Histologic Assessment of Thromboemboli Due to Plaque Rupture, Plaque Erosion, or COVID-19 Microthrombi.

Plaque rupture, plaque erosion, and COVID-19 infection can cause acute coronary syndromes (ACS). We illustrate case examples demonstrating the distinctive and characteristic pathologic findings underlying each of these various causes of acute myocardial infarction. A deeper understanding of the pathophysiology of ACS is necessary for the development of newer agents and techniques to improve outcomes after ACS. (Level of Difficulty: Advanced.).

Comprehensive Assessment of Human Accessory Renal Artery Periarterial Renal Sympathetic Nerve Distribution.

OBJECTIVES: The aim of this study was to understand the anatomy of periarterial nerve distribution in human accessory renal arteries (ARAs). BACKGROUND: Renal denervation is a promising technique for blood pressure control. Despite the high prevalence of ARAs, the anatomic distribution of periarterial nerves around ARAs remains unknown. METHODS: Kidneys with surrounding tissues were collected from human autopsy subjects, and histological evaluation was performed using morphometric software. An ARA was defined as an artery arising from the aorta above or below the dominant renal artery (DRA) or an artery that bifurcated within 20 mm of the takeoff of the DRA from the aorta. The DRA was defined as an artery that perfused >50% of the kidney. RESULTS: A total of 7,287 nerves from 14 ARAs and 9 DRAs were evaluated. The number of nerves was smaller in the ARA than DRA (median: 30 [interquartile range: 17.5 to 48.5] vs. 49 [interquartile range: 36 to 76]; p < 0.0001). In both ARAs and DRAs, the distance from the arterial lumen to nerve was shortest in the distal, followed by the middle and proximal segments. On the basis of the post-mortem angiography, ARAs were divided into large (≥3 mm diameter) and small (<3 mm) groups. The number of nerves was greatest in the DRA, followed by the large and small ARA groups (53 [41 to 97], 38 [25 to 53], and 24.5 [10.5 to 36.3], respectively; p = 0.001). CONCLUSIONS: ARAs showed a smaller number of nerves than DRAs, but these results were dependent on the size of the ARA. Ablation, especially in large ARAs, may allow more complete denervation with the potential to further reduce blood pressure.

Hospitalization Costs for Patients With Acute Congestive Heart Failure in Japan.

BACKGROUND: With aging of the population, the economic burden associated with heart failure (HF) is expected to increase. However, little is known about the hospitalization costs associated with HF in Japan. Methods and Results: In this cross-sectional study, using data from The Japanese Registry of All Cardiac and Vascular Diseases (JROAD) and JROAD-Diagnosis Procedure Combination databases between 2012 and 2014, we evaluated hospitalization costs for acute cardiovascular diseases (CVDs), including HF. A total of $1,187 million/year (44% of the hospitalization costs for acute CVDs) was spent on patients with HF. We identified 273,865 patients with HF and the median cost per patient was $8,089 ($5,362-12,787) per episode. The top 1% of spenders accounted for 8% ($80 million/year), and the top 5% of spenders accounted for 22% ($229 million/year) of the entire cost associated with HF. The costs associated with HF for patients over 75 years of age accounted for 68% of the total cost. CONCLUSIONS: The costs associated with HF were higher than the hospitalization cost for any other acute CVD in Japan. Understanding how the total hospitalization cost is distributed may allow health providers to utilize limited resources more effectively for patients with HF.

Ex vivo assessment of neointimal characteristics after drug-eluting stent implantation: Optical coherence tomography and histopathology validation study.

BACKGROUND: Optical coherence tomography (OCT) is one of the tools trying to distinguish neoatherosclerosis from other neointimal tissue but its role has to be still validated. This study evaluated the diagnostic accuracy of OCT for characterization of lipid-atherosclerotic neointima following drug-eluting stent (DES) implantation. METHODS: Twelve stented coronary arteries from the 7 autopsy hearts were imaged by OCT. These OCT images were compared with histology. By OCT, the morphological appearances of neointima were classified into three patterns: homogeneous pattern, heterogeneous pattern with visible strut, or heterogeneous pattern with invisible strut. RESULTS: Of 21 histological cross-sections, 6 were categorized as homogeneous patterns (29%), 11 as heterogeneous patterns with visible stent strut (52%), and 4 as heterogeneous patterns with invisible stent strut (19%). All homogeneous patterns were composed of smooth muscle cells with collagen fibers. The heterogeneous patterns with visible stent strut included proteoglycan-rich myxomatous matrix and calcium deposition. On the other hand, the heterogeneous patterns with invisible stent strut comprised atheromatous tissue, including a large amount of foam cell accumulation (25%) or large fibroatheroma/necrotic core (75%) inside the stent struts within neointima. The optical attenuation coefficient was highest in the heterogeneous pattern with invisible stent strut due to scattering of light by atheromatous tissue. CONCLUSION: The heterogeneous patterns with invisible stent strut on OCT imaging identify the presence of lipid-atherosclerotic tissue within neointima after DES. This may suggest the potential capability of OCT based on visualization of stent struts for discriminating atheromatous formation within neointima from other neointimal tissue.