Natriuretic peptides (NPs) regulate blood pressure and fluid homeostasis and exert various effects on the cardiovascular system. Recently, the relationship between NPs and the energy metabolism has been reported, and using a cell culture experiment system, we previously showed that NP activated brown cells in a low temperature environment while also suppressing a decrease in the cell temperature. However, few reports have described the secretion of NPs in cold environments, and there have been almost no studies of B-type natriuretic peptide (BNP) in humans. We investigated how NPs respond to cold environments in 21 patients who underwent therapeutic hypothermia (TH) after cardiac arrest. The plasma BNP levels were significantly increased (more than fivefold) during TH (logarithmically from 1.98 ± 0.79 to 2.63 ± 0.59, P < 0.01). During TH, diastolic pulmonary artery pressure (PAP) significantly decreased, and there were no significant changes in the stroke volume index (SVI). This increase of BNP was not associated with any hemodynamic changes. In contrast to our findings for BNP, the change in A-type NP (ANP) was quite small. We detected a significant increase in the plasma BNP levels during TH, unrelated to hemodynamics. This elevation of BNP levels seems to be potential influenced by hypothermia.

Background: Acute myocardial infarction (AMI) patients complicated by out-of-hospital cardiac arrest (OHCA) show poor in-hospital outcomes. However, the post-discharge outcomes of survivors of OHCA have not been well studied. Methods and Results: Data for patients admitted to The Jikei University Kashiwa Hospital with AMI between April 2012 and March 2020 were examined retrospectively. The Jikei University Kashiwa Hospital is a tertiary emergency medical facility, so the frequency of OHCA in this hospital is higher than in an ordinary AMI population. Of 803 patients, 92 (11.5%) were complicated by OHCA. Of the 92 OHCA patients, 37 died in hospital, compared with 45 of 711 non-OHCA patients who died in hospital (P<0.001). OHCA was more frequent in men than in women. The estimated glomerular filtration rate was lower in those with than without OHCA. Long-term mortality was evaluated in patients discharged alive and followed-up at an outpatient clinic (n=635; median follow-up period 607 days). The long-term post-discharge mortality was comparable between AMI patients with and without OHCA. Conclusions: The post-discharge mortality of AMI patients with OHCA was comparable that of patients without OHCA.

High serum uric acid (UA) has been reported to be associated with left ventricular (LV) dysfunction; however, the relationship between UA and plasma B-type natriuretic peptide (BNP), a sensitive biomarker of heart failure, is still unclear. This study investigated their relationship to provide an accurate assessment of high UA. The study patients consisted of 3,077 subjects who underwent cardiac catheterization because of various cardiovascular disorders. Since the explanatory factors of multiple regression analysis were mostly confounding with each other, subgroup analysis was performed by quartering the study population using the respective risk factors and by covariance structure analysis. This analysis revealed that UA was almost always well associated with a reduced LV ejection fraction (LVEF), but generally not with BNP. UA was significantly associated with BNP in lean aged females, but not in obese adolescent males, although LVEF was significantly reduced in response to a high UA in both groups. A high UA is a direct risk factor for cardiac dysfunction from the perspective of BNP; however, augmentation of BNP in response to a high UA would likely be restricted among obese adolescent males. On the other hand, the observed LV systolic dysfunction, such as LVEF, reflects a high UA on an almost constant basis.

The results suggest that the role of uric acid in blood pressure might differ between hypertensive drinkers and non-drinkers. In regular alcohol drinkers, there was a positive association of uric acid level with blood pressure and the severity of cardiac hypertrophy. In non-regular drinkers, an increased uric acid level is likely to be closely associated with increased BMI.