Daily Cardiology Research Analysis

BACKGROUND: Implantation of drug eluting stents (DESs) is currently the default approach for percutaneous coronary interventions, but long-term adverse events still exist. An approach with minimal stenting deserves to be assessed in a randomized trial. We studied a novel sirolimus-eluting balloon (SEB) that elutes sirolimus over a 90-day period using a biodegradable polymer microreservoir technology. METHODS: In a multicenter, open-label, randomized trial, we compared an SEB-based strategy with provisional DES with one of systematic DES for de novo lesions in coronary arteries between 2 and 5 mm in diameter. Subjects were randomized 1:1 before percutaneous coronary intervention. The primary end point was target vessel failure, a composite of cardiac death, target vessel-related myocardial infarction, and clinically driven target vessel revascularization. It was tested for noninferiority at 1 year with the use of an absolute margin equal to 50% of the combined event rate at a significance level of 0.025. The primary analysis population included all randomized subjects with completed or attempted percutaneous revascularization, analyzed according to the intention-to-treat principle. A sensitivity analysis was performed on the per-protocol population.

BACKGROUND: Aortic dissection (AD) is a life-threatening cardiovascular disease with limited effective therapeutic options. Phenotypic switching of aortic vascular smooth muscle cells (VSMCs) from a contractile to a pathological state is a critical driver of AD progression. However, the molecular regulators governing this transition remain incompletely understood. This study aimed to identify a critical regulator of VSMC phenotypic switching in AD and to investigate its underlying mechanisms and translational relevance. METHODS: Single-cell RNA sequencing (scRNA-seq) and bulk RNA sequencing datasets obtained from the Gene Expression Omnibus (GEO) database were integrated for analysis. To enhance robustness and reduce dataset-specific bias, weighted gene co-expression network analysis (WGCNA) was performed in both aortic aneurysm (AA) and AD cohorts to identify gene modules associated with VSMC function. Overlapping VSMC-related modules were intersected to define candidate genes. Key regulators were further prioritized in AD datasets using LASSO regression and validated by single-cell RNA sequencing (scRNA-seq) pseudotime trajectory analysis to delineate dynamic gene expression during VSMC phenotypic switching. Functional validation was conducted in an angiotensin II (Ang II)-induced experimental AD mouse model with AAV9-mediated CASQ2 overexpression, as well as in primary VSMCs isolated from the abdominal aorta of mice and treated with Ang II in vitro. Aortic morphology, medial calcification, VSMC phenotypic markers, intracellular Ca RESULTS: WGCNA identified a conserved gene module comprising 64 genes associated with VSMC phenotypic transition. Integrative LASSO and scRNA-seq analyses prioritized CASQ2 as a key gene with reduced expression in AD VSMCs. Pseudotime analysis revealed progressive downregulation of CASQ2 during osteochondrogenic phenotypic switching. In AngII-induced experimental AD mice, CASQ2 expression was decreased in the aortic media and accompanied by enhanced medial calcification. In vivo, Ang II infusion markedly reduced aortic CASQ2 expression and induced medial dilation and calcification, accompanied by increased mortality. AAV9-mediated CASQ2 overexpression significantly improved survival, attenuated aneurysmal enlargement, reduced vascular calcification and partially restored contractile marker expression. In vitro, Ang II stimulation decreased CASQ2 levels in primary VSMCs, promoted osteochondrogenic marker expression, and induced intracellular Ca²⁺ overload. CASQ2 overexpression restored calcium-release complex components, suppressed cytosolic Ca²⁺ elevation, and markedly reduced ER stress activation. CONCLUSIONS: CASQ2 may represent a VSMC-enriched functional regulator involved in AD-associated phenotypic switching through calcium homeostasis and ER stress. These findings suggest that CASQ2 represents a potential therapeutic target in AD. Further studies are needed to determine its disease specificity and translational relevance.

Hypertrophic cardiomyopathy (HCM) is driven by sarcomeric mutations that cause energetic failure and secondary inflammation. This study demonstrates that targeting this metabolic-inflammatory axis with pioglitazone or its peroxisome proliferator-activated receptor gamma inactive enantiomer, R-pioglitazone, reverses disease progression in a murine HCM model. Both agents restored mitochondrial function (including Mitochondrial Pyruvate Carrier 1 [MPC1] levels) and resolved inflammation. Notably, R-pioglitazone showed superior efficacy, reducing interstitial fibrosis by >95% and hypertrophy by 33% without affecting healthy control hearts. These findings identify R-pioglitazone as a promising, mechanism-based candidate for disease-modifying therapy in HCM.