Surveillance and treatment of dyslipidemia in the post-infarct patient: Can a nurse-led management approach make a difference?

Abstract

Lowering plasma lipid levels in patients in the months following hospital discharge for a myocardial infarction (MI) is clearly beneficial if recurrent cardiac events and mortality are to be prevented; traditionally, however, there has been a large gap between guidelines and levels achieved in routine practice. A randomized, open-label clinical trial was conducted to assess the impact of nurse-centred surveillance and treatment in achieving nationally recognized lipid targets in post-MI patients. This program had the following features: systematic telephone follow-up of patients discharged from the University of Sherbrooke (Sherbrooke, Quebec) after an MI; systematic lipid testing three months after discharge; close liaison with, and guidance of, patients' primary care physicians to intervene on results of this test if targets were not obtained; and continued monitoring of patients until lipid profiles consistent with consensus targets were achieved. The impact of this approach was tested and compared with that of a control group that continued to be followed by a primary care physician for up to 18 months. A total of 127 patients were randomly assigned into an intervention group (n=64) or a control group (n=63). The intervention group was followed by telephone for an average (+/-SD) of 4.4+/-2.0 months post-MI. At this point, when intervention was optimized, the mean low-density lipoprotein cholesterol (LDL-C) level was 2.19+/-0.65 mmol/L in the intervention group, and 87.3% of patients had LDL-C levels of less than 2.5 mmol/L. Patients from both experimental groups returned at 12 months and 18 months post-MI for a new blood lipid assessment. In total, 12.5% of patients in each group were lost to follow-up. At 12 months and 18 months, the mean LDL-C level was not different between the two groups, nor was there a significant difference in the proportion of patients achieving LDL-C levels of less than 2.5 mmol/L (51.6% in the intervention group and 65% in the control group at 18 months; P>0.05). When the combined end point of an LDL-C level of less than 2.5 mmol/L, a triglyceride level of less than 2.0 mmol/L and a total cholesterol to high-density lipoprotein cholesterol ratio of less than 4.0 was considered, the proportion of patients achieving this composite at 18 months was low and not different between the two groups (23.4% in the intervention group and 38.3% in the control group; P>0.05). Over 95% of patients in both groups were on a lipid-lowering medication, and more than 90% had complied with their medication regimen at 18 months. This trial did not support the role of nurse-managers and a system of telephone-based contacts to ensure the continuity of care and aggressive intervention when considering cardiovascular risk factors in post-MI patients. This trial also re-emphasized the important remaining treatment gap in secondary prevention of coronary artery disease, particularly if composite lipid end points are to be targeted.