Yuya Ishihara

AIMS: The global distribution of lipoprotein(a) [Lp(a)] levels varies due to racial and ethnic differences. However, the clinical relevance of Lp(a) levels in Japanese patients has not been fully explored. METHODS: We investigated the association of Lp(a) levels, the Suita score, and the presence of high-risk plaque (HRP) as well as that of ≥ 50% stenosis, quantitative plaque volume, and the value of coronary artery calcium score in coronary computed tomographic angiography (CCTA), among 272 Japanese patients (mean age: 65 years) in whom serum Lp(a) levels were measured due to suspected coronary artery disease. HRP was defined as positive remodeling and/or low attenuation. Plaque volume was quantified as the percent plaque volume. RESULTS: HRP was identified in 33 (12.1%) patients. The prevalence of HRP, ≥ 50% stenosis, and percent plaque volume progressively increased with higher Lp (a) levels and Suita scores. In multivariate analyses, Lp(a) and the Suita score independently predicted HRP when assessed as continuous (p = 0.02, p＜0.001, respectively) or categorical variables (p = 0.005, p = 0.007, respectively). Patients in the highest tertile of Lp(a) and classified as high- or intermediate-risk by the Suita score had the highest HRP risk, whereas those in the lower 2 tertiles and low-risk group had the lowest. Incorporating Lp(a) into the Suita score improved the prediction of HRP beyond the Suita score alone (p = 0.005). CONCLUSIONS: The combinatorial value of assessing Lp(a) levels and Suita score may provide useful insight regarding Japanese patients undergoing CCTA for the prediction of HRP.

BACKGROUND: Packed red blood cells (PRBC) are stored at 2°C-6°C to ensure quality. Improper temperature control during PRBC transport reduces the quality of downstream blood products and wastes PRBC units. This study evaluated the suitability of the BioBox LAB10 for in-hospital PRBC transport. METHODS: Temperatures of the box interior and simulated formulation were measured to assess cooling capabilities. Quality was evaluated by measuring red blood cell count, haemoglobin concentration, haematocrit, pH, potassium concentration, and ATP concentration of PRBC samples. The storage capacity, size, weight, and cost of the BioBox was compared with that of the ATR700. RESULTS: The BioBox cooled to ≤6°C within 14 min. PRBC temperature remained ≤6°C for approximately 19 h. None of the quality parameters, including ATP concentration, differed significantly between samples stored in the BioBox or in a refrigerator. The BioBox is smaller, lighter, and 84% less expensive than the ATR700, with an equivalent storage capacity. CONCLUSIONS: The BioBox effectively maintains temperature and PRBC quality during transport and provides a practical solution for in-hospital transport of blood for transfusion owing to its compact, lightweight design, and affordability.

BACKGROUND AND OBJECTIVES: Reports on the changes in plasma fibrinogen levels in patients receiving cryoprecipitates synthesized using different methods are lacking. Therefore, we investigated these changes in patients who underwent cardiovascular surgery. MATERIALS AND METHODS: We included 309 patients who underwent cardiovascular surgery and received 12 cryoprecipitate units between February 2020 and March 2024 and 204 patients were selected by propensity score matching. The cryoprecipitates were prepared using two methods. Fresh frozen plasma (FFP) was thawed at 2 to 6°C for 24 h and centrifuged to remove the supernatant in the one-step method, whereas FFP was thawed, refrozen at -20°C, and subsequently rethawed in the two-step method. We investigated the association between different cryoprecipitate preparation methods and ICU admission for ≥ 1 week, with in-hospital mortality considered as a competing risk in the analysis. In addition, we evaluated the changes in plasma fibrinogen levels before and after cryoprecipitate administration. RESULTS: Baseline plasma fibrinogen levels were significantly higher in the two-step method group than in the one-step method group. Differences in cryoprecipitate preparation methods were not significantly associated with ICU admission for ≥ 1 week, in the analysis that considered in-hospital mortality as a competing risk (P = 0.93). The increase in plasma fibrinogen levels after cryoprecipitate administration was significantly higher with the two-step method than with the one-step method (36 mg/dL vs. 51 mg/dL, P = 0.020). CONCLUSION: The cryoprecipitates synthesized using the two-step method showed a higher increase in plasma fibrinogen levels than those prepared using the one-step method. These findings may help guide appropriate transfusion protocols by confirming intraoperative plasma fibrinogen levels.

We investigated the prognostic value of cardiac myosin-binding protein C (cMyC), a novel cardiospecific marker, both independently and in combination with N-terminal pro-B-type natriuretic peptide (NT-proBNP), for predicting 6-month all-cause mortality in patients without acute coronary syndrome (ACS) treated at medical (nonsurgical) cardiac intensive care units (CICUs). Admission levels of cMyC, high-sensitivity cardiac troponin T (hs-cTnT), and NT-proBNP were measured in 1032 consecutive patients (mean age; 70 years) without ACS hospitalized acutely in medical CICUs for the treatment of cardiovascular disease. Serum cMyC was closely correlated with hs-cTnT and moderately with NT-proBNP (r = 0.92 and r = 0.49, respectively, p < 0.0001). During the 6-month follow-up period after admission, there were 109 (10.6%) all-cause deaths, including 72 cardiovascular deaths. Both cMyC and NT-proBNP were independent predictors of 6-month all-cause mortality (all p < 0.05). Combining cMyC and NT-proBNP with a baseline model of established risk factors improved patient classification and discrimination beyond any single biomarker (all p < 0.05) or the baseline model alone (both p < 0.0001). Moreover, patients were divided into nine groups using cMyC and NT-proBNP tertiles, and the adjusted hazard ratio (95% confidence interval) for 6-month all-cause mortality in patients with both biomarkers in the highest vs. lowest tertile was 9.67 (2.65-35.2). When cMyC was replaced with hs-cTnT, similar results were observed for hs-cTnT. In addition, the C-indices for addition of cMyC or hs-cTnT to the baseline model were similar (0.798 vs. 0.800, p = 0.94). In conclusion, similar to hs-cTnT, cMyC at admission may be a potent, independent predictor of 6-month all-cause mortality in patients without ACS treated at medical CICUs, and their prognostic abilities may be comparable. Combining cMyC or hs-cTnT with NT-proBNP may substantially improve early risk stratification of this population.

BACKGROUND: Ethylenediamine tetraacetate/glycine acid (EGA) and chloroquine diphosphate (CDP) are used in transfusion testing to dissociate IgG antibodies from red blood cells (RBCs). However, the ability of these reagents to dissociate IgM antibodies sensitized to RBCs has not been comprehensively elucidated. We investigated whether EGA and CDP could dissociate cold-reactive antibodies from RBCs and their effect on RBCs after dissociation treatment. STUDY DESIGN AND METHODS: Cold-reactive antibody-sensitized RBC samples were prepared by mixing group A RBCs and group B plasma and treated with EGA, CDP, and dithiothreitol (DTT). Before and after the dissociation treatment, changes in the agglutination of these RBCs were assessed using the test tube method. Flow cytometric analysis was used to confirm the nature of antibodies bound to RBCs. Additionally, RBC morphology was evaluated using scanning electron microscopy. This study utilized off-label use of EGA and CDP. RESULTS: Flow cytometric analysis showed that antibodies sensitized to RBCs were mainly IgM antibodies. After antibody dissociation, agglutination disappeared in the EGA-treated samples to the same degree as in the DTT-treated samples. However, IgM antibodies remained in the CDP-treated samples. Regarding RBC morphology, RBC surface appeared coarser in both EGA- and CDP-treated samples, and RBC area was significantly smaller in the CDP-treated samples than in the EGA-treated samples. DISCUSSION: EGA could dissociate cold-reactive antibodies, whereas CDP had a higher residual antibody content. This difference in dissociation ability appears to correlate with the antibody pH of the dissociation reagent. EGA treatment may be useful in cases of sensitization by high-titer cold-reactive antibodies.