Guidelines for lipid-lowering therapy recommend intensive low-density lipoprotein (LDL) cholesterol lowering for patients with coronary artery disease. Previous studies have found that many high-risk patients are not achieving their LDL cholesterol goals, and many patients, despite being treated with lipid-lowering therapy, also have elevated triglycerides or low levels of high-density lipoprotein (HDL) cholesterol. To evaluate lipid goals in a “real world” clinical setting, the electronic medical records of 10,040 patients with coronary artery disease from a large cardiology subspecialty practice from September 2008 to September 2009 were reviewed. Overall, 79% of patients achieved an LDL cholesterol goal of <100 mg/dl, while only 35% achieved the more aggressive goal of <70 mg/dl. Non-HDL cholesterol goals of <130 and <100 mg/dl were achieved in 79% and 44% of patients, respectively. Only 69% achieved normal triglyceride levels, and only 63% of men and 56% of women achieved normal levels of HDL cholesterol. Women and younger men were less likely to achieve their lipid goals. In conclusion, most patients with coronary artery disease achieve the minimal LDL cholesterol goal of 100 mg/dl, but few achieve the more aggressive goals of <70 mg/dl. Many high-risk patients have elevated levels of triglycerides or low levels of HDL cholesterol despite treatment. Combination lipid-lowering therapy is used infrequently in practice. There exists a significant opportunity for physicians to more aggressively treat lipids to achieve the levels recommended by clinical guidelines.
Previous studies have found that many patients with coronary artery disease (CAD) are not achieving their minimal recommended low-density lipoprotein (LDL) and non–high-density lipoprotein (HDL) cholesterol goals, and few achieve normal levels of HDL cholesterol and triglycerides. More recent studies have found that even fewer patients with CAD are achieving an LDL cholesterol level <70 mg/dl and a non-HDL cholesterol level <100 mg/dl; however, most of these studies either evaluated patients shortly after the guidelines were updated in 2004 or focused only on LDL cholesterol goal attainment. The purpose of this study was to evaluate whether patients with CAD are achieving all their lipid goals in a current, “real world” clinical practice.
Methods
The study site was Cardiology Consultants of Philadelphia, a large cardiology subspecialty practice in the Philadelphia area. Using an electronic medical record, we identified 23,408 patients with histories of CAD who had been seen at 1 of our outpatient offices over a 12-month period from September 2008 to September 2009. Patients were excluded if they did not have a complete lipid profile in the electronic medical record flow sheet dated within the study period or within 6 months of their last office visit. In patients with >1 complete lipid panel, the most recent lipid panel was used. Age, gender, history of current cigarette smoking, type 2 diabetes, hypertension, current lipid-lowering medications, and patient demographics were extracted from the electronic medical record. The study was approved by the Institutional Review Board of Drexel University College of Medicine.
The primary outcome measures were the percentages of patients who achieved an LDL cholesterol goal of <100 mg/dl and a non-HDL cholesterol goal of <130 mg/dl and the percentages of patients who achieved an LDL goal cholesterol of <70 mg/dl and a non-HDL cholesterol goal of <100 mg/dl. Additional outcome measures included the percentage of patients with low levels of HDL cholesterol (defined as an HDL cholesterol level of <40 mg/dl for men and <50 mg/dl for women) and the percentage of patients with high triglycerides (defined as a triglyceride level of ≥150 mg/dl).
For statistical analysis, chi-square tests were used to test differences for categorical variables and Student’s t tests for continuous variables. Multivariate logistic regression analysis methods were applied to control confounding effects using the study outcomes (achieved vs not achieved) as the dependent variable and predictors of age, gender, cigarette smoking, body mass index, and diabetes as the independent variables. All data analyses were conducted using SAS version 9.1 (SAS Institute Inc., Cary, North Carolina). A 2-sided p value ≤0.05 was considered statistically significant.
Results
A total of 10,040 patients with CAD met the criteria for inclusion in the study. The clinical characteristics of the patients are listed in Table 1 . Among patients prescribed ezetimibe, 88% were also taking statins, while the remaining 12% were treated with ezetimibe alone. Among patients prescribed fibrates, 61% were taking fenofibrate, 23% fenofibric acid, and 16% gemfibrozil.
| Variable | Value |
|---|---|
| Age (years) | 71 ± 12 |
| Men | 6,650 (66%) |
| Women | 3,390 (34%) |
| Diabetes mellitus | 2,691 (27%) |
| Hypertension | 6,738 (67%) |
| Current smokers | 878 (9%) |
| Body mass index (kg/m 2 ) | 31 ± 6 |
| LDL cholesterol (mg/dl) | 82 ± 29 |
| Non-HDL cholesterol (mg/dl) | 109 ± 34 |
| Triglycerides (mg/dl) | 211 ± 129 |
| HDL cholesterol (mg/dl) | 39 ± 12 |
| Statin therapy | 8,727 (87%) |
| Pravastatin | 554 (6%) |
| Fluvastatin | 46 (0.5%) |
| Lovastatin | 466 (5%) |
| Simvastatin | 4,414 (44%) |
| Atorvastatin | 1,880 (19%) |
| Rosuvastatin | 1,367 (14%) |
| Ezetimibe therapy | 1,577 (16%) |
| Bile acid sequestrant therapy | 88 (0.9%) |
| Niacin therapy | 1,051 (11%) |
| Fibrate therapy | 914 (9%) |
| High-dose omega-3 fatty acid therapy | 88 (0.9%) |
Overall, 79% of patients achieved the LDL cholesterol goal of <100 mg/dl, while only 35% achieved the lower LDL cholesterol goal of <70 mg/dl. The distribution of achieved LDL cholesterol levels among the patients is depicted in Figure 1 . Women compared with men were less likely to achieve an LDL cholesterol goal of <100 mg/dl (73% vs 83%, p <0.001) and an LDL cholesterol goal of <70 mg/dl (31% vs 38%, p <0.0001). Multivariate predictors of not achieving an LDL cholesterol goal of <70 mg/dl included age <65 years (p <0.001), female gender (p <0.001), and obesity, defined as body mass index ≥30 kg/m 2 (p = 0.02). Among patients whose LDL cholesterol was >70 mg/dl, 51% were treated with simvastatin (average dose 42 mg), 22% were treated with atorvastatin (average dose 38 mg), and 16% were treated with rosuvastatin (average dose 19 mg). Only 11% of patients whose LDL cholesterol was >70 mg/dl were treated with bile acid sequestrants, and only 15% were taking ezetimibe.
With regard to non-HDL cholesterol, 79% of patients achieved a non-HDL cholesterol goal of <130 mg/dl, while only 44% achieved the lower non HDL cholesterol goal of <100 mg/dl. Among those patients with triglyceride levels >200 mg/dl, a non-HDL cholesterol goal of <130 mg/dl was achieved in 72% of patients and a non-HDL cholesterol goal of <100 mg/dl in 43%.
Overall, 85% of patients achieved triglyceride levels <200 mg/dl, while only 69% achieved normal triglyceride levels of <150 mg/dl. The distribution of the patients’ triglyceride levels is depicted in Figure 2 . Women were less likely to achieve optimal triglyceride levels than men (66% vs 70%, p = 0.0004). Multivariate predictors of not achieving normal triglyceride levels included age <65 years, female gender, obesity, current smoking, and diabetes (p <0.001). In patients with triglyceride levels >200 mg/dl only 28% were being treated with triglyceride-lowering medications. Among these patients, 18% were taking fibrates, 11% were taking niacin, and 2% were treated with high-dose prescription omega-3 fatty acids.
Overall, 63% of men and 56% of women achieved normal levels of HDL cholesterol. The mean value of HDL cholesterol for men was 36 ± 10 mg/dl and for women was 42 ± 14 mg/dl. The distribution of HDL cholesterol values for the patients is depicted in Figure 3 . Multivariate predictors of not achieving normal HDL cholesterol levels included female gender, obesity, current smoking, and diabetes (p <0.001) as well as age <65 years (p = 0.002). Women were less likely to achieve normal levels of HDL cholesterol than men (56% vs 63%, p <0.0001). Only 12% of patients with low HDL cholesterol were treated with niacin, and women were less likely than men to be treated with niacin (6% vs 16%, p <0.001).
