Multiple risk intervention trial in high risk hypertensive men: comparison of ultrasound intima‐media thickness and clinical outcome during 6 years of follow‐up
Authors: Agewall S. , Fagerberg B. , Berglund G. , Schmidt C. , Wendelhag I. , Wikstrand J. ,   FOR THE RISK FACTOR INTERVENTION STUDY GROUP, SWEDEN
Published: March 2003

Abstract. Agewall S, Fagerberg B, Berglund G, Schmidt C, Wendelhag I, Wirkstand J, for the Risk Factor Intervention Study Group (Sahlgrenska University Hospital, Göteborg University; Lund University, Malmö; Sweden). Multiple risk intervention trial in high risk hypertensive men: comparison of ultrasound intima‐media thickness and clinical outcome during 6 years of follow‐up. J Intern Med 2001; 249: 305–314.

Objectives. The objective was to analyse whether a favourable change in risk factors, caused by a comprehensive risk factor modification programme, affected intima‐media thickness (IMT) in the common carotid artery, and whether any such change was associated with a change in cardiovascular events during a 6‐year follow‐up.

Design. Patients were randomized 1 : 1 to special intervention or usual care.

Setting. Hypertension Unit at university hospital.

Subjects. A total of 164 patients were randomized. Inclusion criteria were male, aged 50–72 years (at randomization) and one or more of the following: Serum cholesterol level > 6.5 mmol L–1, smoking or diabetes mellitus. All patients were prescribed antihypertensive treatment since many years. In 142 men good quality ultrasound recording of the common carotid IMT were achieved at baseline, 119 were re‐examined after 3.3 years, and 97 patients were available for examination after mean follow‐up time of 6.2 years. Cardiovascular events were available for all randomized patients.

Interventions. The nonpharmacological special intervention programme was based on one information meeting followed by five weekly 2‐h sessions with participation of patients and spouses. The diet recommendations were similar to established guidelines. Overweight patients were instructed to lose weight, and diabetic patients were systematically taught self‐monitoring of blood glucose. Smokers were invited to a smoking cessation programme with five weekly meetings. Follow‐up visits were thereafter scheduled every 6 months. Lipid lowering drugs were recommended in the intervention group if the treatment goals using nonpharmacological measures were not achieved. Patients in the usual care group were told to quit smoking and to lower their consumption of fat and glucose. Antihypertensive treatment (i.e. selection of drugs) was on purpose kept similar in the two groups.

Main outcome measures. The IMT of the common carotid artery as measured by ultrasound. Cardiovascular events during follow‐up.

Results. Significant net reductions were seen for serum cholesterol, triglycerides, fasting glucose and smoking. No difference in change in IMT was observed during follow‐up between the two randomization groups. The explanation was that patients with positive plaque status at baseline had a much larger increase in IMT over time than patients with negative plaque status, and that patients with positive plaque status more often survived and were available for re‐examination after 6 years in the intervention group than in the usual care group. Total mortality was lower in the intervention group, compared with the usual care group, 13 and 29%, respectively (P=0.028).

Conclusions. In high risk populations, long‐term studies with surrogate endpoints may be misleading because of missing data in patients where a large increase in IMT would have been observed, had they been re‐examined. Another important conclusion from our study was that the gloomy prognosis for this patient category may be improved by a dedicated risk factor intervention programme. The improved prognosis was observed mainly in those patients at highest risk judged from history of cardiovascular disease or positive ultrasound plaque status at baseline.