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Original Contribution
Impact of Routine In-Hospital Assessment of Low-Density Lipoprotein Levels and Standardized Orders on Statin Therapy
in Patient
October 2005
Elevated cholesterol is a well-established major cardiac risk factor for the development of coronary artery disease (CAD). Multiple randomized controlled trials have clearly demonstrated that lowering low-density lipoprotein (LDL) levels with statin therapy significantly reduces overall mortality and major adverse cardiac events.1–4 This significant benefit also extends to patients undergoing percutaneous coronary intervention (PCI).4–7
Despite the recommendations of national guidelines and the overwhelming evidence, multiple quality assurance reviews have demonstrated suboptimal statin use in cardiovascular disease patients, with rates of statin therapy at the time of discharge reported as low as 26.5%, and only a minority of patients attaining ideal LDL levels.6,8–11 Considering that a large proportion of patients are not receiving statin therapy post-PCI, there is an urgent need to develop appropriate strategies to improve this treatment gap.
The safety of statin therapy has clearly been demonstrated in the literature.7,12 Standardized orders for CAD patients concentrating on in-hospital initiation of cardiovascular protective therapy significantly increased statin therapy at the time of discharge by 80%.13 Consequently, numerous organizations and national guidelines now support the in-hospital initiation of statin therapy as a method to increase treatment rates, improve patient compliance and decrease adverse clinical outcomes.14–16 Measurements of cholesterol profiles and the implementation of standardized orders for statin therapy at the time of PCI affords an excellent opportunity for optimizing a patient’s medication profile in an effort to improve cardiovascular morbidity and mortality.
The purpose of our study was to assess the impact of the implementation of routine cholesterol profile measurements and standardized orders post-PCI on the number of patients receiving statin therapy.
Methods
We conducted a prospective, observational study to determine whether the implementation of standardized post-PCI orders and the routine measurement of cholesterol profiles would result in an increase in the proportion of patients receiving statin therapy at the time of hospital discharge following their PCI procedure. The study population included all patients undergoing PCI at our institution from February 2002 to March 2003. The only exclusion criterion was in-hospital death. Patient baseline characteristics, statin therapy pre- and post-PCI, and fasting lipid profiles including LDL, total cholesterol (TC), high-density lipoproteins (HDL), and triglycerides (TG) were recorded as part of an ongoing PCI database. A similar cohort of patients undergoing PCI in the one-year time period immediately before the intervention was used as a comparison group. Implementation of standardized post-PCI orders began in February of 2002. The order form included instructions to obtain fasting lipid profiles on all post-PCI patients. For patients not already on cholesterol medication, statin therapy was initiated by a nurse clinician prior to discharge unless contraindications were present. For patients already on cholesterol medication, the dose of their current statin was doubled if the LDL was above recommended guidelines. If the patient was already at the maximum dose of a statin and continued to have a suboptimal cholesterol profile, the nurse clinician was asked to consult the cardiologist for further instructions.
Continuous variables were expressed as a mean ± standard deviation, and categorical data are displayed as frequencies and percentages. Chi-squared analysis was used for bivariate analysis of categorical data.
Results
From February 2002 to March 2003, 1,748 patients underwent PCI. Twenty-eight patients died in-hospital and thus were excluded from the study. Fasting lipid profiles were collected on 1,268 patients, or 75% of the total. In some cases, patients were transferred back to the referring hospital the same day, thus fasting levels could not be obtained.
The baseline characteristics of the patients are shown in Table 1. The mean age of patients undergoing PCI was 63, and 70% were male. The majority of patients had multiple cardiac risk factors including 68% with a history of hypertension and 25% with known diabetes. Approximately 74% of patients had previously identified hyperlipidemia at the time of PCI. Most patients had known coronary artery disease, with 62% having a history of previous myocardial infarction (MI). A total of 61% of the patients underwent previous heart catheterization with 20% of patients having undergone previous PCI.
For the 1,268 patients, the median total cholesterol was 3.92 with the 10th and 90th percentile values being 2.86 and 5.55, respectively (Figure 1). The median LDL value was 2.10 with the 10th and 90th percentile being 1.31 and 3.50, respectively. Seventy-eight percent of patients were already on statin therapy before PCI (Figure 2). As expected, the median LDL level was lower in this group compared to the median LDL level in the patients who were not previously on statin therapy (2.08 versus 2.40).
Overall, 30% of patients had an LDL level higher than the recommended Canadian guideline of 2.5 for high-risk or secondary prevention.17 Even among the group of patients already on statin therapy, 23% did not reach target LDL levels. More than two-thirds of patients had an LDL level greater than 1.6, which matched the mean LDL level of the atorvastatin–treated group in the PROVE-IT study.7
Figure 3 demonstrates statin therapy before and after the implementation of standardized orders. In the year before implementation of the standardized post-PCI orders, there was a 5% absolute increase in statin use after PCI compared to a 14% absolute increase in the following time period (p = 1–4 However, despite the compelling scientific evidence and the recommendations of national guidelines, the use of statin therapy after PCI remains suboptimal. We conducted a prospective observational study to determine whether the routine measurement of LDL levels and the institution of standardized post-PCI orders could increase utilization of lipid-lowering therapy.
Patients undergoing PCI at our center had similar baseline characteristics to patients studied in other large PCI registries. The mean age was 63 and most patients were male. Patients were at high risk for future cardiac events, with 62% having had previous MI, 61% with a history of previous heart catheterization, and more than 25% with a known history of diabetes. At baseline, 78% of our patients were on statin therapy. This contrasts with previously published data of patients undergoing PCI at university hospitals where only 26–48% of patients were on appropriate lipid-lowering therapy at the time of the intervention.6,8 The main reason for this difference is probably the fact that most of these registries were several months older and since then, a considerably greater body of evidence has emerged regarding the beneficial effects of statins. In addition, most of our patients were referred by cardiologists, while in other centers, a considerable proportion of the referrals may have been from primary care physicians who have been shown in a number of studies to prescribe statin therapy less frequently.18
The current Canadian Lipid Guidelines recommend an LDL value of less than 2.5 for secondary prevention.17 The optimal LDL level, however, is not yet known and the literature suggests that it may be much lower than the current recommendation. For example, the HPS study demonstrated that high-risk patients benefited from statins regardless of their baseline cholesterol value.4 The PROVE-IT study showed that patients presenting with ACS, the majority of whom underwent PCI, had better outcomes when treated with intensive lipid-lowering therapy compared to more moderate lipid-lowering therapy. In PROVE-IT, patients in the intensive therapy arm had a mean LDL level of 1.67. In our center, 77.7% of patients overall had an LDL value greater than 1.6, and thus were probably not on optimal statin therapy. In fact, 30% of all patients even had LDL values greater than the recommended level of 2.5 for high-risk and secondary prevention.
By routinely measuring LDL levels in all patients at the time of PCI and using standardized post-PCI orders, an overall 18% increase in statin therapy was accomplished. In the preceding 12 months prior to the intervention, there was only a 7% increase in statin therapy at the time of admission for PCI. The incremental rise in statin use from one year was statistically significant when using Chi-square analysis, with a p-value Limitations. Information relating to the type and dose of statin therapy was not collected. Follow-up information was not available regarding the effect of the intervention on clinical outcomes and postdischarge LDL levels. Since interest in aggressive lipid management grows yearly, it is possible that some of the improvements observed are the result of heightened sensitivity of the medical staff. As we have seen from previous studies however, heightened sensitivity does not necessarily translate into increased implementation of recommended guidelines.
Conclusions
Statin therapy reduces cardiovascular morbidity and mortality in patients undergoing PCI. Despite the overwhelming evidence, many patients are not on statins and a large number of patients have suboptimal LDL levels. We conclude that routine assessment of LDL levels and medications at the time of PCI results in a substantial increase in the use of lipid-lowering therapy. Further studies should be conducted to confirm this benefit at other centers, and to determine the effect on long-term clinical outcomes.
1. Randomized trial of cholesterol lowering in 4,444 patients with coronary artery disease: The Scandinavian Simvastatin Survival Study (4S). Lancet 1994;344:1383–1389.
2. Sacks FM, Pfeffer MA, Moye LA, et al. The effect of pravastatin on coronary events after myocardial infarction in patients with average cholesterol levels: Cholesterol and Recurrent Events Trial investigators (CARE). N Engl J Med 1996;335:1001–1009.
3. Prevention of cardiovascular events and death with pravastatin in patients with coronary heart disease and a broad range of initial cholesterol levels: The Long-Term Intervention with Pravastatin in Ischemic Disease (LIPID) study group. N Engl J Med 1998;339:1349–1357.
4. Heart Protection Study Collaborative Group. MRC/BHF heart protection study of cholesterol lowering with simvastatin in 20,536 high-risk individuals: A randomized controlled trial. Lancet 2002;360:7–22.
5. Serruys PW, de Feyter P, Macaya C, et al. Fluvastatin for prevention of cardiac events following successful first percutaneous coronary intervention. Lescol Intervention Prevention Study (LIPS): A randomized controlled trial. JAMA 2002;287:3215–3222.
6. Chan AW, Bhatt DL, Chew DP, et al. Early and sustained survival benefit associated with statin therapy at the time of percutaneous coronary intervention. Circulation 2002;105:691–696.
7. Cannon CP, Braunwald E, McCabe CH, et al. Intensive versus moderate lipid lowering with statins after acute coronary syndromes (PROVE-IT). N Engl J Med 2004;350:1495–1504.
8. Fonarow GC, French WJ, Parsons LS, et al. for the National Registry of Myocardial Infarction 3 Participants. Use of lipid-lowering medications at discharge in patients with acute myocardial infarction: Data from the National Registry of Myocardial Infarction 3. Circulation 2001;103:38–44.
9. Sueta CA, Chowdhury M, Boccuzzi SJ, et al. Analysis of the degree of under treatment of hyperlipidemia and congestive heart failure secondary to coronary artery disease. Am J Cardiol 1999;83:1303–1307.
10. Pearson TA, Laurora I, Chu H, et al. The lipid treatment assessment project (L-TAP): A multicenter survey to evaluate the percentages of dyslipidemic patients receiving lipid-lowering therapy and achieving low-density lipoprotein cholesterol goals. Arch Intern Med 2000;160:459–567.
11. EUROASPIRE II Study Group: Lifestyle and risk factor management and use of drug therapies in coronary patients from 15 countries. Principal results from EUROASPIRE II Euro Heart Survey Program. Eur Heart J 2001;22:554–572.
12. Schwartz GG, Olsson AG, Ezekowitz MD, et al. Effects of atorvastatin on early recurrent ischemic events in acute coronary syndromes: The Myocardial Ischemia Reduction with Aggressive Cholesterol Lowering (MIRACL) Study Investigators. JAMA 2001;285:1711–1718.
13. Fonorow GC, Gawlinski A, Moughrabi S, et al. Improved treatment of cardiovascular disease by implementation of a cardiac hospitalization atherosclerosis management program: CHAMP. Am J Cardiol 2001;87:819–822.
14. Smith SCJ, Blair SN, Bono RO, et al. AHA/ACC guidelines for preventing heart attack and death in patients with atherosclerotic cardiovascular disease: 2001 update. Circulation 2001;104:1577–1579.
15. Braunwald E, Antman EM, Beasley JW, et al. ACC/AHA guideline for the management of patients with unstable angina and non-ST segment elevation myocardial infarction: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2002;106:1893–1900.
16. Adult Treatment Panel III: Executive summary of the third report on the National Cholesterol Education Program (NCEP) expert panel on detection, evaluation and treatment of high blood cholesterol in adults. JAMA 2001;285:2486–2497.
17. Genest J, Frohlich J, Fodor G, McPherson R. Working Group on Hypercholesterolemia and Other Dyslipidemias. Recommendations for the management of dyslipidemia and the prevention of cardiovascular disease: Summary of the Canadian 2003 update. Can Med Assoc J 2003;169:921–924.
18. Steg, P, Goldberg, R, Gore, J, et al. Baseline characteristics, management practices, and in-hospital outcomes of patients hospitalized with acute coronary syndromes in the Global Registry of Acute Coronary Events (GRACE). Am J Cardiol 2002;90:358.
