Impact of Long-term Glycosylated Hemoglobin in Patients with Acute Myocardial Infarction: a retrospective cohort study

Abstract

Little clinical evidence supports the strict implementation of glycemic control for diabetic patients with AMI. We aimed to demonstrate the effect of long-term glycemic control on mortality in patients with diabetes mellitus after acute myocardial infarction (AMi). eight hundred and twenty-four consecutive diabetic patients were divided into three groups according to the mean hemoglobin (HbA1c) value: <6% (group A), ≥6% to <7.5% (group B), and ≥7.5% (group C). The best long-term mortality outcome was observed in Group B, followed by groups C and A. Groups B and C were further compared in-depth because the baseline characteristics of group A differed significantly. A Cox regression analysis indicated that Group C was associated with an adjusted hazard ratio (HR) of 1.55 [95% confidence interval (CI): 1.02-2.34, P = 0.038]. An inverse probability of treatment weight analysis was performed to compare groups B and C. Group C had significantly higher mortality, compared to group B (adjusted HR: 1.58; 95% CI: 1.21-2.06, P < 0.001). In conclusion, Glycemic status was associated with the long-term survival outcome in diabetic patients after AMi. However, further study is needed to prove whether HbA1c-targeted glycemic control can effectively improve survival after AMI.A significant proportion of patients with acute myocardial infarction (AMI) have diabetes mellitus or pre-diabetes at the time of the diagnosis, and these patients have worse clinical outcome 1-3 . Higher mortality was observed in patients with AMI who presented with hyperglycemia or a higher glycated hemoglobin (HbA1c) level at admission 4,5 . Therefore, the glycemic status should be evaluated in all AMI patients, regardless whether the case involves a known history of diabetes or hyperglycemia at admission 6 . During the acute phase post-MI, current recommendations based on a study of intensive insulin therapy in critically ill patients suggest that patients should maintain a blood glucose concentration ≤11.0 mmol/L or ≤200 mg/dL but absolutely avoid hypoglycemia 7 .However, no study has assessed the long-term glycemic control status after a diagnosed AMI and the prognostic impact of this parameter. One cohort study of patients with ST-eleveation MI (STEMI) who underwent percutaneous coronary intervention (PCI) reported long-term prognosis, but based on the HbA1c level at admission 8 .To date, robust data have been unavailable to guide optimal glucose management (e.g., treatment thresholds and glucose targets) in patients with AMI after discharge and during follow-up. Therefore, we investigated the association between the average HbA1c level during a long-term follow-up and the all-cause mortality rate in patients with diabetes and AMI. MethodsStudy population and data collection. A total of 2,753 patients with AMI were treated at our institution between June 2003 and February 2015 (Fig. 1). Among these patients, we used the Clinical Data Warehouse system to identify 2,376 patients for whom HbA1c measurements were recorded during the admission for AMI and...

Diabetes Mellitus and Vitamin D Deficiency: Comparable Effect on Survival and a Deadly Association after a Myocardial Infarction

“…Samefors et al [58], in a cohort of 698 patients with type 2 DM, found that low 25(OH)D3 is associated with an increased cardiovascular morbidity/mortality. In our population, diabetic patients had worse long-term outcomes when compared to non-diabetic patients, coherently with previously published data [59].…”

Changes over Time in Hemoglobin A1C (HbA1C) Levels Predict Long-Term Survival Following Acute Myocardial Infarction among Patients with Diabetes Mellitus

“…Other studies often used admission HbA 1C values while we evaluated all values (not necessarily upon admission). The association between low and high HbA 1C and ∆HbA 1C with long-term mortality following AMI is consistent with a recent study by Lee et al [ 22 ] that evaluated the association of long-term mean HbA 1C with long-term survival following AMI. They reported that patients with a mean HbA 1C value ≥ 6.0% to <7.5% had a better prognosis than patients with HbA 1C values of <6.0% or >7.5%.…”

“…Lower glycemic levels can be attributed not only to intensive glycemic control. Other factors such as old age and comorbidities may cause low HbA 1C [ 22 , 27 , 28 , 29 , 30 ]. In addition, increased oxidative stress and endothelial dysfunction, which are markers of worse outcomes, were reported to be associated with significant glycemic changes [ 31 , 32 ].…”

“…Additionally, various medications may signal more complicated cardiac disease (e.g., hydrochlorothiazides, beta-blockers) or systemic illness (e.g., corticosteroids) and may cause an increase in glucose levels, explaining this association [ 38 ]. Finally, a decrease of HbA 1C may occur due to other causes such as hypoglycemia (often associated with older age and other comorbidities), frailty and comorbidities (e.g., chronic inflammation, liver function derangement), rather than related to DM itself, thus potentially explaining the relatively weak association between the rate of decrease in HbA 1C and mortality [ 21 , 22 , 28 ]. Moreover, changes in HbA 1C levels could result from false decreases/increases, occurring due to various clinical situations and diseases such as iron deficiency anemia, deficiency of vitamin B12 or folic acid, severe hypertriglyceridemia, severe hyperbilirubinemia, chronic salicylate ingestion, chronic opioid ingestion, lead poisoning, acute or chronic blood loss, splenomegaly, pregnancy, vitamin E ingestion, red blood cell transfusion, ribavirin and interferon-alpha use, hemoglobin variants, vitamin C ingestion, uremia, hemodialysis and erythropoietin injections [ 39 ].…”

“…In contrast, more stable HbA 1C control may benefit patients [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. In addition, Lee et al recently reported that long-term mean HbA 1C was significantly associated with long-term survival following AMI [ 22 ]. However, data regarding long-term HbA 1C changes following AMI and the association with the survival of these patients are scarce.…”