How Tight Should Hypertension Control in CAD Be? - A Review

It is well proved that hypertension (HTN) is a risk factor for coronary artery disease (CAD), heart failure, and stroke. It is a more powerful risk factor for acute myocardial infarction (MI) than diabetes mellitus (DM) as per data from INTERHEART study. High BP accelerates atherosclerosis and destabilizes vascular lesions and precipitates acute coronary syndromes (ACS).[1] Risk of having a fatal coronary event doubles for every 20/10 mm rise in blood pressure (BP). Hypertensive heart disease with the left ventricular hypertrophy (LVH) has impaired coronary autoregulation and reduced coronary flow reserve causing ischemia with normal coronary arteries (INOCAs). In this context, it is logical to assume that control of BP should reduce coronary risk. However, there are differing opinions on how much to reduce BP and what target to keep. Is lower the better? Are there any concerns if BP is lowered beyond a limit? This review tries to address these concerns and zero in on a target value to achieve for systolic BP (SBP) and diastolic BP (DBP) in hypertensive with CAD. Current ACC/AHA guidelines[2] recommend a blood pressure target of <130/80 mm of Hg in hypertensive with relaxation up to <140/80 mm of Hg in the elderly. The core practical concern is that attempts to lower SBP below 130 mm of Hg often lower DBP to levels as low as <60–70 mm of Hg, which may be harmful in CAD. Framingham study showed that low DBP and wide pulse pressure increase cardiovascular events.