Secondary prevention clinics for coronary heart disease: four year follow up of a randomised controlled trial in primary care

Abstract

Objectives: To evaluate the effects of nurse led clinics in primary care on secondary prevention, total mortality, and coronary event rates after four years.

Design: Follow up of a randomised controlled trial by postal questionnaires and review of case notes and national datasets.

Setting: Stratified, random sample of 19 general practices in north east Scotland.

Participants: 1343 patients (673 intervention and 670 control) under 80 years with a working diagnosis of coronary heart disease but without terminal illness or dementia and not housebound.

Intervention: Nurse led secondary prevention clinics promoted medical and lifestyle components of secondary prevention and offered regular follow up for one year.

Main outcome measures: Components of secondary prevention (aspirin, blood pressure management, lipid management, healthy diet, exercise, non-smoking), total mortality, and coronary events (non-fatal myocardial infarctions and coronary deaths).

Results: Mean follow up was at 4.7 years. Significant improvements were shown in the intervention group in all components of secondary prevention except smoking at one year, and these were sustained after four years except for exercise. The control group, most of whom attended clinics after the initial year, caught up before final follow up, and differences between groups were no longer significant. At 4.7 years, 100 patients in the intervention group and 128 in the control group had died: cumulative death rates were 14.5% and 18.9%, respectively (P=0.038). 100 coronary events occurred in the intervention group and 125 in the control group: cumulative event rates were 14.2% and 18.2%, respectively (P=0.052). Adjusting for age, sex, general practice, and baseline secondary prevention, proportional hazard ratios were 0.75 for all deaths (95% confidence intervals 0.58 to 0.98; P=0.036) and 0.76 for coronary events (0.58 to 1.00; P=0.049) CONCLUSIONS: Nurse led secondary prevention improved medical and lifestyle components of secondary prevention and this seemed to lead to significantly fewer total deaths and probably fewer coronary events. Secondary prevention clinics should be started sooner rather than later.

Figure 1

Study profile

Figure 2

Kaplan-Meier survival plot for total mortality

Figure 3

Kaplan-Meier survival plot for coronary events (coronary death or non-fatal myocardial infarction)