Biomedical subjects

Ramin Garmany

Publications and source records attributed to Ramin Garmany.

3 recordsLinked to original sources

PubMed2026

Incidence of Atrial and Ventricular Arrhythmias in Patients With Titin Truncating Variants Across the Ventricular Morphofunctional Phenotypic Spectrum.

BACKGROUND: Titin truncating variants (TTNtvs), the most common genetic cause of dilated cardiomyopathy (DCM), are over-represented in early-onset atrial fibrillation (AF) and unexplained sudden cardiac arrest/death (SCA/SCD), suggesting they can cause arrhythmias before development of overt ventricular cardiomyopathy. OBJECTIVES: This study sought to compare the incidence of atrial and ventricular arrhythmias (VAs) between TTNtv-positive patients with genotype-positive but phenotype-negative (G+/P-) disease, nondilated left ventricular cardiomyopathy (NDLVC), and DCM. METHODS: A retrospective review of 1,229 patients in our Arrhythmogenic/Dilated Cardiomyopathy Registry was used to identify those with pathogenic/likely pathogenic TTNtvs. Patients were classified as having G+/P- disease, NDLVC, or DCM using the 2023 European Society of Cardiology guideline for cardiomyopathies. The incidence of AF, sustained VA, appropriate defibrillator therapies, SCA, and SCD was ascertained from medical records. RESULTS: Among 253 TTNtv-positive patients (mean age of 45 ± 16 years; 59% male), 54 (21%) were G+/P-, 49 (20%) were NDLVC, and 150 (59%) were DCM. During a median follow-up of 3.8 years at our institution, new-onset AF was seen in 67 patients (26% of those at risk). There was no significant difference in survival from new-onset AF in patients with NDLVC (HR: 3.29; 95% CI: 0.71-15.3; P = 0.13), although DCM was associated with worse AF-free survival (HR: 4.86; 95% CI: 1.17-20.1; P = 0.03). New-onset VAs were seen in 44 (17%) patients during follow-up, including SCA in 12 (5%) patients. There was no association between NDLVC (HR: 0.71; 95% CI: 0.19-2.69; P = 0.62) and DCM (HR: 0.97; 95% CI: 0.37-2.54; P = 0.95) phenotypes compared with G+/P- patients. Cardiac transplantation was done in 14 (6%) patients, and 6 (2%) died of cardiac causes, including 2 cases of SCD. CONCLUSIONS: When stratified by morphofunctional phenotype, there was no difference in VAs across morphofunctional phenotypes in patients with TTNtvs. This highlights that patients with TTNtvs may be at risk of SCA/SCD even without overt ventricular cardiomyopathy. The risk of new-onset AF was highest in patients with DCM but was seen at all phenotypic stages during follow-up.

arrhythmia↗

PubMed2026

Clinical characteristics and prognostic impact of multiple pathogenic variants across the genetic spectrum of arrhythmogenic and dilated cardiomyopathies.

BACKGROUND: Arrhythmogenic and dilated cardiomyopathies (ACM and DCM, respectively) are genetically heterogeneous disorders of the right and/or left ventricles associated with an increased risk of major arrhythmic events (MAE) and end-stage heart failure (ESHF). In arrhythmogenic right ventricular cardiomyopathy (ARVC), the presence of >1 pathogenic or likely pathogenic (P/LP) variant is associated with worse outcomes. Whether this phenomenon occurs for non-desmosomal arrhythmogenic left ventricular cardiomyopathy (ALVC)/DCM genes is unknown. OBJECTIVE: This study aimed to evaluate the impact of single vs multiple P/LP variants on arrhythmic and heart failure outcomes across the ACM/DCM genetic spectrum. METHODS: We retrospectively analyzed 1054 genotype-positive patients with ≥1 P/LP variant in a definitive or strong evidence ARVC- or ALVC/DCM-causative gene. Primary endpoints were MAE (sustained ventricular tachycardia, ventricular fibrillation, aborted cardiac arrest, appropriate implantable cardioverter-defibrillator therapy, and sudden cardiac death) and ESHF (transplant or heart failure death). RESULTS: Of the 1054 patients, 27 (3%) harbored >1 P/LP variants (21 with ≥1 ALVC/DCM gene; 6 with >1 ARVC gene). MAE occurred in 20% of single-variant patients compared with 48% and 50% of those with >1 P/LP variants in ≥1 ALVC/DCM- and >1 ARVC-susceptibility gene(s), respectively. ESHF occurred in 9%, 29%, and 17% of patients, respectively. On adjusted analysis, >1 P/LP variants in ≥1 ALVC/DCM-susceptibility (MAE hazard ratio [HR], 2.46 [1.28-4.72]; P = .01 and ESHF HR, 3.15 [1.35-7.37], P = .01) and >1 ARVC-susceptibility gene(s) (MAE HR, 2.67 [1.28-8.72], P = .03) were independent predictors of the primary endpoints. CONCLUSION: Multiple P/LP variants confer an increased risk of arrhythmic events and heart failure across the ACM/DCM spectrum.

Arrhythmogenic cardiomyopathy↗

PubMed2026

Beyond ion channel dysfunction: Integration of the transcriptome and proteome from patient-specific re-engineered cardiac cells, and population-level QT genome-wide association study reveals broad cellular dysfunction.

BACKGROUND: Congenital long QT syndrome (LQTS) is a cardiac channelopathy with increased risk of cardiac-triggered syncope/seizures, sudden cardiac arrest, and sudden cardiac death. OBJECTIVE: This study aimed to describe the transcriptomic and proteomic profiles in patient-derived inducible pluripotent stem cell-derived cardiomyocyte (iPSC-CM) models of the 3 canonical genotypes of congenital LQTS: LQT1, LQT2, and LQT3 and integrate these omics-level findings with each other and with population/clinical level QT-genome-wide association study (GWAS) data. METHODS: LQT1, LQT2, LQT3 and respective isogenic control iPSC-CMs were cultured, and RNA and protein samples were collected. RNA sequencing and mass spectrometry-enabled proteomic analysis was performed. PrediXcan analysis was performed using QT GWAS summary statistics and transcriptome expression data. Differential gene and protein expression and ingenuity pathway analysis (IPA) was performed comparing each LQT genotype with its respective isogenic control. RESULTS: 1645 differentially expressed genes (DEGs) were identified; 13 were altered in all 3 LQTS genotypes. IPA analysis of DEGs revealed 301 altered pathways; 47 were altered in all LQTS genotypes. Proteomic analysis identified 2561 differentially expressed proteins (DEPs); 30 were altered in all 3 genotypes. IPA analysis of DEPs identified 646 altered pathways. 306 genes/proteins were identified as significantly altered in both the transcriptome and proteome; pathway analysis of these 301 genes identified 201 altered pathways. 7 pathways were altered in all 3 LQTS genotypes in both the transcriptome and proteome. Integration of the population-level PrediXcan results and the cardiomyocyte-derived omics results identified multiple shared pathways. CONCLUSION: Multi-omics analysis of LQTS and integration of omics results with QT GWAS data reveals that primary LQTS-causative ion channel defects precipitate secondary alterations in a wide range of cellular pathways. Our findings suggest more broad molecular level changes throughout the cell. This study lays the foundation for further exploration of broad cellular changes resulting from ion channel disturbances and how they contribute to disease mechanism.

Humans↗