INFLUENCE OF MULTIPLE RISK-FACTORS ON THE HAZARD OF HYPERTENSION

Atherosclerosis and coronary artery disease (CAD) are now the commonest sequelae of hypertension and all clinical manifestations of CAD occur in excess in persons with elevated blood pressure. Risk increases in relation to the extent of blood pressure elevation whether this is in the systolic or diastolic component, at any age and in either sex. Even isolated systolic hypertension increases cardiovascular risk. Elevated pressures are often accompanied by lipid abnormalities, hyperglycemia, elevated fibrinogen, obesity, and ECG abnormalities, all of which augment the risk. These risk factors associated with hypertension influence the coronary risk potential more than the nature of the blood pressure elevation. Although blood pressure makes an independent contribution to CAD, the risk at any level of pressure is markedly influenced by the cardiovascular risk profile. In mild to moderate hypertension in particular, the risk of CHD is concentrated in those who have impaired glucose tolerance, increased total/HDL ratio, ECG abnormalities, and smoke cigarettes. One or more of these associated risk factors also predisposes to other cardiovascular sequelae of hypertension, including stroke, peripheral vascular disease, and cardiac failure. The presence of organ involvement indicated by proteinuria, evidence of impaired ventricular function, or left ventricular hypertrophy greatly escalates the risk and usually indicates a compromised coronary circulation. Most myocardial infarctions and sudden deaths occur prior to the appearance of such evidence. Hypertensive risk assessment requires consideration of the multivariate risk profile because of the interdependence of the risk factors. The nature and urgency of treatment is better determined from such a risk profile than from the blood pressure parameters alone. Optimal preventive management of hypertension requires more than normalization of the blood pressure if coronary sequelae are to be avoided.