Unfortunately the smoking, immobilization, maybe a little dehydration, and maybe sedentary lifestyle didn't help him. Long time pre-existing heart disease (narrowing of the coronary arteries was also likely present. Blood clots typically form in the lower or upper legs, break off and migrate quickly to either the heart (heart attack), lungs (pulmonary embolism), or brain (embolic stroke). None of those have good outcomes.
Moral of the story - smoking and other poor health choices put your life and health at risk in general, and in most case, in specific instances. Being less active physically (sedentary life style) is a huge risk but a problem for all of us as we get older - so keep walking at least 20-30 minutes a day beyond what you do now, engage in more active aerobic exercise if you can (pickleball, tennis, basketball, cycling, swimming, running, treadmill, etc.) that gets your heart rate up to at least 100-120 (see your doctor for specific recommendations) for at least 20 minutes a day, 3 times a week (yes, sex is also recommended, at least 20-30 minutes, 3-4 times a week, PM me for a written prescription you can give to your spouse, GF, or friend with benefits
) and help your spouse to remain just as active. You'll both be healthier, and possibly live longer, YMMV.
Also, watch the alcohol and other chemical intakes.
i am proper worn out thinking of doing those things .. yes i must get more active . 20 minutes walking might be a good start .. in the meanwhile i have been doing 1/4 or 1/2 an aspirin a day .. works wonders .