Shock Index-C: An Updated and Simple Risk-Stratifying Tool in ST-Segment Elevation Myocardial Infarction

Abstract

Background: Shock index (heart rate/systolic blood pressure, SI) is a simple scale with prognostic value in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI). The present study introduces an updated version of SI that includes renal function.Methods: A total of 1,851 consecutive patients with STEMI undergoing PCI were retrospectively included at Cardiac Care Unit in Guangdong Provincial People's Hospital and divided into two groups according to their admission time: derivation database (from January 2010 to December 2013, n = 1,145) and validation database (from January 2014 to April 2016, n = 706). Shock Index-C (SIC) was calculated as (SI × 100)–estimated CCr. Calibration was evaluated using the Hosmer-Lemeshow statistic. The predictive power of SIC was evaluated using receiver operating characteristic (ROC) curve analysis.Results: The predictive value and calibration of SIC for in-hospital death was excellent in derivation [area under the curve (AUC) = 0.877, p < 0.001; Hosmer-Lemeshow chi-square = 3.95, p = 0.861] and validation cohort (AUC = 0.868, p < 0.001; Hosmer-Lemeshow chi-square = 5.01, p = 0.756). SIC exhibited better predictive power for in-hospital events than SI (AUC: 0.874 vs. 0.759 for death; 0.837 vs. 0.651 for major adverse clinical events [MACEs]; 0.707 vs. 0.577 for contrast-induced acute kidney injury [CI-AKI]; and 0.732 vs. 0.590 for bleeding, all p < 0.001). Cumulative 1-year mortality was significantly higher in the upper SIC tertile (log-rank = 131.89, p < 0.001).Conclusion: SIC was an effective predictor of poor prognosis and may have potential as a novel and simple risk stratification tool for patients with STEMI undergoing PCI.

Shock Index-C: A Newfound Spectrum of Shock Index With Great Accuracy to Predict Contrast Induced Nephropathy in Primary Percutaneous Coronary Intervention Cohort

“…Another pertinent finding exhibited on multivariate regression analysis was that SI-C retained the predictive power as an independent and significant risk stratification tool for CIN with p-value of <0.001 in contrast to Mehran risk score which lost its statistical significance (p=0.796) to demonstrate the correlation with CIN as an independent factor. Our findings contradict the observation made by Ran P et al 15 , who introduced SI-C as a novel risk score and explored its discriminative ability against MRS to identify the risk of CIN. According to their study, SIC didn't perform well in comparison with MRS for predicting CIN (AUC: 0.707 vs. 0.749, p = 0.029).…”

“…23 CHA2DS2-VASc score of > 4 has also emerged as a strong contender for the identification of increased risk of CIN in STEMI patients with AUC reported as 0.88 (CI 0.82-0.94). 14 Last but not least, the AUC of SI 15 for estimation of CIN in post primary PCI patients has been documented as 0.577 (p<0.001).…”

“…Likewise, renal function has been used as an integral component of established risk stratification models like Mehran, 12 CRUSADE, 13 GRACE, 20 and ACEF 21 scores to name a few. Very recently, Ran P et al 15 , introduced a novel concept of merging the prognostic implication of Shock Index and creatinine clearance which successfully exhibited the predictive power of SI-C to evaluate the potential risk of poor In-hospital outcome for STEMI patients including death, MACEs, bleeding, and CIN.…”

“…This Shock-Index CrCl (SI-C) score has effectively predicted the poor outcome including the increased risk of CIN in STEMI patients undergoing PPCI in the Chinese Population. 15 The purpose of this study is to assess the utilization of this simple clinical tool of SI-C to predict the risk of CIN in the PPCI cohort and to compare the predictive utility of this risk score with that of the conventional Mehran model.…”

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

“…Furthermore, Shangguan et al revealed that the MSI has a better predictive value for seven-day mortality and MACEs in STEMI when compared with SI [ 15 ]. Recently, Ran et al established a new score, the shock index-C (SIC; (SI × 100) estimated creatinine clearance rate (CCr)), and found that SIC had a better predictive value than the SI and even better than traditional risk scales, such as TIMI risk scales [ 16 ]. However, there is a lack of evidence comparing SIC, the SI, MSI, and delta-SI in predicting the short-term outcomes of STEMI.…”