2421Immunosuppressive therapy and prognosis in biopsy-proven fulminant lymphocytic myocarditis requiring veno-arterial extracorporeal membranous oxygenation support

Background

Fulminant myocarditis is one of the fatal diseases for which effective management has not yet been established. Immunosuppressive therapy (IST) using corticosteroid has been actively applied to giant cell or eosinophilic myocarditis, there is no consensus on the efficacy of lymphocytic myocarditis, which is suspected of involving viral infection. Actually, IST for lymphocytic myocarditis is not recommended in the European Society of Cardiology guidelines, but in the Japanese Circulation Society guidelines, it is approved for use in refractory cases in the absence of curative therapy for myocarditis established.

Purpose

The purpose of this study was to explore the potential efficacy of immunosuppressive therapy on acute phase in fulminant lymphocytic myocarditis (FLM) requiring veno-arterial extracorporeal membranous oxygenation (VA-ECMO) support.

Method

We conducted CHANGE-PUMP study that was retrospectively enrolled 99 patients with fulminant myocarditis required VA-ECMO support in the Tokai area (central part of Japan) for the past 20 years. Lymphocytic myocarditis was defined by pathological category. Patients were divided into two groups depending on whether IST using corticosteroid was performed in the clinical course. Results: Sixty-six patients were pathologically diagnosed as fulminant myocarditis by endomyocardial biopsy, of which only 49 patients were FLM. IST were indicated in 8 (16%) out of 49 patients of FLM (IST group; n=8, non-IST group; n=41). Kaplan-Meier survival analysis showed a lower survival rate in the IST group than in the non-IST group (p=0.073). However, in all cases, based on our guidelines, IST was initiated after becoming refractory to MCS treatment.

Immunosupressive therapy and prognosis

Conclusion

In the retrospective analysis, biopsy-proven FLM patients with IST required VA-ECMO support had low survival rates. However, the timing of IST introduction was late and concerned. In the present era when advanced mechanical support appears and the survival rate of fulminant myocarditis is expected to improve, a multicenter prospective study is needed to establish an indication of IST in the acute phase of fulminant myocarditis.

P5633Diagnostic impact of resting full-cycle ratio as newly developed non-hyperemic indices for physiological lesion assessment

Background

Although fractional flow reserve (FFR) is a gold standard method to evaluate functional lesion severity in the catheterization laboratory, the need of hyperemic condition limits the widespread adoption of FFR. Recently, the resting full-cycle ratio (RFR) which was newly developed resting indices was launched. It is unclear whether RFR as resting condition could assess physiological lesion severity of coronary artery stenosis. The aim of this study was to evaluate the diagnostic impact of RFR compared to FFR in entire range of coronary artery stenosis.

Method

A total of 53 patients with 70 lesions were enrolled in this study. The RFR was measured after adequately waiting for stable condition, while FFR was measured after intravenous administration of ATP (180mcg/kg/min). Lesions with FFR ≤0.80 were considered functionally significant coronary artery stenosis.

Results

In all lesions, reference diameter, diameter stenosis, lesion length, RFR, and FFR were 3.3±0.8mm, 44±12%, 14.6±7.2mm, 0.90±0.11, and 0.83±0.11, respectively. Functional significance was observed in 24 lesions (34%) of all lesions. The RFR showed a significant correlation with FFR (y = 0.800x + 0.239, R = 0.817, p<0.001). The Bland-Altman plot demonstrated a good agreement with a mean difference of 0.07 and a standard deviation of 0.06 between RFR and FFR across entire range of coronary artery stenosis. ROC curve analysis showed an excellent accuracy of RFR cut-off of ≤0.90 in predicting FFR ≤0.80 which had 78% sensitivity and 87% specificity (AUC 0.87, diagnostic accuracy 84%).

Conclusion

The RFR as newly resting indices is reliable to the assessment of functional lesion severity. This physiology-based approach may be a possible alternative method for FFR measurements in daily practice.

Upstream Enhancer Elements of Shh Regulate Oral and Dental Patterning

Sonic hedgehog ( Shh) is important in pattern formation during development. Shh transcription is modulated by a long-range regulatory mechanism containing a number of enhancers, which are spread over nearly 850 kb in the mouse genome. Shh enhancers in the nervous system have been found between intron and 430 kb upstream of Shh. Enhancers in the oral cavity, pharynx, lung, gut, and limbs have been discovered between 610 kb and 850 kb upstream of Shh. However, the intergenic region ranging from 430 to 610 kb upstream of Shh remains to be elucidated. In the present study, we found a novel long-range enhancer located 558 kb upstream of Shh. The enhancer showed in vivo activity in oral cavity and whiskers. A targeted deletion from the novel enhancer to mammal reptile conserved sequence 1 (MRCS1), which is a known enhancer of Shh in oral cavity, resulted in supernumerary molar formation, confirming the essential role of this intergenic region for Shh transcription in teeth. Furthermore, we clarified the binding of Lef1/Tcfs to the new enhancer and MRCS1, suggesting that Wnt/β-catenin signaling regulates Shh signaling in the oral cavity via these enhancers.