Serum calcium and long-term outcome after ischemic stroke: Results from the China National stroke registry III

Can baseline serum calcium levels predict outcomes of intracerebral hemorrhage? A systematic review and meta-analysis

OBJECTIVE

The prognostic role of baseline calcium levels in patients with intracerebral hemorrhage (ICH) is conflicting. We aimed to conduct the first meta-analysis in the literature to examine if baseline calcium levels can predict outcomes after ICH.

METHODS

English-language studies listed on the databases of Embase, PubMed, ScienceDirect, and Web of Science were searched up to 20th November 2023. Meta-analysis was conducted for baseline hematoma volume, hematoma expansion, unfavorable functional outcome, and mortality.

RESULTS

Ten studies were included. Meta-analysis showed that patients with hypocalcemia have significantly higher baseline hematoma volume (MD: 8.6 95 % CI: 3.30, 13.90 I2 = 88 %) but did not have a higher risk of hematoma expansion (OR: 1.82 95 % CI: 0.89, 3.73 I2 = 82 %). Meta-analysis of crude (OR: 1.86 95 % CI: 1.25, 2.78 I2 = 63 %) and adjusted data (OR: 2.05 95 % CI: 1.27, 3.28 I2 = 64 %) showed those with hypocalcemia had a significantly higher risk of unfavorable functional outcomes. Meta-analysis of both crude (OR: 2.09 95 % CI: 1.51, 2.88 I2 = 80 %) and adjusted data (OR: 1.38 95 % CI: 1.14, 1.69 I2 = 70 %) also demonstrated a significantly higher risk of mortality in patients with hypocalcemia.

CONCLUSION

Baseline serum calcium may have a prognostic role in ICH. Hypocalcemia at baseline may lead to large hematoma volume and poor functional and survival outcomes. However, there seems to be no relation between hypocalcemia and the risk of hematoma expansion. Further studies examining the role of calcium on ICH prognosis are needed.

Association between serum calcium and prognosis in patients with acute ischemic stroke in ICU: analysis of the MIMIC-IV database

BACKGROUND

While serum Ca has proven to be a reliable predictor of mortality across various diseases, its connection with the clinical outcomes of ischemic stroke (IS) remains inconclusive. Our research aimed to explore the relationships between serum total Ca (tCa) and serum ionized Ca (iCa) and mortality among acute IS (AIS) patients.

METHODS

We gathered data from 1773 AIS patients in the Medical Information Mart for Intensive Care Database IV, including baseline demographic data, comorbidities, vital signs, laboratory-based data, and scoring systems. Endpoints for the study encompassed 30-d, 90-d, and 365-d all-cause mortalities. Employing restricted cubic spline Cox regression, we explored potential nonlinear relationships between admission serum iCa and tCa levels and mortality. Participants were categorized into four groups based on serum iCa and tCa quartiles. Multivariable Cox regression analysis was then conducted to evaluate the independent association of iCa and tCa quartiles with all-cause mortality.

RESULTS

The restricted cubic spline revealed a U-shaped association between iCa and 30-d and 90-d mortality (P<0.05), while the relationship between iCa and 365-d mortality was linear (P<0.05). After adjusting for confounders, multivariable Cox analysis demonstrated that the lowest serum iCa level quartile was independently associated with increased risks of 30-d, 90-d, and 365-d mortality. Similarly, the highest serum iCa level quartile was independently associated with increased risks of 30-d and 90-d mortality, but not 365-d mortality. Notably, serum tCa level showed no association with increased risks of 30-d, 90-d, and 365-d mortality.

CONCLUSIONS

Our findings suggest that serum iCa, rather than tCa, is linked to ischemic stroke prognosis. Both high and low serum iCa levels are associated with poor short-term prognosis, while only low serum iCa is associated with poor long-term prognosis in AIS patients.

Serum calcium is associated with sudden cardiac arrest in stroke patients from ICU: a multicenter retrospective study based on the eICU collaborative research database

This primary objective of our study was to investigate the relationship between serum calcium levels and the occurrence of sudden cardiac arrest (SCA) in stroke patients. We analyzed the clinical data of 10,423 acute stroke patients admitted to the intensive care unit. The association between serum calcium and SCA following an acute stroke was assessed through multivariate logistic regression. We explored the non-linear connection between serum calcium levels and SCA in stroke patients using a generalized additive model and smooth curve fitting. Our study uncovered that serum calcium serves as an independent risk factor for sudden cardiac arrest in stroke patients. Notably, we observed that the relationship between serum calcium levels upon admission and the occurrence of SCA in stroke patients within the hospital was non-linear. Furthermore, we identified inflection points in serum calcium levels at 8.2 and 10.4 mg/dL. These findings emphasize a non-linear relationship between serum calcium levels and the risk of SCA in stroke patients. Maintaining serum calcium within the range of 8.2-10.4 mg/dL could lead to a significant reduction in the incidence of cardiac arrest among stroke patients.

Elevated Calcium after Acute Ischemic Stroke Predicts Severity and Prognosis

The aim of this study is to investigate whether there is a correlation between serum calcium levels and clinical severity or functional outcome at discharge in Chinese patients with acute ischemic stroke. Data from 339 patients admitted to our hospital between July 2020 and July 2021 were analyzed. Baseline demographic and clinical information was collected within 24 h of admission, including serum calcium levels, stroke severity (measured by the National Institutes of Health Stroke Scale [NIHSS] score), and lesion volumes. The modified Rankin Scale [mRS] assessed functional outcomes at discharge. Our analysis showed that the median age of patients included in the study was 65 years (interquartile range [IQR], 60-70), and 60.8% were men. We found a positive correlation between serum calcium levels and stroke severity (r[spearman] = 0.266, P < 0.001), with calcium levels increasing as stroke severity increased. In a subgroup of 188 patients with available MRI data, serum calcium concentrations positively correlated with infarct size. Furthermore, in multivariate analysis, a calcium serum level in the highest quartile was associated with a higher risk of unfavorable outcome (odds ratios [OR] = 3.27; 95% confidence intervals [CI] = 1.91-5.59; P < 0.001). In conclusion, our study indicates that higher calcium serum levels are associated with stroke severity and early neurologic outcome after acute ischemic stroke, indicating that calcium may serve as a prognostic biomarker for stroke in Chinese patients.

Low serum calcium is a novel predictor of unfavorable prognosis after traumatic brain injury

Background

Accurate and convenient serological markers for prognosis after traumatic brain injury (TBI) are still lacking. We aimed to explore the predictive value of serum calcium for prognosing outcomes within 6 months after TBI.

Methods

In this multicenter retrospective study, 1255 and 719 patients were included in development and validation cohorts, respectively, and their 6-month prognoses were recorded. Serum calcium was measured through routine blood tests within 24 h of hospital admission. Two multivariate predictive models with or without serum calcium for prognosis were developed. Receiver operating characteristics and calibration curves were applied to estimate their performance.

Results

The patients with lower serum calcium levels had a higher frequency of unfavorable 6-month prognosis than those without. Lower serum calcium level at admission was associated with an unfavorable 6-month prognosis in a wide spectrum of patients with TBI. Lower serum calcium level and our prognostic model including calcium performed well in predicting the 6-month unfavorable outcome. The calcium nomogram maintained excellent performance in discrimination and calibration in the external validation cohort.

Conclusions

Lower serum calcium level upon admission is an independent risk factor for an unfavorable 6-month prognosis after TBI. Integrating serum calcium into a multivariate predictive model improves the performance for predicting 6-month unfavorable outcomes.

The association of admission ionized calcium with outcomes of thrombolysed patients with anterior circulation ischemic stroke

BACKGROUND AND PURPOSE

The relationship between ionized calcium and prognosis of ischemic stroke is controversial. We aim to determine the relationship of admission ionized calcium levels with acute ischemic stroke (AIS) after intravenous thrombolysis (IVT).

METHODS

Consecutive anterior circulation AIS patients treated with recombinant tissue plasminogen activator (rt-PA) were retrospectively enrolled. According to ionized calcium quartiles, the patients were divided into four groups and clinical data were analyzed between groups. Ionized calcium was entered into logistic regression analysis in two models, separately: model 1, calcium as a continuous variable (per 1-mmol/L increase), and model 2, calcium as the four-categorized variable (being collapsed into quartiles: Q1-Q4). Early neurologic improvement (ENI) was defined as improvement of four or more points at 24 h after intravenous rt-PA, while long-term good outcome as the modified Rankin Scale (mRS) 0-1 at 90 days.

RESULTS

A total of 546 patients met the study criteria (mean age was 63.51 ± 11.26 years and 365 [66.8%] were men). The median admission National Institute of Health Stroke Scale was 9 (range 4 to 15). When not adjusted, in model 1: ionized calcium was related to good outcome (odds ratio [OR] 69.061, 95%CI: 1.638-2911.111, p=0.027), but not ENI (OR 14.097, 95%CI: 0.133-1492.596, p=0.266); in model 2: compared with Q4, while good outcome was less common in Q1 (OR 0.623, 95%CI: 0.388-0.999, p=0.049). After adjusting for confounding factors, calcium in Q2 (OR 0.502, 95%CI: 0.253-0.997, p=0.049) was independently associated with ENI, but no matter as a continuous variable or categorized variable, ionized calcium displayed no association with a good outcome.

CONCLUSION

The current results found that ionized calcium might be associated with early neurological improvement, but had no association with 3 months' outcome in anterior circulation AIS patients after IVT.

Higher serum albumin-corrected calcium levels are associated with revascularization and poor outcome after mechanical thrombectomy

Background

Serum calcium abnormalities have been determined to be associated with the risk and outcome of stroke. The aim of the present study was to examine the associations of serum calcium with vascular recanalization, symptomatic intracranial haemorrhage and functional outcome in stroke patients after mechanical thrombectomy.

Methods

A total of 192 patients treated with mechanical thrombectomy for anterior circulation large vessel occlusion were consecutively included from August 2017 to June 2021. Serum calcium levels were measured on admission, and albumin-corrected calcium levels were calculated for subsequent analysis. Successful arterial revascularization was defined as a modified Thrombolysis in Cerebral Infarction scale score ≥ 2b. Symptomatic intracranial haemorrhage was assessed according to the European Cooperative Acute Stroke Study (ECASS) III criteria. Poor functional outcome was defined as a modified Rankin Scale score > 2 at 3 months.

Results

Patients with poor outcomes had higher albumin-corrected calcium levels than patients with good outcomes before (2.20 (2.10, 2.30) mmol/L vs. 2.13 (2.04, 2.24) mmol/L, P = 0.002), and after adjusting for other factors (AOR 95% CI, 1.812 (1.253, 2.621), P = 0.002). Patients with unsuccessful recanalization had higher albumin-corrected calcium levels than those with recanalization (2.26 (2.09, 2.46) mmol/L vs. 2.17 (2.07, 2.27) mmol/L, P = 0.029), and after adjusting for other factors (AOR 95% CI, 2.068 (1.214, 3.524)), P = 0.008). No association was found between albumin-corrected calcium and symptomatic intracranial haemorrhage.

Conclusions

Higher serum albumin-corrected calcium levels are independently associated with revascularization and poor outcome in stroke patients after mechanical thrombectomy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02856-2.

Admission Serum Calcium Level and Short-Term Mortality After Acute Ischemic Stroke: A Secondary Analysis Based on a Norwegian Retrospective Cohort

Background

Disturbed serum calcium levels are related to the risk of stroke. However, previous studies exploring the correlation between serum calcium and the clinical outcome of ischemic stroke (IS) have shown inconsistent results.

Object

The study aimed to investigate the relationship between admission serum calcium and 30-day mortality in patients with IS.

Methods

A total of 876 IS patients from a Norwegian retrospective cohort were included for secondary analysis. The exposure variable and the primary outcome were albumin-corrected serum calcium (ACSC) at baseline and all-cause mortality within 30 days after the first admission, respectively. Multivariable logistic regression analysis was used to estimate the risk of 30-day mortality according to ACSC levels. Moreover, the potential presence of a non-linear relationship was evaluated using two-piecewise linear regression with a smoothing function and threshold level analysis. The stability of the results was evaluated by unadjusted and adjusted models.

Results

The result of multiple regression analysis showed that ACSC at baseline was positively associated with the incidence of 30-day mortality after adjusting for the potential confounders (age, gender, serum glucose, hypertension, atrial fibrillation/atrial flutter, renal insufficiency, heart failure, chronic obstructive pulmonary disease, pneumonia, paralysis, and aphasia) (OR = 2.43, 95% CI 1.43–4.12). When ACSC was translated into a categorical variable, the ORs and 95% CIs in the second to the fourth quartile vs. the first quartile were 1.23 (0.56, 2.69), 1.16 (0.51, 2.65), and 2.13 (1.04, 4.38), respectively (P for trend = 0.03). Moreover, the results of two-piecewise linear regression and curve-fitting revealed a linear relationship between ACSC and 30-day mortality.

Conclusion

ACSC is positively associated with 30-day mortality in IS patients, and the relationship between them is linear.

Risk of Post-stroke Epilepsy Following Stroke-Associated Acute Symptomatic Seizures

Objective: Post-stroke epilepsy (PSE) is associated with increased morbidity and mortality. Stroke-associated acute symptomatic seizures are an important risk factor: 20.8–34.3% of these patients will go on to develop PSE. Identifying these “high risk” individuals may result in earlier PSE diagnosis, treatment, and avoidance of seizure-related morbidity. This study was to identify predictors of PSE development in patients with stroke-associated acute symptomatic seizures.

Participants and Methods: This was a retrospective cohort study of 167 patients with stroke-associated acute symptomatic seizures admitted to the Neurology Department of a tertiary Hospital of China, from 1 May 2006 to 30 January 2020. Both those with primary ischemic stroke and intracerebral hemorrhage were included in the study. Patient demographics, medical history, stroke-associated, and seizure-related variables were evaluated with univariable analysis and multivariable Cox regression analysis. PSE was defined as unprovoked seizures occurring > 7 days post-stroke. Data points were extracted from medical records and supplemented by tele-interview.

Results: Of the 167 patients with stroke-associated acute symptomatic seizures, 49 (29.3%) developed PSE. NIHSS score > 14 [hazard ratio (HR) 2.98, 95% CI 1.57–5.67], longer interval from stroke to acute symptomatic seizures (days 4–7 post-stroke) (HR 2.51, 95% CI 1.37–4.59) and multiple acute symptomatic seizures (HR 5.08, 95% CI 2.58–9.99) were independently associated with PSE development. This association remained in the sub-analysis within the ischemic stroke cohort. In the sub-analysis of the hemorrhagic stroke cohort, multilobar involvement (HR 4.80, 95% CI 1.49–15.39) was also independently associated with development of PSE. Further, we developed a nomogram to predict individual risk of developing PSE following stroke-associated acute symptomatic seizures. The nomogram showed a C-index of 0.73.

Conclusion: More severe neurofunctional deficits (NIHSS score > 14), longer interval from stroke to acute symptomatic seizures (days 4–7 post-stroke), and multiple acute symptomatic seizures were independently associated with development of PSE in patients with stroke-associated acute symptomatic seizures. This knowledge may increase clinical vigilance for development of PSE, facilitating rapid diagnosis and treatment initiation, and subsequently reduce seizure-related morbidity.