Will sex aggravate a heart condition?

My uncle had a heart attack in 1994 with quadruple bypass surgery. He was told in 1996 that he had congestive heart failure (CHF) and needed a heart transplant but because he had chronic obstructive pulmonary disease (COPD), enphysemia and diabetes along with blood clots in his lungs he could not be put on the donor list. He is on Digoxin and Koreg plus Wafrin and Plavix. He takes Laxis for swelling about once a week. He has bad days, especially after yard work, but has always tried to live his life like is was his last. He will tell you he did not expect to live this long. He has never let some things bother him because he figured he would not live much longer anyway so why let it! I am taking care of him now and he is a great man! My question is, has there been cases of people with CHF to live longer than he has? I would like to hope that he has at least 5 more years or more. Is this possible? And he wants to know if having sex will prolong his life or shorten it? Thanks.