I’m 68 and had a CT heart scan two years ago that showed moderate calcium narrowing of my LAD (a/k/a widowmaker). I performed a nuclear stress test afterward and my cardiologist told me to ride as hard as I want. If you haven’t had a CT scan, I’d suggest it to quantify the degree of atherosclerosis.
Like Oldcrank, I’ve also moved away from the Ramp Test, which I think is too VO2 Max intense (and left me nauseous) and may not be the best measuring device for some 60+ cyclists. And I didn’t show any increase in FTP from RT. The Kolie Moore test takes longer but is more tolerable and yielded a nice bump in my FTP. (My experience: Kolie Moore's FTP test protocol - #535 by DavidWms)
If you use a PM, Intervals.icu provides an estimated FTP from your Strava data. I did a hilly, intense (97% IF) 23 miles yesterday, and Intervals bumped my eFTP 5 watts. In truth, I haven’t tested my FTP since last Fall so no doubt it’s declined some through my sporadic Winter training, and I think the Intervals eFTP is likely accurate.