Investigate clinical characteristics and genetic mutations of CPVT patients in Taiwan and risk stratification

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Technology

Background

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare and lethal arrhythmia in children and young adults. RYR2 mutation accounts for 60% of CPVT patients. While many articles about CPVT are published in the Caucasian population, only a few studies are based on Asian ethnicity. A CPVT scorecard proposed using Caucasian patients is proven effective in reducing the burden of variants of uncertain significance (VUS) of RYR2 mutations is not yet tested in the Asian population.

Purpose

Identify mutations among Taiwanese CPVT patients and compare genetic and clinical results with other ethnicities. We also tested the efficacy of the CPVT scorecard in Taiwanese CPVT patients.

Methods

40 clinically diagnosed CPVT patients and their family members were consecutively enrolled from multi-centers. We compared clinical characteristics and genetic results with other ethnicities, and applied the Caucasian CPVT scorecard to test whether it is applicable in Taiwanese CPVT patients.

Results

This is the first nationwide CPVT cohort in Taiwan. Among the 29 patients with CPVT-related gene mutation, 12 RYR2 variants was identified in our cohort with 5 of them unreported in previous studies. The RYR2 yield rate was 55%, similar to other ethnicities. Exercise-induced symptoms including syncope and cardiac arrest were more severe in Taiwanese CPVT cohort, compared to Japanese and Caucasian cohorts. The CPVT scorecard also successfully reduced the VUS rate for the Taiwanese cohort.

Conclusions

Our study demonstrated genetic difference in CPVT patients across ethnicities, suggesting the importance of genetic testing in Taiwan. The CPVT scorecard is applicable to Taiwanese CPVT patients and is a helpful tool in interpreting genetic test results in clinical practice. Clinical characteristics of the cohort Gender (male, %) 15 (52%) Mean age of onset (years) 18 ± 15 Exercise-related syncope or cardiac arrest (n, %) 23 (79%) Exercise-related cardiac arrest (n, %) 14 (48%) Family history of unexplained sudden cardiac death (n, %) 5 (17%) Heart rate (bpm) 73 ± 16 Exercise stress test or Holter positive (n, %) 14 (48%) Ventricular arrhythmia (n, %) 23 (79%) Beta-blockers only (n, %) 10 (35%) Intracardiac defibrillator implantation (n, %) 15 (52%) CPVT score 6 ± 3

299 The prevalence and role of SCN10A variants in Han Chinese patients with Brugada syndrome: the SADS-TW BrS registry

On Behalf

SADS-TW BrS registry

Background

Brugada syndrome (BrS) is an inheritable arrhythmic disease responsible for sudden cardiac death. Information on the prevalence and role of SCN10A variants in BrS is limited and equivocal.

Purpose

We aimed to investigate the prevalence and role of SCN10A variants in BrS in Han Chinese.

Methods

From 2000 to 2017, we prospectively and consecutively enrolled 176 unrelated BrS patients from the Han Chinese population in Taiwan (the SADS-TW BrS registry). Thirty-four BrS-related genes were screened by next-generation sequencing, using Taiwan Biobank as the population reference. The pathogenicity was evaluated by literature review and in silico analyses, including the SKAT-O algorithm.

Results

The SKAT-O algorithm showed that rare variants of SCN10A, but not common variants, were significantly different between BrS patients and healthy controls in the additive and dominant models (p-value <0.001), suggesting that rare SCN10A variants may play a role in BrS. Six likely pathogenic SCN10A variants were found in 6 patients and were compared to 25 pathogenic or likely pathogenic SCN5A variants found in 29 patients. The patients with likely pathogenic SCN10A variants tended to exhibit sudden death in older age and have a shorter QRS interval than those carrying pathogenic or likely pathogenic SCN5A variants or no variants in either gene (p = 0.06, 0.07, respectively). Collectively, the prevalence of likely pathogenic SCN10A variants was 3.4% in Han Chinese patients with BrS in Taiwan.

Conclusions

SCN10A likely pathogenic variants were present in 3.4% of Han Chinese BrS patients. Rare SCN10A variants may play a role in BrS, and may have impact on clinical and electrocardiographic manifestations.

Table 1. Patient Nucleotide Amino acid TWB gnomAD_EA REVEL CADD PHRED SIFT Polyphen-2 GERP++ 1 c.5789A > T p.D1930V 0.001318 0.0008700 0.479 24.5 Damaging Possibly damaging 4.22 2 c.2341G > A p.G781R 0 0.00005301 0.866 33 Damaging Probably damaging 4.83 3 c.5587C > T p.R1863W 0.000502 0 0.832 27.8 Damaging Probably damaging 1.97 4 c.2161C > T p.P721S 0.000989 0.0009016 0.933 28.5 Damaging Probably damaging 4.19 5 c.3749G > A p.R1250Q 0 0 0.907 31 Damaging Probably damaging 4.23 6 c.1825A > T p.R609W 0.000659 0.0001591 0.811 32 Damaging Probably damaging 4.28 Clinical and predicted functional characteristics of 6 likely pathogenic SCN10A variants. EA = East Asian; GERP = Genomic Evolutionary Rate Profiling; TWB = Taiwan Biobank. Transcript: NM_006514.3.

Abstract 299 Figure. Location of the SCN10A variants

P1880Entropy-based algorithm for atrial fibrillation detection using photoplethysomgraphic signal recorded by a smart watch

Background

Atrial fibrillation (AF) is the most common arrhythmia, and its paroxysmal and short duration nature makes its detection challenging. The most important limitation of current smartwatches is that patients need to touch to the sensor of the watch to record signals when patients feel discomfort. We developed a wearable smart watch and evaluated its accuracy to differentiate AF from sinus rhythm, which can continuously detecting heart rhythm without hand touching the device.

Methods and results

A wearable smart watch with PPG sensor and electrocardiogram (ECG) recording function was used for signal acquisition. A total 399 patients with a mean age of 67 years old were enrolled in the study, of whom 237 (81.5%) were male, and 101 have been diagnosed with AF. Pulse wave extracted from the green light spectrum of the signal and ECG were recorded for about 10 minutes for each patient. Pulse-to-pulse intervals (PPI) were automatically identified. All ECG signals were verified by two cardiologists. The correlation between R-to-R interval on ECG and PPI were excellent, with a correlation coefficient R >0.99 (p<0.05). An entropy-based algorithm which combined Shannon entropy of successive difference of PPI and sample entropy of PPI was used to discriminate between AF and sinus rhythm. This method had high sensitivity and specificity (96% and 98%, respectively), the area under receiver operating characteristic curve reached 0.98.

Conclusions

We developed an entropy-based algorithm for AF detection with PPG signal recorded by a wearable smart watch. This algorithm discriminates AF from sinus rhythm accurately. This advance in technology overcomes an important clinical obstacle and can increase the AF detection rate tremendously.

The impact of lesion length on angiographic restenosis after vertebral artery origin stenting

OBJECTIVE

To evaluate the effect of lesion length on in-stent restenosis (ISR) of vertebral artery (VA) origin stenting.

METHODS

We retrospectively analyzed the medical and radiological records of patients receiving VA origin stenting from March 1999 to June 2005. They were subdivided according to lesion length. ISR was defined as >50% diameter narrowing in stent.

RESULTS

Eighty symptomatic patients (64 male, mean age 72 years) with 90 lesions treated with balloon expandable tubular coronary stents were enrolled. There were 34 patients with 38 short lesions (length<or=5 mm, group 1), 37 patients with 42 medium lesions (length>5 mm, <10 mm, group 2) and 9 patients with 10 long lesions (length>or=10 mm, group 3). Eighty seven bare-metal stents and 3 drug-eluting stents were implanted. Repeat angiography was done in 40 lesions (44%) at 11.7+/-9.6 months. The ISR rate in group 1, 2, 3 is 21%, 29%, and 50% (p=0.486). Multivariable Cox regression analysis showed lesion length was the only significant independent predictor of ISR (hazard ratio: 1.19, p=0.039).

CONCLUSION

ISR of VA origin stenting is common. Lesion length is an important predictor of ISR in VA origin stenting.

Keratosis lichenoides chronica: report of a case developing after erythroderma

A 66-year-old male presented with keratosis lichenoides chronica after a presumed drug-induced erythroderma. After resolution of the erythroderma, slightly scaly erythematous and violaceous papules in a reticular arrangement over the trunk and limbs developed in association with hoarseness, palmoplantar keratoderma, onycholysis and subungual keratosis. Histology from a lichenoid lesion showed pseudo-epitheliomatous hyperplasia, hyperorthokeratosis, parakeratosis, dyskeratosis, neutrophil exocytosis and focal vacuolar degeneration of the basal layer of the epidermis. There was a band-like chronic inflammatory infiltrate in the upper dermis. The skin improved with prednisone 40 mg/day for 15 days, leaving atrophic hypopigmented scars. A diagnosis of keratosis lichenoides chronica was made.

A high-performance double-crystal monochromator soft X-ray beamline

A high-performance double-crystal-monochromator soft X-ray (DCMSX) beamline has been constructed at the Synchrotron Radiation Research Center (SRRC). This beamline delivers monochromatic photon beams with energies from 1 to 9 keV and a resolving power (E/DeltaE) of up to 7000. This beamline provides users with an opportunity to study many important materials, such as high-T(c) superconductors, magnetic materials, catalysts, super-alloy compounds etc. Excellent EXAFS and NEXFS spectra have been routinely obtained from this beamline. Several interesting research projects are currently being conducted at this beamline. All the results show that this beamline has been constructed to meet its design goals.

[Neurocutaneous melanosis. Case report of a malignant melanoma of the central nervous system]

The neurocutaneous melanosis is a rare syndrome in which the congenital melanocytic nevi and excessive melanosis are the main features. The syndrome seems to be a morphogenesis error of the embryonic neuroectoderm. A clinical case with necroscopy in a 19 year-old man who had developed malign melanoma in his central nervous system is reported.