What is the clinical evidence from this study?

Study design: Cohort. Population: Adult ICU patients with sepsis-induced myocardial injury (diagnosed by Sepsis-3 criteria and cardiac troponin T >0.01 ng/mL) (n=1631). Intervention: High lactate-to-ionized calcium ratio (LCR) vs. Low lactate-to-ionized calcium ratio (LCR). Primary outcome: 28-day all-cause mortality (HR not specified exactly but positive association with mortality; Log-rank P < 0.001, p=<0.001).

March 3, 2026Open Access

Association between lactate-to-calcium ratio and 28-day mortality in patients with sepsis-induced myocardial injury: a retrospective cohort study based on the MIMIC-IV database

Q: What are the key findings of this study?

High lactate-to-ionized calcium ratio (LCR) was significantly associated with increased 28-day mortality (50.9% vs 31.9% in low LCR; log-rank P < 0.001) in ICU patients with sepsis-induced myocardial injury.

Q: What question did this study set out to answer?

This study investigates the prognostic value of the lactate-to-calcium ratio (LCR) in patients with sepsis-induced myocardial injury (SIMI).

Key Result

High lactate-to-ionized calcium ratio (LCR) was significantly associated with increased 28-day mortality (50.9% vs 31.9% in low LCR; log-rank P < 0.001) in ICU patients with sepsis-induced myocardial injury.

Key Points

This study investigates the prognostic value of the lactate-to-calcium ratio (LCR) in patients with sepsis-induced myocardial injury (SIMI).
Conducted a retrospective cohort analysis using MIMIC-IV database data.
Included ICU patients diagnosed with SIMI.
Calculated lactate-to-calcium ratio based on arterial blood gas analysis within 24 hours of admission.
Utilized restricted cubic spline models to analyze relationships between LCR and mortality.
Employed Kaplan–Meier survival curves and Cox regression for mortality comparisons.
Higher lactate-to-calcium ratio was positively associated with increased 28-day mortality.
Cut-off values established: 2.96 for the overall group, 2.91 for females, and 2.16 for males.
Cox regression indicated high LCR significantly correlates with increased mortality (log-rank P < 0.001).
LCR showed greater predictive value in patients under 65, especially in younger males.
In females, the association between high LCR and mortality remained consistent across age groups.

Study Design

Type

Cohort (n=1,631)

Structured PICO

Does a high lactate-to-calcium ratio predict increased 28-day mortality in ICU patients with sepsis-induced myocardial injury?

Population

1,631 adult patients (age ≥18 years) diagnosed with sepsis-induced myocardial injury (SIMI) admitted to the ICU for the first time. SIMI defined as cardiac troponin T (cTnT) > 0.01 ng/mL within the first 24 hours of ICU admission. Excluded patients with acute coronary syndrome, myocarditis, pericarditis, valvular heart disease, congestive heart failure, or cardiac arrest. 671 females (41.14%), 960 males (58.86%).

Intervention

High lactate-to-calcium ratio (LCR) calculated from the first arterial blood gas analysis within 24 hours of ICU admission (cut-off values: ≥2.96 overall, ≥2.91 for females, ≥2.16 for males).

Comparator

Low lactate-to-calcium ratio (LCR) based on the respective cut-off values.

Outcome

28-day mortality (survival status at 28 days starting from the day of ICU admission).hard clinical

A higher lactate-to-calcium ratio is independently associated with increased 28-day mortality in ICU patients with sepsis-induced myocardial injury, serving as a potential prognostic indicator.

Main Result

Effect estimate: HR not specified exactly but positive association with mortality; Log-rank P < 0.001

Absolute Event Rate: 50.9% vs 31.86%

p-value: p=<0.001

Limitations

Retrospective cohort design limits causal inference.
Use of single-center MIMIC-IV database may limit generalizability.
Exact hazard ratio values and confidence intervals for mortality risk associated with LCR were not reported.

Abstract

Patients with sepsis-induced myocardial injury (SIMI) face a high risk of mortality. Although various biomarkers can be used to predict prognosis in SIMI patients, each has certain limitations. This study aimed to investigate the prognostic value of the lactate-to-calcium ratio (LCR) in patients with SIMI. This retrospective cohort study was conducted using data from the MIMIC-IV database. Patients diagnosed with SIMI who were admitted to the ICU were included. The LCR was calculated based on the first arterial blood gas analysis performed within 24 h of ICU admission. A restricted cubic spline (RCS) model was used to explore the nonlinear relationship between LCR and 28-day mortality. Patients were divided into high and low LCR groups based on the cutoff values, both overall and by sex. Kaplan–Meier survival curves were used to compare 28-day mortality between groups. Stratification analyses were conducted to assess the prognostic value of LCR across different age strata. A total of 1,631 patients were included. The RCS model revealed a positive association between higher LCR and increased 28-day mortality. The cut-off values for LCR were 2.96 for the overall population, 2.91 for females, and 2.16 for males. Cox regression analysis showed that high LCR was significantly associated with higher 28-day mortality (log-rank P < 0.001). Age-stratified analysis indicated that LCR had a higher predictive value in patients younger than 65 years. Among males, high LCR was associated with increased 28-day mortality only in those younger than 65. In females, the association was consistent regardless of age. A higher LCR is associated with increased 28-day mortality in ICU patients with SIMI. The sex-specific cut-off values (2.91 for females and 2.16 for males) suggest that LCR may serve as a useful prognostic indicator for identifying high-risk patients with sepsis-induced myocardial injury.

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