Glycosylated haemoglobin assessment in diabetic patients with acute coronary syndromes

A systematic review considering risk factors for mortality of patients discharged from hospital with a diagnosis of diabetes

AIM

To identify known risk factors for mortality for adult patients, discharged from hospital with diabetes.

METHOD

The systematic review was based on the PRISMA protocol. Studies were identified through EMBASE & MEDLINE databases. The inclusion criteria were papers that were published over the last 6 years, in English language, and focused on risk factors of mortality in adult patients with diabetes, after they were discharged from hospitals. This was followed by data extraction "with quality assessment and semi-quantitative synthesis according to PRISMA guidelines".

RESULTS

There were 35 studies identified, considering risk factors relating to mortality for patients, discharged from hospital with diabetes. These studies are distributed internationally. 48 distinct statistically significant risk factors for mortality can be identified. Risk factors can be grouped into the following categories; demographic, socioeconomic, lifestyle, patient medical, inpatient stay, medication related, laboratory results, and gylcaemic status. These risk factors can be further divided into risk factors identified in generalized populations of patients with diabetes, compared to specific sub-populations of people with diabetes.

CONCLUSION

A relatively small number of studies have considered risk factors relating to mortality for patients, discharged from hospital with a diagnosis of diabetes. Mortality is an important outcome, when considering discharge from hospital with diabetes. However, there has only been limited consideration within the research literature.

HbA1c screening for new onset diabetes following acute coronary syndrome: is it a worthwhile test in clinical practice?

Background

Diabetes and pre-diabetes are prevalent in acute coronary syndrome (ACS) and relate to adverse outcomes. This study used HbA_1c to screen for degrees of glucose intolerance amongst patients without known diabetes presenting with ACS.

Methods

Over a 1-year period (June 2014–2015) consecutive patients admitted to a single centre cardiology unit with an initial diagnosis of ACS without prior diabetes diagnosis were electronically referred to our diabetes team. Patients were screened for the presence of diabetes by use of an initial HbA_1c blood test on day 2 or 3 post admission. If abnormal (≥42 mmol/mol; ≥6.0%), patients were invited for a repeat HbA_1c at 2 weeks, and if an intermediate result (42–47 mmol/mol; 6.0–6.4%), for an oral glucose tolerance test (OGTT) at 3 months. Patients were diagnosed with Type 2 diabetes if the repeat HbA_1c result was high (≥48 mmol/mol; ≥6.5%) or the OGTT at 3 months confirmed the diagnosis. Other data collected included baseline demographics, risk factors and any history of cardiovascular disease. All patients with ACS were stratified according to the diagnosis and subsequent management.

Results

We screened 399 patients in total. The mean age was 65 ± 14 years, 268 (67%) were men, 290 (73%) were Caucasian, 95 (24%) were South Asian and 14 (4%) were Afro-Caribbean ethnicity. Of all patients, 57 (14.3%) were diagnosed as pre-diabetes and 43 (10.8%) newly diagnosed diabetes. During the study 28 (7%) patients could not be classified; 6 (1.5%) patients died during the study and 22 (5.5%) patients were missing either initial or repeat HbA_1c and were subsequently lost to follow up. Of the baseline variables assessed, there were significantly more patients of South Asian ethnicity in the diabetes group compared to the normal group (42 vs 20%; p = 0.003). There was no difference in detection rates in patients with more severe ACS requiring percutaneous or cardiac surgical intervention.

Conclusions

The use of a simple HbA_1c screening method in clinical practice can detect new onset diabetes in approximately 1 in 10 high-risk post ACS patients.

Rule-In and Rule-Out of Myocardial Infarction Using Cardiac Troponin and Glycemic Biomarkers in Patients with Symptoms Suggestive of Acute Coronary Syndrome

BACKGROUND

Early rule-in/rule-out of myocardial infarction (MI) in patients presenting to the emergency department (ED) is important for patient care and resource allocation. Given that dysglycemia is a strong risk factor for MI, we sought to explore and compare different combinations of cardiac troponin (cTn) cutoffs with glycemic markers for the early rule-in/rule-out of MI.

METHODS

We included ED patients (n = 1137) with symptoms suggestive of acute coronary syndrome (ACS) who had cTnI, high-sensitivity cTnI (hs-cTnI), hs-cTnT, glucose, and hemoglobin A_1c (Hb A_1c) measurements. We derived rule-in/rule-out algorithms using different combinations of ROC-derived and literature cutoffs for rule-in and rule-out of MI within 7 days after presentation. These algorithms were then tested for MI/cardiovascular death and ACS/cardiovascular death at 7 days. ROC curves, sensitivity, specificity, likelihood ratios, positive and negative predictive values (PPV and NPV), and CIs were determined for various biomarker combinations.

RESULTS

MI was diagnosed in 133 patients (11.7%; 95% CI, 9.8-13.8). The algorithms that included cTn and glucose produced the greatest number of patients ruled out/ruled in for MI and yielded sensitivity ≥99%, NPV ≥99.5%, specificity ≥99%, and PPV ≥80%. This diagnostic performance was maintained for MI/cardiovascular death but not for ACS/cardiovascular death. The addition of hemoglobin A_1c (Hb A_1c) (≥6.5%) to these algorithms did not change these estimates; however, 50 patients with previously unknown diabetes may have been identified if Hb A_1c was measured.

CONCLUSIONS

Algorithms incorporating glucose with cTn may lead to an earlier MI diagnosis and rule-out for MI/cardiovascular death. Addition of Hb A_1c into these algorithms allows for identification of diabetes. Future studies extending these findings are needed for ACS/cardiovascular death. ClinicalTrials.gov identifier: NCT01994577.