Community cardiology clinics for secondary prevention of coronary heart disease and heart failure in primary care

January 5, 2009

Coronary heart disease (CHD) and chronic heart failure (CHF) are common chronic conditions encountered in primary care. Studies have shown that despite a strong evidence base, these conditions are often poorly diagnosed and inadequately managed in primary care.

The chronic conditions of coronary heart disease (CHD) and chronic heart failure (CHF) are frequently encountered in primary care but often inadequately diagnosed and managed.1,2 The Community Cardiology Trial investigated the effects of a disease-management program in the primary care setting for patients with CHD, CHF, or both.

Subjects and methods

The study was a cluster randomized controlled trial involving 1316 patients at 20 volunteer practices in the United Kingdom. Participants were recruited from the primary care databases using medication and disease registers. Patients were included if they had a diagnosis of CHD (angina and past myocardial infarction [MI]) or CHF. Patients in the intervention practices were followed by peripatetic nurse specialists, trained to manage patients with CHD and CHF. The nurse practitioners reviewed the patients’ cases, arranged investigations to confirm diagnoses (eg, echocardiography) if they had not yet been confirmed, and initiated and titrated medications. The nurses also liaised with a hospital cardiologist and visited housebound patients. Patients who received a referral to the cardiologist underwent additional investigation as needed. Patients in the control group received usual care from their primary care physicians. All participating practices had access to echocardiography.

The 3 primary outcomes of the study were the proportion of patients with an MI who received a beta blocker, the proportion of patients with CHD whose serum cholesterol level was <5 mmol/L in the previous year, and the proportion of patients with left ventricular systolic dysfunction (LVSD) who received an angiotensin-converting enzyme (ACE) inhibitor. Secondary outcome measures included process of care, body mass index (BMI), and the proportion of patients with presumed CHF confirmed using echocardiography. Other outcome measures included a generic quality-of-life questionnaire (SF-36) and disease-specific questionnaires, including the Seattle Angina Questionnaire (for patients with angina) and the Left Ventricular Dysfunction (LVD-36) questionnaire (for patients presumed to have CHF). All participants were followed up for 12 months after randomization. Data were collected at baseline, at follow-up (from the primary care records), and from questionnaires completed by the participants.

Overall, the intervention and control practices were well matched in terms of size, level of deprivation, and practice development. A total of 1316 patients with CHD and CHF were recruited (intervention, 608; control, 708). Ineligible patients were excluded, leaving 1163 participants in the intention-to-treat analysis (intervention, 505; control, 658). The intervention arm had a higher proportion of men than the control group (68% vs 58%, respectively).

Results

At 12-month follow-up, significantly more patients with CHD in the intervention arm had undergone assessments of their blood pressure (odds ratio [OR], 22.6; 95% confidence interval [CI], 6.5-70.1), smoking status (OR, 34.0; CI, 14.5-79.6), and BMI or weight (OR, 10.1; CI, 5.0-20.6). Additionally, significantly more patients in the intervention arm had their blood pressure controlled to <140/85 mm Hg (OR, 1.6; CI, 1.2-2.1) and their cholesterol level managed to <5 mmol /L (OR, 1.6; CI, 1.1-2.4). Secondary prevention measures were prescribed for significantly more patients with CHD in the intervention arm compared with the routine arm, including lipid-lowering medication (OR, 2.0; CI, 1.1-3.7) and beta blockers (OR, 1.4; CI, 1.2-2.0). No significant differences were observed between the cohorts regarding the number of prescriptions issued for aspirin or ACE inhibitors. Significant reductions in risk factor control were observed in the CHD cohort after adjusting for baseline results: a 4.1-mm Hg (CI, 2.3-6.9) reduction in systolic blood pressure (CI, 2.3-6.9), a 3.5-mm Hg reduction in diastolic blood pressure (CI, 2.3-4.8), and a 0.2-mmol/L reduction in cholesterol levels (CI, 0.1-0.3). There was no significant reduction in BMI in patients with CHD.

In the group of 362 patients with presumed CHF, no statistical difference existed between the proportion of patients treated with renin-angiotensin-aldosterone system inhibitors and the proportion who received beta blockers. In the intervention arm, significantly more patients with an unconfirmed CHF diagnosis underwent echocardiographic examination (OR, 5.6; CI, 2.8-11.3). Significantly more patients in the intervention arm than the control arm had an LVSD diagnosis confirmed (adjusted OR, 4.7; CI, 1.9-11.7) or excluded (adjusted OR, 3.8; CI, 1.5-9.6) by echocardiography. In patients with a history of MI, significantly more in the intervention arm than the control arm had newly diagnosed LVSD confirmed via echocardiography (adjusted OR, 2.7; CI, 1.0-7.1).

At 12-month follow-up, an assessment of the SF-36 found that patients with CHD reported significant improvement in their quality of life (Table). Patients with angina enrolled in the intervention arm also reported significant improvement in their quality of life, compared with patients in the control arm; however, no significant differences were noted between the intervention and control arms in the SF-36 and LVD-36 scores for

patients with a confirmed diagnosis of LVSD.

Discussion

This is one of the largest trials to evaluate use of a primary care disease-management program for patients with CHD and CHF. This study shows that employing a specially trained cardiology nurse in a primary care setting to help manage patients with CHD significantly improves the care process and produces better intermediate outcomes. Intervention by the cardiology nurses also improved the rate of confirmation or exclusion of LVSD in those with an unconfirmed diagnosis of CHF. Generic and disease-specific quality-of-life assessments of patients with CHD also demonstrated improvement.

The current trial differs from previous studies in several ways. For example, this trial included patients with concomitant CHD and CHF, whereas other trials limited participation to patients with either CHD or CHF. Many patients with CHF whose condition is managed in a primary care setting have concomitant CHD; thus, this trial’s design more accurately reflects actual clinical care in a primary health care setting. Although only 36% of eligible patients agreed to participate in the intervention arm of the trial versus 53% who participated in the control arm, no major differences were observed between the 2 groups.

A previous trial randomized 1173 patients to undergo intervention at a clinic that employed primary care staff to promote the medical and lifestyle aspects of secondary prevention.3 Patients with CHD who received care at this clinic experienced health improvements and fewer hospital admissions.3 Another study that involved 1906 participants found that a patient recall system used by general and nurse practitioners improved intermediate outcomes more effectively than audit and feedback.4 A United Kingdom trial assessed the effects of having a specialist liaison nurse coordinate care for 597 adults with newly diagnosed MI or angina. The aim was to improve communication between the hospital and general practice and encourage nurse practitioners to provide structured follow-up. The intervention arm showed no significant improvement in health outcomes compared with the control arm.5

Prior studies involving patients with CHF have mainly enrolled patients discharged from a secondary care setting. A recent, large trial recruited patients with a confirmed diagnosis of symptomatic systolic dysfunction from large managed care centers and found that a disease-management program offered significant survival benefits.6

Conclusions

Using specialist cardiology nurses to administer disease-management programs can improve care for patients with CHD and presumed CHF in primary care. Although instituting a nurse-led disease-management program can increase costs, the benefits it provides suggest that it is actually a cost-effective strategy.

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Disclosure

The authors have no relationship with any commercial entity that might represent a conflict of interest with the content of this article.


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