Blood pressure targets in high risk patients

In this article, the latest clinical trials are reviewed in an attempt to conclude what is the optimal blood pressure target for patients of cardiovascular (CV) events, such as heart attack or stroke.

Hypertension is defined as blood pressure higher than 140/90 mmHg at rest. The higher value is called systolic (SBP), whereas the lower is known as diastolic blood pressure (DBP). High blood pressure puts patients at an elevated risk for CV events. Current guidelines recommend blood pressure should be reduced to a SBP of less than 140 mmHg. The traditional belief has been that "lower is better", especially when it comes to patients at high risk of CV events (such as patients with diabetes, kidney disease or coronary artery disease). However, evidence to this effect is still controversial. Some studies have shown that very low SBP actually increases the risk of heart attacks and death.

In this review, the latest data from clinical trials is covered. The researchers review the benefits and harms of intensive blood pressure reduction in high risk patients.

Several of the trials reviewed here showed that an intensive reduction in blood pressure (SBP<130mmHg) in patients with coronary artery disease significantly reduces the risk of strokes compared to conservative blood pressure reduction. However, a SBP of less than 130 mmHg also showed a greater risk of heart attacks in these patients. This is especially true for patients who already had one or more heart attacks.

Another large trial reviewed here, examined the effect of intensive blood pressure reduction (SBP < 120mmHg) in type 2 diabetic patients. This trial failed to show any benefit on major life threatening events with intensive blood pressure lowering. These events included strokes, heart attacks and the overall number of deaths.

While blood pressure lowering is important in the prevention of heart attacks and strokes, caution is indicated when intensive therapy strategies are considered for high risk patients. Blood pressure targets should be considered individualy, taking into account the basic pressure, and risk factors of each patient. 

The trials reviewed here did not take into account additional medications taken by patients. These drugs (such as aspirin or cholesterol reducing medications) have a protective effect from cardiovascular events, and might have influenced the results. In addition, many of the trials reviewed here were funded by drug companies producing anti-hypertensive medications.

Consult with your doctor regarding your individual target blood pressure and how to reach it.