Infective endocarditis in the Netherlands: current epidemiological profile and mortality : An analysis based on partial ESC EORP collected data.

INTRODUCTION: Infective endocarditis (IE) is associated with a high in-hospital and long term mortality. Although progress has been made in diagnostic approach and management of IE, morbidity and mortality of IE remain high. In the latest European guidelines, the importance of the multi-modality imaging in diagnosis and follow up of IE is emphasized. AIM: The aim was to provide information regarding mortality and adverse events of IE, to determine IE characteristics and to assess current use of imaging in the diagnostic workup of IE. METHODS: This is a prospective observational cohort study. We used data from the EURO-ENDO registry. Seven hospitals in the Netherlands have participated and included patients with IE between April 2016 and April 2018. RESULTS: A total of 139 IE patients were included. Prosthetic valve endocarditis constituted 32.4% of the cases, cardiac device related IE 7.2% and aortic root prosthesis IE 3.6%. In-hospital mortality was 14.4% (20 patients) and one-year mortality was 21.6% (30 patients). The incidence of embolic events under treatment was 16.5%, while congestive heart failure or cardiogenic shock occurred in 15.1% of the patients. Transthoracic and transoesophageal echocardiography were performed most frequently (97.8%; 81.3%) and within 3 days after IE suspicion, followed by 18F­fluorodeoxyglucose positron emission tomography/computed tomography (45.3%) within 6 days and multi-slice computed tomography (42.4%) within 7 days. CONCLUSION: We observed a high percentage of prosthetic valve endocarditis, rapid and extensive use of imaging and a relatively low in-hospital and one-year mortality of IE in the Netherlands. Limitations include possible selection bias.

Prophylactic veno-arterial extracorporeal membrane oxygenation in patients undergoing high-risk percutaneous coronary intervention.

PURPOSE: Complex high-risk percutaneous coronary intervention (PCI) is challenging and frequently accompanied by haemodynamic instability. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) can provide cardiopulmonary support in high-risk PCI. However, the outcome is unclear. METHODS: A two-centre, retrospective study was performed of all patients undergoing high-risk PCI and receiving VA-ECMO for cardiopulmonary support. RESULTS: A total of 14 patients (92% male, median age 69 (53-83) years), of whom 50% had previous coronary artery disease in the form of a coronary artery bypass graft (36%) and a PCI (14%) underwent high-risk PCI and received VA-ECMO support. The main target lesion was a left main coronary artery in 78%, a left anterior descending artery in 14%, a right coronary artery in 7%, and 71% underwent multi-vessel PCI in addition to main target vessel PCI. The median SYNTAX score was 27.2 (8-42.5) and in 64% (9/14) there was a chronic total occlusion. Left ventricular function was mildly impaired in 7% (1/14), moderately impaired in 14% (2/14) and severely impaired in 64% (9/14). Cannulation was femoral-femoral in all patients. Median ECMO run was 2.57 h (1-4). Survival was 93% (13/14). One patient died during hospitalisation due to refractory cardiac failure. All other patients survived to discharge. Complications occurred in 14% (2/14), with one patient developing a transient ischaemic attack post-ECMO and one patient developing a thrombus in the femoral vein used for ECMO cannulation. CONCLUSION: VA-ECMO in high-risk PCI is feasible with a good outcome. It can be successfully used for cardiopulmonary support in selected patients.

Defects in articular cartilage metabolism and early arthritis in fibroblast growth factor receptor 3 deficient mice.

Fibroblast growth factor (FGF) receptor 3 has been identified as a key regulator of endochondral bone development and of post-natal bone metabolism through its action on growth plate chondrocytes and osteoblasts, respectively. It has also been shown to promote chondrogenesis and cartilage production by cultured pre-chondrogenic cells in response to FGF18. In the current studies, we show that the absence of signaling through Fgfr3 in the joints of Fgfr3(-/-) mice leads to premature cartilage degeneration and early arthritis. Degenerative changes in cartilage matrix included excessive proteolysis of aggrecan core protein and type II collagen, as measured by neo-epitope immunoreactivity. These changes were accompanied by increased expression of metalloproteinase MMP13, type X collagen, cellular hypertrophy and loss of proteoglycan at the articular surface. Using a novel micro-mechanical indentation protocol, it was shown that articular cartilage in the humeral head of 4-month-old Fgfr3(-/-) mice was less resistant to compressive force and less stiff than that of littermate controls. These results identify Fgfr3 signaling as a potential target for intervention in degenerative disorders of cartilage metabolism.

Type II collagen degradation in articular cartilage fibrillation after anterior cruciate ligament transection in rats.

OBJECTIVE: To investigate the kinetics of early cartilage changes in mechanically induced osteoarthritis (OA) and the association of these changes with damage to the type II collagen network. METHODS: Experimental OA was induced by anterior cruciate ligament transsection in the rat knee joint (ACLT-OA). Animals were sacrificed after 2, 7, 14, 28 and 70 days. Knee joints were evaluated using routine histology and immunohistochemistry for denatured (unwound) type II collagen to detect collagen damage. An antibody recognizing the collagenase cleavage site in type II collagen was used to study the role of collagenase in this process. RESULTS: The first changes of the articular cartilage after anterior cruciate ligament transection occurred in the superficial zone. These changes included loss of superficial chondrocytes, swelling of the remaining chondrocytes and superficial fibrillation. The swelling of the chondrocytes did not result from a change towards the hypertrophic phenotype, since these cells did not stain for type X collagen. A marked increase in denatured type II collagen staining was present in the fibrillated areas. Staining of the collagenase cleavage site showed the same distribution as denatured collagen but was clearly less intense. Collagen damage could never be detected before fibrillation occurred and was not present in non-fibrillated areas. CONCLUSIONS: These results indicate that in this model cartilage degeneration starts at the articular surface and that this degeneration is associated with a localized expression of type II collagen degradation products.

Expression of type X collagen in young and old C57Bl/6 and Balb/c mice. Relation with articular cartilage degeneration.

OBJECTIVE: To investigate whether the development of osteoarthritic lesions in the knee joints of mice is associated with increased immunostaining of type X collagen. METHODS: Sections of total knee joints in combination with immunohistochemistry were used to study the distribution of type X collagen in the cartilage of young and old mice of two mouse strains, Balb/c and C57Bl/6, known to develop osteoarthritic lesions at different locations. Expression of type X collagen and PTH/PTHrP-receptor mRNA were studied by RT-PCR. RESULTS: Young adult Balb/c and C57Bl/6 mice both expressed type X collagen in the non-calcified cartilage of the tibia-femoral joint. Old mice of both strains had a strongly increased deposition of type X collagen in the patella-femoral but not in the tibia-femoral joint. The locations in the murine knee joints prone to develop osteoarthritis (OA) did not preferentially express increased amounts of type X collagen. Thus, whereas increased type X was observed in both strains in the patella-femoral joints, only Balb/c mice preferentially developed osteoarthritic lesions in these joints. Also cartilage degeneration was usually seen only in the lateral compartment of the knee joints of C57Bl/6 mice but this was not accompanied by increased type X collagen immunostaining. Increased deposition of type X collagen was not associated with elevated levels of type X collagen mRNA or with decreased levels of PTH/PTHrP-receptor mRNA. CONCLUSION: Type X collagen expression and spontaneous OA in mice are not necessarily related since OA prone locations in the murine knee joint do not preferentially express type X collagen.

Postnatal expression in hyaline cartilage of constitutively active human collagenase-3 (MMP-13) induces osteoarthritis in mice.

It has been suggested that increased collagenase-3 (MMP-13) activity plays a pivotal role in the pathogenesis of osteoarthritis (OA). We have used tetracycline-regulated transcription in conjunction with a cartilage-specific promoter to target a constitutively active human MMP-13 to the hyaline cartilages and joints of transgenic mice. Postnatal expression of this transgene resulted in pathological changes in articular cartilage of the mouse joints similar to those observed in human OA. These included characteristic erosion of the articular cartilage associated with loss of proteoglycan and excessive cleavage of type II collagen by collagenase, as well as synovial hyperplasia. These results demonstrate that excessive MMP-13 activity can result in articular cartilage degradation and joint pathology of the kind observed in OA, suggesting that excessive activity of this proteinase can lead to this disease.

Collagen type I antisense and collagen type IIA messenger RNA is expressed in adult murine articular cartilage.

OBJECTIVE: Articular cartilage has only limited capacities for repair and it is not known what is the exact mechanism of matrix restoration. It was investigated whether the reparative process in murine articular cartilage after moderate proteoglycan depletion is accompanied by a change in the chondrocyte phenotype either to hypertrophy or to a less differentiated phenotype as assayed by the expression of specific collagen subtypes. DESIGN: Moderate proteoglycan depletion was induced by injection of papain whereafter the expression of collagen type I mRNA, collagen IIA and IIB mRNA and type X collagen mRNA in patellar cartilage, as markers for chondrocyte phenotype, was investigated by RT-PCR during normal cartilage physiology and matrix restoration. In addition, in-situ expression of collagen subtypes was assayed by immunolocalisation. RESULTS: In normal articular cartilage collagen I, collagen IIB and collagen type X transcripts were easily detected. Surprisingly, collagen type I sense as well as antisense mRNA was detected and in addition to IIB transcripts collagen IIA transcripts were detected in a number of samples. During cartilage matrix restoration no change in the expression of collagen I, collagen IIA or IIB or collagen type X mRNA transcripts could be detected. Immunolocalization demonstrated the presence of type I (pericellular) and type II collagen in the extracellular matrix. The pericellular matrix of hypertrophic chondrocytes showed collagen type X staining in the calcified cartilage in normal and papain-injected knee joints. Increased staining for collagen type X was found in the upper cartilage layer in the interterritorial matrix from day 7 after papain injection. CONCLUSION: The absence of changes in collagen mRNA expression indicates that alteration of chondrocyte phenotype does not occur during the successful repair process after moderate proteoglycan depletion. Collagen type X appears to be deposited in the upper cartilage layer during this process.