I am 74 old, 73 in. tall, 4.8cm ascending aortic aneurysm, with bicuspid aortic valve, when should it be repaired?

Need careful: Evaluation and follow up care by your surgeon , 74 is not considered very old , but your functional status , associated systemic diseases will play in decision for surgery , most likely your you are asymptomatic and aneurysm is stable , you are under observation , follow your doctors advise

Variable recs: Recommendations continue to evolve. If your aorta grows more than 0.5 cm/yr->operate. If your aorta is over 5.5 cm->operate. If you have other risk factors, maybe operate at 5.0 cm. Control your blood pressure, use beta-blockers. A very important corollary to these recommendations is to choose your surgeon carefully. Some surgeons have much better outcomes than others.

Valve is problem: Aneurysm is small and secondary to turbulant blood flow across the abnormal valve. Bicuspid valves generally begin to calcify in the 5th and 6th decades of life leading to Aortic Valve stenosis. You should have a cardiologist and get annual echocardiograms and when the gradient across the valve is > 40mmHG and you have symptoms the valve should be replaced. Tx of aneurysm unnecessary at that size.

Expansion: Agree with Dr. Sheppard and would add that you need evaluation to know the rate that the aneurysm is growing as that may also influence timing of intervention.