Infective endocarditis.

Despite the progress in medicine, infectious endocarditis is often diagnosed late, as its symptomatology is subject to a high variability. The clinical features are usually atypical. Since the introduction of the Duke criteria, clinical, bacteriological and echocardiographical findings are being integrated, allowing an earlier definitive diagnosis. The incidence remains practically stable. The decrease in post-rheumatic valvular heart disease at population level is compensated by an increase in degenerative valvular heart disease as predisposing factor. Moreover, the share of patients with intravascular foreign material is increasing. Endocarditis is usually characterized by a complicated development. About half of the patients develop heart failure as a consequence of the destruction of the affected valve with serious valvular insufficiency. One third of the patients present cerebral or peripheral embolization. Embolization predominantly occurs at the beginning, until the first two weeks of antibiotic treatment. Abscess formation occurs more frequently than is suspected based on echographical examinations. Particularly a Staphylococcus aureus infection in the presence of an artificial valve leads to extravalvular extension with abscess formation around the artificial valve. Treatment should be initiated promptly. High doses of antibiotics, tailored to the microorganism and the valve type (native or artificial valve), are administered intravenously during four, or more frequently, six weeks. In more than half of the patients cardiac surgery is also required. As soon as an indication for cardiac surgery is present, the operation should not be postponed. Experience learns that a smaller risk is associated with an early intervention. The operation is performed in a technically easier way. Eventually, also the total duration of hospitalization is shorter. Despite the available antibiotics and the technical progress in cardiac surgery, mortality remains high. This is the consequence of an increasing share of aggressive hospital germs, on the one hand, and an older population, characterized by a higher comorbidity, on the other hand.

Rosuvastatin restores superoxide dismutase expression and inhibits accumulation of oxidized LDL in the aortic arch of obese dyslipidemic mice.

BACKGROUND AND PURPOSE: Our goal was to elucidate mechanisms of the inhibitory effect of rosuvastatin on the accumulation of plaque oxidized low density lipoproteins (oxLDL) and on plaque volume, without lowering cholesterol, in mice with combined leptin and LDL-receptor deficiency (DKO). EXPERIMENTAL APPROACH: Twelve-week old DKO mice were treated with rosuvastatin (10 mg kg(-1) day(-1), s.c.) or placebo or no treatment for 12 weeks. The effect on blood variables, aortic plaque volume and composition and gene expression in the aorta and in THP-1 cells was assessed. KEY RESULTS: Rosuvastatin lowered free fatty acids (FFA), triglycerides, and increased insulin sensitivity, without affecting cholesterol. Rosuvastatin lowered the plaque volume, inhibited macrophage, lipid and oxLDL accumulation, and decreased the oxLDL-to-LDL ratio of plaques in the aortic arch. It increased superoxide dismutase 1 (SOD1), CD36, LXR-alpha, ABCA-1 and PPAR-gamma RNA expression in aortic extracts. SOD1 was the strongest inverse correlate of oxLDL. In THP-1 macrophages and foam cells, expression of SOD1 was lower than in THP-1 monocytes. Rosuvastatin restored expression of SOD1 in THP-1 macrophages and foam cells. CONCLUSIONS AND IMPLICATIONS: Rosuvastatin restored SOD1 expression in THP-1 macrophages and foam cells in vitro and in the aorta of DKO mice. The latter was associated with less oxLDL accumulation within atherosclerotic plaques and inhibition of plaque progression. This effect was obtained at a dose not affecting cholesterol levels but improving insulin sensitivity. SOD1 is a potentially important mediator of the prevention of oxLDL accumulation within atherosclerotic plaques.

Added diagnostic value and impact on antimicrobial therapy of 16S rRNA PCR and amplicon sequencing on resected heart valves in infective endocarditis: a prospective cohort study.

OBJECTIVES: For adequate management and therapy of infective endocarditis (IE), identification of the causative pathogen is crucial but molecular testing results are not currently included in diagnostic criteria. The added diagnostic value and impact on antimicrobial therapy of 16S rRNA PCR and amplicon sequencing (16S rRNA PCR) performed on excised heart valves from patients with IE was evaluated alongside the effect of pre-operative antibiotics on the performance of blood culture (BC), valve culture (VC) and 16S rRNA PCR. METHODS: All patients undergoing valve surgery for definite or possible IE, according to modified Duke Criteria, were prospectively included from July 2013 up to and including June 2016. RESULTS: In all, 127 patients were included. Sensitivity for detecting the causative micro-organism in 120 post-operative definite IE patients was 26% for VC and 87% for BC and 16S rRNA PCR. 16S rRNA PCR, VC and BC were equally sensitive for different valve types and causative pathogens. In 27 (21%) definite IE patients, 16S rRNA PCR clarified discrepant culture results or was the only method identifying the causative pathogen. In 12 (10%) post-operative definite IE cases, molecular testing results influenced antimicrobial therapy. CONCLUSIONS: The very good performance characteristics, added diagnostic value and impact on antimicrobial therapy of molecular testing of heart valves should support the incorporation of molecular testing in diagnostic criteria and guidelines for IE.

Evolving trends in infective endocarditis.

Infective endocarditis is a microbial infection of the endocardial surface and, despite improvements in diagnostic accuracy, medical therapy and surgical techniques, mortality remains high. This review focuses on changes in epidemiology, microbiology and diagnosis, as well as changes in medical and surgical management of infective endocarditis affecting native and prosthetic valves in adults, that have evolved during the past two decades. Significant changes have included an increasing involvement of prosthetic valves and nosocomially-acquired disease, an increased involvement of staphylococci as the causative agents, and a recognition that elderly individuals with degenerative valvular disease are the most vulnerable population. Topics still requiring study include whether and when valve replacement should be performed, and how to predict perivalvular complications or embolisation based on echocardiography findings. Optimisation of antimicrobial treatment schemes (choice of the antibiotic, dose and duration) also requires further investigation.

Clinical and molecular features of FIP1L1-PDFGRA (+) chronic eosinophilic leukemias.

Detection of the FIP1L1-PDGFRA fusion gene or the corresponding cryptic 4q12 deletion supports the diagnosis of chronic eosinophilic leukemia (CEL) in patients with chronic hypereosinophilia. We retrospectively characterized 17 patients fulfilling WHO criteria for idiopathic hypereosinophilic syndrome (IHES) or CEL, using nested RT-PCR and interphase fluorescence in situ hybridization (FISH). Eight had FIP1L1-PDGFRA (+) CEL, three had FIP1L1-PDGFRA (-) CEL and six had IHES. FIP1L1-PDGFRA (+) CEL responded poorly to steroids, hydroxyurea or interferon-alpha, and had a high probability of eosinophilic endomyocarditis (n=4) and disease-related death (n=4). In FIP1L1-PDGFRA (+) CEL, palpable splenomegaly was present in 5/8 cases, serum vitamin B(12) was always markedly increased, and marrow biopsies revealed a distinctively myeloproliferative aspect. Imatinib induced rapid complete hematological responses in 4/4 treated FIP1L1-PDGFRA (+) cases, including one female, and complete molecular remission in 2/3 evaluable cases. In the female patient, 1 log reduction of FIP1L1-PDGFRA copy number was reached as by real-time quantitative PCR (RQ-PCR). Thus, correlating IHES/CEL genotype with phenotype, FIP1L1-PDGFRA (+) CEL emerges as a homogeneous clinicobiological entity, where imatinib can induce molecular remission. While RT-PCR and interphase FISH are equally valid diagnostic tools, the role of marrow biopsy in diagnosis and of RQ-PCR in disease and therapy monitoring needs further evaluation.

Post-operative echocardiographic evaluation of bioprosthetic mitral valve implantation in sheep.

The ovine model is generally considered to be the best for testing bioprosthetic heart valve durability. Although echocardiography is the method of choice for the interim evaluation of the valve, literature on sheep echocardiography is scarce. Within the context of a study on treatment of pericardial heart valve prostheses, 19 adolescent sheep underwent transthoracic echocardiography six days after mitral implantation of bioprosthetic valves. Echocardiographic examination was performed under mild anesthesia and animals were put in a right lateral decubitus position. Four images were obtained: right parasternal long axis four and five chamber views, right parasternal long axis view with left ventricular outflow, and right parasternal short axis view through the mitral valve. We measured aortic annulus and velocity time integral over the aortic valve to determine stroke volume, cardiac output and cardiac index. The mitral valve was evaluated through color Doppler imaging for valvular and paravalvular leakages. Pulsed wave spectral Doppler was used for the measurement of velocities, pressures and velocity time integrals. For the evaluation of valve stenosis deceleration time and pressure half-time were determined. Effective orifice area of the mitral valve was derived. And, although not measured, other structures could clearly be visualized: right and left ventricle and atrium, wall thicknesses, tricuspid valve. This study shows that echocardiography in sheep is feasible, and that right parasternal images, obtained in animals in a right lateral decubitus position, are well qualified for the interim evaluation of bioprosthetic valves implanted in the mitral position. Besides the implanted valve, other cardiac structures like atria and ventricles can be visualized and evaluated.

Usefulness of transesophageal echocardiography in patients with hemodynamic deterioration late after cardiac surgery.

Two patients with large pericardial thrombi following cardiac surgery presented as having right cardiac tamponade. Transesophageal echocardiography (TEE) identified a large pericardial hematoma compressing the right atrium and was well tolerated by these critically ill patients. These case reports demonstrate the diagnostic value of TEE in the identification of this severe complication in the late postoperative period.

Dobutamine stress echocardiography after heart transplantation.

Dobutamine stress echocardiography was performed in 28 heart transplant recipients to study its value in the detection and staging of transplant vasculopathy. Fourteen patients had angiographic evidence of coronary artery disease (group 1), and 14 had angiographically normal coronary arteries (group 2). The dobutamine stress protocol called for a dose increase of dobutamine every 3 minutes until the age-predicted maximal heart rate was achieved. In groups 1 and 2, the mean maximal dose of dobutamine was, respectively, 24 +/- 9 micrograms/kg min and 29 +/- 8 micrograms/kg min, and the mean rate-pressure product was, respectively, 12386 +/- 1777 mm Hg/min and 10753 +/- 1085 mm Hg/min at rest, increasing to 20987 +/- 4020 mm Hg/min and 19795 +/- 2728 mm Hg/min at maximal dose. No patient in group 1 or 2 had deterioration of global or regional wall motion under dobutamine stress. In group 1, seven patients had wall motion abnormalities at rest, normalizing in five of them under dobutamine stress. In group 2, four patients had wall motion abnormalities at rest, normalizing in all patients under dobutamine stress. Consequently, this protocol of dobutamine stress echocardiography is unsuitable for the early detection of transplant vasculopathy despite its proven value in the general population. Conversely, these data suggest that the functional sequelae of transplant vasculopathy are not necessarily prominent, despite the known angiographic underestimation of the extent of the disease.

Diagnostic value of transesophageal echocardiography in platypnea.

Platypnea is a rare syndrome of orthostatic dyspnea frequently caused by an interatrial right-to-left shunt. The diagnosis is difficult. Assessment of arterial blood gases reveals orthostatic desaturation. In the past, definite diagnosis necessitated catheterization in the supine and upright position. Now transesophageal echocardiography on a tilt table combined with a peripheral venous contrast study provides correct diagnosis in a safe and easy way.

Are changes in myocardial integrated backscatter restricted to the ischemic zone in acute induced ischemia? An in vivo animal study.

Integrated backscatter (IB) from a myocardial region, calculated from radiofrequency echocardiographic data, has been proposed as a useful parameter for investigating changes in myocardial tissue induced by ischemia. In 10 closed-chest dogs, 5 minutes of myocardial ischemia was induced by either a proximal occlusion of the circumflex coronary artery (CX) (5 dogs), resulting in extensive ischemia in the posterior wall, or by occluding the distal CX vessel (5 dogs) to produce a small localized ischemic zone in the posterior wall. High-resolution digital radiofrequency data from the whole left ventricular myocardium, in the imaging plane during one complete heart cycle, were acquired with a whole-image real-time acquisition approach. Regions in the septum and posterior wall (both ischemic tissue and, in the case of distal occlusions, tissue surrounding the ischemic zone) were chosen for analysis, and IB and cyclic variation (CV) of IB were calculated. Post occlusion, an increase in mean IB values was found in the ischemic segment. However, an increase in CV was also observed in the peri-ischemic zone for the distal CX occlusion and in the septum after proximal CX occlusion. These findings show that changes in CV are not restricted to the ischemic zone but may also occur in distal myocardium. This may be explained by changes in the regional contractile state and loading conditions of the "normal" myocardium, which are altered in response to the distal ischemia.

Silzone coating and paravalvular leak: an independent, randomized study.

BACKGROUND AND AIM OF THE STUDY: The study aim was to address independently, in a randomized patient cohort, the impact of Silzone coating on the prevalence and impact of paravalvular leak in patients undergoing mechanical valve replacement. METHODS: Randomized implantation of the uncoated St. Jude Medical Masters, and the Silzone-coated prosthesis was performed in 95 patients, excluding those with suspected or diagnosed infective endocarditis. The company did not support the study; this cohort is not contained in the AVERT trial. Following recall of the Silzone-coated valves, all patients in this cohort were invited to undergo control transthoracic echocardiography and plasma LDH determination. RESULTS: Silzone-coated valves were implanted in 46 patients (57 valves; 34 aortic, 20 mitral, three tricuspid), and uncoated valves in 49 patients (55 valves; 38 aortic, 16 mitral, one tricuspid). One patient with an uncoated mitral valve died from left ventricular dissection. In total, 73 patients returned for specifically planned echocardiography (mean interval 478+/-78 days). Sixteen patients underwent echocardiography on another occasion (mean interval 113+/-202 days). Six hospital survivors did not undergo any postoperative echocardiography. In total, 51 Silzone-coated valves (31 aortic, 18 mitral, two tricuspid), and 53 uncoated valves (37 aortic, 15 mitral, one tricuspid) were evaluated. No patients were reoperated for intrinsic or extrinsic valve dysfunction. No major paravalvular leaks were seen. Five of 51 Silzone-coated valves showed minimal (grade <1+; four aortic, one mitral) paravalvular leak when specifically sought; two showed minimal (grade <1+; one aortic, one mitral), and one slight (grade 1+; one mitral) paravalvular leak in the uncoated group (p = 0.55). The LDH level was 654+/-163 U/I in the Silzone group, and 598+/-124 U/l in the control group (p = 0.10). CONCLUSION: No differences were detected in the incidence of paravalvular leak between Silzone-coated and uncoated mechanical St. Jude Medical valves. The incidence of major paravalvular leaks appears to be lower in the present cohort than was reported in the AVERT trial.

Postoperative hemodynamics of two bileaflet heart valves in the aortic position.

BACKGROUND AND AIMS OF THE STUDY: In vivo hemodynamic assessment of bileaflet aortic valve prostheses using standardized echocardiography is still uncommon; hence, adequate comparison of valve types can rarely be made. We compared the postoperative hemodynamics of St. Jude Standard valves (SJS) with those of Sorin Bicarbon valves (BC) implanted in the aortic position, using pulsed, continuous and color Doppler echocardiography. METHODS: The examination was performed four months after aortic valve prosthesis implantation in 76 patients (39 SJS valves, 37 BC valves). Valve sizes varied from 19 mm to 25 mm. Maximal and mean instantaneous pressure gradients were measured by Doppler echocardiography. Effective valve orifice area (EOA) was calculated and prosthetic valve regurgitation was assessed by color Doppler flow imaging. RESULTS: At valve sizes of 21 mm, 23 mm and 25 mm, SJS valves had a significantly lower EOAs than BC valves (p < 0.05). However, for a given nominal size, BC valves are larger, i.e. they have a larger anatomic (AOA) and geometric orifice area (GOA) than SJS valves. Consequently, BC valves were implanted in patients with a larger left ventricular outflow tract (p < 0.05). When EOA is related to the corresponding AOA, BC valves still show a larger EOA than SJS valves (p < 0.05). Prosthetic valve regurgitation is low in both valve types. CONCLUSIONS: (a) Nominal valve size is not always a good basis for comparison of hemodynamic profiles between valve types. (b) Using the relationship between EOA and AOA, the hemodynamic profile of BC valves in the aortic position is shown to be superior to that of SJS valves.

Acquisition and processing of the radio-frequency signal in echocardiography: a new global approach.

Recently there has been an increasing interest in the use of the "raw" radio-frequency (RF) signal generated in echocardiography for use in tissue-characterization to distinguish between normal and pathological myocardium, for automatic delineation of the endocardial border without being limited by the weak contrast of the traditional video images, and for use in contrast echography, where it could offer the possibility to visualize perfusion using intravenous contrast injections. One of the main problems in this kind of research is the acquisition of the signal having a high frequency and large bandwidth. We have developed a new global method for the acquisition of this RF signal. To digitize the data, a video sequencer is used. In this way it becomes possible to sample all available data generated by the echographic equipment during at least 1 s. This means that all data of the complete sector scan during a complete heart-cycle can be digitized without using any data reduction technique or triggering on the electrocardiogram. The advantage of this approach is that all characteristics of the signal can be studied, without being limited by data reduction techniques used during acquisition. This method enables us to calculate parameters such as "integrated backscatter," or to investigate the signal more extensively, e.g., by using spectrum analysis. We can compare different regions of the myocardium and examine them during the heart-cycle, all within the same beat. We have also written a software package for the processing of the large amount of data resulting from the acquisition.

Robustness of integrated backscatter for myocardial tissue characterization.

Integrated backscatter (IB) has been used for ultrasonic tissue characterization. To assess the potential variables in IB measurements, we performed both theoretical simulations and in vitro phantom measurements. First, we simulated data in which the scatterer position randomly was varied. IB values for the resulting images were calculated. Second, RF data from a tissue-mimicking phantom were acquired. Third, an adapted imaging approach, based on phase insensitivity, was evaluated. For both the simulations and phantom measurements, IB showed a standard deviation of +/-20%. These large deviations can be explained by variations in interference of signals and are not related to the state of the tissue. Small deviations in position of the scatterers resulted in important variations in IB. They must be taken into account and may limit the use of IB in cardiological applications. An improvement potentially can be obtained using phase insensitivity in new ultrasound processing schemes.

Thrombolytic therapy and acute aortic dissection.

Thrombolytic (tissue plasminogen activator) and antithrombotic treatment (heparin and aspirin) were given to a 47-year-old man with an acute type II aortic dissection presenting as an acute anterior myocardial infarction. During treatment he developed cardiac tamponade and an ischaemic stroke. Transoesophageal echocardiography (but not computed tomographies of the chest) revealed the correct diagnosis. After surgical repair (Bentall procedure) there was a complete recovery.

The use of intracoronary ultrasound for quantitative assessment of coronary artery lumen diameter and for on-line evaluation of angioplasty results.

UNLABELLED: The value of intracoronary ultrasound for quantitative assessment of minimal coronary arterial diameter and for on-line evaluation of balloon angioplasty result was studied in 42 patients undergoing single vessel coronary angioplasty. Measurement of minimal luminal diameter of 75 matched coronary arterial segments showed a significant correlation between both the ultrasound and angiographic method (r: 0.759; p < 0.001). Furthermore using intravascular ultrasound it was possible to classify the obtained coronary balloon angioplasty results. A preliminary correlation between ultrasound classification and the in-hospital acute rethrombosis as well as late restenosis was attempted in individual patients. CONCLUSIONS: 1) Clinical use of coronary ultrasound is feasible and safe in selected cases. 2) A significant correlation between intracoronary ultrasound and quantitative coronary angiography is demonstrated. 3) Using intracoronary ultrasound seems promising for evaluation of the postangioplasty result, and may finally lead to improved selection of the interventional strategy.

Role of intravascular ultrasound in coronary artery disease: a new gold standard? An overview.

Although selective contrast coronary arteriography has been the gold standard approach for coronary imaging since more than 30 years, new coronary imaging techniques are currently under development. Intravascular ultrasound (IVUS) is perhaps the most promising of these additional techniques. IVUS makes use of miniaturised crystals incorporated at catheter tips and provides real time, cross-sectional and longitudinal, high resolution images of the arterial wall with three-dimensional reconstruction capabilities (Pandian, 1989; Coy et al., 1991; Liebsen & Klein, 1992). Different devices have been constructed. Actually two types are being used: mechanical (hand-rotated or motor-driven) systems and phased array systems using high-frequency (20-30 MHz) transducers (Bom et al., 1989). Coronary ultrasound imaging performed during catheterization is feasible and safe as demonstrated in several studies examining normal and pathologic coronary arteries (De Scheerder et al., in press).

Complete occlusion of the main left coronary artery. A clinical study.

Between 1975 and 1985, 12 patients with complete occlusion of the main left coronary artery (MLCA) were seen. The historical, clinical, biochemical, radiological, electrocardiographic, angiographical, surgical and follow-up findings were analyzed. Eight of the 12 patients presented on admission an unstable clinical situation. A normal ECG at rest was found in only 3 patients. Exercise testing elicited definite electrocardiographic changes in 5 of 6 cases. Coronary atherosclerosis was the cause of occlusion in 11 patients; in 1 patient the underlying disease process remained unclear. Significant lesions of the right coronary artery (RCA) were found in 9 and of the left anterior descending (LAD) or circonflex (CFLX) artery in 6 patients. Global and/or regional left ventricular dysfunction at rest was present in 10 patients. Angiographically visible collateral circulation was found in all patients but its extent was variable. All patients underwent bypass surgery. There were 1 operative and 2 late deaths.

Isolated left sided superior vena cava draining into the left atrium associated with recurring intracerebral abscesses. A case report.

A case is reported of recurrent intracerebral abscesses occurring in a patient with isolated drainage of a persistent left superior vena cava to the left atrium without causing cardiac symptoms or arterial desaturation. The diagnosis and therapy are discussed.

Clinical applications of echocardiography in patients with acute myocardial infarction.

The ability of echocardiography to visualize ventricular wall motion abnormalities induced by ischaemia and infarction makes it an ideal tool in the assessment of patients with acute myocardial infarction. Echocardiographic derived measurements of infarction severity, such as the wall motion score index, correlate well with both early and late complications. Echocardiography is of considerable value in the detection of mechanical complications of myocardial infarction such as aneurysm and thrombus formation, infarction expansion, ventricular septal rupture and mitral regurgitation; Doppler echocardiography is of particular worth in the detection of the latter two complications. Serial echocardiographic imaging before and after various coronary reperfusion strategies allows useful assessment of the success of these strategies. Following a myocardial infarction, a predischarge resting or exercise 2-dimensional echocardiographic study provides valuable information regarding the likelihood of adverse cardiac events during long term follow-up.