the same MAP regardless of if heart rate is 100 and stroke volume
100 ml, or the heart rate is 50 and stroke volume
200 ml, the same is not true for pulse pressure (sys minus dia). While the first might have a blood pressure of 140/90 and a MAP of 105 mmHg, the latter may have a blood pressure of 180/70 and the same MAP.
Everyone have their unique stroke volume:pulse pressure ratio, depending on arterial compliance/stiffness. In general, a lower number may indicate higher arterial stiffness.