Risk Factors Identified for Recurrent Cardiac Events in Type 2 Diabetes 

Risk factors have been identified for recurrent cardiac events in patients with type 2 diabetes, according to the results of a new study. 

“Preventing relapses of cardiovascular disease (CVD) in patients with previous CVD is a daunting task for clinicians,” write Carlo B. Giorda, MD, from the Metabolism and Diabetes Unit, Regione Piemonte, Chieri, Italy, and colleagues from the Diabetes and Informatics Study Group. “The clinical and socioeconomic impact of recurrence is such that many health care systems regard secondary prevention as worthy of free prescription of expensive medications. Nonetheless, relatively little is known of the natural history of this manifestation of atherosclerotic cardiovascular disease.”

The goal of the study was to determine the incidence of and to evaluate risk factors for recurrent CVD in patients with type 2 diabetes, aged 40 to 97 years, observed by a network of diabetes clinics. The investigators conducted 2 separate analyses: 1 for 2788 patients with CVD at enrollment (cohort A) and 1 for 844 patients who experienced a first episode of CVD during the observation period (cohort B). Duration of follow-up was 4 years.

The age-adjusted incidence of a recurrent event during follow-up (per 1000 person-years) in cohort A was 72.7 in men and 32.5  in women. In cohort B, it was 40.1 in men and 22.4 in women.

In cohort A, male sex, older age, and insulin use were significant independent risk predictors, after controlling for familial CVD, obesity, smoking, diabetes duration, glycemic control, microvascular complications, geographic area, and antihypertensive and lipid-lowering treatment. In cohort B, a serum triglyceride level of 1.69 mmol/L or more was the only metabolic (negative) prognostic factor. A previous CVD episode, particularly myocardial infarction, was, by far, the strongest predictor of recurrent CVD in both cohorts.

“Approximately 6% of unselected diabetic patients in secondary prevention develop recurrent major CVD every year,” the study authors write. “Those with long-standing previous CVD show a higher incidence of recurrence. Male sex, age, high triglyceride levels, and insulin use are additional predictors of recurrence.”

“The observed risk profile has significant clinical implications. First, diabetic patients, especially elderly men, whose CVD onset is myocardial infarction or revascularization (or combined events) warrant close follow-up and intensive management,” the study authors conclude. “Second, patients using insulin show a higher frequency of recurrent events. Third, diabetic patients with high triglycerides levels may be targeted by aggressive treatment in secondary CVD prevention.”

Practice Pearls

• The incidence of a recurrent major CVD event in adults with type 2 diabetes mellitus is 6% and is higher if the previous CVD event occurs earlier.
• In adults with type 2 diabetes mellitus and a history of a CVD event, the risk factors for a recurrent CVD event are male sex, older age, insulin use, high triglyceride level, and, especially, a previous CVD event.

Diabetes Care. 2008;31:2154-2159.