To the Editor,
We read with great interest the article recently published in your journal about the importance of the magnitude of the variation in glycemia in the risk assessment of patients with the acute coronary syndrome (ACS).1 The authors provide another variant of glucose measurement to those already proposed elsewhere,2 and which may help us determine the risk in our patients.
The relation between diabetes mellitus and coronary heart disease is unquestioned; indeed, this is the main cause of death in diabetic patients. The prevalence of diabetes mellitus is growing and it will become even greater due to the increase in life expectancy and the prevalence of obesity in our population.3 The percentage of patients seen in cardiology services who have diabetes and coronary disease may well now reach 50% in the real world.
However, we believe that it still remains unclear whether stress hyperglycemia in the ACS is a marker or a risk factor, that is, whether it is a mere spectator of ACS or whether it plays a true role in myocardial damage. Irrespectively, what remains to be resolved is whether glucose lowering treatment is beneficial in this context,4 and relevant clinical studies are currently under way to elucidate this aspect.
As treatment of stress hyperglycemia has failed to show any conclusive results, we believe that the true emphasis should be on the detection of early stages of abnormal glucose regulation, mainly occult diabetes mellitus (ODM). This latter situation has already been shown to have a prognostic impact in coronary patients,3 and starting early glucose lowering treatment seems to improve the events during follow-up.5 Furthermore, we can improve secondary prevention and adapt it to the objectives of the diabetic coronary patient (low-density lipoproteins <70 mg/dL and blood pressure <130/80 mm Hg). Consequently, performing an oral glucose tolerance test (OGTT) would be advisable to diagnose ODM, even though we recognize its variable reproducibility6 and the scarce additional information provided by ODM in particular situations, such as coronary interventional procedures.7
In summary, we feel that, whilst glucose measurement is useful in patients with the ACS, we should insist on detecting ODM by means of an OGTT (Class I indication, level of evidence: B, in the European guidelines),8 because in this setting we really will be able to help our patients with demonstrated efficacy.
Article partly financed with a research grant from the Red Temática de Investigación Cooperativa en Enfermedades Cardiovasculares RECAVA, from the Instituto de Salud Carlos III.