Association of medication adherence and depression with the control of low-density lipoprotein cholesterol and blood pressure in patients at high cardiovascular risk

Abstract

Background: Many patients at high cardiovascular risk do not reach targets for low-density lipoprotein cholesterol (LDL-C) and blood pressure (BP). Depression is a frequent comorbidity in these patients and contributes to poor medication adherence. Objective: The aim of this study was to elucidate the associations between adherence to lipid- and BP-lowering drugs, the diagnosis of depression, and the control of LDL-C and BP. Patients and methods: This study was conducted as multicenter, single-visit cross-sectional study in Germany. Adherence was assessed by the Morisky Medication Adherence Scale-8 (MMAS-8), and depression was assessed as documented in the patient chart. Results: A total of 3,188 ambulatory patients with hypercholesterolemia (39.8%), stable coronary artery disease (CAD; 7.4%), or both (52.9%) were included. Patients had a history of myocardial infarction (30.8%), diabetes (42.0%), were smokers (19.7%), and 16.1% had the investigator-reported diagnosis of depression. High or moderate adherence to lipid-lowering medication compared to low adherence was associated with lower LDL-C levels (105.5±38.3 vs 120.8±42.4 mg/dL) and lower BP (systolic BP 133.4±14.5 vs 137.9±13.9 mmHg, diastolic BP 78.3±9.6 vs 81.8±9.6 mmHg) and with a higher proportion of patients achieving the guideline-recommended LDL-C (16.9% vs 10.1%) and BP target (52.2% vs 40.8%, all comparisons P<0.0001). Adherence was worse in patients with depression. Correspondingly, patients with depression showed higher LDL-C levels, higher BP, and a lower probability of achieving the LDL-C and BP goal. Medication adherence correlated between BP- and lipid-lowering medications. Conclusion: Self-reported medication adherence can be easily obtained in daily practice. A low adherence and the diagnosis of depression identify patients at risk for uncontrolled LDL-C and BP who likely benefit from intensified care.