Modified shock index: A bedside clinical index for risk assessment of ST-segment elevation myocardial infarction at presentation

Prognostic Significance of Nucleated RBCs in Predicting Mortality Among ST-Elevation Myocardial Infarction Patients Admitted to the ICU

Background The nucleated red blood cells (NRBCs) are a readily available hematological parameter with potential for risk stratification for mortality. Therefore, our objective was to assess the predictive significance of NRBCs for ICU mortality among ST-elevation myocardial infarction (STEMI) patients admitted to an ICU. Additionally, we aimed to compare the predictive capacity of NRBCs with that of the acute physiology and chronic health evaluation (APACHE) II score and the sequential organ failure assessment (SOFA) score. Methodology This descriptive cross-sectional study was conducted in the ICU of the National Institute of Cardiovascular Diseases (NICVD) in Karachi, Pakistan, from the 1st of February to the 30th of June, 2023. We included adult patients (≥18 years) diagnosed with STEMI who were subsequently admitted to the ICU. NRBCs were assessed in all patients over up to five days at 24-hour intervals, and the highest NRBC levels were used for the final analysis. Furthermore, the APACHE II score and the SOFA score were also documented. Patients were monitored throughout their ICU stay, and any adverse events or complications, such as re-intubation, bleeding necessitating transfusion, requirement for renal replacement therapy, arrhythmias, re-infarction, and mortality, were recorded. Results This study included 151 patients, of whom 97 (64.2%) were male, with an average age of 61.1 ± 10.7 years. Patients with positive NRBCs had higher mean SOFA scores (7.4 ± 2.9 vs. 5.4 ± 2.6; p < 0.001) and APACHE II scores (14.6 ± 6.3 vs. 12.6 ± 5.5; p = 0.037) compared to those with negative NRBCs. The culprit vessel showed greater mean stenosis (%) in patients with positive NRBCs (98.8 ± 3.0% vs. 96.8 ± 5.7%; p = 0.004). Post-procedure thrombolysis in myocardial infarction (TIMI) flow grade III was lower in patients with positive NRBCs (77.8% vs. 91.8% for positive vs. negative NRBCs, respectively). Moreover, patients with positive NRBCs experienced significantly higher mortality rates (63% vs. 8.2%; p < 0.001), a higher occurrence of arrhythmias (35.2% vs. 19.6%; p = 0.034), and an increased requirement for vasopressors/inotropic support (96.3% vs. 71.1%; p < 0.001) compared to those with negative NRBCs. NRBCs demonstrated superior discriminatory ability compared to the SOFA and APACHE II scores, with an area under the curve of 0.818 (95% CI: 0.738-0.899) for NRBCs, 0.774 (95% CI: 0.692-0.857) for SOFA, and 0.707 (95% CI: 0.613-0.801) for APACHE II. Positive NRBCs exhibited a sensitivity of 81.0% and a specificity of 81.7% in predicting ICU mortality. Conclusion In conclusion, positive NRBCs emerge as a robust and reliable prognostic indicator, strongly associated with an elevated risk of ICU mortality in STEMI patients. Moreover, the predictive power of positive NRBCs surpasses that of both SOFA and APACHE II scoring systems.

Shock index and modified shock index are predictors of long-term mortality not only in STEMI but also in NSTEMI patients

BACKGROUND

Shock index (SI) and modified shock index (mSI) are useful instruments for early risk stratification in acute myocardial infarction (AMI) patients. They are strong predictors for short-term mortality. Nevertheless, the association between SI or mSI and long-term mortality in AMI patients has not yet been sufficiently examined.

MATERIAL AND METHODS

For this study, a total of 10,174 patients with AMI was included. All cases were prospectively recorded by the population-based Augsburg Myocardial Infarction Registry from 2000 until 2017. Endpoint was all-cause mortality with a median observational time of 6.5 years [IQR: 3.5-7.4]. Using ROC analysis and calculating Youden-Index, the sample was dichotomized into a low and a high SI and mSI group, respectively. Moreover, multivariable adjusted COX regression models were calculated. All analyses were performed for the total sample as well as for STEMI and NSTEMI cases separately.

RESULTS

Optimal cut-off values were 0.580 for SI and 0.852 for mSI (total sample). AUC values were 0.6382 (95% CI: 0.6223-0.6549) for SI and 0.6552 (95% CI: 0.6397-0.6713) for mSI. Fully adjusted COX regression models revealed significantly higher long-term mortality for patients with high SI and high mSI compared to patients with low indices (high SI HR: 1.42 [1.32-1.52], high mSI HR: 1.46 [1.36-1.57]). Furthermore, the predictive ability was slightly better for mSI compared to SI and more reliable in NSTEMI cases compared to STEMI cases (for SI and mSI).

CONCLUSION

High SI and mSI are useful tools for early risk stratification including long-term outcome especially in NSTEMI cases, which can help physicians to make decision on therapy. NSTEMI patients with high SI and mSI might especially benefit from immediate invasive therapy.Key messagesShock index and modified shock index are predictors of long-term mortality after acute myocardial infarction.Both indices predict long-term mortality not only for STEMI cases, but even more so for NSTEMI cases.

Clinical Validation of the Shock Index, Modified Shock Index, Delta Shock Index, and Shock Index-C for Emergency Department ST-Segment Elevation Myocardial Infarction

Background: ST-segment elevation myocardial infarction (STEMI) is a leading cause of death worldwide. A shock index (SI), modified SI (MSI), delta-SI, and shock index-C (SIC) are known predictors of STEMI. This retrospective cohort study was designed to compare the predictive value of the SI, MSI, delta-SI, and SIC with thrombolysis in myocardial infarction (TIMI) risk scales. Method: Patients > 20 years old with STEMI who underwent percutaneous coronary intervention (PCI) were included. Receiver operating characteristic (ROC) curve analysis with the Youden index was performed to calculate the optimal cutoff values for these predictors. Results: Overall, 1552 adult STEMI cases were analyzed. The thresholds for the emergency department (ED) SI, MSI, SIC, and TIMI risk scales for in-hospital mortality were 0.75, 0.97, 21.00, and 5.5, respectively. Accordingly, ED SIC had better predictive power than the ED SI and ED MSI. The predictive power was relatively higher than TIMI risk scales, but the difference did not achieve statistical significance. After adjusting for confounding factors, the ED SI > 0.75, MSI > 0.97, SIC > 21.0, and TIMI risk scales > 5.5 were statistically and significantly associated with in-hospital mortality of STEMI. Compared with the ED SI and MSI, SIC (>21.0) had better sensitivity (67.2%, 95% CI, 58.6−75.9%), specificity (83.5%, 95% CI, 81.6−85.4%), PPV (24.8%, 95% CI, 20.2−29.6%), and NPV (96.9%, 95% CI, 96.0−97.9%) for in-hospital mortality of STEMI. Conclusions: SIC had better discrimination ability than the SI, MSI, and delta-SI. Compared with the TIMI risk scales, the ACU value of SIC was still higher. Therefore, SIC might be a convenient and rapid tool for predicting the outcome of STEMI.

Modified Shock Index as Simple Clinical Independent Predictor of In-Hospital Mortality in Acute Coronary Syndrome Patients: A Retrospective Cohort Study

Introduction

Despite being the current most accurate risk scoring system for predicting in-hospital mortality for patients with acute coronary syndrome (ACS), the Global Registry of Acute Coronary Events (GRACE) risk score is time consuming due to the requirement for electrocardiography and laboratory examinations. This study is aimed to evaluate the association between modified shock index (MSI), as a simple and convenient index, with in-hospital mortality and revascularization in hospitalized patients with ACS.

Methods

A single-centered, retrospective cohort study, involving 1,393 patients with ACS aged ≥ 18 years old, was conducted between January 2018 and January 2022. Study subjects were allocated into two cohorts: high MSI ≥ 1 (n = 423) and low MSI < 1 group (n = 970). The outcome was in-hospital mortality and revascularization. The association between MSI score and interest outcomes was evaluated using binary logistic regression analysis. The area under the curve (AUC) between MSI and GRACE score was compared using De Long’s method.

Results

Modified shock index ≥ 1 had 61.1% sensitivity and 73.7% specificity. A high MSI score was significantly and independently associated with in-hospital mortality in patients with ACS [odds ratio (OR) = 2.72(1.6–4.58), p < 0.001]. However, ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) patients with high MSI did not significantly increase the probability of revascularization procedures. Receiver operating characteristic (ROC) analysis demonstrated that although MSI and GRACE scores were both good predictors of in-hospital mortality with the AUC values of 0.715 (0.666–0.764) and 0.815 (0.775–0.855), respectively, MSI was still inferior as compared to GRACE scores in predicting mortality risk in patients with ACS (p < 0.001).

Conclusion

Modified shock index, particularly with a score ≥ 1, was a useful and simple parameter for predicting in-hospital mortality in patients presenting with ACS.

Validation of the Shock Index, Modified Shock Index, and Shock Index-Paediatric age-Adjusted (SIPA) for predicting length of stay and outcome in children admitted to a paediatric intensive care unit

Background

Maintaining hemodynamic stability requires constant complex interaction between multiple vascular and extravascular factors. There are varieties of parameters that determine the same and few of them are used to predict the hemodynamic instability at earliest. Shock Index (SI), Modified Shock Index (MSI) and Shock Index-Pediatric age-Adjusted (SIPA) have been studied constantly in different clinical settings. They are best non-invasive measures for early prediction in resource poor setting or at community referral centers. We would like to compare the predictive value of each parameter in our tertiary care center.

Methods

It was a retrospective study carried out in PICU of a tertiary care centre and includes data collected from 15 August 2019 to 14 August 2021 over a period of 2 years. We recorded demographic data, age, gender, final diagnosis, outcome, and length of stay in PICU. We compared Outcome (Survived/Expired) and length of stay with SI ≥ 0.7 or < 0.7, MSI ≥ 1.3 or < 1.3 and SIPA > 1.22 or < 1.22 (age 4–6 years) > 1 or < 1 (7–12 years) and > 0.9 or < 0.9 (13–16 years).

Results

This study includes 235 children who were admitted to PICU during study period. The median age was 8 years the median length of stay was 5 days and mortality rate being 11.48% (27). Median SI, MSI were 0.78, 1.6 respectively. 61.70% (145) of patients had SI > 0.7. Median value of SI for septic shock patients was 0.92 on admission. The mortality of the patients with SI > 0.7 was 13.10% (19) and those with MSI > 1.3 was 14.89% (21). Mortality in accordance with SIPA for ages 4–6 years, 7–12 years, and 13–16 years were 15.25% (9), 23% (9) and 19.23% (5) respectively. Basically, SIPA was designed to monitor post trauma cases but in our study we got significant correlation with outcome and length of stay in conditions other than trauma.

Conclusions

The SI, MSI, and SIPA are simple bedside parameters may be used for prioritizing the patients who require strict monitoring on admission to PICU and intervention whenever required. These parameters were best in predicting the severity of sepsis and septic shock in comparison to other diagnosis. SIPA can be generalised for monitoring any high-risk case.

Risk Prediction in Cardiogenic Shock: Current State of Knowledge, Challenges and Opportunities

Cardiogenic shock (CS) is a condition associated with high mortality rates in which prognostication is uncertain for a variety of reasons, including its myriad causes, its rapidly evolving clinical course and the plethora of established and emerging therapies for the condition. A number of validated risk scores are available for CS prognostication; however, many of these are tedious to use, are designed for application in a variety of populations and fail to incorporate contemporary hemodynamic parameters and contemporary mechanical circulatory support interventions that can affect outcomes. It is important to separate patients with CS who may recover with conservative pharmacological therapies from those in who may require advanced therapies to survive; it is equally important to identify quickly those who will succumb despite any therapy. An ideal risk-prediction model would balance incorporation of key hemodynamic parameters while still allowing dynamic use in multiple scenarios, from aiding with early decision making to device weaning. Herein, we discuss currently available CS risk scores, perform a detailed analysis of the variables in each of these scores that are most predictive of CS outcomes and explore a framework for the development of novel risk scores that consider emerging therapies and paradigms for this challenging clinical entity.

Usefulness of a Novel Risk Score to Predict In-Hospital Mortality in Patients ≥ 60 Years of Age with ST Elevation Myocardial Infarction

Numerous algorithms are available to predict short-term mortality in ST elevation myocardial infarction (STEMI) but none are focused on elderly patients or include invasive hemodynamics. A simplified risk score (LASH score) including left ventricular end diastolic pressure > 20 mm Hg, age > 75 years, systolic blood pressure < 100 mm Hg and heart rate > 100 bpm was tested in a retrospective, single-center study of 346 patients ≥ 60 years old who underwent primary percutaneous coronary intervention (PPCI). The median age was 70 years [IQR: 64, 79], 60.1% were men, and 77.8% identified as White. In-hospital all-cause mortality was 10.1%. Patients with a LASH score ≥ 3 (n = 34) had an in-hospital mortality rate of 44.1% compared to 6.4% for LASH score ≤ 2 (p < 0.0001). The odds ratio for in-hospital mortality for patients with LASH score ≥ 3 was 13.2 (95% CI 5.3-33.1) compared to patients with a LASH score ≤ 2 when adjusted for sex, cardiac arrest, heart failure, and prior cerebrovascular event. The LASH score had an area under the ROC curve for predicting in-hospital mortality of 0.795 [CI 0.716-0.872], as compared to TIMI-STEMI (0.881, CI 0.829-0.931; p = 0.01), GRACE (0.849, CI 0.778-0.920; p = 0.19), shock index (0.769, CI 0.667-0.871; p = 0.51) and modified shock index (0.765, CI 0.716-0.873; p = 0.48). In summary, a simplified, easy to calculate risk score that incorporates age and invasive hemodynamics predicts in-hospital mortality in patients ≥ 60 years old undergoing PPCI for STEMI.

Ability of a novel shock index that incorporates invasive hemodynamics to predict mortality in patients with ST-elevation myocardial infarction

OBJECTIVE

To determine whether the use of invasively measured hemodynamics improves the prognostic ability of a shock index (SI).

BACKGROUND

SI such as Admission-SI, Age-SI, Modified SI (MSI), and Age-MSI predict short-term mortality in ST-elevation myocardial infarction (STEMI).

METHODS

Single-center study of 510 patients who underwent primary percutaneous coronary intervention. STEMI SI was defined as age × heart rate (HR) divided by coronary perfusion pressure (CPP).

RESULTS

The mean age was 62 ± 14 years, 66% were males with hypertension (69%), tobacco use (38%), diabetes (28%) and chronic kidney disease (6%). The mean HR, systolic blood pressure (SBP), and CPP were 81 ± 18 bpm, 124 ± 28 mmHg, and 52.8 ± 16.3 mmHg, respectively. Patients with STEMI SI ≥182 (n = 51) were more likely to experience a cardiac arrest in the catheterization laboratory (9.8% vs. 2.0%; p = .001), require mechanical circulatory support (47.1% vs. 8.5%; p < .0001) and be treated with vasopressors (56.9% vs. 10.7%; p < .0001) compared to STEMI SI < 182 (n = 459). After multivariate adjustment, patients with STEMI SI ≥182 were 10, 10.1 and 4.8 times more likely to die during hospitalization, at 30 days and at 5 years, respectively. The C statistic of STEMI SI was 0.870, similar to GRACE score (AUC = 0.902; p = .29) and TIMI STEMI score (AUC = 0.895; p = .36).

CONCLUSION

STEMI SI is an easy to calculate risk score that identifies STEMI patients at high risk of in-hospital death.

Comparison of shock index-based risk indices for predicting in-hospital outcomes in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention

Objective

We aimed to determine whether the prognostic value of the shock index (SI) and its derivatives is better than that of the Thrombolysis In Myocardial Infarction risk index (TRI) for predicting adverse outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

Methods

A total of 257 patients with STEMI undergoing primary PCI from January 2018 to June 2019 were analyzed in a retrospective cohort study. The SI, modified shock index (MSI), age SI (age × the SI), age MSI (age × the MSI), and TRI at admission were calculated. Clinical endpoints were in-hospital complications, including all-cause mortality, acute heart failure, cardiac shock, mechanical complications, re-infarction, and life-threatening arrhythmia.

Results

Multivariate analyses showed that a high SI, MSI, age SI, age MSI, and TRI at admission were associated with a significantly higher rate of in-hospital complications. The predictive value of the age SI and age MSI was comparable with that of the TRI (area under the receiver operating characteristic curve: z = 1.313 and z = 0.882, respectively) for predicting in-hospital complications.

Conclusions

The age SI and age MSI appear to be similar to the TRI for predicting in-hospital complications in patients with STEMI undergoing primary PCI.

Age shock index and age-modified shock index are strong predictors of outcomes in ST-segment elevation myocardial infarction patients undergoing emergency percutaneous coronary intervention

BACKGROUND

Early identification of high-risk patients provides clinicians with greater decision-making time and better informs strategies to cope with disease. The predictive values of age shock index (age SI) and age-modified shock index (age MSI) in ST-segment elevation myocardial infarction (STEMI) patients undergoing emergency percutaneous coronary intervention (PCI) have rarely been reported, especially compared with those for SI, MSI, and the Global Registry of Acute Coronary Events (GRACE) risk score.

PATIENTS AND METHODS

Nine hundred and eighty-three STEMI patients undergoing emergency PCI between January 2014 and September 2017 were analyzed in a retrospective cohort study. The primary outcomes were rates of in-hospital cardiovascular events, and 6-month and long-term all-cause mortality.

RESULTS

In multivariate analyses, the predictive values of age SI and age MSI were comparable to that of the GRACE score, but superior to those of SI and MSI for in-hospital cardiac mortality [age SI: odds ratio (OR) = 1.05, P < 0.001, area under the receiver operating characteristic (ROC-AUC) = 0.805, P < 0.001; age MSI: OR = 1.04, P < 0.001, ROC-AUC = 0.813, P < 0.001; GRACE score: OR = 1.03, P < 0.001, ROC-AUC = 0.827, P < 0.001], 6-month all-cause mortality (age SI: OR = 1.04, P < 0.001, ROC-AUC = 0.791, P < 0.001; age MSI: OR = 1.03, P < 0.001, ROC-AUC = 0.801, P < 0.001; GRACE score: ROC-AUC = 0.828, P < 0.001), long-term all-cause mortality [age SI: hazard ratio (HR) = 1.06, P < 0.001, ROC-AUC = 0.798, P < 0.001; age MSI: HR = 1.04, P < 0.001, ROC-AUC = 0.84, P < 0.001; GRACE score: ROC-AUC = 0.822, P < 0.001] and post-discharge all-cause mortality (age SI: HR = 1.05, P < 0.001, ROC-AUC = 0.78, P = 0.001; age MSI: HR = 1.05, P < 0.001, ROC-AUC = 0.789, P < 0.001; GRACE score: ROC-AUC = 0.812, P < 0.001).

CONCLUSION

Age SI and age MSI are stronger predictors than SI and MSI for in-hospital cardiovascular events, and 6-month and long-term all-cause mortality in STEMI patients undergoing emergency PCI. Age SI and age MSI appear to be convenient and simpler indicators than the GRACE score.

Optimal Hemodynamic Parameter to Predict the Neurological Outcome in Out-of-Hospital Cardiac Arrest Survivors Treated with Target Temperature Management

Current guidelines suggest the maintenance of systolic blood pressure (SBP) at >90 mmHg and mean arterial pressure (MAP) at >65 mmHg in postcardiac arrest patients. There remains a lack of clarity regarding optimal values and timing of blood pressure parameters associated with the improvement of neurologic outcome. We investigated the association of time-weighted average (TWA) blood pressure parameters with favorable neurological outcome (FO) in postcardiac arrest patients. This was a registry-based observational study with consecutive adult out-of-hospital cardiac arrest (OHCA) survivors who were treated using targeted temperature management (TTM). During 72 hours of TTM period, we abstracted hemodynamic parameters such as SBP, diastolic blood pressure, pulse rate (PR), and MAP. Shock index (SI; PR/SBP) and modified shock index (MSI; PR/MAP) were calculated from each measured hemodynamics. Logistic regression was performed to assess the associations between TWA blood pressure parameters and FO, defined as cerebral performance category 1 or 2 at hospital discharge. Among the 173 patients (median age: 58 years; 64% male), 51 (29.3%) had FO in this study. MAP, SI, and MSI at 6 hours after return of spontaneous circulation (ROSC) showed considerable differences in patients with FO (MAP: 89.1 ± 14.7 vs. 83.6 ± 15.8 mmHg, p = 0.033, SI: 0.7 ± 0.2 vs. 0.9 ± 0.9, p = 0.002, MSI: 1.0 ± 0.3 vs. 1.2 ± 0.3, p ≤ 0.001). Among them, MSI, especially at 6 hours, had the highest area under the curve for prediction of FO (0.685; 95% confidence interval: 0.597-0.772, p < 0.001). Also, MSI <1.0 had a sensitivity of 64.7%, a specificity of 64.2% to predict FO. In comatose survivors of OHCA with TTM, MSI at 6 hours after ROSC had the highest prognostic value for neurologic outcome among blood pressure parameters.