Does acute hyperglycemia add prognostic value to the GRACE score in individuals with non-ST elevation acute coronary syndromes?

The stress hyperglycemia ratio improves the predictive ability of the GRACE score for in-hospital mortality in patients with acute myocardial infarction

BACKGROUND

The Global Registry of Acute Coronary Events (GRACE) score is a powerful tool used to predict in-hospital mortality after acute myocardial infarction (AMI) and does not include a glycometabolism-related index. We investigated whether the addition of the stress hyperglycemia ratio (SHR) provides incremental prognostic value in addition to the GRACE score.

METHODS

A retrospective cohort of 613 AMI patients was enrolled in the present analyses. The patients were stratified according to the primary endpoint (in-hospital mortality) and the tertiles of the SHR.

RESULTS

During hospitalization, 40 patients reached the primary endpoint, which was more frequently observed in patients with a higher SHR. The SHR, but not admission blood glucose (ABG), adjusted for the GRACE score independently predicted in-hospital mortality [odds ratio 2.5861; 95% confidence interval (CI), 1.3910-4.8080; P = 0.0027]. The adjustment of the GRACE score by the SHR improved the predictive ability for in-hospital death (an increase in the C-statistic value from 0.787 to 0.814; net reclassification improvement, 0.6717, 95% CI 0.3665-0.977, P < 0.01; integrated discrimination improvement, 0.028, 95% CI 0.0066-0.0493, P = 0.01028). The likelihood ratio test showed that the SHR significantly improved the prognostic models, including the GRACE score. Adding the SHR to the GRACE score presented a larger net benefit across the range of in-hospital mortality risk than the GRACE score alone.

CONCLUSION

The SHR, but not the ABG, is an independent predictor of in-hospital mortality after AMI even after adjusting for the GRACE score. The SHR improves the predictability and clinical usefulness of prognostic models containing the GRACE score.

Admission glucose level and short-term mortality in older patients with acute myocardial infarction: results from the KORA Myocardial Infarction Registry

STUDY OBJECTIVES

To investigate the association between admission blood glucose levels and 28-day mortality as well as in-hospital complications in older patients with incident acute myocardial infarction (AMI) undergoing modern treatment.

METHODS

From a German population-based regional MI registry, 5530 patients (2016 women), aged 65-84 years, hospitalised with an incident AMI between 1 January 2009 and 31 December 2016 were included in the study. Multivariable logistic regression models were used to assess the associations between admission blood glucose and 28-day mortality as well as in-hospital complications after AMI. Analyses stratified according to age, diabetes and type of infarction (ST-elevation MI (STEMI)/non-STEMI) were conducted.

RESULTS

The adjusted ORs for the association between admission blood glucose and 28-day mortality in young-old (65-74 years) and old (75-84 years) patients with AMI were 1.40 (95% CI: 1.21 to 1.62) and 1.21 (95% CI: 0.98 to 1.50) per 1 SD increase in admission blood glucose, respectively. Furthermore, higher admission blood glucose was related to case fatality irrespective of the diabetes status and type of infarction only in the under-75 group. For the patients aged 75-84 years, it was only true for those without diabetes and STEMI. Admission blood glucose was also associated with major cardiac complications in both age groups.

CONCLUSION

Admission blood glucose was significantly associated with 28-day case fatality in patients with AMI aged 65-74 years but not 75-84 years; furthermore, in both age groups there was an increased risk of major complications. It seems that admission glucose may play a rather minor role in terms of case fatality in higher aged patients with AMI.

Two-Hour Post-Load Plasma Glucose, a Biomarker to Improve the GRACE Score in Patients without Known Diabetes

OBJECTIVE

To assess improvement in predictive performance of Global Registry of Acute Coronary Events risk score (GRS) by addition of a glucose matrix.

METHODS

1,056 acute coronary syndrome (ACS) survivors without known diabetes had pre-discharge fasting (FPG) and 2-h post-load plasma glucose (2h-PG) measured. GRS was calculated. Major adverse cardiac events (MACE; death and non-fatal myocardial infarction) were recorded during follow-up. Cox proportional hazard regression predicted event-free survival. Likelihood ratio test, Akaike's information criteria, continuous net reclassification index (NRI>0), and integrated discrimination improvement (IDI) were used to test the additional prognostic value of glycaemic indices over GRS.

RESULTS

During a median follow-up of 36.5 months, 211 MACEs (20.0%), 96 deaths (9.1%), and 115 non-fatal re-infarctions (10.9%), occurred. 2h-PG, but not FPG, independently predicted MACE-free survival at all time points (HR 1.08, 95% CI 1.03-1.13, p = 0.002, at 3 years). Risk of MACE increased by 8-11% with every 1 mmol/L rise in 2h-PG. 2h-PG significantly improved the prognostic models containing GRS. Models containing GRS and 2h-PG yielded lowest corrected Akaike's information criteria compared to that with only GRS. 2h-PG, but not FPG, improved NRI>0 (NRI>0 0.169, p = 0.028 at 3 years) and IDI (IDI of 0.66%, p = 0.018 at 3 years) significantly at all time points during the follow-up.

CONCLUSIONS

2h-PG, but not FPG, improves performance of GRS-containing models in predicting post-ACS prognosis in the short to medium term.

Adjustment of the GRACE score by 2-hour post-load glucose improves prediction of long-term major adverse cardiac events in acute coronary syndrome in patients without known diabetes

Aims

Global Registry of Acute Coronary Events (GRACE) risk score (GRS), a powerful predictor of prognosis after acute coronary event (ACE), does not include a glucometabolic measure. We investigate whether 2 h post-load plasma glucose (2h-PG) could improve GRS based prognostic models in ACE patients without known diabetes mellitus (DM).

Methods and results

A retrospective cohort study of 1056 ACE survivors without known DM who had fasting plasma glucose (FPG) and 2h-PG measured pre-discharge. Death and non-fatal myocardial infarction were recorded as major adverse cardiac events (MACE) during follow-up. GRS for discharge to 6 months was calculated. Cox proportional-hazards regression was used to identify predictors of event free survival. The predictive value of 2h-PG alone and combined with GRS was estimated using likelihood ratio test, Akaike's information criteria, continuous net reclassification improvement (NRI>0), and integrated discrimination improvement (IDI). During 40.8 months follow-up 235 MACEs (22.3%) occurred, more frequently in the upper 2h-PG quartiles. Two-hour PG, but not FPG, adjusted for GRS independently predicted MACE (hazard ratio 1.091, 95% confidence interval 1.043-1.142; P = 0.0002). likelihood ratio test showed that 2h-PG significantly improved the prognostic models including GRS (χ2 = 20.56, 1 df; P = 0.000). Models containing GRS and 2h-PG yielded lowest corrected Akaike's information criteria, compared to that with only GRS. 2h-PG, when added to GRS, improved net reclassification significantly (NRIe>0 6.4%, NRIne>0 24%, NRI>0 0.176; P = 0.017 at final follow-up). Two-hour PG, improved integrated discrimination of models containing GRS (IDI of 0.87%, P = 0.008 at final follow-up).

Conclusion

Two-hour PG, but not FPG, is an independent predictor of adverse outcome after ACE even after adjusting for the GRS. Two-hour PG, but not FPG, improves the predictability of prognostic models containing GRS.

Glycated hemoglobin, admission blood glucose delta, and associated mortality in patients with acute ST-segment elevation myocardial infarction

The importance of glucose metabolism in patients with acute coronary syndrome has been increasingly recognized. We conducted a retrospective study of the associations between prior glycated hemoglobin (HbA1c) levels, admission glucose values, HbA1c-derived estimated average glucose levels (eAG), admission glucose delta (admission glucose - eAG), and mortality in patients presenting with ST-segment elevation myocardial infarction. A total of 676 and 566 patients were included in the in-hospital and 12-month mortality models, respectively. Mean admission blood glucose values were higher in the in-hospital and 12-month mortality groups in patients with no prior diagnosis of diabetes (P < 0.001). Pre, post, and admission HbA1c levels and eAG levels were not associated with in-hospital or 12-month all-cause mortality. The admission glucose delta was higher in patients with in-hospital mortality (87.3 ± 122.7 mg/dL) than in patients who survived (35.88 ± 81.23 mg/dL; P = 0.040). The in-hospital death rate was significantly higher (17% vs 4%, P = 0.017) for patients with admission glucose delta ≥140 mg/dL compared to lower values. In conclusion, HbA1c-derived admission glucose delta is associated with in-hospital mortality in patients with ST-segment elevation myocardial infarction. The mechanisms for the association of acute hyperglycemia with increased acute coronary syndrome mortality are unclear.

Does N-terminal pro-brain natriuretic peptide add prognostic value to the Mehran risk score for contrast-induced nephropathy and long-term outcomes after primary percutaneous coronary intervention?

PURPOSE

To evaluate the prognostic value of plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) in relation to Mehran risk score (MRS) for contrast-induced nephropathy (CIN) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).

METHODS

We prospectively enrolled 283 consecutive patients treated with PPCI for STEMI. NT-proBNP was measured, and the MRS was calculated. The primary end point was CIN, defined as an absolute increase in serum creatinine ≥0.5 mg/dL from baseline within 48-72 h after contrast medium exposure.

RESULTS

The incidence of CIN was 9.2 %. Patients with CIN had higher NT-proBNP and MRS than those without CIN. The value of NT-proBNP was similar to MRS for CIN (C statistics 0.760 vs. 0.793, p = 0.689). After adjustment for MRS, elevated NT-proBNP (defined as the best cutoff point) was significantly associated with CIN. The addition of elevated NT-proBNP to MRS did not significantly improve the C statistics, over that with the original MRS model (0.833 vs. 0.793, p = 0.256). In addition, similar results were observed for in-hospital and long-term major adverse clinical events.

CONCLUSIONS

Although NT-proBNP did not add any prognostic value to the MRS model for CIN, NT-proBNP, as a simple biomarker, was similar to MRS, and may be another useful and rapid screening tool for CIN and death risk assessment, identifying subjects who need therapeutic measures to prevent CIN.

Prognostic impact of admission blood glucose for all-cause mortality in patients with acute coronary syndromes: added value on top of GRACE risk score

BACKGROUND

Abnormal glucose metabolism is a predictor of worse outcome after acute coronary syndrome (ACS). However, this parameter is not included in risk prediction scores, including GRACE risk score. We sought to evaluate whether the inclusion of blood glucose at admission in a model with GRACE risk score improves risk stratification.

METHODS

Study of consecutive patients included in a single centre registry of ACS. Our primary endpoint was the occurrence of all-cause mortality at one-year follow-up. The ability of the two logistic regression models (GRACE risk score alone and in combination with blood glucose) to predict death was analysed. Continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI), with corresponding 95% confidence intervals (CIs), were also calculated.

RESULTS

We included 2099 patients, with a mean age of 64 (SD=13) years, 69% males. In our sample, 55.1% presented with ST-segment elevation ACS and 13.1% in Killip class ≥ 2. Only 25% were known diabetic at admission. In-hospital mortality was 5.8% and 9.7% at one-year follow-up. The best cut-point for blood glucose was 160 mg/dl (sensitivity 62% and specificity 68%), and 35.2% of the patients had increased levels. This group was elderly, had more prevalence of cardiovascular risk factors, worse renal function and GRACE score as well as more frequently Killip class ≥2. Treatment was similar in both groups besides less frequent use of clopidogrel in high glycaemic patients. The hyperglycaemia group had higher one-year mortality (17.2% vs. 5.6%, p<0.001). Moreover, binary blood glucose remained a predictor of death independently of the GRACE risk score and the presence of diabetes (odds ratio (OR) 1.99, 95% CI 1.40-2.84, p<0.001). The inclusion of blood glucose, as a continuous variable, in a logistic regression model with GRACE score, increased the area under the ROC curve from 0.80 to 0.82 (p=0.018) as well as the goodness-of-fit and was associated with an improvement in both the NRI (37%) and the IDI (0.021), suggesting effective reclassification.

CONCLUSIONS

A blood glucose level on admission ≥ 160 mg/dl is an independent predictor of mortality in medium-term follow-up. It offers an incremental predictive value when added to the GRACE risk score, although with a modest magnitude of improvement, probably due to the high predictive performance of the GRACE risk score alone.

BNP and admission glucose as in-hospital mortality predictors in non-ST elevation myocardial infarction

OBJECTIVES

Admission hyperglycemia and B-type natriuretic peptide (BNP) are associated with mortality in acute coronary syndromes, but no study compares their prediction in-hospital death.

METHODS

Patients with non-ST-elevation myocardial infarction (NSTEMI), in-hospital mortality and two-year mortality or readmission were compared for area under the curve (AUC), sensitivity (SEN), specificity (SPE), positive predictive value (PPV), negative predictive value (NPV), and accuracy (ACC) of glycemia and BNP.

RESULTS

Respectively, AUC, SEN, SPE, PPV, NPV, and ACC for prediction of in-hospital mortality were 0.815, 71.4%, 84.3%, 26.3%, 97.4%, and 83.3% for glycemia = 200 mg/dL and 0.748, 71.4%, 68.5%, 15.2%, 96.8% and 68.7% for BNP = 300 pg/mL. AUC of glycemia was similar to BNP (P = 0.411). In multivariate analysis we found glycemia ≥200mg/dL related to in-hospital death (P = 0.004). No difference was found in two-year mortality or readmission in BNP or hyperglycemic subgroups.

CONCLUSION

Hyperglycemia was an independent risk factor for in-hospital mortality in NSTEMI and had a good ROC curve level. Hyperglycemia and BNP, although poor in-hospital predictors of unfavorable events, were independent risk factors for death or length of stay >10 days. No relation was found between hyperglycemia or BNP and long-term events.

Additional predictive value of serum potassium to Thrombolysis In Myocardial Infarction risk score for early malignant ventricular arrhythmias in patients with acute myocardial infarction

OBJECTIVE

The aim of this study was to evaluate the additional predictive value of serum potassium (SK) to Thrombolysis In Myocardial Infarction (TIMI) risk score for malignant ventricular arrhythmias (MVA) in patients within 24 hours of acute myocardial infarction (AMI).

METHODS

This was a 6-year retrospective study. The receiver operating characteristic curve was used to evaluate the predictive value of SK and TIMI risk score for MVA attack. In addition, SK-modified TIMI risk score was created by incorporating SK information into the usual score; the accuracy of new score was compared with that of the usual TIMI risk score by comparing the area under the receiver operating characteristic curves (AUC).

RESULTS

Among the 468 patients enrolled, the incidence of MVA 24 hours after AMI was 9.4%, and it was higher in the hypokalemia group compared with that of the normokalemic group (27.3% vs 7.5%, P < .001; odds ratio, 4.594; 95% confidence interval [CI], 2.159-9.774). A significant predictive value of SK was indicated by AUC of 0.787 (95% CI, 0.747-0.823, P < .01). Serum potassium remained a predictor of MVA after being adjusted by the variables in TIMI risk score. The AUC of TIMI risk score in relation to MVA was 0.586 (95% CI, 0.54-0.631; P = .0676). The incorporation of SK into TIMI risk score improved its predictive value for MVA attack (AUC = 0.66; 95% CI, 0.568-0.753; P < .001), with significant difference between AUC of the new score and that of the original risk score (Z = 2.474, P = .013).

CONCLUSIONS

Serum potassium on admission to the emergency department may be used as a valuable predictor and could add predictive information to some extent to TIMI risk score for MVA attack during 24-hour post-AMI.

Use of reclassification for assessment of improved prediction: an empirical evaluation

BACKGROUND

An increasing number of studies evaluate the ability of predictors to change risk stratification and alter medical decisions, i.e. reclassification performance. We examined the reported design and analysis of recent studies of reclassification and the robustness of their claims for improved reclassification.

METHODS

Two independent investigators searched PubMed and citations to the article that introduced the currently most popular reclassification metric (net reclassification index, NRI) to identify studies performing reclassification analysis (January 2006-January 2010). We focused on articles that included any analyses comparing the performance of a baseline predictive model vs the baseline model plus some additional predictor for a prospectively assessed outcome. We recorded information on the baseline model used, outcomes assessed, choice of risk thresholds and features of reclassification analyses.

RESULTS

Of 58 baseline models used in 51 eligible papers, only 14 (24%) were previously described, used as described and had same outcomes as originally intended. Calibration was examined in 53% of the studies. Sixteen studies (31%) provided a reference for the choice of risk thresholds and only six used the previously proposed categories or justified the use of alternative thresholds. Only 14 studies (27%) stated that the chosen risk thresholds had different therapeutic intervention implications. NRI was calculated in 38 studies and was smaller in studies with adequately referenced or justified risk thresholds vs others (P < 0.0001).

CONCLUSIONS

Reclassification studies would benefit from more rigorous methodological standards; otherwise claims for improved reclassification may remain spurious.