Abstract
A 29-year-old man was hospitalized because of heart failure causing dilated cardiomyopathy (DCM). On admission, he had elevated creatinine kinase levels (hyper CKemia) (4283 IU l−) and false enlargement of bilateral calves. By a muscular biopsy, he was diagnosed as Fukuyama-type muscular dystrophy. Although neuromuscular diseases are often related to cardiomyopathy, reports showing a relation between cardiomyopathy and Fukuyama-type muscular dystrophy have been rare. Our group performed the partial left venticulectomy of the posterior wall and approximation of the papillary muscle, mitral valve annuloplasty, and tricuspid valve annuloplasty for DCM in the patient with Fukuyama-type muscular dystrophy, after obtaining informed consent from the patient and his family. At the 1-year follow-up examination, the neuromuscular symptoms had not progressed, and the left ventricular function was improved (left ventricular end-diastolic dimension (LVDd) 77–66 mm, left ventricular end-systolic dimension (LVDs) 73–59 mm, and ejection fraction (EF) 26–30%). This is the first case report of a left ventriculoplasty in a patient with Fukuyama-type muscular dystrophy.
1 Introduction
Fukuyama-type muscular dystrophy is characterized by congenital muscular dystrophy associated with mental retardation due to brain malformation [1–3].
Although neuromuscular diseases are often related to cardiomyopathy, reports showing a relation between cardiomyopathy and Fukuyama-type muscular dystrophy have been rare.
In Japan, there have been only six reported cases of Fukuyama-type muscular dystrophy associated with dilated cardiomyopathy (DCM) [4].
Patients with cardiomyopathy are usually treated with diuretics, angiotensin-converting enzyme (ACE) inhibitors and/or β-blockers, but these medical treatments are often refractory. Orthotopic heart transplantation may be one of the best options for the treatment of DCM, yet neuromuscular diseases are a contraindication for heart transplantation in Japan (http://plaza.umin.ac.jp/∼hearttp/).
Our group performed a left ventriculoplasty for DCM in an adult male with Fukuyama-type muscular dystrophy after obtaining informed consent from the patient and his family. This is the first case report of a left ventriculoplasty in a patient with Fukuyama-type muscular dystrophy.
2 Case
A 29-year-old man was hospitalized because of heart failure (New York Heart Association (NYHA) class IV) in July 2008. The patient was of normal intelligence and had no past history of cardiac failure or any other disease. From 2007, he began experiencing worsening dyspnea at rest and was diagnosed with DCM. He suffered from a recurrent non-sustained ventricular tachycardia that required amiodarone. His symptom did not improve in response to optimal medical management with diuretics, ACE inhibitor, and fluid and salt restriction.
A two-dimensional echocardiogram showed an enlarged left ventricle with diffuse hypokinesia. The left ventricular end-diastolic dimension (LVDd) was 77 mm, the end-systolic dimension (LVDs) was 73 mm, and the ejection fraction (EF) was 26% with inotropic support. Mitral valve regurgitation (MR) was severe (grade 4) and tricuspid valve regurgitation (TR) was moderate (grade 2) (video 1).
Coronary angiography was normal. The central venous pressure, right ventricular mean pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure (PCWP), and cardiac index measured by Fick’s method were 18 mmHg, 20 mmHg, 33 mmHg, 26 mmHg, and 1.60 l min−1 m−2, respectively, in Swan–Ganz catheter examination, with inotropic support.
On admission, brain natriuretic peptide was 431 pg ml−1, creatine kinase was 4283 IU l−1, and creatine kinase MB was 41 IU l−1. The patient had no significant muscular weakness, but false enlargement of bilateral calves and talipes equines of bilateral feet were observed. Three uncles on his mother’s side had muscular weakness of bilateral lower limbs and hyperCKemia.
Suspecting neuromuscular disease, we performed a muscular biopsy, and it showed severe dystrophic changes with dense deposition of fibrous and adipose tissues (Fig. 1 ). Immunohistochemical analysis of the biopsied muscle sample showed a marked decrease of α-dystroglycan staining, whereas the distribution and expression of β-dystroglycan were unchanged. This finding was consistent with Fukutin gene (FKTN) mutations, and the condition was diagnosed as Fukuyama-type muscular dystrophy.
Hematoxylin and eosin staining. Muscle biopsy showed severe dystrophic changes with dense deposition of fibrous and adipose tissues.
There was no improvement in his hemodynamic condition despite medications and intravenous inotropic support. The patient and family met with a group of neurologists, cardiologists, and cardiac surgeons to discuss the treatment options. The patient and family hoped for surgical treatment, as the neurologic symptoms were slight and the neurologists assessed the prognosis of the muscular dystrophy as potentially favorable.
Under general anesthesia, we performed the partial left ventriculectomy of the posterior wall and approximation of the papillary muscle, as the posterolateral wall was thin and akinetic, and the septum was relatively good as assessed by an intra-operative volume reduction test. Furthermore, mitral valve annuloplasty with a 26-mm Carpentier Edwards Physio Ring (Edwards Lifesciences, Irvine, CA, USA) and tricuspid valve annuloplasty with a 28-mm Edwards MC3 ring (Edwards Lifesciences, Irvine, CA, USA) were performed. The patient was discharged 1 month after the surgery. He returned to normal life and began working 3 months postoperatively.
At the 1-year follow-up examination, the neuromuscular symptoms had not progressed. Further, LVDd, LVDs, and EF were 66 mm, 59 mm, and 30% with diffuse hypokinesia, MR was mild, and TR was mild by a two-dimensional echocardiogram (video 2).
The patient had neither MR nor symptoms of heart failure (edema, ascites, or lung congestion).
3 Discussion
Fukuyama-type muscular dystrophy caused by a deficient laminin-binding ability due to altered glycosylation of α-dystroglycan is the second most common muscular dystrophy in Japan. Patients with this condition carry the founder mutation of the 3-kb retrotransposal insertion in the fukutin gene (FKTN), either homozygously or heterozygously [5,6].
Fukuyama-type muscular dystrophy is one of the most severe congenital muscular dystrophies. The condition is caused by brain malformation, mainly cerebral and cerebellar cortical dysplasia [2,3]. In contrast to the severely affected skeletal muscle, clinical manifestations of cardiac impairment are quite rare. Murakami et al. recently showed that the compound heterozygous mutations may also be associated with DCM accompanied by minimal limb-girdle-muscle involvement and normal intelligence [4].
Surgical treatment has been selected in patients with refractory heart failure caused by DCM associated with neuromuscular disease. Some patients with neuromuscular diseases have gone on to live normal daily lives without assistance after undergoing ventricular assist device (VAD) implantation or heart transplantation [7]. Transplantation is contraindicated for patients in Japan, however, principally because of the extreme shortage of donors and the risks of respiratory failure and infection due to immunosuppressive therapy. The Toyobo VAD (Nipro, Inc., Osaka, Japan) is the only commercially available VAD in Japan. This VAD is highly susceptible to device-related infection (nearly 40–50%) and cerebrovascular events (nearly 40–50%). The cumulative survival at 2 years after implantation is 18.1–56.1%. Worse, patients who undergo Toyobo VAD implantation are unable to leave the hospital, as the device is designed for an inpatient setting [8].
Our group previously reported favorable outcomes in patients undergoing ventriculoplasty for idiopathic DCM. The hospital mortality was 11.6% in these patients. The mean NYHA class, cardiac index, and left-ventricular dimension were all significantly improved, and the 1-, 3-, and 5-year survival rates were 72.8%, 61.4%, and 50.5%, respectively [9,10]. These results suggest that left ventriculoplasty has many advantages over VAD implantation and heart transplantation, and it may be a good therapeutic option, especially in patients with muscular dystrophy and other neurologic diseases.
References
Appendix A
Supplementary data
Supplementary data associated with this article (video 1 and video 2) can be found, in the online version, at doi:10.1016/j.ejcts.2010.12.018.
