Risk factors for lack of statin therapy in patients with diabetes and coronary artery disease

- Many patients with DM and CAD, a very high risk group, are not treated with statins.
- Adverse reactions were the strongest predictor of discontinuation of statin therapy.
- Less than 30% of patients not on long-term statins had tried more than 1 statin.
- Higher CV risk and cardiologist evaluation were associated with statin therapy.
- The apparent further risk stratification in high-risk patients is unjustified.

BackgroundPatients with both diabetes and coronary artery disease (CAD) have exceedingly high cardiovascular risk. Nevertheless, little is known about prevalence of statin therapy in this population and reasons why some patients may not be receiving this potentially life-saving treatment.ObjectiveTo investigate prevalence and predictors of statin therapy in patients with combined diabetes and CAD.MethodsWe conducted a retrospective cohort study of primary care patients with diabetes and CAD followed at 2 academic medical centers between 2000 and 2011. We used multivariable logistic regression to identify patient and provider characteristics associated with (1) statin initiation (any history of statin therapy) and (2) statin persistence (active statin prescription at the study end).ResultsOf 8488 study patients, 7427 (87.5%) ever received statins and 6212 (73.2%) had persistent statin therapy. Younger age (odds ratio [OR], 1.26 per decade), smoking (OR, 1.49) and cardiologist evaluation (OR, 2.26) were associated with statin initiation (P < .0001 for all). Younger age (OR, 1.17), family history of CAD (OR, 1.39), no adverse reactions to statins (OR, 1.40; P < .0001 for all), female sex (OR, 1.22; P = .005), history of smoking (OR, 1.22; P = .003), cardiologist evaluation (OR, 1.23; P = .002), and lower HbA1c (OR, 1.04; P = 0.003) were associated with persistent statin therapy. Only 362 (29.8%) of the 1215 patients without persistent statin therapy had tried at least 2 statins, and 58 (4.8%) tried 3 statins.ConclusionsMany patients with combined CAD and diabetes are not treated with statins, although in this very high-risk group, even moderate-intensity statins result in meaningful reductions in cardiovascular events. Higher cardiovascular risk and cardiologist evaluation were associated with higher prevalence of statin therapy.