Rare clinical phenotype of filaminopathy presenting as restrictive cardiomyopathy and myopathy in childhood

Background

FLNC is one of the few genes associated with all types of cardiomyopathies, but it also underlies neuromuscular phenotype. The combination of concomitant neuromuscular and cardiac involvement is not often observed in filaminopathies and the impact of this on the disease prognosis has hitherto not been analyzed.

Results

Here we provide a detailed clinical, genetic, and structural prediction analysis of distinct FLNC-associated phenotypes based on twelve pediatric cases. They include early-onset restrictive cardiomyopathy (RCM) in association with congenital myopathy. In all patients the initial diagnosis was established during the first year of life and in five out of twelve (41.7%) patients the first symptoms were observed at birth. RCM was present in all patients, often in combination with septal defects. No ventricular arrhythmias were noted in any of the patients presented here. Myopathy was confirmed by neurological examination, electromyography, and morphological studies. Arthrogryposes was diagnosed in six patients and remained clinically meaningful with increasing age in three of them. One patient underwent successful heart transplantation at the age of 18 years and two patients are currently included in the waiting list for heart transplantation. Two died due to congestive heart failure. One patient had ICD instally as primary prevention of SCD. In ten out of twelve patients the disease was associated with missense variants and only in two cases loss of function variants were detected. In half of the described cases, an amino acid substitution A1186V, altering the structure of IgFLNc10, was found.

Conclusions

The present description of twelve cases of early-onset restrictive cardiomyopathy with congenital myopathy and FLNC mutation, underlines a distinct unique phenotype that can be suggested as a separate clinical form of filaminopathies. Amino acid substitution A1186V, which was observed in half of the cases, defines a mutational hotspot for the reported combination of myopathy and cardiomyopathy. Several independent molecular mechanisms of FLNC mutations linked to filamin structure and function can explain the broad spectrum of FLNC-associated phenotypes. Early disease presentation and unfavorable prognosis of heart failure demanding heart transplantation make awareness of this clinical form of filaminopathy of great clinical importance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02477-5.

Transcatheter interventions of coarctation of the aorta (CoA): a multinational population-based registry – procedural complications

Background

Patients with a native or re CoA with an invasively meassured peak to peak gardient >20 mmHg have a guideline indication for intervention. The decision regarding transcatheter versus surgical intervention depends on a variety of factors including location and complexity of CoA, patient/parent preference and availability of a team capable to perform the intevention with a low rate of complications. The aim of the present analysis was to describe factors associated with risk for procedural complications during transcatheter interventions in CoA. Separate anlysis was done for complications at intervention site and at access site.

Methods

All consecutive patients undergoing catheter interventions for CoA from 1st of January 2000 to 31st of December 2016 were identified by each of the particpating nine centers. The nine centers perform all catheter interventions for CoA for a complete population coverage of 25 millions inhabitants. A common protocol was filled out from medical records. Exclusion criteria were weight less than 20 kg at the time of intervention or Norwood surgery for hypoplastic left heart surgery. Complications at the intervention site included aneurysm formation, dissection of the aorta, extravasation of the aorta or neurological impairment. Complications at the access site was defined as any complication that prolonged the hospital stay.

Results

590 interventions were performed on 520 patients: two interventions n=76, three: n=11, four n=2 and one patient underwent five interventions. There was no mortality in relation to the procedure or during the hospitalisation. The age span of the patients was wide; 4–79 years old (median= 23). 51% had a native CoA, 42% post surgery re-CoA, 22% had had a previous catheter intervention. In 160 (27%) of the interventions balloon dilatation only was performed. Overall, procedural succes was 87%, n=513, 44 procedures (8%) were partially successful and 9 procedures (2%) were not successful. 512 (87%) had one day in hospital stay and 17 patients (6%) had a hospital stay longer than 3 days. In 11 procedures (1.9%) at least one complication occurred at the intervention site; (6 aneurysm formation, 3 neurological impairment, 3 dissection of aorta, 2 extra vasation of aorta), nine of them without prolonged hospital stay. In 25 procedures (4.2%) at least one complications at the access site was observed. Access site complications were associated with older age (mean 38 years (10–79))

Conclusions

In a large, multicenter registry with complete follow-up, complications at the intervention site occurred in 1.9% and at the access site in 4.2% of interventions. Transcatheter intervention of CoA can be performed with low risk of complications.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): ALF-LUA, Gothenburg Heart and Lung Foundation

Transcatheter intervention of coarctation of the aorta (CoA): a multinational population-based registry – effect on hypertension

Background

CoA is associated with hypertension caused by reduced wind kessel function in the aortic arch, general hypoplasia of the arch and/or essential hypertension. In patients with a native or recurrent/rest CoA, a gradient >20 mmHg by non-invasive meassurement if associated with hypertension is an ESCguideline indication for intervention. We studied the persistence and presence of hypertension after transcatheter intervention of a CoA

Methods

All consecutive patients undergoing catheter interventions for CoA from 1st of January 2000 to 31st of December 2016 were identified by each of the particpating nine centers. The nine centers perform all catheter interventions for CoA for a complete population coverage of 25 millions inhabitants. A common protocoll was filled out from medical records. Hypertension was defined as a pre-intervention blood pressure above 140/80 or pharmacological treatment of hypertension. Exclusion criteria were weight less than 20 kg at the time of intervention or Norwood surgery

Results

590 interventions were performed on 520 patients: two interventions n=76, three: n=11, four n=2 and one patient underwent five interventions. Before intervention, 437 (74%) of the patients were hypertensive and 285 were on pharmacologocal treatment; 134 (48%) were treated with one drug, 79 patients (28%) with two drugs, 41 patients (15%) with three drugs and 14 (5%) with four drugs. After the intervention during follow up hypertension was present in 294 patients (50%, p<0.001 vs pre) of whom 270 (46%) were on pharmacological treatment; with one drug, n=128 (48%), two drugs n=93 (34%), three drugs n=34 (13%) or 4 drugs n=7 (3%).

Conclusions

Catheter intervention of CoA reduced the presence of hypertension significantly from 74% down to 50% but many patients will remain hypertensive and in need for treatment. Life time follow up also after transcatheter CoA intervention seems warranted.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): ALF-LUA, Heart and Lung Foundation

Desmin mutations in a St. Petersburg cohort of cardiomyopathies

Several desmin mutations have been described over the past few years in patients with dilated and restrictive cardiomyopathy, often in association with distal myopathy. However, the role of desmin mutations as a cause of various types of cardiomyopathy is still undetermined. The aim of this study was to analyse the frequency of desmin mutations in patients with cardiomyopathy identified and diagnosed in the St. Petersburg area of Russia. We screened 98 patients with dilated, 40 with hypertrophic and 4 with restrictive cardiomyopathy. All exons of the desmin gene were amplified by PCR and studied by sequencing. Two out of 98 patients showed the presence of desmin gene mutations, not previously described in dilated cardiomyopathy. A novel IVS2-2A-->G splice site mutation, presumably causing skipping of exon 3, was detected in a case of familial right ventricular dilated cardiomyopathy. An A213V mutation was associated with a case of late onset dilated cardiomyopathy. No desmin mutations were found in patients with hypertrophic or restrictive cardiomyopathy. Desmin mutations should be considered a relatively rare cause of dilated cardiomyopathy in this specific geographic area.