Pulse Pressure
The gap between systolic and diastolic blood pressure is called pulse pressure, calculated as systolic minus diastolic blood pressure. 1
Definition and Calculation
Pulse pressure is mathematically defined as the difference between systolic blood pressure (SBP) and diastolic blood pressure (DBP), expressed as: Pulse Pressure = SBP - DBP 1, 2
A pulse pressure of 50-55 mmHg is commonly cited as the upper limit of normal in the general population, though no definitive cutoff values separating normality from abnormality at different ages have been established 1, 3
Clinical Significance
Pulse pressure reflects arterial stiffness and the compliance of large elastic arteries, with elevated values indicating advanced vascular damage, particularly in elderly patients 1, 3
In middle-aged and elderly hypertensive patients with cardiovascular risk factors, pulse pressure demonstrates strong predictive value for cardiovascular events 1
The predictive value is strongest after age 55-60 years, when pulse pressure becomes a more powerful cardiovascular risk marker than diastolic pressure alone 4, 5
Wide pulse pressure (>50-55 mmHg) independently predicts cardiovascular mortality and morbidity, particularly cardiac ischemic events such as angina, left ventricular hypertrophy, and coronary artery disease 3, 4
Age-Related Considerations
In younger individuals (aged <55 years), the contribution of pulse pressure to cardiovascular risk prediction is relatively small compared to systolic and diastolic pressures 1
As age increases, progressive arterial stiffening causes systolic pressure to rise while diastolic pressure falls or plateaus, resulting in widening pulse pressure 4, 6
This age-related arterial stiffening results from thinning and fragmentation of vascular elastin fibers combined with increased collagen deposition, reducing arterial compliance 3
Clinical Application Limitations
Pulse pressure should NOT be used as the primary basis for treatment decisions or blood pressure targets 1, 3
Classification of hypertension and treatment thresholds should continue to be based on systolic and diastolic blood pressure values, as these were the criteria used in randomized controlled trials demonstrating benefit 1
Pulse pressure is a derived measure that combines the imperfections of both systolic and diastolic measurements, making it less reliable as a standalone metric 1, 2
Practical Clinical Use
Pulse pressure may be used to identify elderly patients with isolated systolic hypertension who are at particularly high cardiovascular risk 1
In these high-risk elderly patients, a high pulse pressure serves as a marker of pronounced large artery stiffness and advanced organ damage 1, 3
Central (aortic) pulse pressure, which accounts for pressure wave amplification between peripheral arteries and the aorta, provides more precise cardiovascular risk assessment than brachial pulse pressure 1