Wang, W

Abstract: Cardiovascular disease (CVD) remains the leading cause of death worldwide. While advances in treatment have improved outcomes, the greatest gains in public health will come from primary prevention. Risk stratification is the foundation of CVD prevention. Traditional tools, such as pooled cohort equations (PCEs) and SCORE2, do not capture non-traditional risk factors and individual variability, driving efforts to refine existing approaches. We critically discuss emerging risk determinants for primary CVD prevention. Coronary artery calcium scoring can reclassify CVD risk but has limitations related to cost, access, and unvalidated improvements in clinical endpoints. Biomarkers such as apolipoprotein B and lipoprotein(a) may identify residual risk beyond LDL-C, particularly in patients with lipid discordance, but remain underused due to uncertain thresholds and the lack of prospective triallevel outcome data. Trials of colchicine in primary prevention have yielded mixed results, making the role of targeting inflammation unclear in CVD prevention. Polygenic risk scores can stratify genetic risk but face challenges in sensitivity, specificity, and generalizability. Multiomics approaches, while offering the promise of deeper phenotyping, lack established clinical applications and consensus on when their use is appropriate. Artificial intelligence may allow better prediction across cohorts but requires broader validation. Clonal hematopoiesis of indeterminate potential, a marker of inflammation and age-related CVD risk, lacks evidence supporting routine screening or intervention in younger, asymptomatic individuals. The proliferation of new risk stratification tools poses a key challenge: determining when additional data meaningfully alter clinical decisions. Until robust outcome-based evidence emerges, risk enhancers should guide, but not dictate, therapy in selected patients.

Abstract Introduction The inhalation of aerosolized therapeutics is a promising strategy for the targeted delivery of drugs and biologics to the lungs. We have previously demonstrated the efficacy and feasibility of nebulized exosomes using a platelet-derived exosome product (PEP: Rion, Inc.), which significantly attenuated emphysema in a murine model (PMID: 38325750). However, the PEP aerosol’s physical properties—such as size, tissue deposition, anatomic location, and stability remain incompletely characterized. To address this, we utilized a cascade impactor to define aerosol particle size and deposition patterns and employed immunofluorescence staining to assess the regional and anatomic localization of nebulized PEP within the murine lung. Methods PEP particle size and tissue deposition were determined by passing the aerosol through a Marple cascade impactor (CI, DSI), which was connected to an inhalation tower (DSI). PEP aerosols were generated by a vibrating mesh nebulizer (Aerogen, Cat No AG-AL1100) at a controlled velocity and humidity and delivered to the CI at a flow rate of 2L/min. Aerosols were separated by size and allowed to deposit at the corresponding stages as they passed through the pinholes of the stage, by design. The stages were weighed after nebulization, and the percentage of aerosol deposition was calculated to simulate the human respiratory tree, according to the manufacturer’s specifications. In parallel, fluorescence DiR-labeled PEP was nebulized to spontaneously breathing mice, and confocal microscopy was used to determine intrapulmonary distribution. Results A total of 2.25 mL of PEP reconstituted in 0.9% normal saline (11.4 mg/mL final concentration) was nebulized for 35 minutes at a flow rate of 2 L/min, yielding 3.5 mg of total aerosol deposition, which is 13.6% of the total PEP mass (25.65mg) being nebulized, across the CI stages. Of this, 74% of the aerosolized particles with a particle size ≤ 1µm and deposited in Stages 7, 8 & F, corresponding to the deep regions of the lungs, specifically regions beyond the alveolar ducts and within the alveoli. In vivo 3D confocal imaging corroborated these findings, revealing abundant DiR-labeled PEP deep into the alveolar space within the peripheral regions of all lung lobes. Conclusion The study result demonstrates the feasibility and capability of delivering aerosolized PEP deeply into the alveolar regions of the lung at the given pressure, humidity, flow rate and nebulizer settings. This study establishes a methodological framework for characterizing and optimizing aerosolized exosome therapeutics for precise, region-specific delivery within the respiratory tract. This abstract is funded by: Department of Defense, Mayo Clinic Funding