Higher serum phosphorus and calcium levels provide prognostic value in patients with acute myocardial infarction

Association Between the Serum Phosphate Levels and Hospital Mortality as Well as 90-Day Mortality Among Critically Ill Patients with Chronic Obstructive Pulmonary Disease: A Retrospective Cohort Study

Purpose

COPD patients frequently have abnormal serum phosphorus levels. The objective of this study was to examine the correlation between serum phosphorus levels with hospital and 90-day mortality in critically ill patients with COPD.

Patients and Methods

The MIMIC IV database was used for this retrospective cohort analysis. We extracted demographics, vital signs, laboratory tests, comorbidity, antibiotic usage, ventilation and scoring systems within the first 24 hours of ICU admission. Restricted cubic splines and multivariate cox regression analysis models were used to evaluate the connection between serum phosphorus with hospital and 90-day mortality. We assessed and classified various factors including gender, age, renal disease, severe liver disease, the utilization of antibiotics and congestive heart failure.

Results

We included a total of 3611 patients with COPD, with a median age of 70.7 years. After adjusting for all other factors, we observed a significant positive association between serum phosphate levels with both hospital mortality (HR 1.19, 95% CI: 1.07-1.31, p<0.001) and 90-day mortality (HR 1.15, 95% CI: 1.06-1.24, p<0.001). Compared to the medium group (Q2 ≥3.15, <4.0), the adjusted hazard ratios for hospital mortality were 1.47 (95% CI: 1.08-2, p=0.013), and 1.31 (95% CI: 1.06-1.61, p=0.013) for 90-day mortality in the high group (Q3≥4.0). Hospital mortality decreased at serum phosphate levels below 3.8 mg/dl (HR 0.664, 95% CI: 0.468-0.943, p=0.022), but increased for both hospital (HR 1.312, 95% CI: 1.141-1.509, p<0.001) and 90-day mortality (HR 1.236, 95% CI: 1.102-1.386, p<0.001) when levels were above 3.8 mg/dl. Subgroup and sensitivity analyses yielded consistent results.

Conclusion

In critical ill COPD patients, this study demonstrated a non-linear association between serum phosphate levels and both hospital and 90-day mortality. Notably, there was an inflection point at 3.8 mg/dl, indicating a significant shift in outcomes. Future prospective research is necessary to validate this correlation.

Investigating Potential Correlations between Calcium Metabolism Biomarkers and Periprocedural Clinical Events in Major Cardiovascular Surgeries: An Exploratory Study

Background: There is emerging but conflicting evidence regarding the association between calcium biomarkers, more specifically ionized calcium and the prognosis of intensive care unit (ICU) postoperative cardiac patients. Methods: Our study investigated the relationship between ionized calcium, vitamin D, and periprocedural clinical events such as cardiac, neurologic and renal complications, major bleeding, vasoactive-inotropic score (VIS), and length of ICU and hospitalization. Results: Our study included 83 consecutive subjects undergoing elective major cardiac surgery requiring cardiopulmonary bypass. The mean age of the participants was 64.9 ± 8.5 years. The majority of procedures comprised isolated CABG (N = 26, 31.3%), aortic valve procedures (N = 26, 31.3%), and mitral valve procedures (N = 12, 14.5%). A difference in calcium levels across all time points (p < 0.001) was observed, with preoperative calcium being directly associated with intraoperative VIS (r = 0.26, p = 0.016). On day 1, calcium levels were inversely associated with the duration of mechanical ventilation (r = -0.30, p = 0.007) and the length of hospital stay (r = -0.22, p = 0.049). At discharge, calcium was inversely associated with length of hospital stay (r = -0.22, p = 0.044). All calcium levels tended to be lower in those who died during the 1-year follow-up (p = 0.054). Preoperative vitamin D levels were significantly higher in those who experienced AKI during hospitalization (median 17.5, IQR 14.5-17.7, versus median 15.3, IQR 15.6-20.5, p = 0.048) Conclusion: Fluctuations in calcium levels and vitamin D may be associated with the clinical course of patients undergoing cardiac surgery. In our study, hypocalcemic patients exhibited a greater severity of illness, as evidenced by elevated VIS scores, and experienced prolonged mechanical ventilation time and hospital stays. Additional larger-scale studies are required to gain a deeper understanding of their impact on cardiac performance and the process of weaning from cardiopulmonary bypass, as well as to distinguish between causal and associative relationships.

Propensity score analysis of red cell distribution width to serum calcium ratio in acute myocardial infarction as a predictor of in-hospital mortality

Objective

Red cell distribution width (RDW) and serum calcium (Ca) levels are predictors of in-hospital mortality in acute myocardial infarction (AMI) patients. However, their sensitivity and specificity are limited. Therefore, this study aimed to determine whether the RDW to Ca ratio (RCR) acquired on admission can be used to predict the in-hospital mortality of AMI patients.

Methods

This retrospective cohort study extracted clinical information from the Medical Information Market for Intensive IV (MIMIC-IV) database on 2,910 AMI patients enrolled via propensity score matching (PSM). Prognostic values were assessed using a multivariate logistic model and three PSM approaches. Analysis was performed based on stratified variables and interactions among sex, age, ethnicity, anemia, renal disease, percutaneous transluminal coronary intervention (PCI), coronary artery bypass grafting (CABG), atrial fibrillation, congestive heart failure, dementia, diabetes, paraplegia, hypertension, cerebrovascular disease, and Sequential Organ Failure Assessment (SOFA) score.

Results

A total of 4,105 ICU-admitted AMI patients were analyzed. The optimal cut-off value of the RCR for in-hospital mortality was 1.685. The PSM was performed to identify 1,455 pairs (2,910) of score-matched patients, with balanced differences exhibited for nearly all variables.The patients' median age was 72 years (range, 63-82 years) and 60.9% were male. The risk of in-hospital mortality incidence increased with increasing RCR levels. After adjusting for confounders, the risk ratio for the incidence of in-hospital mortality for high RCR was 1.75 [95% confidence interval (CI): 1.60-1.94, P = 0.0113] compared to that associated with low RCR in the PSM cohort. High RCR was also substantially implicated in in-hospital mortality incidence in the weighted cohorts [odds ratio (OR) = 1.76, 95% CI: 1.62-1.94, P = 0.0129]. Assessment of RCR in three groups showed that patients with high RCR also had a higher risk of in-hospital mortality (OR = 3.04; 95% CI, 2.22-4.16; P < 0.0001) than in patients with RCR in the adjusted model. In the sensitivity analysis, both the original and weighted groups showed similar results.

Conclusion

The RCR at admission may be useful for predicting in-hospital mortality in ICU-admitted AMI patients.