Relationship between cardioscopic images and histological changes in the left ventricle of patients with idiopathic myocarditis

Decrease in dendritic cells in endomyocardial biopsies of human dilated cardiomyopathy

AIMS

Dendritic cells (DCs) are sentinels of the immune system-their role in myocardial disease is unknown as yet. We investigated their myocardial presence in human dilated cardiomyopathy (DCM).

METHODS AND RESULTS

Endomyocardial biopsies from 72 patients with DCM (EF ∼30%), as well as myocardial specimens from 18 suicide or accident victims were immunohistochemically analysed for myeloid and plasmacytoid DCs, antigen-presenting cells (APCs), and other leucocytes; also tissue fibrosis and apoptosis were histologically quantified. The myocardial viral genome was identified through polymerase chain reaction, and patients underwent clinical follow-up in 3-6 months. We found myocardial DCs of all examined subtypes and maturation stages (fascin, CD11c, CD209, CD83, and CD304), as well as markers for APCs (HLA-DR and CD40) and T-cell activation (CD69) to be significantly decreased in DCM compared with controls. In contrast, regulatory T cells (the GITR epitope), apoptosis (by TUNEL reaction and immunostaining with BCL-2), and a DC chemokine receptor (CCR7) were overexpressed, while no significant differences were observed for macrophages (CD68). Immature myeloid and plasmacytoid DCs strongly correlated with endothelial progenitor cells (CD34), which were similarly reduced in DCM, and inversely correlated with fibrosis. Myeloid DCs were especially reduced in virus-positive biopsies, and their numbers correlated with positive change in EF (ΔEF) at follow-up.

CONCLUSION

Myocardial DCs are reduced in heart biopsies of symptomatic DCM patients. Such a reduction correlates with an unfavourable short-term outcome in terms of EF, and could result from myocardial tissue damage, cellular death, and insufficient vascularization in chronic heart failure.

The diagnostic role of cardiac magnetic resonance imaging in detecting myocardial inflammation in systemic lupus erythematosus. Differentiation from viral myocarditis

Objective

The objective of this paper is to evaluate the diagnostic role of cardiac magnetic resonance imaging (CMR) in detecting myocardial inflammation in systemic lupus erythematosus (SLE) and its differentiation from viral myocarditis.

Patients and methods

Fifty patients with suspected infective myocarditis (IM), with chest pain, dyspnoea or altered ECG, increase in troponin I and/or NT-pro BNP, with or without a history of flu-like syndrome or gastroenteritis and elevated C-reactive protein (CRP) within three to five (median four) weeks before admission, 25 active SLE patients, aged 38 ± 3 years, and 20 age-matched controls were prospectively evaluated by clinical assessment, ECG, echocardiogram and CMR. All patients underwent coronary angiography, and those with significant coronary artery disease (CAD) were excluded. CMR was performed using STIR T2-W (T2W), early T1-W (EGE) and late T1-W (LGE). Endomyocardial biopsies were performed when clinically indicated by current guidelines. Specimens were examined by immunohistological and polymerase chain reaction (PCR) analysis.

Results

Positive coronary angiography for CAD excluded 10/50 suspected IM and 5/25 active SLE. Positive clinical criteria for acute myocarditis were fulfilled by 28/40 suspected IM and only 5/20 active SLE. CMR was positive for myocarditis in 35/40 suspected IM and in 16/20 active SLE. Endomyocardial biopsy (EMB), performed in 25/35 suspected IM and 7/16 active SLE with positive CMR, showed positive immunohistology in 18/25 suspected IM and 3/7 active SLE. Infectious genomes were identified in 24/25 suspected IM and 1/7 active SLE.

Conclusions

CMR-positive IM patients were more symptomatic than active SLE. More than half of CMR-positive patients also had positive EMB. PCR was positive in almost all IM, but unusual in SLE. Due to the subclinical presentation of SLE myocarditis and the limitations of EMB, CMR presents the best alternative for the diagnosis of SLE myocarditis.

High prevalence of myocarditis in patients with hypertensive heart disease and cardiac deterioration

AIMS

Structural abnormalities causing cardiac deterioration in hypertensive heart disease (HHD) are poorly understood. The aim of the study was to evaluate left ventricular (LV) myocardial changes in patients with HHD and cardiac failure.

METHODS AND RESULTS

Among 1229 patients undergoing an LV or biventricular endomyocardial biopsy because of unexplained LV dysfunction from 2000 to 2010, 45 had HHD. The HHD population had non-invasive assessment of cardiac wall thickness, diameters, and function; endomyocardial samples were processed for histology, immunohistochemistry, and polymerase chain reaction (PCR) for cardiotropic viruses. Mean LV end-diastolic diameter was 63.3 ± 5.9 mm, LV ejection fraction 29.7 ± 7.6%, and maximal wall thickness 12.8 ± 0.9 mm. At histology, hypertrophy with degeneration of cardiomyocytes, increased external/lumen ratio of intramural arterioles, and myocardial fibrosis were observed in 17 patients (38%). In the remaining 28 patients (62%), these histological changes were associated with myocarditis. Myocarditis was present in 40.4% of the cohort without HHD. PCR was negative in HHD without inflammation while it was positive in 10 subjects with myocarditis (enterovirus in 3 cases, adenovirus 4, influenza virus 3). Addition of immunosuppression to supportive therapy in the 18 virus-negative myocarditis subjects was followed at 6 months by significant recovery of LV function in 15 (83%; ejection fraction from 25.3 ± 9.3% to 49.5 ± 9.8%) while LV function improved to a minor extent ( ejection fraction from 25 ± 5.1% to 36 ± 4.4%) in 12 of 27 patients (44%) on supportive treatment alone.

CONCLUSION

Myocarditis is a major cause of cardiac deterioration in patients with HHD; its recognition may improve patient treatment and outcome.

Nitroglycerin-induced heterogeneous subendocardial myocardial blood flow observed by cardioscopy in patients with coronary artery disease

It is controversial as to whether or not nitroglycerin (NTG) increases subendocardial myocardial blood flow (SMBF), and if it does, whether arterial or venous blood flow is increased in patients with coronary artery disease. This study was performed to examine NTG-induced changes in SMBF.Changes in SMBF induced by NTG (200 µg, i.v.) were examined by cardioscopy in 58 left ventricular wall segments of 58 patients with coronary artery disease. NTG-induced red and purple endocardial colors were defined as increased arterial and venous SMBF, respectively. Endocardial color before NTG administration was classified into brown, light brown, pale and white. Endomyocardial biopsy of the observed portion and (201)Tl scintigraphy were performed in 40 of these patients immediately after cardioscopy and several days after cardioscopy, respectively.Upon administration of NTG, SMBF increased in 48 of 58 wall segments; arterial SMBF in 34 and venous SMBF in 12 wall segments; arterial SMBF in all 24 brown to light brown segments; venous SMBF, arterial SMBF and no change in 12, 10 and 5 of pale segments, respectively; and no change in all 10 white wall segments. (201)Tl-scintigraphy and endomyocardial biopsy revealed that brown, light brown, pale and white endocardial color represented no ischemia, mild ischemia, severe ischemia and fibrosis, respectively.NTG caused an increase in either arterial or venous SMBF depending on control endocardial color, wall motion and severity of coronary stenosis.

Recent Advances in Percutaneous Cardioscopy

Percutaneous cardioscopy, using high-resolution fiberoptic imaging, enables direct visualization of the cardiac interior, thereby enabling macroscopic pathological diagnosis. Percutaneous cardioscopy has demonstrated that the endocardial surface exhibits various colors characteristic of different heart diseases. This imaging modality can now be used for evaluation of the severity of myocardial ischemia, and staging of myocarditis. Myocardial blood flow recovery induced by vasodilating agents or percutaneous coronary interventions can be clearly visualized. Morphological and functional changes in the cardiac valves can also be evaluated. Cardioscope-guided endomyocardial biopsy enables pin-point biopsy of the diseased myocardium. Recently, dye-image cardioscopy and fluorescence cardioscopy were developed for evaluation of the subendocardial microcirculation. Cardioscope-guided intracardiac therapies such as myotomy, myectomy, valvulotomy, and transendocardial angiogenic and myogenic therapy have been trialed using animal models in anticipation of future clinical applications. Percutaneous cardioscopy has the potential to contribute to our understanding of heart disease, and to assist in guidance for intracardiac therapies.

Myocarditis as a precipitating factor for heart failure: evaluation and 1-year follow-up using cardiovascular magnetic resonance and endomyocardial biopsy

AIMS

The aim of this study was to evaluate myocarditis as a precipitating factor for heart failure using cardiovascular magnetic resonance (CMR) and endomyocardial biopsy.

METHODS AND RESULTS

Eighty-five patients with suspected myocarditis and 20 controls were evaluated. Seventy-one patients with positive CMR were referred for endomyocardial biopsy and re-evaluation after 1 year. Cardiovascular magnetic resonance was performed using STIR T2-weighted (T2W), early T1-weighted (EGE), and late gadolinium-enhanced (LGE) images. Immunohistological and polymerase chain reaction (PCR) analysis of myocardial specimens was employed. In patients with myocarditis, T2 and EGE were increased compared with controls (2.6 ± 0.9 vs. 1.57 ± 0.13, P < 0.001 and 7.9 ± 5.5 vs. 3.59 ± 0.08, P < 0.001, respectively). Late gadolinium enhancement was found in all myocarditis patients. Endomyocardial biopsy performed in 50 of 71 patients with positive CMR showed positive immunohistology in 48% and presence of infectious genomes in 80% (mainly Chlamydia, Herpes, and Parvovirus B19). Left ventricular ejection fraction (LVEF) was significantly decreased compared with controls (47.7 ± 19.2 vs. 64 ± 0.2, P < 0.001). After 1 year, CMR showed normalization of T2 and EGE, and decreased LGE. Left ventricular ejection fraction increased in 36.5% of patients, remained stable in 56.5% and decreased in 7% of patients, in whom biopsy showed persistence of the initial infective agents. A negative correlation was identified between EGE, LGE, and LVEF. Patients with positive biopsies had lower LVEFs.

CONCLUSION

In a Greek population with myocarditis, Chlamydia with viruses was a common finding. Cardiovascular magnetic resonance and PCR proved useful for the detection of myocarditis; EGE and LGE had the best correlation for the development of heart failure. Persistence of the initially detected infective agents was identified in patients who deteriorated further.