How dangerous is a systolic pressure of 156 when i have 3 brain aneurysms, 2 of which are not coiled or clipped?

Risk is increased: Certainly your BP should be managed aggressively and patients are strongly encouraged to stop smoking as this clearly increases the risk of rupture.

Blood pressure: Your pressure shouldn't get higher, above present level risk rises.

That systolic BP: Is too high for anyone, and the presence of aneurysms carries an even higher risk. Please see your doctor and get your BP back down to appropriate levels.