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A five-year follow-up of 18 403 male British civil servants between the age of 40 and 64, who had been the subject of an earlier clinical survey found 277 deaths from coronary heart-disease (C.H.D.). After adjusting for age, current cigarette smoking, systolic and diastolic blood-pressure, and blood-cholesterol were shown to be related to both the prevalence of one or more indices of cardiac ischaemia and to the risk of cardiac death. Neither blood-glucose two hours after a 50 g load nor weight/height showed any such simple linear association with mortality. Multivariate analysis confirmed that the main risk factors were independently related to cardiac morbidity and mortality. Irrespective of blood-pressure or plasma-cholesterol, current cigarette smokers thus had a higher risk of C.H.D. death than those not smoking cigarettes.

A screening examination including an electrocardiogram (limb leads only) coded by the Minnesota Code, using rigorous quality control was done on 18 403 male civil servants aged 40 to 64. The association of the findings with coronary heart disease has been tested in relation to age trends, symptomatic history, and coronary heart disease mortality rates in the ensuing five years. The results were positive for Q waves, left axis deviation, ST depression, and T wave changes (including minor T wave items as an isolated finding), ventricular conduction defects, and atrial fibrillation; but they were generally unimpressive for increased R amplitude and for lengthening or shortening of the PR interval, QT interval duration, premature beats, and extremes of heart rate. The prognosis of specific electrocardiographic findings discovered at screening is quite different from when they arise in clinical practice. Among the 6 per cent of men in this study with patterns suggesting ischaemia, the subsequent coronary heart disease mortality was little more than 1 per cent per year; and among those who were symptom free it was even less.

Mortality follow-up is now complete for 5 years in the 18 403 male civil servants aged 40-64 who were examined between 1967-69 in the Whitehall Study of British civil servants. During this period, 277 of them died of coronary heart-disease (C.H.D.); half of these deaths were in subjects in whom the findings at initial screening had suggested early myocardial ischaemia (angina or history of possible infarction according to standard questionnaire, or electrocardiographic evidence of ischaemia). The finding of suspect ischaemia had greater predictive power than the "primary" coronary risk factors, from which it was generally independent. At each level of the primary risk factors, the risk of death from C.H.D. was much greater in the presence of suspect ischaemia; and, with the possible exceptions of glucose tolerance and physical activity, the main risk factors still operated even at the stage of early ischaemia. These findings have implications for future studies of the effects of intervention.