Chronic Active Myocarditis After Transapical Transcatheter Aortic Valve Implantation

An 87-year-old man with symptomatic aortic stenosis (left ventricular ejection fraction [LVEF] 63%, aortic valve area 0.88 cm², mean pressure gradient 26 mmHg, stroke volume index 23 mL/min², Agatston score 2,781) underwent transapical (TA) transcatheter aortic valve implantation (TAVI) with SAPIEN3 (Edwards Lifesciences, Irvine, CA, USA) to avoid stroke risk from aortic arch atherosclerosis. After TAVI, transthoracic echocardiography showed LVEF of 59% (Supplementary Movie 1). Serum troponin T peaked at 24 ng/L. Four months later, the patient was hospitalized for worsening heart failure, with LVEF having decreased to 26% (Supplementary Movie 2) and serum troponin T having increased to 84 ng/L. Coronary angiography showed no significant coronary artery stenosis. Cardiac magnetic resonance imaging showed prolonged myocardial T₂ relaxation time throughout the left ventricle and late gadolinium enhancement at the TA-TAVI approach site (Figure A,B). ¹⁸F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography showed abnormal FDG uptake only at the same site (Figure C). Endomyocardial biopsy revealed severe inflammatory cell infiltration, interstitial fibrosis, and positive tenascin-C immunostaining, suggesting chronic active myocarditis (Figure D–F).¹ Symptoms were relieved by guideline-directed medical therapy; however, LVEF was not improved.

Figure.

(A) Late gadolinium enhancement (arrow) at the apex and (B) prolonged T₂ relaxation time (arrows) on cardiac magnetic resonance imaging. (C) Fluorodeoxyglucose (FDG) uptake in the apex on ¹⁸F-FDG positron emission tomography/computed tomography. (D,E) Hematoxylin and eosin staining of right ventricular endomyocardial septum. Arrows indicate infiltration of inflammatory cells. (F) Tenascin C immunostaining of right ventricular endomyocardial septum.

To our knowledge, this is the first report of chronic active myocarditis after TA-TAVI, possibly myocardial inflammation due to an immune response at the TA-TAVI approach site.

Disclosures

T.A. and T.N. are members of Circulation Journal’s Editorial Team.

Supplementary Files

Supplementary Movie 1. TTE four days after TA-TAVI.

Supplementary Movie 2. TTE four months after TA-TAVI.

Please find supplementary file(s);

https://doi.org/10.1253/circj.CJ-23-0910

Reference

• 1.   Nagai T, Inomata T, Kohno T, Sato T, Tada A, Kubo T, et al. JCS 2023 guideline on the diagnosis and treatment of myocarditis. Circ J 2023; 87: 674–754, doi:10.1253/circj.CJ-22-0696.