On-screen image-guided lead placement in cardiac resynchronization therapy: Feasibility and outcome in a multicenter setting.

Background: Image guidance to assist left ventricular (LV) lead placement may improve outcome after cardiac resynchronization therapy (CRT), but previous approaches and results varied greatly, and multicenter feasibility is lacking altogether. Objective: We sought to investigate the multicenter feasibility of image guidance for periprocedural assistance of LV lead placement for CRT. Methods: In 30 patients from 3 hospitals, cardiac magnetic resonance imaging was performed within 3 months prior to CRT to identify myocardial scar and late mechanical activation (LMA). LMA was determined using radial strain, plotted over time. Segments without scar but clear LMA were classified as optimal for LV lead placement, according to an accurate 36-segment model of the whole heart. LV leads were navigated using image overlay with periprocedural fluoroscopy. After 6 months, volumetric response and super-response were defined as ≥15% or ≥30% reduction in LV end-systolic volume, respectively. Results: Periprocedural image guidance was successfully performed in all CRT patients (age 66 ± 10 years; 59% men, 62% with nonischemic cardiomyopathy, 69% with left bundle branch block). LV leads were placed as follows: within (14%), adjacent (62%), or remote (24%) from the predefined target. According to the conventional 18-segment model, a remote position occurred only once (3%). On average, 86% of patients demonstrated a volumetric response (mean LV end-systolic volume reduction 36 ± 29%), and 66% of all patients were super-responders. Conclusion: On-screen image guidance for LV lead placement in CRT was feasible in a multicenter setting. Efficacy will be further investigated in the randomized controlled ADVISE (Advanced Image Supported Lead Placement in Cardiac Resynchronization Therapy) trial (NCT05053568).

A head-to-head comparison of speckle tracking echocardiography and feature tracking cardiovascular magnetic resonance imaging in right ventricular deformation.

AIMS: Speckle tracking echocardiography (STE) and feature tracking cardiovascular magnetic resonance imaging (FT-CMR) are advanced imaging techniques which are both used for quantification of global and regional myocardial strain. Direct comparisons of STE and FT-CMR regarding right ventricular (RV) strain analysis are limited. We aimed to study clinical performance, correlation and agreement of RV strain by these techniques, using arrhythmogenic right ventricular cardiomyopathy (ARVC) as a model for RV disease. METHODS AND RESULTS: We enrolled 110 subjects, including 34 patients with definite ARVC, 30 preclinical relatives of ARVC patients, and 46 healthy control subjects. Global and regional RV longitudinal peak strain (PS) were measured by STE and FT-CMR. Both modalities showed reduced strain values in ARVC patients compared to ARVC relatives (STE global PS: P < 0.001; FT-CMR global PS: P < 0.001) and reduced strain values in ARVC relatives compared to healthy control subjects (STE global PS: P = 0.042; FT-CMR global PS: P = 0.084). There was a moderate, albeit significant correlation between RV strain values obtained by STE and FT-CMR [global PS r = 0.578 (95% confidence interval 0.427-0.697), P < 0.001]. Agreement between the techniques was weak (limits of agreement for global PS: ±11.8%). Correlation and agreement both deteriorated when regional strain was studied. CONCLUSION: RV STE and FT-CMR show a similar trend within the spectrum of ARVC and have significant correlation, but inter-modality agreement is weak. STE and FT-CMR may therefore both individually have added value for assessment of RV function, but RV PS values obtained by these techniques currently cannot be used interchangeably in clinical practice.

Smoking cessation and risk of recurrent cardiovascular events and mortality after a first manifestation of arterial disease.

AIMS: To quantify the relation between smoking cessation after a first cardiovascular (CV) event and risk of recurrent CV events and mortality. METHODS: Data were available from 4,673 patients aged 61 ± 8.7 years, with a recent (≤1 year) first manifestation of arterial disease participating in the SMART-cohort. Cox models were used to quantify the relation between smoking status and risk of recurrent major atherosclerotic cardiovascular events (MACE including stroke, MI and vascular mortality) and mortality. In addition, survival according to smoking status was plotted, taking competing risk of non-vascular mortality into account. RESULTS: A third of the smokers stopped after their first CV event. During a median of 7.4 (3.7-10.8) years of follow-up, 794 patients died and 692 MACE occurred. Compared to patients who continued to smoke, patients who quit had a lower risk of recurrent MACE (adjusted HR 0.66, 95% CI 0.49-0.88) and all-cause mortality (adjusted HR 0.63, 95% CI 0.48-0.82). Patients who reported smoking cessation on average lived 5 life years longer and recurrent MACE occurred 10 years later. In patients with a first CV event >70 years, cessation of smoking had improved survival which on average was comparable to former or never smokers. CONCLUSIONS: Irrespective of age at first CV event, cessation of smoking after a first CV event is related to a substantial lower risk of recurrent vascular events and all-cause mortality. Since smoking cessation is more effective in reducing CV risk than any pharmaceutical treatment of major risk factors, it should be a key objective for patients with vascular disease.

Four ECG left ventricular hypertrophy criteria and the risk of cardiovascular events and mortality in patients with vascular disease.

OBJECTIVE: The relation between different electrocardiographic left ventricular hypertrophy (ECG-LVH) criteria and cardiovascular risk in patients with clinical manifest arterial disease is unclear. Therefore, we determined the association between four ECG-LVH criteria: Sokolow-Lyon, Cornell product, Cornell/strain index and Framingham criterion; and risk of cardiovascular events and mortality in this population. METHODS: Risk of cardiovascular events was estimated in 6913 adult patients with clinical manifest arterial disease originating from the Secondary Manifestations of ARTerial disease (SMART) cohort. Cox proportional regression analysis was used to estimate the risk of the four ECG-LVH criteria and the primary composite outcome: myocardial infarction (MI), stroke or cardiovascular death; and secondary outcomes: MI, stroke and all-cause mortality; adjusted for confounders. RESULTS: The highest prevalence of ECG-LVH was observed for Cornell product (10%) and Cornell/strain index (9%). All four ECG-LVH criteria were associated with an increased risk of the primary composite endpoint: Sokolow-Lyon (hazard ratio 1.37, 95% CI 1.13-1.66), Cornell product (hazard ratio 1.54, 95% CI 1.30-1.82), Cornell/strain index (hazard ratio 1.70, 95% CI 1.44-2.00) and Framingham criterion (hazard ratio 1.78, 95% CI 1.21-2.62). Cornell product, Cornell/strain index and Framingham criterion ECG-LVH were additionally associated with an elevated risk of secondary outcomes. Cardiovascular risk increased whenever two, or three or more ECG-LVH criteria were present concurrently. CONCLUSION: All four ECG-LVH criteria are associated with an increased risk of cardiovascular events. As Cornell/strain index is both highly prevalent and carries a high cardiovascular risk, this is likely the most relevant ECG-LVH criterion for clinical practice.

Risk Factors for Recurrent Cardiovascular Events Before Age 65 Years or Within 2.5 Years of a Recent First Cardiovascular Event.

The aim of this study was to quantify the relation between classical risk factors (smoking, diabetes, BMI, waist circumference, blood pressure, and lipids), risk factor targets, and risk of recurrent major atherosclerotic cardiovascular events (MACE). This was first done for recurrent MACE ≤65 years in patients aged <60 years and second for recurrent MACE ≤2.5 years after a first cardiovascular event. Data were used from the Second Manifestations of Arterial Disease study (n = 5,115), a prospective cohort of patients with a recent (≤1 year) first cardiovascular event. During follow-up, 746 recurrent MACE occurred. Smoking (hazard ratio [HR] 1.43, 95% CI 1.11 to 1.84), diabetes (HR 1.83, 95% CI 1.11 to 1.84), diastolic blood pressure (>90 vs 70 to 90 mm Hg, HR 1.54, 95% CI 1.15 to 2.07), and high-density lipoprotein cholesterol (≤1.0 vs >1.0 mmol/L, HR 1.34, 95% CI 1.03 to 1.76) were related to increased risk of recurrent MACE ≤65 years in patients aged <60 years. Smoking (HR 1.65, 95% CI 1.23 to 2.22), physical inactivity (highest vs lowest tertile, HR 1.48, 95% CI 1.05 to 2.09), body mass index (per kg/m2, HR 1.04, 95% CI 1.00 to 1.08), diastolic blood pressure (>90 vs 70 to 90 mm Hg, HR 1.61, 95% CI 1.17 to 2.21), low-density lipoprotein cholesterol (per mmol/L, HR 1.18, 95% CI 1.02 to 1.37), and non-high-density lipoprotein cholesterol (per mmol/L, HR 1.15, 95% CI 1.03 to 1.28) were related to recurrent MACE ≤2.5 years of follow-up. In conclusion, in patients with a recent cardiovascular event, smoking, blood pressure, and lipids are related to increased risk of recurrent cardiovascular events at young age or within a short time span, and intensive treatment of modifiable risk factors may contribute to prevent recurrent MACE in these patients.

Identification of the Asymptomatic Patient With Severe Mitral Regurgitation: Discrepancy Between Research and Clinical Practice.

Organic mitral regurgitation (MR) is a common disorder, and because of the increase in population and its aging, the occurrence of MR is steadily increasing. Current guideline recommendations on the management of asymptomatic severe MR are conflicting and based solely on registries or nonrandomized trials in expert heart valve clinics, resulting in a lack of evidence for the best treatment strategy. In this review, we will evaluate the latest evidence on diagnostic approaches and treatment strategies for asymptomatic patients without a clear indication for surgical intervention. Implications for management in daily practice are discussed, including an update on the diagnostic approaches that are currently available for the evaluation of MR. For optimal care, it is important that every severe MR patient, including the unidentified patient, is referred to a specialized heart team and is assessed on an individual basis according to the guideline recommendations, experience of the surgical center, and the patient's characteristics and preferences. Screening and diagnostic approaches need to be performed on the basis of standardized protocols and strict criteria. In addition, specialized valve centers must meet the surgical criteria to guarantee high reparability rates in asymptomatic patients. Awareness among cardiologists and cardiothoracic surgeons, improved guidelines adherence, and a systematic approach, including strict criteria in the management of asymptomatic patients with severe organic MR, will ensure reliable and applicable results in research and daily clinical practice.

Staged decision making was an attractive alternative to a plenary approach in panel diagnosis as reference standard.

OBJECTIVES: To assess differences between three different decision-making approaches in the method of panel diagnosis as reference standard in diagnostic research. STUDY DESIGN AND SETTING: Within a diagnostic study, the prevalence of heart failure (HF) and chronic obstructive pulmonary disease (COPD) was compared using three approaches of decision making in panel diagnosis. These were (1) a plenary discussion among experts followed by a consensus decision (plenary); (2) a predefined decision rule based on final diagnoses made by each member individually (individual); and (3) a staged procedure in which first the final diagnosis per individual member is generated followed by a plenary discussion of those cases with disagreement (staged). RESULTS: Prevalence of HF and COPD according to plenary approach was 46% and 28%, respectively. Individual approach diagnosed 28% of patients with HF and 31% with COPD and revealed 28 and 8 discordant diagnoses, respectively, compared with plenary approach. Staged approach revealed a prevalence of 43% and 28% for HF and COPD, respectively, with eight discordant diagnoses for HF and none for COPD. CONCLUSION: The staged approach is an attractive choice as it produces very similar results to the full plenary approach, while having the advantage of being less time consuming. Additionally, it provides insights into the decision-making process of the panel, and the "difficult-to-diagnose" patients can easily be identified.

The predictive value of the exercise ECG for major adverse cardiac events in patients who presented with chest pain in the emergency department.

BACKGROUND: To improve early diagnostic and therapeutic decision making, we designed the HEART score for chest pain patients in the emergency department (ED). HEART is an acronym of its components: History, ECG, Age, Risk factors and Troponin. Currently, many chest pain patients undergo exercise testing on the consecutive days after presentation. However, it may be questioned how much diagnostic value the exercise ECG adds when the HEART score is already known. METHODS: A subanalysis was performed of a multicenter prospective validation study of the HEART score, consisting of 248 patients who underwent exercise testing within 7 days after presentation in the ED. Outcome is the predictive value of exercise testing in terms of major adverse cardiac events (MACE) within 6 weeks after presentation. RESULTS: In low-risk patients (HEART score ≤ 3), 63.1 % were negative tests, 28.6 % non-conclusive and 8.3 % positive; the latter were all false positives. In the intermediate-risk group (HEART score 4-6), 30.9 % were negative tests, 60.3 % non-conclusive and 8.8 % positive, half of these positives were false positives. In the high-risk patients (HEART score ≥ 7), 14.3 % were negative tests, 57.1 % non-conclusive and 28.6 % positive, of which half were false positives. CONCLUSION: In a chest pain population risk stratified with HEART, exercise testing has only a modest contribution to clinical decision making. 50 % of all tests are non-conclusive, with high rates of false positive tests in all three risk groups. In intermediate-risk patients, negative exercise tests may contribute to the exclusion of disease. Clinicians should rather go for sensitive tests, in particular in patients with low HEART scores.

[Heart failure with preserved ejection fraction: Diastolic heart failure]. / Hartfalen met gepreserveerde ejectiefractie: diastolisch hartfalen.

Heart failure with preserved ejection fraction (HF-PEF) is part of the 'heart-failure spectrum', but differs pathophysiologically from heart failure with reduced ejection fraction (HF-REF). Metabolic abnormalities in HF-PEF cause intrinsic stiffness of the cardiac myocyte and alternation of the collagen turn-over in the extracellular matrix of the heart. HF-PEF is most often present in elderly women with a history of hypertension, diabetes mellitus or metabolic syndrome, and obesity. Signs of fluid retention are often not present on physical examination in patients with HF-PEF. The most notable echocardiographic abnormalities seen in HF-PEF are an enlarged left atrium with hypertrophy, reduced left ventricular relaxation and elevated filling pressures. Co-morbidly and advanced age are largely determinant for mortality, which in HF-PEF is somewhat lower than in HF-REF. Evidence-based drug therapy for HF-PEF is currently lacking; ongoing studies are evaluating medications other than the well-established drugs used to treat HF-REF.

Transendocardial cell injection is not superior to intracoronary infusion in a porcine model of ischaemic cardiomyopathy: a study on delivery efficiency.

Stem cell therapy is a new strategy for chronic ischaemic heart disease in patients. However, no consensus exists on the most optimal delivery strategy. This randomized study was designed to assess cell delivery efficiency of three clinically relevant strategies: intracoronary (IC) and transendocardial (TE) using electromechanical mapping guidance (NOGA) compared to surgical delivery in a chronic pig model of ischaemic cardiomyopathy. Twenty-four animals underwent delivery of 10(7) autologous Indium-oxine-labelled bone marrow-derived mesenchymal stem cells (MSC) 4 weeks after infarction and were randomized to one of three groups (n = 8 each group): IC, TE or surgical delivery (reference group). Primary endpoint was defined as percentage (%) of injected dose per organ and assessed by in vivo gamma-emission counting. In addition, troponin and coronary flow were assessed before and after MSC injection. Blinded endpoint analysis showed no significant difference in efficiency after surgical (16 ± 4%), IC (11 ± 1%) and TE (11 ± 3%) (P = 0.52) injections. IC showed less variability in efficiency compared with TE and surgical injection. Overall, TE injection showed less distribution of MSC to visceral organs compared with other modalities. Troponin rise and IC flow did not differ between the percutaneous groups. This randomized study showed no significant difference in cell delivery efficiency to the myocardium in a clinically relevant ischaemic large animal model between IC and TE delivery. In addition, no differences in safety profile were observed. These results are important in view of the choice of percutaneous cell delivery modality in future clinical stem cell trials.

Surgical left ventricular radius enlargement by patch insertion on the beating heart: a new experimental aneurysm model.

We presented a novel experimental aneurysm model for studies in left ventricular (LV) reconstruction techniques and assessed LV function. In eight pigs, the LV radius and geometry were enlarged surgically on the beating heart by inserting an aortic allograft construct. Haemodynamics and LV dimensions were assessed by echocardiography at baseline and under dobutamine stress. Surgery was successfully performed without lethal blood loss or arrhythmias. LV end-diastolic and end-systolic short-axis areas increased from 13.0 ± 1.7 to 17.0 ± 4.3 cm(2) (P = 0.001) and from 4.0 ± 0.9 to 13.0 ± 2.6 cm(2) (P = 0.001), respectively. Stroke volume decreased from 56 ± 11 to 33 ± 16 ml (P = 0.001). Incremental dobutamine infusion concurred with a biphasic response on fractional area shortening. Mitral valve insufficiency ranging from grades 2 to 4 was observed. In the pig, a novel, reproducible aneurysm model for acute cardiac dysfunction was created on the beating heart. Innovative (surgical) strategies for (staged) reconfiguration of the ventricle, e.g. adjustable Dor procedures and stepwise volume restraining cardiac support devices, can be tested for efficacy using this acute model.

Inducible cardiac ischaemia is related to a decrease in the whole-blood Toll-like receptor 2 and 4 response.

TLR (Toll-like receptor) activation-induced inflammatory responses are important in the progression of atherosclerosis. We previously showed that TLR-dependent leucocyte responsiveness is acutely attenuated following percutaneous coronary intervention or vascular surgery. Furthermore, cytokine release following whole-blood TLR-2 and TLR-4 stimulation is negatively correlated with fractional flow reserve, suggesting that chronic ischaemia can elicit an enhanced inflammatory response. In the present study, we assessed the association between leucocyte TLR-2 and TLR-4 responsiveness and pre-existent and inducible ischaemia in patients undergoing SPECT (single-photon emission computed tomography)-MPI (myocardial perfusion imaging). TLR-2, TLR-4 and CD11b expression on monocytes were measured in blood samples that were obtained from 100 patients with suspected coronary artery disease before and after myocardial stress testing for SPECT-MPI. IL-8 (interleukin-8) levels were determined after whole-blood stimulation with Pam3Cys (TLR-2) and LPS (lipopolysaccharide; TLR-4). On the basis of SPECT-MPI, patients were categorized into three groups: reversible defect, irreversible defect and no defect. Myocardial stress induced a reduction in TLR-4 expression (2.46±0.21 compared with 2.17±0.16 arbitrary units, P=0.001) and CD11b expression (83.2±1.73 compared with 76.0±1.89 arbitrary units, P<0.001). TLR-induced IL-8 production before myocardial stress induction was not associated with the results of SPECT-MPI. However, a significant decrease in IL-8 production following TLR stimulation was observed after stress, which was more pronounced in patients with a reversible defect. In conclusion, inducible ischaemia is associated with a decrease in whole-blood TLR-2 and TLR-4 response. These results point to a regulating role of TLRs in order to prevent excessive inflammatory events known to occur during acute ischaemia.

Non-surgical stem cell delivery strategies and in vivo cell tracking to injured myocardium.

Heart failure is a major economic and public health problem. Despite the recent advances in drug therapy and coronary revascularization, the lost cardiomyocytes due to necrosis and apoptosis are not replaced by new myocardial tissue. Cell therapy is an interesting therapeutic option as it potentially improves contractility and restores regional ventricular function. Early clinical data demonstrated that cell transplantation, mainly delivered through non-surgical methods, is safe and feasible. However, several important issues need to be elucidated. This includes, next to determining the best cell type, the optimal delivery strategy, the biodistribution and the survival of implanted stem cells after transplantation. In this view, pre-clinical animal experiments are indispensable. Reporter genes, magnetic or radioactive labeling of stem cells have been developed to observe the fate and the distribution of transplanted cells using non-invasive imaging techniques. Several studies have demonstrated that these direct and non-direct labeling techniques may become an important tool in cell therapy. Integration of cell delivery and cell tracking will probably be a key for the success of cell therapy in patients. This review will provide a comprehensive overview on the various cell tracking and non-surgical cell delivery techniques, which are highly important in view of experimental and clinical studies.

The nitric oxide donor molsidomine rescues cardiac function in rats with chronic kidney disease and cardiac dysfunction.

We recently developed a rat model of cardiorenal failure that is characterized by severe left ventricular systolic dysfunction (LVSD) and low nitric oxide (NO) production that persisted after temporary low-dose NO synthase inhibition. We hypothesized that LVSD was due to continued low NO availability and might be reversed by supplementing NO. Rats underwent a subtotal nephrectomy and were treated with low-dose NO synthase inhibition with N(ω)-nitro-l-arginine up to week 8. After 3 wk of washout, rats were treated orally with either the long-acting, tolerance-free NO donor molsidomine (Mols) or vehicle (Veh). Cardiac and renal function were measured on weeks 11, 13, and 15. On week 16, LV hemodynamics and pressure-volume relationships were measured invasively, and rats were killed to quantify histological damage. On week 15, blood pressure was mildly reduced and creatinine clearance was increased by Mols (both P < 0.05). Mols treatment improved ejection fraction (53 ± 3% vs. 37 ± 2% in Veh-treated rats, P < 0.001) and stroke volume (324 ± 33 vs. 255 ± 15 µl in Veh-treated rats, P < 0.05). Rats with Mols treatment had lower end-diastolic pressures (8.5 ± 1.1 mmHg) than Veh-treated rats (16.3 ± 3.5 mmHg, P < 0.05) and reduced time constants of relaxation (21.9 ± 1.8 vs. 30.9 ± 3.3 ms, respectively, P < 0.05). The LV end-systolic pressure-volume relationship was shifted to the left in Mols compared with Veh treatment. In summary, in a model of cardiorenal failure with low NO availability, supplementing NO significantly improves cardiac systolic and diastolic function without a major effect on afterload.

Characterization and in vitro and in vivo testing of CB2-receptor- and NGAL-targeted paramagnetic micelles for molecular MRI of vulnerable atherosclerotic plaque.

PURPOSE: Atherosclerotic plaque macrophages express the peripheral cannabinoid receptor (CB2-R) and promote fibrous cap degradation by secretion of neutrophil gelatinase-associated lipocalin 2 (NGAL). In this study, we report the preparation, characterization, and in vitro and in vivo testing of double-labeled (MR and fluorescent) CB2-R- and NGAL-targeted micelles. PROCEDURES/RESULTS: Specific CB2-R agonists or antibodies directed to 24p3 (mouse homolog of NGAL) were incorporated into di-oleoyl-polyethylene glycol-phosphatidylethanolamine 1000 (DOPE-PEG1000) micelles or di-stearoyl-polyethylene glycol-phosphatidylethanolamine 2000 (DSPE-PEG2000) micelles. The hydrodynamic diameter, determined by dynamic light scattering, was 16.5 and 19.0 nm for CB2-R-targeted DOPE-PEG1000 and DSPE-PEG2000 micelles, respectively, and 23.0 nm for Ab-conjugated DSPE-PEG2000 micelles. In vitro and in vivo MRI and fluorescence microscopy showed specific binding of CB2-R-targeted and 24p3-targeted micelles to in vitro systems and to aortic plaque in apoE(-/-)/eNOS(-/-) mice, respectively. CONCLUSIONS: CB2-R- and NGAL-targeted micelles show promise as tools for in vivo characterization of vulnerable plaque.

Erythropoietin treatment in patients with combined heart and renal failure: objectives and design of the EPOCARES study.

BACKGROUND: Anemia is common in patients with the combination of chronic heart failure and chronic kidney disease and is associated with increased mortality. Recent clinical studies suggest that recombinant human erythropoietin (EPO) treatment has desirable as well as undesirable effects, related to its hematopoietic or nonhematopoietic effects. Therefore a translational study is needed to elucidate mechanistic aspects of EPO treatment. METHODS: In this open-label randomized 12-month trial (the Mechanisms of Erythropoietin Action in the Cardiorenal Syndrome [EPOCARES]), patients with the combination of chronic heart failure and chronic kidney disease (glomerular filtration rate 20-70 ml/min) and mild anemia (hemoglobin 10.3-12.6 g/dL in men, and 10.3-11.9 g/dL in women) are being randomized into 3 groups: 1 group (n=25) receives a fixed dose of 50 IU/kg per week EPO to increase hemoglobin level to a maximum of 13.7 g/dL for men and 13.4 g/dL for women; another group (n=25) is treated with 50 IU/kg per week EPO maintaining baseline hemoglobin levels for the first 6 months by phlebotomy. The control group (n=25) receives standard care without EPO. RESULTS: Cardiac and renal function as well as a panel of biomarkers and iron parameters are being assessed. Furthermore, the effects of EPO on monocyte gene expression profiles and on endothelial progenitor cells are being evaluated. CONCLUSION: This translational study is designed primarily to discern hematopoietic from nonhematopoietic effects of EPO in cardiorenal patients. The study will add insights into the mechanisms that could explain the fragile balance between desirable and undesirable effects of EPO (Trial registration: ClinicalTrials.gov identifier NCT00356733).

Recent developments and new perspectives on imaging of atherosclerotic plaque: role of anatomical, cellular and molecular MRI part III.

Atherosclerotic plaque disruption accounts for the major part of cardiovascular mortality and the risk of disruption appears to depend on plaque composition. Carotid plaques in patients, scheduled for endarterectomy, have been successfully characterised with MRI. MRI has the advantage of combining information about morphology and function. Unfortunately, the tortuosity and size of the coronary arteries, and the respiratory and cardiac motion hinder the in vivo characterisation of human coronary plaque. In addition to plaque composition several molecular markers of the different processes involved in atherosclerosis, such as integrins, matrix metalloproteinases and fibrin seem to correlate with risk of plaque rupture and clinical outcome. These molecular markers can be targeted with antibodies coupled to carriers, which are loaded with gadolinium for detection (molecular MRI). Several cellular/molecular MRI studies in animal models and some in human patients have been conducted with varying levels of success. The advent of clinical high field magnets, the development of contrast agent carriers with high relaxivity and the development of relatively new MR contrast techniques appear to be promising in the field of plaque imaging. Future MRI studies will have to focus on the molecular target of the atherosclerotic process, which has the highest prognostic value with regard to acute coronary syndromes and on the most suitable contrast agent to visualize that target.

Differences in determinants of left ventricular mass assessed by cardiac magnetic resonance imaging across subjects with and without previous symptomatic atherosclerotic disease.

BACKGROUND: Most previous studies on determinants of left ventricular (LV) mass have used echocardiography, which is less accurate than cardiac MRI (CMR). Furthermore, studies that used CMR to study the determinants of LV mass were performed in the general population. However, determinants may differ between those with and without previous symptomatic events. We studied the relation between atherosclerotic risk factors and LV mass in subjects free from cardiac disease, yet with and without atherosclerotic disease elsewhere. METHODS: A CMR was performed in 531 hypertensive subjects with clinically manifest extra-cardiac atherosclerotic disease or marked risk factors for atherosclerosis. In all subjects information on atherosclerotic risk factors was collected. Multivariable linear regression was used to study the relation of risk factors with LV mass. Interaction was evaluated with multiplicative interaction terms. RESULTS: Overall, male gender, weight, height, systolic blood pressure, albuminuria, current smoking, and a history of abdominal aortic aneurysm (AAA) were related to an increased LV mass. In subjects without a history of symptomatic atherosclerotic disease, gender, weight, height and systolic blood pressure were related to LV mass. In addition to these risk factors, albuminuria, current smoking and a history of AAA were related to LV mass in subjects with a history of symptomatic atherosclerotic disease. CONCLUSION: Our study points towards differences in risk factor relations across populations with and without symptomatic atherosclerotic disease. The observed relationship between cardiovascular risk factors and LV mass re-emphasizes the importance of adequate treatment of modifiable risk factors in the prevention of cardiovascular disease.

Variability of coronary calcium scores throughout the cardiac cycle: implications for the appropriate use of electrocardiogram-dose modulation with retrospectively gated computed tomography.

OBJECTIVE: To study how much the calcium scores at various phases throughout the cardiac cycle deviate from the score in the most motionless phase during retrospectively electrocardiogram (ECG)-gated multidetector row computed tomography (MDCT) of the heart and to evaluate how to optimize ECG-based tube current modulation so that errors in calcium scoring can be minimized while dose savings can be maximized. MATERIALS AND METHODS: In 73 subjects with known or suspected coronary artery disease we performed retrospectively ECG-gated 64-detector row computed tomography for calcium scoring. Four subjects were excluded after scanning because of breathing artifacts or lack of coronary calcification. The scans of 69 subjects (46 men, mean age 62 +/- 6 years) were used for further analysis. Heart rate during the scan was recorded. In each patient, calcium scoring [Agatston score (AS), mass score (MS), and volume score, (VS)] was performed on 10 data sets reconstructed at 10%-intervals throughout the cardiac cycle. The most motionless phase was subjectively determined and used as the reference phase. For the score in each phase, deviation from the score in the reference phase was determined. An ECG-simulator was used to determine the amount of dose saving while scanning with dose modulation and applying diagnostic dose during 1 or several phases. RESULTS: Mean heart rate was 63 (+/-13) beats per minute (bpm). In 51% of patients the reference phase was the 70% phase. Using the calcium score in the 70% phase (mid-diastole) instead of the reference at heart rates below 70 bpm would have induced a median score deviation of 0% [interquartile range: 0%-6% (AS, MS, and VS)] and using the calcium score in the 40% phase (end-systole) at heart rates > or =70 bpm would also have induced a median score deviation of 0% [interquartile range: 0%-7% (AS), 0%-5% (MS), and 0%-3% (VS)]. Errors in calcium scores of more than 10% occur in around 10% of subjects for all 3 scoring algorithms. Dose savings increased with lower heart rates and shorter application of diagnostic dose. CONCLUSIONS: The optimum phases for dose modulation are 70% (mid-diastole) at heart rates below 70 bpm and 40% (end-systole) at heart rates above 70 bpm. Under these conditions dose saving is maximum and a median error of 0% is found for the various calcium scoring techniques with score errors of more than 10% in around 10% of subjects.