Title: Infectious endocarditis of
the mitral valve with hypertrophic cardiomyopathy in Costello syndrome
Authors:
Shinichi Ishida MD1, Masato Mutsuga
MD,PhD2, Takashi Fujita MD1, Kei
Yagami MD,PhD1
1Department of
Cardiac Surgery, Gifu Prefectural Tajimi Hospital, Tajimi, Gifu, Japan.
2Department of Cardiac Surgery, Nagoya University
Graduate School of Medicine, Nagoya, Aichi, Japan.
Short running title: Infectious endocarditis in Costello syndrome
Keywords: Infectious endocarditis, Costello syndrome, mitral valve
regurgitation, hypertrophic cardiomyopathy, systolic anterior motion
Corresponding Author:
Shinichi
Ishida, 5-161 Maebata-cho,
Tajimi-city, Gifu 507-8522, Japan,
Tel: +81-572-22-5311, e-mail:
shin1dinho@yahoo.co.jp
Abstract:
Costello syndrome is a rare congenital disease caused by activating
germline mutations, and it is often associated with cardiac
abnormalities. A 17-year-old male, who had a history of Costello
syndrome, presented with persistent fever. The vegetation attached to
anterior mitral leaflet was detected, and antibiotic therapy was
administered as treatment for infectious endocarditis. However, it was
difficult to manage his heart failure owing to the worsening of mitral
valve regurgitation. Therefore, mitral valve repair with vegetation
resection was performed. His hypertrophic cardiomyopathy and systolic
anterior motion caused left ventricle outflow tract obstruction. A
floating stitch on the anterior mitral leaflet from the posterior ring
annulus was effective. Herein, we report a successfully repaired case of
infectious endocarditis on the mitral valve with hypertrophic
cardiomyopathy complicated by Costello syndrome.
Introduction:
Costello syndrome (CS) is a rare congenital disease caused by activating
germline mutations.1 It is characterized by deficient
postnatal development of multiple organs, mental retardation, and
predisposition to cancer. Congenital malformations such as pulmonary
valve stenosis, hypertrophic cardiomyopathy (HCM), and atrial septal
defect have been reported.2 Infectious endocarditis in
a patient with CS has not been previously reported. We herein present
the rare case of a 17-year-old male with CS who developed mitral valve
regurgitation (MR) because of infectious endocarditis.
Case Report:
A 17-year-old male presented with fever of unknown origin and was
admitted for examination and treatment. He had a history of CS and
atopic dermatitis as well as mental retardation according to CS. Blood
cultures detected methicillin-susceptible Staphylococcus aureus .
Echocardiography showed HCM and vegetation attached to the anterior
mitral leaflet (AML) with MR. MR was less than mild and severe symptoms
of heart failure were not present. Therefore, antibiotic and medication
therapy for heart failure were initiated. Although the infection
responded to treatment, the MR and heart failure symptoms worsened.
Consequently, surgery for vegetation resection and mitral valve repair
was planned.
After median sternotomy, cardiopulmonary bypass was established with
ascending aortic cannulation and bicaval drainage, and the heart was
arrested with antegrade cardioplegia. The mitral valve was visualized
through a right-sided left atriotomy. After shaving the vegetation on
the AML, mitral valve annuloplasty was performed using a 25-mm Tailor
Flexible Annuloplasty Ring (St. Jude Medical, St. Paul, MN, USA) with
single-pair artificial chordae reconstruction using CV4 Gore-Tex suture
(WL Gore and Associates, Inc., Flagstaff, AZ, USA). Transesophageal
echocardiography showed systolic anterior motion (SAM) of the mitral
valve with moderate MR and left ventricular outflow tract obstruction
(LVOTO) owing to HCM after unclamping the aorta (Figure 1). To reduce
SAM, the floating stitch technique was used:3 a
double-arm CV4 Gore- Tex suture was applied just to the middle of
the tip (A2) of the AML in a figure-eight fashion, and both arms of the
suture were fixed to the annuloplasty ring at the middle of the
posterior annulus (P2) (Figure 2). After application and fixation, SAM
and MR disappeared (Figure 3). The patient’s postoperative course was
uneventful, and he was later discharged home.
Discussion:
CS is often associated with multiple growth retardation and malformation
in multiple organs, including cardiac abnormalities. In this case,
remarkable complication interfering with a surgery was HCM, and the
ascending aorta was small relative to his physique. In addition, the
disorder of connective tissue and deposition of elastic fiber was one of
the characteristics of CS, and the elastic fibers of aorta and coronary
arteries are thinner in patients with CS than in normal
individuals.4 Therefore, detailed preoperative
examination and careful technique are required in these patients. We
used a flexible ring because of the irregularly shaped annulus. To
manage LVOTO, the floating stitch technique was used to reduce SAM of
the mitral valve after valve repair.3 This method is a
simple, reproducible, and effective for preventing SAM. Further
follow-up and studies on this technique are needed.
Conclusion:
In patients with CS with associated cardiac and tissue abnormalities,
mitral valve repair using a flexible ring and artificial chordae
reconstruction using the floating stitch technique to manage LVOTO are
feasible.
Conflicts of Interest: The authors declare that there are no conflict of
interests.
Author contributions:
S.I., M.M., T.F. and K.Y. designed and performed the experiments,
analyzed data and interpreted it. S.I. and K.Y. Drafted article. S.I.,
M.M., F.T. and K.Y. revised it critically. S.I., M.M., F.T. and K.Y.
approved of the article, collected data and supported technical and
logistical.
References:
1. Gripp KW, Morse LA, Axelrad M, et al. Costello syndrome: clinical
phenotype, genotype, and management guidelines. Am J Med Genet.2019;179:2725-1744.
2. Roberts A, Allanson J, Jadico SK, et al. The cardiofaciocutaneous
syndrome. J Med Genet. 2006;43:833-842.
3. Mutsuga M, Narita Y, Usui A. A floating stitch on the anterior mitral
leaflet can eliminate systolic anterior motion in hypertrophic
obstructive cardiomyopathy. Semin Thorac Cardiovasc Surg.2020;32:266-268.
4. Hinek A, Smith AC, Cutiongco EM, et al. Decreased elastin deposition
and high proliferation of fibroblasts from Costello syndrome are related
to functional deficiency in the 67-kD elastin-binding protein. Am
J Hum Genet. 2000;66:859-872.
Figure.1 Systolic anterior motion of anterior mitral leaflet (arrow)
developed and it caused mitral valve regurgitation after the initial
mitral valve repair. LA, left atrium; LV, left ventricle; AO, aorta
Figure.2 Intraoperative images from the surgeon’s perspective showing
the floating stitch technique. A double-arm CV4 Gore-Tex suture (arrows)
is applied just to the middle of the tip (A2) of anterior mitral leaflet
(AML) in a figure-eight fashion, and both arms of the suture are fixed
to the annuloplasty ring (asterisk) at the middle of the posterior
annulus (P2).
Figure.3 Postoperative transthoracic echocardiography. A, The anterior
leaflet (red arrow) was retracted to the posterior annulus by Gore-tex
suture during diastole. Mitral stenosis did not exist. B, Systolic
anterior motion was not shown, and the anterior leaflet was in a closed
position (yellow arrow) during systole. LA, left atrium; LV, left
ventricle; AO, aorta