duration ≥ 120 ms, QS or rS in V1, absence of Q waves in V5-6). Electrocardiograms were digitally analysed and classified according to three LBBB definitions: European Society of Cardiology (ESC), Strauss and American Heart Association (AHA).

Results

A total of 177 patients (59 LBBB_AVI and 118 LBBB_control) were enrolled in the study. LBBB_AVI patients had more lateral QRS notching/slurring (100% vs 85%, p = 0.001), included a higher percentage with a QRS duration ≥ 130 ms (98% vs 86%, p = 0.007) and had a less leftward oriented QRS axis (−15° vs −30°, p = 0.013) compared to the LBBB_control group. ESC and Strauss criteria were fulfilled in 100% and 95% of LBBB_AVI patients, respectively, but only 18% met the AHA criteria. In LBBB_control patients, concordance with LBBB definitions was lower than in the LBBB_AVI group: ESC 85% (p = 0.001), Strauss 68% (p < 0.001) and AHA 7% (p = 0.035). No differences in electrocardiographic characterisation or concordance with LBBB definitions were observed between LBBB_AVI and LBBB_control patients with lateral QRS notching/slurring.

Conclusion

Non-uniformity exists among current LBBB definitions concerning the detection of proximal LBBB. LBBB_AVI may provide a framework for more consensus on defining proximal LBBB.

Supplementary Information

The online version of this article (10.1007/s12471-021-01565-8) contains supplementary material, which is available to authorized users.

620 Normalized stroke volume in severe aortic stenosis with preserved ejection fraction: reference values and outcome implications

Funding Acknowledgements

none

Background

Appropriate normalization methods to scale Doppler-derived stroke volume (SV) in patients with aortic stenosis (AS) are poorly defined and reference values are lacking.

Purpose

We aim to establish reference values for normalized SV, to compare the prognostic value of SV normalized by different methods in AS and to examine the outcome of low-flow(LF) low-gradient(LG) AS with preserved ejection fraction(LVEF) based on newly defined reference values.

Methods

In 2781 normotensive adults without cardiovascular disease we defined normal relationships between SV and body size by nonlinear regression. We analyzed the prognostic performance of ratiometric and allometric normalized SV in 1450 patients with severe AS and preserved LVEF.

Results

The allometric exponents that described the SV-height (H) and SV-body surface area (BSA) relationships were 1.32 and 0.88, respectively. In males, LF reference values were: &lt;28ml/m²,&lt;30ml/m,&lt;30ml/(m²)^0.88, and, respectively,&lt;26 ml/m^1.32, and in females &lt;27ml/m²,&lt;28ml/m,&lt;29ml/(m²)^0.88, and, respectively,&lt;24 ml/m^1.32. In patients with severe AS, SV/H^1.32 was most consistently associated with mortality and showed better prognostic performance than other normalized SV parameters. Compared to H-normalization, BSA-normalization markedly overestimated the frequency of LF (2% vs. 11%). In 1354 AS patients managed initially medically, LF/LG AS defined based on the 35ml/m² cut-off showed better outcome than high gradient(HG) AS (adjusted HR 0.85[0.62-0.96]). When new reference values were used, the mortality risk of LF/LG AS was higher than that of HGAS (adjusted HR 1.37[1.06-1.89] for SV/BSA and adjusted HR 1.42[1.10-2.15] for SV/H^1.32).

Conclusion

We provide reference values and appropriate normalization methods for SV by Doppler-echocardiography. Patients with LG severe AS, preserved LVEF and "true" LF are at high risk of death during follow-up.

Abstract 620 Figure. Frequency of flow-gradient patterns

P576The first handheld device for autonomic self-detection of symptomatic acute coronary artery occlusion: feasibility, performance and implications for time-efficient self-triage of outpatients with CAD

Background

Time delay between onset of symptoms and seeking medical attention is a major determinant of mortality and morbidity in patients with acute coronary artery occlusion (ACAO). Response time might be reduced by reliable self-detection of ACAO. Currently no self-applicable device can accurately detect ACAO. We have recently shown that an automatic algorithm based upon a three lead system (RELF method) accurately detects ACAO.

Purpose

In this multicenter observational study we tested the operational feasibility, sensitivity and specificity of our RELF method, built into a mobile handheld device, for detection of ACAO.

Methods

Patients with planned elective percutaneous coronary intervention (PCI), who were able to use a smartphone, were asked to perform random ambulatory self-recordings for at least one week. A similar self-recording was made before angioplasty and at 60 s of balloon occlusion.

Results

The operational feasibility of ambulatory self-recordings in enrolled patients with CAD was 59/64 (92.1%, 95% CI: 83.0–96.6). Of all self-recordings 91.1% (n=4567) were automatically classified as successful within one minute. The mean false positive rate during daily life conditions was 4.19% (95% CI: 3.29–5.10). Amongst 65 balloon occlusions, 63 index-tests at 60 s of occlusion were available. The sensitivity for the target conditions “ACAO”, “ACAO with ECG changes” and “ACAO with ECG changes and ST segment elevation myocardial infarction (STEMI) criteria” was respectively 55/63 (0.87; 95% CI: 0.77–0.93), 54/57 (0.95; 95% CI: 0.86–0.98) and 35/35 (1.00). The figure depicts all (n=3936) ST difference vector (STDVn) measurements obtained during ambulatory postural changes, exercise and coronary artery occlusion with and without ECG changes and/or STEMI criteria. Receiver Operator Curve (ROC) for ACAO at different cut-off values of the magnitude of STDVn was 0.973 (95% CI: 0.956–0.990).

Boxplots of all STDVn test recordings

Conclusions

Self-recording with our RELF device is feasible for the majority of patients with CAD. The sensitivity and specificity for automatic detection of the earliest phase of acute coronary artery occlusion support the concept of our RELF device for patient empowerment to reduce delay and increase survival without overloading emergency services. This is the first clinical study that confirms the proof-of-concept of self-detection of acute coronary artery occlusion in outpatients with CAD.

Acknowledgement/Funding

Ghent University, Industrial Research Fund (IOF reference: F2015/IOF-advanced/084).

P3372Prediction of outcome in functional mitral regurgitation using the average pixel intensity method

Background

Functional mitral regurgitation (FMR) is a frequent finding in patients with systolic heart failure. However, the echocardiographic grading of MR is challenging and different severity cut-offs are recommended by international guidelines. We developed and validated a novel echocardiographic parameter to grade MR, the average pixel intensity (API) method, based on pixel intensity analysis of the continuous wave Doppler signal.

Purpose

In this study, we assessed the long-term predictive value of the API method on clinical endpoints in FMR.

Methods

Transthoracic echocardiography was performed in consecutive heart failure patients with reduced EF (HF-REF) (n=221). MR was assessed using the API method, vena contracta width (VCW), effective regurgitant orifice area (PISA-EROA) and regurgitant volume (PISA-RV). The primary clinical events were major adverse cardiac events (MACE: cardiovascular mortality, mitral valve surgery, percutaneous mitral intervention or heart failure hospitalization).

Results

The API method was feasible in 97% of all FMR patients, which was significantly higher than parameters such as VCW, PISA-EROA and PISA-RV. 84 patients (37%) had one or more clinical events during the follow-up period (cardiovascular mortality (20%), mitral valve surgery (5%), percutaneous mitral intervention (5%), heart failure hospitalization (16%) or heart transplantation (2%)). Based on ROC curves, an API cut-off of 121 au was defined as “severe” MVP-MR with an overall better sensitivity and specificity than current guideline-recommended parameters. On multivariate analysis, MR graded with API was independently predictive for clinical events, whereas PISA-based methods were not independent. In addition, pulmonary pressures and NYHA class were powerful independent predictors of clinical outcome in FMR on multivariate analysis.

Conclusions

The API method better predicts clinical events and outcome in FMR compared to established grading methods. Therefore, the API method may be considered for grading FMR severity in clinical practice.

Relationship between Venous and Arterial Haemodynamics during Postural Changes in Venous Insufficiency

Objective:

To study the changes in central haemodynamics and the relationship between arterial blood pressure and the venous dynamics of the lower limbs in patients with venous insufficiency.

Design:

Prospective haemodynamic study during postural changes in 14 patients with venous insufficiency with no other concomitant cardiovascular disease or disturbances in autonomic nervous system.

Setting:

Department of Cardiology and Angiology, University Hospital, Gent, Belgium.

Patients:

Fourteen patients with venous valve insufficiency in the lower limbs.

Interventions:

Measurements of arterial blood pressure, heart rate, stroke volume and cardiac output were performed in the supine position after 30 min rest and 5, 15 and 30 min after standing and during the recovery. Venous pressure at the ankle and calf circumference were also measured.

Main outcome measures:

Changes in cardiac output and total peripheral vascular resistance in order to maintain blood pressure during postural changes.

Results:

Arterial blood pressure was maintained constant owing to an increase in total peripheral vascular resistance despite a decrease in cardiac output. Venous pressure is also related to arterial blood pressure.

Conclusions:

The arterial and venous systems, even in venous insufficiency, are integrated to maintain blood pressure constant during postural changes.

Cardiovascular determinants and prognostic significance of CC Chemokine Ligand-18 (CCL18/PARC) in patients with stable coronary artery disease

Chemokines are important mediators of angiogenesis, hematopoiesis and leucocyte trafficking. CC Chemokine Ligand-18 (CCL18)/ pulmonary and activation-regulated chemokine (PARC) is a circulating chemokine that plays a role in injury healing, physiological homing of mononuclear blood cells and inflammatory responses. CCL18/PARC is also expressed in atherosclerotic plaques. We prospectively evaluated CCL18/PARC levels and their cardiovascular and biological determinants in a large cohort of 285 patients with stable coronary heart disease who were subsequently followed for 3 years for hard cardiac events. It was found that CCL18/PARC levels were associated with decreased cardiac function, decreased exercise capacity and increased inflammatory parameters including interleukin-6 (IL-6) and hs-CRP. More importantly high CCL18/PARC levels were an independent predictor of future cardiovascular events. Therefore, CCL18/PARC is a potential diagnostic and prognostic parameter in patients with stable coronary artery disease.

Numerical validation of a new method to assess aortic pulse wave velocity from a single recording of a brachial artery waveform with an occluding cuff

Recently a new method has been proposed as a tool to measure arterial pulse wave velocity (PWV), a measure of the stiffness of the large arteries and an emerging parameter used as indicator of clinical cardiovascular risk. The method is based on measurement of brachial blood pressure during supra-systolic pressure inflation of a simple brachial cuff [the device is known as the Arteriograph (Tensiomed, Budapest, Hungary)]. This occlusion yields pronounced first and secondary peaks in the pressure waveform, the latter ascribed to a reflection from the aortic bifurcation, and PWV is calculated as the ratio of twice the jugulum-symphysis distance and the time difference between the two peaks. To test the validity of this working principle, we used a numerical model of the arterial tree to simulate pressures and flows in the normal configuration, and in a configuration with an occluded brachial artery. A pronounced secondary peak was indeed found in the brachial pressure signal of the occluded model, but its timing was only related to brachial stiffness and not to aortic stiffness. We also compared PWV's calculated with three different methods: PWVATG (approximately Arteriograph principle), PWVcar-fem (approximately carotid-femoral PWV, the current clinical gold standard method), and PWVtheor (approximately Bramwell-Hill equation). Both PWVATG (R2=0.94) and PWVcar-fem (R2=0.95) correlated well with PWVtheor, but their numerical values were lower (by 2.17+/-0.42 and 1.08+/-0.70 m/s for PWVATG and PWVcar-fem, respectively). In conclusion, our simulations question the working principle of the Arteriograph. Our data indicate that the method picks up wave reflection phenomena confined to the brachial artery, and derived values of PWV rather reflect the stiffness of the brachial arteries.

Poststress left ventricular ejection fraction is an independent predictor of major cardiac events in patients with coronary artery disease and impaired left ventricular function

AIM

The aim of this study was to investigate the prognostic value of myocardial perfusion and function SPECT imaging in patients with coronary artery disease (CAD) and poor left ventricular (LV) function.

METHODS

We studied 261 patients (231 men, age 66+/-10 years) with CAD and a resting LV ejection fraction (LVEF) <or= 40% assessed during myocardial gated SPECT. Perfusion defect extent was calculated using 4D-MSPECT software (Michigan University). Ischemia scoring was performed visually. Considered end points were: 1) major adverse cardiac events (MACE) (cardiac death, non-fatal myocardial infarction or late revascularization), 2) MACE or the need for hospitalization due to heart failure (MACE-HF) and 3) cardiac death or non-fatal myocardial infarction.

RESULTS

During a median follow-up of 31 months, 52 patients (20%) died (35 cardiac deaths), 50 (19%) developed a MACE and 69 (26%) a MACE-HF. In a clinical model, diabetes and angina status were the only predictors of MACE (chi-squared=19.3; P<0.001). By multivariate analysis, poststress LVEF (chi-squared-gain of 6.4; P=0.008) and presence of ischemia (chi-squared-gain of 5.8; P=0.018) were predictive of MACE. Similarly, diabetes mellitus (chi-squared=12.1; P<0.001), poststress LVEF (chi-squared-gain of 5.5; P=0.019) and presence of ischemia (chi-squared-gain of 4.3; P=0.044) were independent predictors of MACE-HF. Diabetes mellitus (chi-squared=17.8; P<0.001), presence of angina complaints (chi-squared-gain of 6.8; P=0.028) and poststress LVEF (chi-squared-gain of 6.3; P=0.008) were independent predictors of cardiac death or non-fatal myocardial infarction.

CONCLUSION

In patients with impaired LV function and CAD, poststress LVEF is an independent predictor of future cardiac events.

Coronary risk factors and inflammation in patients with coronary artery disease and internal cardioverter defibrillator implants

BACKGROUND

The internal cardioverter defibrillator (ICD) is increasingly used to treat ventricular tachyarrhythmias in patients with coronary artery disease (CAD). The burden of coronary risk factors and inflammation is however not well studied in these high risk patients.

STUDY AIMS

The aim of the present study was to describe the prevalence of coronary risk factors (including lipid values) and inflammation (including high sensitive-C-reactive protein, hs-CRP) in patients with CAD and ICD implants.

METHODS

Baseline clinical characteristics and laboratory results of all eligible patients for the Cholesterol Lowering and Arrhythmias Recurrences after Internal Defibrillator Implantation trial (CLARIDI trial) were used. All patients had documented CAD, an ICD implant and were not yet treated with statins. Coronary risk factors, lipid values, glycated haemoglobin (HbA(1c)) and hs-CRP levels were determined.

RESULTS

In the 110 included patients (mean age 68+/-9 years, LVEF 40+/-17%, NYHA class II-III in 47%), a high prevalence of coronary risk factors was documented: current smoking in 18%, body mass index > or =30 kg/m(2) in 16%, blood pressure > or =140/90 mm Hg in 40%, history of diabetes in 12%, and HbA(1c) > or =6% in 16% of patients not known with diabetes. A total cholesterol >175 mg/dl was found in 76% of patients and an LDL cholesterol >100 mg/dl in 83%. Finally, median hs-CRP was 4.8 mg/l (interquartile range 2.5-13.9 mg/l). Hs-CRP values > or =2 mg/l were noted in 83% of all patients and in 68% of patients who had an ICD implant more than 6 months before inclusion.

CONCLUSION

In CAD patients with ICD implants, the burden of coronary risk factors is high, often unrecognized and/or under-treated. Persistent inflammation is found in the majority of these patients.

Assessment of LV diastolic filling using color M-mode Doppler echocardiography: validation in a new hydraulic model

The effect of LV properties on v(p) and the E/v(p) ratio remains a matter of debate. Therefore,the objective of this study is to explore - in a new hydraulic model - the individual contributions of LV relaxation, filling pressure and compliance in changes of E, v(p) and E/v(p) for different stages of diastolic function. A new hydraulic model, consisting of an open cylindrical LA connected to an ellipsoidal LV, is designed. E and v(p) are measured for varying values of tau (45-60-90 ms), LV compliance (0.45-1.35 ml/mmHg) and filling pressure (3-10-30 mmHg). The results are used for predicting the evolution of E, v(p) and E/v(p) during different stages of diastolic function. An increase in compliance decreases E, whereas it augments v(p). v(p) is less load-dependent than E. E decreases with delayed relaxation, increases for the case of pseudonormalisation, and becomes higher than the reference values during restrictive filling. The v(p) value is lower for the case of delayed relaxation than for the reference situation. During pseudonormalisation, the value of v(p) remains lower than the reference value but higher than the value for delayed relaxation. v(p) further decreases during restrictive filling. In conclusion, the effect of simultaneous changes in compliance and loading counterbalance changes in v(p). Therefore, under normal physiologic conditions where load and compliance are coupled, v(p) is apparently load-intensive and E/v(p) increases as filling pressure increases. Moreover, in the different stages of diastolic dysfunction, due to the interference of the co-varying relaxation, the increase in E/v(p) is more pronounced.

Task Force II: blood pressure measurement and cardiovascular outcome

OBJECTIVE

To reach a consensus on the prognostic significance of new techniques of automated blood pressure measurement.

METHODS

A Task Force on the prognostic significance of ambulatory blood pressure monitoring wrote this review in preparation for the Eighth International Consensus Conference (28-31 October 2001, Sendai, Japan). This synopsis was amended to account for opinions aired at the conference and to reflect the common ground reached in the discussions.

POINTS OF CONSENSUS

(1) Prospective studies in treated and untreated hypertensive patients and in the general population have demonstrated that, even after adjusting for established risk factors, the incidence of cardiovascular events is correlated with blood pressure on conventional as well as ambulatory measurement. Ambulatory monitoring, however, significantly refines the prediction already provided by conventional blood pressure measurement. (2) White-coat hypertension is usually defined as an elevated clinic blood pressure in the presence of a normal daytime ambulatory blood pressure. Event-based studies in hypertensive patients have convincingly demonstrated that the risk of cardiovascular disease is less in patients with white-coat hypertension than in those with higher ambulatory blood pressure levels even after controlling for concomitant risk factors. Based on prognostic evidence, white-coat hypertension can now be defined as a conventional blood pressure that is persistently equal to or greater than 140/90 mmHg with an average daytime ambulatory blood pressure of below 135/85 mmHg. The issue of whether or not white-coat hypertension predisposes to sustained hypertension needs further research. (3) There is a growing body of evidence showing that a decreased nocturnal fall in blood pressure (<10% of the daytime level) is associated with a worse prognosis, irrespective of whether night-time dipping is studied as a continuous or a class variable. (4) Intermittent techniques of ambulatory blood pressure monitoring are limited in terms of quantifying short-term blood pressure variability. Proven cardiovascular risk factors such as old age, a higher than usual blood pressure and diabetes mellitus are often associated with greater short-term blood pressure variability. After adjusting for these risk factors, some - but not all - studies have nevertheless reported an independent and positive relationship between cardiovascular outcome and measures of variability of daytime and night-time blood pressure, for example standard deviation. (5) Reference values for ambulatory blood pressure measurement in children are currently based on statistical parameters of blood pressure distribution. In children and adolescents, functional rather than distribution-based definitions of ambulatory hypertension have yet to be developed. (6) Several studies of gestational hypertension have shown that, compared with office measurement, ambulatory blood pressure monitoring is a better predictor of maternal and fetal complications. Pregnancy is a special indication for ambulatory monitoring so that the white-coat effect can be measured and pregnant women are not given antihypertensive drugs unnecessarily. (7) Ambulatory pulse pressure and the QKD interval are measurements obtained by ambulatory monitoring that to some extent reflect the functional characteristics of the large arteries. The QKD interval is correlated with left ventricular mass, and ambulatory pulse pressure is a strong predictor of cardiovascular outcome. (8) Under standardized conditions, the self-measurement of blood pressure is equally as effective as ambulatory blood pressure monitoring in identifying the white-coat effect, but further studies are required to elucidate fully the prognostic accuracy of self-measured blood pressure in comparison with conventional and ambulatory blood pressure measurement.

CONCLUSIONS

Ambulatory blood pressure measurement refines the prognostic information provided by conventional blood pressure readings obtained in the clinic or the doctor's office. Longitudinal studies of patients with white-coat hypertension should clarify the transient, persistent or progressive nature of this condition, particularly in paediatric patients, in whom white-coat hypertension may be a harbinger of sustained hypertension and target-organ damage in adulthood. Finally, the applicability, cost-effectiveness and long-term prognostic accuracy of the self-measurement of blood pressure should be evaluated in relation to conventional blood pressure measurement and ambulatory monitoring.

Vascular changes in workers exposed to carbon disulfide

AIM

To assess the effects of occupational exposure to carbon disulfide (CS2) concentrations below the threshold limit value (31 mg/m3) on the structural and the functional properties of the arteries, heart rate, blood pressure and lipids.

METHODS

Study subjects were 85 male workers in the viscose industry and 35 men without such exposure. The CS2 concentration was determined by personal active sampling. From the common carotid artery diameter, the change in diameter (echography) during the heart cycle and the pulse pressure, local arterial distensibility and compliance were calculated. Global large and small artery elasticity were calculated from registrations of radial artery waveforms. Simultaneously, heart rate and blood pressure were recorded and blood samples were collected for lipid measurements.

RESULTS

CS2 concentrations ranged from 2.34 to 32.4 mg/m3. No significant effect of CS2 on blood pressure, total cholesterol, HDL and LDL cholesterol or triglycerides was found. Among the vascular parameters under study, common carotid artery distensibility was significantly lower, and heart rate significantly higher in exposed workers compared to controls. The differences remained significant after adjustment for age, body mass index, smoking habits, alcohol consumption, heart rate and systolic blood pressure. Common carotid artery intima media thickness and global arterial indices did not differ significantly between the two groups.

CONCLUSIONS

Exposure to CS2 under the current level may already cause alterations in common carotid artery elastic properties in apparently healthy individuals. Even before biochemical and clinical findings occur, important functional changes in the vessel wall were observed, at least in some vascular territories.

Fibrinogen and C-reactive protein on admission as markers of final infarct size after primary angioplasty for acute myocardial infarction

BACKGROUND

In acute myocardial infarction (AMI) treated conservatively or with thrombolysis, marked increases of C-reactive protein (CRP) and fibrinogen have been observed. No data are however available concerning a possible relation between CRP and fibrinogen levels on admission and markers of infarct size after obtaining thrombolysis in myocardial infarction (TIMI) flow III by primary angioplasty.

METHODS

We studied 34 patients with a first AMI (29 men, mean age 54+/-11 years) who were treated with primary angioplasty (TIMI flow III in all patients, no concomitant treatment with glycoprotein IIb-IIIa antagonists) within 6 h of onset of pain. CRP and fibrinogen levels on admission were determined and related to the following markers of infarct size: peak creatine kinase MB (CKMB) levels, radionuclide left ventricular ejection fraction (LVEF) at discharge and thallium-201 single-photon emission computed tomography (SPECT) infarct size at 1 month.

RESULTS

Median CRP levels were 0.4 mg/dl (range 0.09-3 mg/dl), median fibrinogen levels 412 mg/dl (range 198-679 mg/dl), mean CKMB was 178+/-151 U/l, mean LVEF 52+/-8% and mean thallium-201 infarct size 7+/-6%. Although CRP levels were related to fibrinogen levels on admission (r=0.56, P=0.002), only fibrinogen levels were related to markers of infarct size (r=0.58, P=0.001 for CKMB, r=-0.44, P=0.01 for LVEF and r=0.64, P=0.001 for thallium-201 infarct size). No relation was found between CRP or fibrinogen levels on admission and the extent of coronary artery disease or the myocardial area at risk. In multiple regression analysis, the relation between fibrinogen and markers of infarct size was independent of CRP levels and the duration of pain on admission.

CONCLUSIONS

These findings indicate a relation between fibrinogen levels on admission and myocardial infarct size in patients treated with primary angioplasty for AMI. This relation seems to be independent of CRP levels and the duration of pain on admission. If confirmed in larger patient populations, fibrinogen levels on admission could have an important value for risk stratification and more aggressive reduction of infarct size in patients who are treated with primary angioplasty.

Decreased carotid artery distensibility as a sign of early atherosclerosis in viscose rayon workers

Carbon disulphide (CS(2)) is known to accelerate atherosclerosis and to increase the risk for cardiovascular diseases. To assess the effect of CS(2) on the functional (distensibility and compliance) and the structural (intima media thickness) properties of the common carotid artery, and blood pressure and lipid metabolism parameters, a cross-sectional study on 85 workers from a viscose rayon factory and 37 controls was carried out. Exposure to CS(2) was assessed by personal monitoring and was well below the threshold limit value-time weighted average. Carotid arterial wall properties were determined using a non-invasive ultrasound wall movement detector system. No significant effect of CS(2) on blood pressure, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol or triglycerides was found. Among the vascular parameters studied, only distensibility was significantly lower and heart rate was significantly higher in exposed subjects compared with the controls. In conclusion, occupational exposure to CS(2) may cause early alterations in arterial elastic properties in young individuals, and even before lipid and clinical findings have occurred, important functional changes in the vessel wall are present.

Serum vitamin C concentration is low in peripheral arterial disease and is associated with inflammation and severity of atherosclerosis

BACKGROUND

Peripheral arterial disease (PAD) is a severe atherosclerotic condition frequently accompanied by inflammation and oxidative stress. We hypothesized that vitamin C antioxidant levels might be low in PAD and are related to inflammation and disease severity.

METHODS AND RESULTS

We investigated vitamin C (L-ascorbic acid) levels in 85 PAD patients, 106 hypertensives without PAD, and 113 healthy subjects. Serum L-ascorbic acid concentrations were low among PAD patients (median, 27.8 micromol/L) despite comparable smoking status and dietary intake with the other groups (P<0.0001). Subclinical vitamin C deficiency (<11.4 micromol/L), confirmed by low serum alkaline phosphatase activity, was found in 14% of the PAD patients but not in the other groups. Serum C-reactive protein (CRP) concentrations were significantly higher in PAD patients (P<0.0001) and negatively correlated with L-ascorbic acid levels (r=-0.742, P<0.0001). In stepwise multivariate analysis, low L-ascorbic acid concentration in PAD patients was associated with high CRP level (P=0.0001), smoking (P=0.0009), and shorter absolute claudication distance on a standardized graded treadmill test (P=0.029).

CONCLUSIONS

Vitamin C concentrations are lower in intermittent claudicant patients in association with higher CRP levels and severity of PAD. Future studies attempting to relate vitamin C levels to disease occurrence should include in their analysis an inflammatory marker such as CRP.

Extensive deep vein thrombosis in a young woman. Case report

We report a case of a young lady with an extensive deep vein thrombosis (DVT) diagnosed by CT scan and duplex ultrasound examination. Contributory factors were relative immobilisation, oral contraception and hyperhomocysteinemia after methionine loading. No other thrombophilic factors could be found. The three main causes of hyperhomocysteinemia are genetic defects, nutritional deficiencies and insufficient elimination. In our case a genetic defect for one of the key enzymes of homocysteine metabolism, may be the underlying cause. Besides stopping oral contraceptive drugs, anticoagulation and supplementation with pyridoxine and folate was started. Family screening was carried out and revealed other members with hyperhomocysteinemia. Whether therapy with pyridoxine and folate can substantially reduce the recurrence of venous thromboembolic disease remains to be established.

Lipid lowering drugs and recurrences of life-threatening ventricular arrhythmias in high-risk patients

OBJECTIVES

To evaluate a possible effect of lipid lowering drugs on recurrences of ventricular arrhythmias (VA) after implantable cardioverter defibrillator (ICD) implantation.

BACKGROUND

In patients with coronary artery disease (CAD), lipid lowering drugs reduce total and sudden cardiac death. Because the mechanism is not completely understood, we studied whether these drugs have a favorable influence on the occurrence of life-threatening VA in patients with CAD and ICD implants.

METHODS

We conducted an observational study in 78 patients with CAD and life-threatening VA, treated with an ICD. After ICD implantation, 27 patients were on treatment with lipid lowering drugs (group I) and 51 were not (group II). Patients were studied for the following end points: recurrences of VA requiring ICD intervention, cardiac death and hospitalization.

RESULTS

After a mean follow-up of 490 +/- 319 days, 35 patients (45%) had recurrences of VA requiring ICD intervention. In multivariate analysis, the use of lipid lowering drugs (chi-square 6.33, p = 0.012) and poorly tolerated sustained monomorphic ventricular tachycardia as initial presentation (chi-square 4.84, p = 0.028) remained as independent predictors of recurrences of VA. Patients in groups I and II had similar baseline clinical characteristics, but patients in group I had a lower incidence of recurrences of VA (6/27 or 22% vs. 29/51 or 57%, p = 0.004) and of the combined end points of cardiac death and hospitalization (4/27 or 15% vs. 23/51 or 45%, p = 0.015) compared with patients in group II.

CONCLUSIONS

This is the first observation that the use of lipid lowering drugs is associated with a reduction of recurrences of VA in patients with CAD and ICD implants. These data require confirmation in a prospective randomized trial.