In patients with acute myocardial infarction, the impact of hyperglycemia as a risk factor for mortality is not homogeneous across age-groups

Association of acute glycemic parameters at admission with cardiovascular mortality in the oldest old with acute myocardial infarction

OBJECTIVES

Stress-related glycemic indicators, including admission blood glucose (ABG), stress-hyperglycemia ratio (SHR), and glycemic gap (GG), have been associated with worse outcomes after acute myocardial infarction (AMI). However, data regarding their prognostic value in the oldest old with AMI are unavailable. Therefore, this study aimed to investigate the association of stress-related glycemic indicators with short- and long-term cardiovascular mortality (CVM) in the oldest old (≥ 80 years) with AMI.

METHODS

In this prospective study, a total of 933 consecutive old patients with AMI admitted to FuWai hospital (Beijing, China) were enrolled. On admission, ABG, SHR, and GG were assessed and all participants were classified according to their quartiles. Kaplan-Meier, restricted cubic splines (RCS), and multivariate Cox regression analyses were performed to evaluate the association between these glycemic indicators and CVM within 30 days and long-term follow-up.

RESULTS

During an average of 1954 patient-years of follow-up, a total of 250 cardiovascular deaths were recorded. Kaplan-Meier analyses showed the lowest CVM in quartile 1 of ABG and in quartile 2 of SHR and GG. After adjusting for potential covariates, patients in quartile 4 of ABG, SHR, and GG had a respective 1.67-fold (95% CI: 1.03-2.69; P = 0.036), 1.80-fold (95% CI: 1.16-2.79; P = 0.009), and 1.78-fold (95% CI: 1.14-2.79; P = 0.011) higher risk of long-term CVM risk compared to those in the reference groups (quartile 1 of ABG and quartile 2 of SHR and GG). Furthermore, RCS suggested a J-shaped relationship of ABG and a U-shaped association of SHR and GG with long-term CVM. Additionally, we observed similar associations of these acute glycemic parameters with 30-day CVM.

CONCLUSIONS

Our data first indicated that SHR and GG consistently had a U-shaped association with both 30-day and long-term CVM among the oldest old with AMI, suggesting that they may be useful for risk stratification in this special population.

Association Between Stress Hyperglycemia Ratio and In-hospital Outcomes in Elderly Patients With Acute Myocardial Infarction

Backgrounds: Emerging evidence suggests that stress hyperglycemia ratio (SHR), an index of relative stress hyperglycemia, is of great prognostic value in acute myocardial infarction (AMI), but current evidence is limited in elderly patients. In this study, we aimed to assess whether SHR is associated with in-hospital outcomes in elderly patients with AMI.

Methods: In this retrospective study, patients who were aged over 75 years and diagnosed with AMI were consecutively enrolled from 2015, January 1st to 2019, December 31th. Admission blood glucose and glycosylated hemoglobin (HbA1C) during the index hospitalization were used to calculate SHR. Restricted quadratic splines, receiver-operating curves, and logistic regression were performed to evaluate the association between SHR and in-hospital outcomes, including in-hospital all-cause death and in-hospital major adverse cardiac and cerebrovascular events (MACCEs) defined as a composite of all-cause death, cardiogenic shock, reinfarction, mechanical complications of MI, stroke, and major bleeding.

Results: A total of 341 subjects were included in this study. Higher SHR levels were observed in patients who had MACCEs (n = 69) or death (n = 44) during hospitalization. Compared with a SHR value below 1.25, a high SHR was independently associated with in-hospital MACCEs (odds ratio [OR]: 2.945, 95% confidence interval [CI]: 1.626–5.334, P < 0.001) and all-cause death (OR: 2.871 95% CI: 1.428–5.772, P = 0.003) in univariate and multivariate logisitic analysis. This relationship increased with SHR levels based on a non-linear dose-response curve. In contrast, admission glucose was only associated with clinical outcomes in univariate analysis. In subgroup analysis, high SHR was significantly predictive of worse in-hospital clinical outcomes in non-diabetic patients (MACCEs: 2.716 [1.281–5.762], P = 0.009; all-cause death: 2.394 [1.040–5.507], P = 0.040), but the association was not significant in diabetic patients.

Conclusion: SHR might serve as a simple and independent indicator of adverse in-hospital outcomes in elderly patients with AMI, especially in non-diabetic population.

Age-Related Difference in the Effect of Acute Hyperglycemia on Myocardial Ischemia-Reperfusion Injury

Age and acute hyperglycemia are known risk factors of myocardial ischemia-reperfusion injury. We investigated age-related difference in the effect of acute hyperglycemia on myocardial ischemia-reperfusion injury in Sprague-Dawley rats (young, 3 months; middle-aged, 10-12 months; and old, 22-24 months). The rats received 1.2 g/kg dextrose or normal saline and were subjected to coronary artery occlusion for 45 minutes followed by reperfusion for 240 minutes. Infarct size and ejection fraction were measured. The levels of apoptosis-related proteins (C-PARP, Bcl-2, Bax, and cytochrome c) and autophagy-related proteins (Bnip3, Beclin-1, Atg5, and LC3B-II) were evaluated. Infarct size increased with acute hyperglycemia in young and middle-aged rats but not in old rats, whereas the reduction of ejection fraction after ischemia-reperfusion was aggravated by acute hyperglycemia in all age groups. Acute hyperglycemia increased Bnip3 and Beclin-1 expressions after ischemia-reperfusion in young and middle-aged rats but not in old rats, whereas it increased the expression of Bax, cytochrome c, Atg5, and LC3B-II only in young or middle-aged rats. Conclusively, acute hyperglycemia does not aggravate myocardial ischemia-reperfusion injury in old rats, unlike in young and middle-aged rats. This heterogeneity may be due to attenuated changes in protein signaling after ischemia-reperfusion injury under acute hyperglycemia in old rats.

Urgent Revascularization Strategies in Patients With Diabetes Mellitus and Acute Coronary Syndrome

The prevalence of diabetes mellitus (DM) is rising globally and in Canada. Besides being a risk factor for the development of coronary artery disease, DM is also a marker of poor prognosis in patients with acute coronary syndrome (ACS), increasing the risks for ischemic and bleeding complications. Patients with DM have a high prevalence of multivessel coronary artery disease (MVD) and robust evidence has supported coronary artery bypass surgery (CABG) as the optimal revascularization strategy in the setting of stable ischemic heart disease. In the acute scenario, particularly in patients with non-ST-segment elevation (NSTE) ACS (NSTE-ACS), there are many uncertainties regarding the best revascularization strategy. Most guidelines suggest an invasive and timely approach (that is, performing coronary catheterization within 72 hours after the onset of the NSTE-ACS) and make recommendations about choosing between percutaneous coronary intervention (PCI) or CABG on the basis of data for patients with stable ischemic heart disease. Recent observational and subgroup analyses suggest that CABG might be the preferential method of revascularization for patients with DM and MVD also in the NSTE-ACS setting; however, dedicated randomized clinical trials are lacking. Finally, in patients who present with an ST-segment elevation myocardial infarction, the initial revascularization method of choice is generally PCI, instead of fibrinolysis or CABG, and DM status most often does not influence this decision. The management of residual MVD after primary PCI for ST-segment elevation myocardial infarction, however, remains controversial.

One-year Mortality after an Acute Coronary Event and its Clinical Predictors: The ERICO Study

Background

Information about post-acute coronary syndrome (ACS) survival have been mostly short-term findings or based on specialized, cardiology referral centers.

Objectives

To describe one-year case-fatality rates in the Strategy of Registry of Acute Coronary Syndrome (ERICO) cohort, and to study baseline characteristics as predictors.

Methods

We analyzed data from 964 ERICO participants enrolled from February 2009 to December 2012. We assessed vital status by telephone contact and official death certificate searches. The cause of death was determined according to the official death certificates. We used log-rank tests to compare the probabilities of survival across subgroups. We built crude and adjusted (for age, sex and ACS subtype) Cox regression models to study if the ACS subtype or baseline characteristics were independent predictors of all-cause or cardiovascular mortality.

Results

We identified 110 deaths in the cohort (case-fatality rate, 12.0%). Age [Hazard ratio (HR) = 2.04 per 10 year increase; 95% confidence interval (95%CI) = 1.75–2.38], non-ST elevation myocardial infarction (HR = 3.82 ; 95%CI = 2.21–6.60) or ST elevation myocardial infarction (HR = 2.59; 95%CI = 1.38–4.89) diagnoses, and diabetes (HR = 1.78; 95%CI = 1.20‑2.63) were significant risk factors for all-cause mortality in the adjusted models. We found similar results for cardiovascular mortality. A previous coronary artery disease diagnosis was also an independent predictor of all-cause mortality (HR = 1.61; 95%CI = 1.04–2.50), but not for cardiovascular mortality.

Conclusion

We found an overall one-year mortality rate of 12.0% in a sample of post-ACS patients in a community, non-specialized hospital in São Paulo, Brazil. Age, ACS subtype, and diabetes were independent predictors of poor one‑year survival for overall and cardiovascular-related causes.

Impact of type 2 diabetes mellitus on hospitalization costs in older patients with acute myocardial infarction

Background

The purpose of this study was to evaluate the impact of type 2 diabetes mellitus on hospitalization costs in older patients with acute myocardial infarction (MI).

Methods

Retrospective analysis of data from the case retrieval system of Qilu Hospital of Shandong University located in Jinan city of Shandong Province was done for patients with acute MI from January 1, 2011 to December 31, 2012.

Results

Stenting was an important factor affecting older patients’ total hospitalization costs (β=0.685, P=0.000) and treatment costs during the follow-up period (duration of hospital stay only, β=0.508, P=0.000). Stenting was also a protective factor in the prevention of acute heart failure (HF) in older patients with acute MI during the follow-up period (odds ratio 0.189, 95% confidence interval 0.059–0.602, P=0.005). Implementation of percutaneous coronary intervention reduced the incidence of acute HF in older inpatients with acute MI (27.8% versus 4.3%, P=0.001) and without diabetes (18.2% versus 3.8%, P=0.001). Moreover, among the elderly, the incremental cost-effectiveness ratio estimate for implementing percutaneous coronary intervention in diabetic patients was higher than in nondiabetic patients.

Conclusion

Stenting was a protective factor for preventing acute HF in the elderly during the follow-up period. From the perspective of reducing the incidence of acute HF in inpatients, implementation of percutaneous coronary intervention after an acute MI is more cost-effective in older patients with diabetes mellitus than in those without it.

Five-Year Outcomes after Acute Myocardial Infarction in Patients with and without Diabetes Mellitus in Taiwan, 1996-2005

BACKGROUND

Diabetes mellitus (DM) is a strong risk factor of cardiovascular disease. To date, the impact of DM on outcomes after acute myocardial infarction (AMI) in Taiwan is undetermined. The aim of this study was to compare five-year outcomes after AMI in patients with and without diabetes in Taiwan.

METHODS

A nationwide cohort of 25,028 diabetic and 56,028 non-diabetic patients who were first hospitalized with AMI between 1996 and 2005 was enrolled through linkage with the Taiwan National Health Insurance research database. Patient mortality rates within 30 days after AMI, and 1, 3, and 5 years thereafter were compared.

RESULTS

Length of hospital stay (8.9 ± 8.7 vs. 8.2 ± 8.0 days, p < 0.01) and medical cost during admission (in Taiwan dollars: $129,123 ± $158,073 vs. $121,631 ± $157,018, p < 0.01) were significantly higher in diabetic patients. The difference in mortality rate within 30 days was insignificant between diabetic and non-diabetic patients (18.1% vs. 17.6%, p = 0.06). Mortalities within 1 year (31.0% vs. 26.8%, p < 0.01), 3 years (42.4% vs. 34.7%, p < 0.01), and 5 years (50.6% vs. 41.1%, p < 0.01) were significantly higher in diabetic patients. In patients with AMI who underwent percutaneous coronary intervention (PCI) during index admission, the mortality rate within 30 days was insignificant (6.3% vs. 6.4%, p = 0.70) but mortalities within 1 year (15.2% vs. 11.6%, p < 0.01), 3 years (24.1% vs. 17.2%, p < 0.01), and 5 years (32.2% vs. 22.6%, p < 0.01) were significantly higher in diabetic patients.

CONCLUSIONS

The average patient length of hospital stay and medical cost during admission were significantly higher in diabetic patients. Additionally, the difference in mortality rate within 30 days after AMI was insignificant between diabetic and non-diabetic patients. Also, long-term mortality after AMI was significantly higher in diabetic patients.

KEY WORDS

Acute myocardial infarction; Diabetes mellitus; Length of hospital stay; Medical cost; Mortality; National health insurance.