Macrophages of the “Heart-Kidney” Axis: Their Dynamics and Correlations with Clinical Data and Outcomes in Patients with Myocardial Infarction

Association of cumulative resting heart rate exposure with rapid renal function decline: a prospective cohort study with 27,564 older adults

OBJECTIVE

To evaluate the prospective association between cumulative resting heart rate (cumRHR) and rapid renal function decline (RRFD) in a cohort of individuals aged 60 and older.

METHODS

In the Tianjin Chronic Kidney Disease Cohort Study, the individuals who underwent three consecutive physical examinations between 2014 and 2017, with estimated glomerular filtration rate (eGFR) greater than 60 mL/min per 1.73 m2 and aged 60 years or older were enrolled. A total of 27,564 patients were prospectively followed up from January 1, 2017 to December 31, 2020. The 3-year cumRHR was calculated. The primary outcome was RRFD, defined as an annualized decline in eGFR of 5 mL/min per 1.73 m2 or greater. Logistic and restricted spline regression models and subgroup analysis were used to investigate the association of cumRHR with RRFD after adjusting for all confounders.

RESULTS

During a median follow-up of 3.2 years, a total of 4,347 (15.77%) subjects developed RRFD. In fully-adjusted models, compared with the lowest quartile of cumRHR, the odds ratio (OR) for the highest was 1.44 (1.28-1.61), P < 0.001. Furthermore, each 1-standard deviation (27.97 beats/min per year) increment in cumRHR was associated with a 17% (P < 0.001) increased risk of RRFD, with a linear positive correlation (P for non-linear = 0.803). Participants with a 3-year cumRHR ≥ 207 (beats/min) * year (equivalent to ≥ 69 beats/min per year in 3 years) were found to be at a higher risk of RRFD.

CONCLUSIONS

The cumRHR is significantly associated with a higher risk of RRFD among older adults. These results might provide an effective goal for managing and delaying the decline of renal function in the older adults.

Macrophages of the Cardiorenal Axis and Myocardial Infarction

The aim of our study was to compare the features of macrophage (mf) composition of the kidneys in patients with fatal myocardial infarction (MI) and in patients without cardiovascular diseases (CVD). We used kidney fragments taken during autopsy. Macrophage infiltration was assessed by immunohistochemistry: antibodies CD68 were used as a common mf marker, CD80-M1 type mf marker, CD163, CD206, and stabilin-1-M2 type. Macrophage composition of the kidneys in patients with fatal MI was characterized by the predominance of CD163+ cells among studied cells, and the control group was characterized by the predominance of CD163+, CD206+, and CD68+. In patients with MI, biphasic response from kidney cells was characterized for CD80+ and CD206+: their number decreased by the long-term period of MI; other cells did not show any dynamics. The exact number of CD80+ cells in kidneys of individuals without CVD was slightly higher than in patients with MI, and the number of CD206+-strikingly predominant. Subsequent analysis of CD80+ and CD206+ cells in a larger sample, as well as comparison of data with results obtained from survivors of MI, may bring us closer to understanding whether the influence on these cells can serve as a new target in personalized therapy in postinfarction complications.

Repeated Glutathione Sodium Salt Infusion May Counteract Contrast-Associated Acute Kidney Injury Occurrence in ST-Elevation Myocardial Infarction Patients Undergoing Primary PCI: A Randomized Subgroup Analysis of the GSH 2014 Trial

BACKGROUND

Contrast-associated acute kidney injury (CA-AKI) is still a major concern for referring physicians, especially in the setting of ST-elevation myocardial infarction (STEMI) patients undergoing primary-PCI (pPCI). To evaluate whether glutathione sodium salt (GSS) infusion impacts favorably on CA-AKI, an unplanned exploratory data analysis of the GSH 2014 trial was performed.

METHODS

One hundred patients with STEMI were assigned at random to an experimental group (No. 50) or to a placebo group (No. 50). Treatment consisted of an intravenous infusion of GSS lasting over 10 min before p-PCI. The placebo group received the same quantity of normal saline solution. After the interventions, glutathione was administered in the same doses to both groups at 24, 48 and 72 h.

RESULTS

CA-AKI occurred in 5 out of 50 patients (10%) allocated to the experimental group (GSS infusion) and in 19 out of 50 patients (38%) allocated to the placebo group (p between groups < 0.001). No patients in either group required renal replacement therapy. After allowing for multiple confounders, GSS administration (OR 0.17, 95% CI 0.04-0.61) and door-to-balloon time (in hours) (OR 1.61, 95% CI 1.01-2.58) have been the only independent predictors of CA-AKI.

CONCLUSIONS

the results of this sub-study, which show a significant trend towards an improved nephroprotection in the experimental group, led to the hypothesis of a possible new prophylactic approach to counteract CA-AKI using repeated GSS infusion. Subsequent studies with specific clinical outcomes would be necessary to confirm these data.

Characteristics of the Cardiosplenic Axis in Patients with Fatal Myocardial Infarction

Myocardial ischemia triggers neurohumoral activation of the cardiosplenic axis. In rodents, adverse outcomes occur upon prolonged entrance of mononuclear cells from the spleen into myocardial tissue. The purpose of this study is to assess the features of spleen structure in patients with fatal myocardial infarction (MI), the dynamics of macrophage infiltration of the spleen and its relationship with cardiac macrophage infiltration and unfavorable outcomes. Using immunohistochemistry techniques, we analyzed the macrophage infiltration of the spleen and myocardium sections collected from patients (n = 30) with fatal MI. The spleen of the patients was decreased and showed a predominance of red pulp with a high concentration of CD68+ and stabilin-1+ cells. The white pulp contained many medium and small follicles and a lower concentration of CD68+ and stabilin-1+ cells, which was comparable to that in the infarct area of the myocardium. The concentration of CD68+ and stabilin-1+ cells increased in the myocardium in the late period of MI, but did not show any dynamics in the spleen. A high number of CD68+ cells in the red pulp and reduced concentration of stabilin-1+ cells in the white pulp were associated with unfavorable post-infarction outcomes. These fundamental findings could be a basis for the development of new personalized therapeutic and diagnostic approaches for the treatment of MI and its complications.