Background: Paravalvular leak (PVL) is a recognized complication following surgical aortic valve replacement (SAVR), with a reported incidence ranging from 1% to 10%. Although some patients with mild PVL remain asymptomatic, others may develop clinically significant complications such as heart failure or hemolysis, underscoring the importance of early detection and timely intervention. While previous research has largely emphasized the risk factors and prognostic implications of PVL, limited literature focuses on the detailed echocardiographic characteristics of both the native aortic valve prior to SAVR and the PVL itself following surgery. Therefore, the objective of this study was to investigate the echocardiographic features of PVL after SAVR—specifically its origin, severity, and correlation with the calcified location of the preprocedural aortic valve.

Methods: This retrospective cohort study, conducted at a single academic institution, investigated all SAVR procedures performed from June 2010 to October 2022. PVL was identified using intraoperative transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE) within 1 year postoperatively. The echocardiographic characteristics of PVL after SAVR, including its origin and severity, as well as its correlation to the calcified location of the preprocedural aortic valve, were investigated along with the incidence.

Results: Of the total 948 SAVR cases, PVL was identified in 77 (8.1%) intra- and/or postoperatively. Ten of the 77 cases were excluded from the analysis due to missing stored echocardiographic images, resulting in 67 PVL cases being investigated. The origin of PVL was identified in 62 cases on a short-axis (SAX) view of the aortic valve, with the most common site being the mid-portion of right coronary cusp (RCC) of the native aortic valve position in 22 cases (35.5%), followed by the non-coronary cusp (NCC) and the left coronary cusp (LCC), each in 12 cases (19.4%). Calcification of the preprocedural native aortic valve, ranging from mild to severe, was observed in 38 cases (56.7%). Among these 38 cases with a calcified native valve, the location of PVL was identified in 36 cases, showing a significant correlation between the location of calcification and the position of PVL (r=0.74, P<0.001). Of the 67 PVL cases detected intraoperatively and/or postoperatively, severity was mild in 58 cases (86.6%) and moderate in 9 cases (13.4%), with no severe cases.

Conclusions: PVL following SAVR was observed in 8.1% of cases either intraoperatively or within the first year postoperatively. The majority of PVL cases were mild in severity. The most common site of PVL was the mid-portion of the RCC at the native aortic valve position. A significant correlation was found between the location of calcification in the preoperative native valve and the site of PVL.

Keywords: Paravalvular leak (PVL); aortic valve replacement; echocardiography; cardiac surgery

Background: Chronic obstructive pulmonary disease (COPD) is a long-term respiratory condition defined by ongoing respiratory symptoms and restricted airflow, resulting in high rates of morbidity, mortality, and disability for this condition. Due to the incomplete understanding of its pathogenesis, no permanent curative measures or specific drugs are available. In recent years, a multitude of research has highlighted the substantial influence of oxidative stress on the development of COPD; however, there has been a deficiency in bibliometric analyses focusing on research trends and hotspots in the field. Therefore, our study aimed at presenting the emerging trends and hotspots related to COPD and oxidative stress.

Methods: Publications concerning oxidative stress in COPD were obtained from the Web of Science Core Collection database, covering the period from 2010 to 2024. On July 25, 2024, all relevant data were downloaded, followed by a process of data screening and analysis.

Results: The analysis incorporated 1,308 articles and 440 reviews, involving contributions from 1,034 researchers affiliated with 512 institutions across 64 countries published in a total of 548 journals. Through a series of analyses using five visualization tools, we identified the top 5 most productive countries, institutions, journals, and highly co-cited journals in the field from 2010 to 2024. We also identified 12 citation clusters, 10 influential authors, co-cited authors and articles, and 11 keyword clusters, established the top 20 keywords, and observed the evolution of reference and keyword bursts.

Conclusions: This study is the first to quantitatively capture the progress of oxidative stress in the field of COPD research, and the results show a marked upward trend in recent years in terms of research on COPD and oxidative stress. Developing novel effective antioxidants is becoming the future direction for COPD treatment. Besides antioxidant therapy, exposure (to air pollution), cigarette smoke, and mitochondrial dysfunction emerged as prominent research hotspots. This extensive bibliometric study offers significant insights into the exploration of oxidative stress in publications related to COPD with the purpose to support and enhance future scientific research for investigators in the field.

Keywords: Oxidative stress; chronic obstructive pulmonary disease (COPD); bibliometric analysis; CiteSpace; VOSviewer

A new study in Engineering introduces an integrated model. It assesses flood risks to people’s life and property in the lower Yellow River under different floodplain management modes. The research validates the model with real-world events and provides insights for floodplain management.