Screening of Coronary Artery Disease in Diabetic Patients: Who and How?

To the Editor:

We read with great interest the excellent paper by Shimabukuro et al recently published in the Journal.¹ We completely agree with the authors that diabetic patients with asymptomatic coronary artery disease have a higher cardiac risk but, so far, coronary screening programmes have not proved a prognostic benefit over the usual practice in this population. And our question is: why?

When a screening programme begins, certain premises should be taken into account. First, a high prevalence of the disease must be present. Although in the study by Shimabukuro et al it is true, from a prognostic point of view and according to recent studies, unknown severe coronary disease in diabetic patients was less prevalent (just 5–6%)² and less harmful (1.5% annual mortality)³ than we used to think. Therefore it seems that medical treatment still works.

Next, those diabetic patients with a higher risk should be identified. As the DIAD study showed, all the asymptomatic diabetic patients with a higher risk in the UKPDS score had five times more events during the follow-up.³ Thus, in our opinion, correct selection of patients is essential.

Otherwise, a diagnostic technique able to identify all those patients who are really at risk should be used. As we know, in diabetic patients strict control of cardiovascular risk factors, similar to coronary disease patients, should be achieved⁴ and, only in certain scenarios (left main or proximal anterior descending disease, 3-vessel disease with left ventricle dysfunction or a high ischemic burden), has revascularization proven to be better than conventional medical therapy.⁵ In this context, the COURAGE study in which medical treatment was similar to revascularization in stable patients at low risk must not be forgotten.⁶

Therefore, from our point of view, what we really need to do is to identify the 4 scenarios previously mentioned and, consequently we should not perform a diagnostic technique with a high sensibility such as multidetector computed tomography but a diagnostic technique with a high specificity such as functional imaging tests just like stress echocardiography or SPECT.

In conclusion, and as we have suggested previously,⁷ we firmly believe that functional imaging techniques must be performed in high-risk diabetic patients with atypical symptoms or ECG abnormalities, and then, if high ischemic burden is present, coronary angiography will be mandatory.

• Jesus M de la Hera, MD, PhD
• Maria Martín, MD, PhD
• Cecilia Corros, MD
• Ana García-Campos, MD
• Juan Calvo, MD, PhD
• Department of Cardiology, University Hospital of Asturias, Oviedo, Spain

(Released online January 15, 2016)

References

• 1.    Shimabukuro  M,  Saito  T,  Higa  T,  Nakamura  K,  Masuzaki  H,  Sata  M; the Fukuoka diabetologists group. Risk stratification of coronary artery disease in asymptomatic diabetic subjects using multidetector computed tomography. Circ J 2015; 79: 2422–2429.
• 2.    Min  JK,  Labounty  TM,  Gomez  MJ,  Achenbach  S,  Al-Mallah  M,  Budoff  MJ, et al. Incremental prognostic value of coronary computed tomographic angiography over coronary artery calcium score for risk prediction of major adverse cardiac events in asymptomatic diabetic individuals. Atherosclerosis 2014; 232: 298–304.
• 3.    Bansal  S,  Wackers  FJT,  Inzucchi  SE,  Chyun  DA,  Davey  JA,  Staib  LH, et al. Five-year outcomes in high-risk participants in the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study: A post hoc analysis. Diabetes Care 2011; 34: 204–209.
• 4.    Perk  J,  De Backer  G,  Gohlke  H,  Graham  I,  Reiner  Z,  Verschuren  M, et al. European Guidelines on cardiovascular disease prevention in clinical practice (version 2012): The Fifth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease Prevention in Clinical Practice (constituted by representatives of nine societies and by invited experts). Eur Heart J 2012; 33: 1635–1701.
• 5.    Windecker  S,  Kolh  P,  Alfonso  F,  Collet  JP,  Cremer  J,  Falk  V, et al. 2014 ESC/EACTS Guidelines on myocardial revascularization: The Task Force on Myocardial Revascularization of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS) Developed with the special contribution of the European Association of Percutaneous Cardiovascular Interventions (EAPCI). Eur Heart J 2014; 35: 2541–2619.
• 6.    Boden  WE,  O’Rourke  RA,  Teo  KK,  Hartigan  PM,  Maron  DJ,  Kostuk  WJ, et al; COURAGE Trial Research Group. Optimal medical therapy with or without PCI for stable coronary disease. N Engl J Med 2007; 356: 1503–1516.
• 7.    De la Hera  JM,  García-Ruiz  JM,  Delgado  E. Diabetes and screening for coronary heart disease: Where should we focus our efforts? Rev Esp Cardiol (Engl Ed) 2015; 68: 830–833.