What is more alarming in an older adult, a high systolic blood pressure or a high diastolic blood pressure?

High Systolic Blood Pressure is More Alarming in Older Adults

In older adults, elevated systolic blood pressure is significantly more concerning than elevated diastolic blood pressure and should be the primary focus of cardiovascular risk assessment and treatment. 1

Age-Related Blood Pressure Patterns

After age 60, systolic blood pressure continues to rise while diastolic blood pressure typically plateaus or decreases, making isolated systolic hypertension the most common form of hypertension in this population. 1 By age 60, isolated systolic hypertension affects more than half of Americans over age 65. 1

• In the Framingham Heart Study, systolic blood pressure alone correctly classified blood pressure stage in 94% of adults over 60 years old, while diastolic blood pressure alone correctly classified only 66%. 1
• Both systolic and diastolic blood pressure increase linearly up to the fifth or sixth decade of life, after which diastolic blood pressure gradually decreases while systolic blood pressure continues to rise. 1

Cardiovascular Risk Prediction

Systolic blood pressure is a superior predictor of cardiovascular events compared to diastolic blood pressure in older adults. 2

• Each 20 mmHg increase in systolic blood pressure doubles the risk of fatal coronary events. 1
• The risk of cardiovascular disease increases in a log-linear fashion from systolic blood pressure levels <115 mmHg to >180 mmHg. 3
• In meta-analyses comparing systolic and diastolic blood pressure readings, systolic blood pressure has consistently been a better predictor of cardiovascular risk. 2
• Isolated systolic hypertension predicts cardiovascular risk better than isolated diastolic hypertension. 2

Pulse Pressure as an Integrated Risk Marker

The widening pulse pressure (systolic minus diastolic) that occurs with aging reflects arterial stiffening and provides additional prognostic information. 1

• In subjects over 60 years old, increased pulse pressure summarizes and integrates the adverse prognostic value of elevated systolic blood pressure and low diastolic blood pressure. 4
• A 60-year-old with blood pressure of 150/90 mmHg has lower cardiovascular risk than someone with 150/50 mmHg, despite identical systolic values. 4
• The greatest practical concern is the undertreatment of systolic hypertension. 2

Treatment Evidence and Targets

Multiple large intervention trials have demonstrated substantial cardiovascular benefit from treating isolated systolic hypertension in elderly patients. 5

• The American College of Cardiology recommends a systolic blood pressure treatment goal of less than 130 mmHg for ambulatory community-dwelling adults ≥65 years with isolated systolic hypertension. 1
• Treatment of isolated systolic hypertension reduces cardiovascular events to a similar degree as treatment of combined systolic-diastolic hypertension. 5
• There are no treatment studies demonstrating benefit from treating isolated diastolic hypertension. 2

Clinical Implications for Diastolic Blood Pressure

While systolic blood pressure is the primary concern, excessively low diastolic blood pressure warrants attention. 6

• Evidence was insufficient to determine the benefit of treating diastolic hypertension in the absence of systolic hypertension. 3
• Most trials assessed treatment outcomes based on systolic blood pressure, and no trials included patients with mean diastolic blood pressure >90 mmHg and mean systolic blood pressure <140 mmHg. 3
• Marked diastolic hypotension should be avoided during treatment, as it may compromise coronary perfusion, particularly in patients with coronary heart disease. 6

Critical Pitfalls to Avoid

• Do not focus solely on diastolic pressure in older adults when systolic pressure is the more important risk factor after age 60. 1
• Do not withhold treatment based on age alone—evidence shows benefit of treatment even in patients over 80 years. 1
• Do not ignore isolated systolic hypertension because diastolic blood pressure is normal; this represents significant cardiovascular risk requiring treatment. 1
• Monitor for orthostatic hypotension during treatment, which is more common in older adults. 1