Low serum calcium is associated with left ventricular systolic dysfunction in a Chinese population with coronary artery disease

Perioperative Modulation of Left Ventricular Systolic Performance: A Retrospective Study on Ionized Calcium and Vitamin D in Cardiac Surgery Patients

Background: The perioperative impact of calcium and vitamin D on left ventricular (LV) performance during major cardiac surgery remains unexplored. We aimed to assess the relation of calcium and vitamin D measured at different time points with the LV ejection fraction (EF), and to investigate whether changes in EF correlate with postoperative outcomes. Methods: We enrolled 83 patients, in whom ionized calcium was measured before, during, and after surgery (until discharge), vitamin D preoperatively, and EF pre- and postoperatively at 24 h. The postoperative outcomes were cardiopulmonary bypass (CPB) time, aortic cross-clamp time, mechanical ventilation time, vasoactive inotropic score (VIS) (intraoperative, day 0, day 1), and ICU stay time. Results: The mean age was 64.9 ± 8.5 years, with 21 of the patients (25%) having an EF < 50%. The median change from preoperative to postoperative EF was -2.0 (-10.0-0.0) % (p < 0.001). At the baseline, the EF < 50% group had significantly lower preoperative vitamin D levels than the EF ≥ 50% group (p = 0.048). The calcium trend did not differ across the groups. Preoperative EF was significantly associated with CPB time (r = 0.22, p = 0.044) and aortic cross-clamp time (r = 0.24, p = 0.031). Postoperative EF was significantly and inversely associated with intraoperative VIS (r = -0.28, p = 0.009), VIS day 0 (r = -0.25, p = 0.020), VIS day 1 (r = -0.23, p = 0.036), and ICU length of stay (r = -0.22, p = 0.047). Finally, the change in ejection fraction was significantly and inversely associated with CPB time (r = -0.23, p = 0.037), aortic cross-clamp time (r = -0.22, p = 0.044), intraoperative VIS (r = -0.42, p < 0.001), VIS day 0 (r = -0.25, p = 0.024), mechanical ventilation time (r = -0.22, p = 0.047), and ICU length of stay (r = -0.23, p = 0.039). Conclusions: The fluctuations in perioperative ionized calcium levels were not associated with the evolution of LVEF, although preoperative vitamin D levels may affect those with low EF. Correspondingly, a reduced EF significantly impacted all the studied postoperative outcomes. Further investigation into biomarkers affecting cardiac inotropic function is warranted to better understand their significance.

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.

Association of admission serum calcium level with left ventricular dysfunction in patients with acute coronary syndrome

Background

The relationship between serum calcium and left ventricular function in patients with acute coronary syndrome (ACS) has not been explored. Our aim was to investigate the correlation of admission serum calcium with left ventricular dysfunction in ACS patients.

Methods

In this cross-sectional study, 658 ACS patients who were admitted in the Department of Cardiovascular Disease from June 1st, 2019 to December 31st, 2019 were enrolled in the present study. Serum calcium and B-type natriuretic peptide (BNP) were measured at admission. Left ventricular ejection fraction (LVEF) was assessed using echocardiography. The correlation between admission serum calcium and left ventricular dysfunction was analyzed.

Results

When stratified by serum calcium quartiles calculated from all patients, patients with lower serum calcium quartile showed a markedly higher BNP and lower LVEF (P &lt; 0.05). Patients with LVEF ≤ 50% showed a significantly lower serum calcium and higher BNP compared to those with LVEF&gt; 50% (P &lt; 0.05). Admission serum calcium was positively correlated with LVEF (P &lt; 0.01) but negatively correlated with BNP (P &lt; 0.01). Multivariate logistic regression analysis showed that lower serum calcium (adjusted OR: 0.720, 95% CI: 0.519–0.997, P = 0.048) was independently associated with BNP ≥ 300 pg/ml in ACS patients. Using LVEF as a dependent variable, no significant correlation between low serum calcium and left ventricular systolic dysfunction was found in ACS patients.

Conclusions

In patients with ACS, admission serum calcium was positively correlated with LVEF and negatively with BNP. Lower admission serum calcium was an independent risk factor for elevated BNP.

Association between serum calcium level and in-hospital mortality in patients with acute myocardial infarction: a retrospective cohort study

The association between serum calcium levels and the prognosis of patients with acute myocardial infarction (AMI) remains controversial. This study aimed to explore the association between serum calcium and in-hospital mortality in patients with AMI. The data of this study were extracted from the Philips eICU Collaborative Research Database. A total of 7284 patients were eventually enrolled in this study, of which 799 (10.97%) died during hospitalization. For each patient, serum calcium, corrected to albumin, was calculated and categorized into four groups: Q1 ≤ 8.5, Q2 8.5-9.5, Q3 9.5-10.5, and Q4 > 10.5 mg/dL. Multivariate analysis demonstrated that corrected sCa was an independent predictor of in-hospital death (Q2 vs. Q1, OR 0.5, 95% CI 0.4-0.7, P < 0.001; Q3 vs. Q1, OR 0.8, 95% CI 0.6-1.0, P = 0.035; Q4 vs. Q1, OR 1.6, 95% CI 1.1-2.3, P = 0.008). The association remained stable in the fully adjusted model. A significant U-shaped association between corrected serum calcium and in-hospital mortality was observed in piecewise linear regression model (Corrected sCa < 9.4 mg/dL, OR 0.8, 95% CI 0.7-0.9, P < 0.001; corrected sCa > 9.4 mg/dL, OR 1.5, 95% CI 1.3-1.8, P < 0.001). In conclusion, both decreased and increased corrected serum calcium is associated with increased in-hospital mortality in patients with AMI, and patients may have the lowest risk of in-hospital death when corrected serum calcium is 9.4 mg/dL (2.35 mmol/L).

The synergy between diurnal temperature range and calcium concentration help to predict hospital mortality in patients with acute myocardial infarction

Epidemiological studies have suggested that cold is an important contributor to acute cardiovascular events and mortality. However, little is known about the Diurnal Temperature Range (DTR) impact on mortality of the patients with myocardial infarction. Calcium ions (Ca²⁺) play a vital role in the human body, such as cardiac electrophysiology and contraction. To investigate whether DTR on admission moderates the association between serum calcium and in-hospital mortality in patients with acute myocardial infarction (AMI). This retrospective study enrolled consecutive adult patients with AMI at a single center in China (2003–2012). Patients were divided into four groups (Ca-Q1–4) according to serum calcium concentration quartiles. Multivariate logistic regression modeling was used to assess whether DTR moderated the association between serum calcium and in-hospital mortality. The predictive value of serum calcium was evaluated by receiver operating characteristic (ROC) curve and net reclassification improvement (NRI) analyses. The study included 3780 patients. In-hospital mortality was 4.97% (188/3780). DTR moderated the association between serum calcium and in-hospital mortality (P-interaction = 0.020). Patients with low serum calcium in the highest DTR quartile exhibited an increased risk of in-hospital mortality (odds ratio for Ca-Q4 vs. Ca-Q1, 0.03; 95% confidence interval [95% CI], 0.01–0.20). In the highest DTR quartile, adding serum calcium concentration to the risk factor model increased the area under the ROC curve (0.81 vs. 0.76; P < 0.001) and increased NRI by 20.2% (95% CI 7.5–32.9; P = 0.001). Low serum calcium was an independent risk factor for in-hospital mortality in patients with AMI, and this association was moderated by DTR. Careful attention should be paid to patients with low serum calcium who experience a higher DTR on admission.

Cardiovascular Effects of Cumulative Doses of Radioiodine in Differentiated Thyroid Cancer Patients with Type 2 Diabetes Mellitus

Radioiodine (131I) therapy for differentiated thyroid cancer (DTC) involves exposure of the whole body, including the heart, to ionizing radiation. This exposure to the subsequent risk of heart disease is uncertain, especially in patients with DTC associated with type 2 diabetes mellitus (DTC/+T2DM). The current study aimed to assess the relationship between left ventricular ejection fraction (LVEF), high cumulative 131I dose, and peripheral blood parameters in patients with DTC/−T2DM and DTC/+T2DM. The study enrolled 72 female patients with DTC/−T2DM and 24 with DTC/+T2DM who received cumulative 131I doses above 150 mCi (5.55 GBq). LVEF was lower in patients with concomitant T2DM than those without (p < 0.001). The cumulative 131I dosage was inversely correlated with LVEF only in DTC/−T2DM patients (r = −0.57, p < 0.001). In the DTC/+T2DM group, LVEF was negatively associated with absolute platelet count (r = −0.67, p < 0.001) and platelet-to-lymphocyte ratio (r = −0.76, p < 0.001). Our results demonstrate that exposure to high cumulative 131I doses has different cardiovascular effects in DTC/−T2DM and DTC/+T2DM.

Acute effects of cardiac contractility modulation on human induced pluripotent stem cell-derived cardiomyocytes

Cardiac contractility modulation (CCM) is an intracardiac therapy whereby nonexcitatory electrical simulations are delivered during the absolute refractory period of the cardiac cycle. We previously evaluated the effects of CCM in isolated adult rabbit ventricular cardiomyocytes and found a transient increase in calcium and contractility. In the present study, we sought to extend these results to human cardiomyocytes using human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to develop a robust model to evaluate CCM in vitro. HiPSC-CMs (iCell Cardiomyocytes2 , Fujifilm Cellular Dynamic, Inc.) were studied in monolayer format plated on flexible substrate. Contractility, calcium handling, and electrophysiology were evaluated by fluorescence- and video-based analysis (CellOPTIQ, Clyde Biosciences). CCM pulses were applied using an A-M Systems 4100 pulse generator. Robust hiPSC-CMs response was observed at 14 V/cm (64 mA) for pacing and 28 V/cm (128 mA, phase amplitude) for CCM. Under these conditions, hiPSC-CMs displayed enhanced contractile properties including increased contraction amplitude and faster contraction kinetics. Likewise, calcium transient amplitude increased, and calcium kinetics were faster. Furthermore, electrophysiological properties were altered resulting in shortened action potential duration (APD). The observed effects subsided when the CCM stimulation was stopped. CCM-induced increase in hiPSC-CMs contractility was significantly more pronounced when extracellular calcium concentration was lowered from 2 mM to 0.5 mM. This study provides a comprehensive characterization of CCM effects on hiPSC-CMs. These data represent the first study of CCM in hiPSC-CMs and provide an in vitro model to assess physiologically relevant mechanisms and evaluate safety and effectiveness of future cardiac electrophysiology medical devices.

Low serum calcium is associated with higher long-term mortality in myocardial infarction patients from a population-based registry

Calcium plays an essential role in physiology of the cardiovascular system. Aberrations from normal serum calcium levels are known to be associated with several cardiovascular diseases. Its possible role as a predictor for long-term mortality after acute myocardial infarction (AMI) is still uncertain. In this study, a total of 3732 patients (aged 25–74 years) with incident AMI surviving at least 28 days after AMI was included. The median follow-up time was 6.0 years. Admission total serum calcium levels were divided into quartiles. The Kaplan–Meier-Curve suggested a division of the follow up time in two different time periods. So, Cox regression models were calculated to assess association between admission serum calcium levels and all-cause long-term mortality with two observation periods: 28–2500 days and > 2500 days. The final model was adjusted for various comorbidities, clinical characteristics, in-hospital treatment and medication. The third quartile (normal-high Calcium levels) served as the reference group. The fully adjusted Cox-regression model shows significantly higher mortality risk for low serum calcium (quartile 1) within the timeframe 28–2500 days after the event (OR 1.53 [1.19–1.98]). The other groups did not differ significantly from each other. In the later observation period (from 2500 days until death or censoring) no more significant differences were seen between the four calcium quartiles. In summary, low serum calcium is an independent predictor of adverse outcome in the first 2500 days (about 7 years) after AMI. On later points in time this effect attenuates, so that no more significant differences can be observed.

Cardiac CT scanning in coronary artery disease: Epicardial fat volume and its correlation with coronary artery lesions and left ventricular function

Coronary artery disease (CAD) is a major and common disease that poses a threat to human health. Recent studies suggested that epicardial fat may have an important role in the pathogenesis of CAD. Therefore, the association between epicardial fat volume (EFV) and left ventricular function with CAD was investigated in the present study. A total of 61 patients with suspected CAD who underwent CT scanning were enrolled. Baseline data, parameters of left heart function and EFV of the subjects were collected and analyzed. The degree of coronary artery lesions was assessed using the Gensini score. Pearson's correlation analysis and a logistic regression model were applied to assess the association between EFV and risk factors for CAD, the Gensini score and left ventricular function index. A total of 29 female and 32 male subjects with a median age of 63 years were enrolled. The median body mass index (BMI) of the subjects was 23.37 kg/m² and the median EFV was 86.41 cm³. It was revealed that risk factors of CAD, specially hypertension, diabetes mellitus, dyslipidemia, history of myocardial infarction and smoking, had no significant association with the EFV (P>0.05); however, the EFV was significantly positively correlated with the BMI (r=0.479, P<0.0001), interventricular septal thickness (r=0.436, P=0.004), left ventricular posterior wall thickness (r=0.350, P=0.0058), left ventricular end diastolic diameter (r=0.265, P=0.0388), left ventricular mass (r=0.445, P=0.0003) and left ventricular mass index (r=0.371, P=0.0035). However, no correlation was identified between the EFV and the Gensini score (r=0.131, P=0.3137). In conclusion, the EFV measured by cardiac CT scanning was positively correlated with the BMI and left ventricular function, but was not associated with the presence of CAD according to the Gensini scores.

Association between Serum Calcium and First Incident Acute Myocardial Infarction: A Cross-Sectional Study

Background:

The role of serum calcium in coronary artery disease (CAD) patients with or without first incident acute myocardial infarction has not been studied previously. This study aimed to assess the relationship between serum calcium and first incident acute myocardial infarction.

Methods:

This cross-sectional study was conducted from Jan 2014 to Dec 2016. All the participants were from our database, described in detail elsewhere including 1609 cases and 3252 controls. Multiple logistic regression was carried out to explore the effect of serum calcium on first incident acute myocardial infarction. Interaction between serum calcium and risk factors were evaluated.

Results:

Patients with first incident acute myocardial infarction have significantly lower serum calcium concentrations than those without acute myocardial infarction (2.18 (0.21) vs 2.24 (0.19) mmol/L, P<0.0001). After adjusting for sex and age, logistic regression showed that serum calcium was significantly associated with first incident acute myocardial infarction (odds ratio (OR): 1.50, 95% confidence interval (CI): 1.41–1.60). Further adjusted for potential confounders, serum calcium was associated with first incident acute myocardial infarction (OR: 1.32, 95% CI: 1.22–1.42). Moreover, the association still existed when patients were divided into subgroups according to gender and age. A significant interaction was found between serum calcium and diabetes mellitus (DM), lipoprotein (a) (Lp (a)), and serum albumin.

Conclusion:

Serum calcium was associated with first incident acute myocardial infarction among CAD patients in both sexes and in age categories. This study provides further evidence showing the value of serum calcium levels in clinical practice.

Manifestations of left ventricular dysfunction and arrhythmia in patients with chronic hypoparathyroidism and pseudohypoparathyroidism: a preliminary study

BACKGROUND

Cardiac damage triggered by severe hypocalcemia is well known. However, the role of chronic hypoparathyroidism (HP) and pseudohypoparathyroidism (PHP) in cardiac health is still unclear. We investigated the effect of chronic HP and PHP on cardiac structure and conductive function in patients compiling with treatment.

METHODS

The study included 18 patients with HP and eight with PHP aged 45.4 ± 15.4 and 22.1 ± 6.4 years, respectively with a previously regular follow-up. In addition, 26 age- and sex-matched healthy controls were included. General characteristics and biochemical indices were recorded. Cardiac function and structure were assessed by estimation of myocardial enzymes, B-type natriuretic peptide (BNP), and echocardiography. The 12-lead electrocardiogram and 24-h Holter electrocardiography were performed to evaluate the conductive function.

RESULTS

Levels of serum calcium in HP and PHP were 2.05 ± 0.16 mmol/L and 2.25 ± 0.19 mmol/L, respectively. The levels of myocardial enzyme and BNP were within the normal range. Adjusting for age at evaluation and body mass index, all M-mode measurements, left ventricular mass (LVM), LVM index (LVMI) and relative wall thickness (RWT) were comparable between patients and controls. Prolongation of corrected QT (QTc) intervals occurred in 52.6% (10/19) of patients, and 6.7% (1/15) of patients manifested more than 100 episodes of supraventricular and ventricular extrasystoles, as well as supraventricular tachycardia. None of the above arrhythmias was related to a severe clinical event.

CONCLUSIONS

From this pilot study, patients diagnosed with HP and PHP and well-controlled serum calcium levels manifested normal cardiac morphology and ventricular function, except for prolonged QTc intervals, and a small percentage of mild arrhythmias needing further investigation.

Association of serum calcium and phosphorus with measures of left ventricular structure and function: The ARIC study

BACKGROUND AND AIMS

Elevated serum calcium and phosphorus have been associated with increased risk of cardiovascular disorders. We evaluated whether abnormal calcium and high serum phosphorus are associated cross-sectionally with echocardiographic measures of left ventricular (LV) structure and function, as doing so may provide insight into the etiology of cardiac disorders.

METHODS AND RESULTS

Included in the analysis were 5213 Atherosclerosis Risk in Communities Study (ARIC) participants who in 2011-2013 had echocardiography and serum calcium and phosphorus measurements. We evaluated the association of serum calcium (corrected for albumin) and phosphorus quintiles with measures of LV structure and function, after adjusting for other cardiovascular risk factors. Participants were on average 75.3 years old; 59.1% were female and 19.8% were African American. Mean (±SD) concentrations of calcium and phosphorus were 9.33 ± 0.38 and 3.46 ± 0.45 mg/dL, respectively. Higher calcium was associated with lower LV end-diastolic diameter (LVEDD) but greater prevalence of concentric remodeling (p-trend: 0.005 and 0.004 respectively). We observed association between high phosphorus and high septal E/e' (p-trend: 0.02). Likewise, higher serum phosphorus was associated with higher left atrial volume index (p-trend: 0.001) and LV hypertrophy prevalence (p-trend: 0.04).

CONCLUSIONS

In conclusion, higher calcium was associated with more concentric remodeling but lower LVEDD, suggesting complex associations between calcium and cardiac function. Serum phosphorus was related to worse indices of LV diastolic function and LV hypertrophy, but not to LV systolic function. However, the magnitudes of association were modest, so clinical implications of these findings may be limited.

Usefulness of Serum Calcium in the Risk Stratification of Midterm Mortality among Patients with Acute Coronary Syndrome

Serum calcium has been reported to be a predictor of short-term prognosis; however, evidence regarding its association with midterm mortality is scarce. We investigated the association between serum calcium levels at admission and midterm mortality in a retrospective cohort of 2594 consecutive patients with acute coronary syndrome (ACS) who presented to the First Affiliated Hospital of Harbin Medical University from November 2014 to December 2016. Patients were assigned to 4 groups according to the quartiles of serum calcium levels (Ca-Q1-4) and were followed longitudinally for the time to all-cause death. During a median follow-up period of 21.8 months (17.5∼29.5, IQR), 124 patients died (4.8%) of all causes. Kaplan-Meier curves showed that the incidence of midterm mortality differed significantly (log-rank P=0.038) among the quartiles of serum calcium levels at admission. After adjustment for the confounders that were significant in the univariate analysis, the hazard ratios for the lowest quartile of serum calcium was 1.86 (95% CI, 1.05-3.31; P=0.033), compared with the third quartile (reference group). A multiple restricted cubic spline regression model suggested a reverse J-shaped association between serum calcium levels and midterm mortality, and the lowest risk of mortality was associated with approximately 2.32 mmol/l of serum calcium. In conclusion, the serum calcium level is an independent predictor of all-cause midterm mortality among ACS patients. Patients with abnormal serum calcium levels at admission need more targeted treatments.

Associations between serum calcium, phosphorus and mortality among patients with coronary heart disease

PURPOSE

Serum calcium and phosphorus abnormalities are associated with cardiovascular disorders in general population, but evidence among patients with established coronary heart disease (CHD) is limited and controversial. This study aimed to investigate the associations of baseline serum calcium and phosphorus levels with long-term mortality risk among patients with CHD.

METHODS

We conducted a prospective cohort study among 3187 patients with CHD from October 2008 and December 2011 in China. Cox proportional hazards model was used to assess the associations of serum calcium and phosphorus at baseline with the risk of death.

RESULTS

During follow-up (mean, 4.9 years), 295 patients died, 193 of which resulted from cardiovascular causes. Multivariable-adjusted hazard ratios (HR) for each 1 mmol/L increase in serum calcium at baseline were 0.27 (95% confidence interval (CI) 0.14-0.51) for all-cause mortality and 0.26 (95% CI 0.12-0.54) for cardiovascular mortality. Patients in the highest compared to the lowest quartile of serum calcium were at lower risk of all-cause mortality (HR, 95% CI 0.57, 0.40-0.82) and cardiovascular mortality (0.50, 0.32-0.79) (both P _trend < 0.001). This inverse association between serum calcium and the risk of mortality did not change when participants were stratified by sex, age groups, level of overweight, types of CHD, and history of diabetes. We also observed a graded positive association between baseline serum phosphorus and the risks of mortality.

CONCLUSIONS

The present study is the first to report that lower serum calcium at baseline is associated with an increased risk of all-cause and cardiovascular mortality in a Chinese coronary heart disease cohort. Further studies are required to investigate the causal relationship and actual mechanisms.