What Does An Ascending Aorta Affect Health?

Hi, I had an AVR done in December 2012. I was just diagnosed with an ascending aorta. The measurement is 4.1. In Decemebr 2013 it was 3.8. I was told by my doctor not to worry until it reaches 5.0. Should I be concerned? Sorry I didn t know I had to pay for this. Thanks anyway.