Microangiopathy as a prognostic indicator in diabetic patients suffering from acute myocardial infarction

Diabetic patients have an increased mortality following myocardial infarction (MI) due to left ventricular failure rather than larger infarcts or dysrhythmias. As this may be due to diabetic microangiopathy affecting the myocardium, we have examined the case records of diabetic clinic patients admitted to the Coronary Care Unit (CCU) with proven MI and compared the hospital outcome of those with and without retinopathy or nephropathy, i.e. markers for generalised microangiopathy. Sixty four consecutive records were traced, for the period when diabetic treatment policy was standardised in CCU, 24 patients had retinopathy (7 proteinuria). When compared to non-retinopathy patients they had similar ages 67 +/- 12 yr [+/- SD] v 63 +/- 9yr) but were of longer duration of diabetes p less than 0.05). There were no differences between the groups in size or site of infarct, previous infarct or hypertension history, blood glucose on admission or diabetic treatment before or after admission. Death occurred in 29% of retinopathy patients compared to 3% of non-retinopathy patients (p less than 0.01). Cardiac failure complicated 75% of retinopathy patients and 25% of non-retinopathy patients (p less than 0.001). Dysrhythmia occurred in 50% and 33% of patients respectively (P = NS). Nine patients had clinical peripheral vascular disease and five of these died. This study, of a selected group of diabetic clinic attenders admitted to CCU with acute MI, demonstrates that microangiopathy and peripheral vascular disease are important prognostic factors in determining hospital outcome as these patients are at increased risk of cardiac failure and death.