Observational studies have suggested that the risk of mortality is equivalent for patients with myocardial infarction (MI) without previous diabetes and for diabetic patients without previous MI.  Because vascular risk-reduction targets are based on a patient’s future risk, clinical practice guidelines recommend that the same or lower blood pressure and lipid targets be applied to diabetic patients as would be applied for secondary prevention following MI.  Patients newly diagnosed with diabetes and those with first MIs enter a high-risk category for subsequent coronary events.  Therefore, if diabetes were treated as a coronary artery disease risk equivalent, one would expect that both groups of patients should have similar increases in utilization of antihypertensive and lipid-lowering medications following their index events.

This study used administrative health databases from Ontario, Canada, including hospital discharge abstracts, physician service claims, and records from the government drug insurance program, which covers all prescriptions filled for individuals aged 65 years and older.  All individuals with no history of MI or diabetes were identified, and two cohorts were assembled: those who either had a first MI or were first diagnosed with diabetes between January 1, 2000 and December 31, 2002, with a five-year look-back window.  In each of eight 100-day intervals before and after each patient’s index date, investigators determined whether the patient received at least one prescription for antihypertensive and for lipid-lowering drugs.

There were 9,742 individuals with incident MI and 38,947 with incident diabetes.  Before the index event, patients who subsequently developed diabetes had greater antihypertensive and lipid-lowering drug utilization than patients who subsequently had an MI.  Following the event, antihypertensive drug utilization rose to 96% of individuals with incident MI compared with 75% of those with incident diabetes, while lipid-lowering drug utilization rose to 70% vs. 41%, respectively.  These changes in utilization for both drug classes were significantly different between cohorts and remained different through all subsequent time intervals

Although patients with MIs and with diabetes are at similarly high risk for mortality, utilization of medications to control hypertension and dyslipidemia increased more dramatically following incident MI than following incident diabetes.  This difference persisted, although it narrowed over subsequent time intervals.