Ms. De La Cruz also began contacting heart transplant centers to determine whether she could pay for the operation with donated money. Because Nevada has no heart transplant center, she contacted several medical centers in California and was told that without insurance, her brother would need to post a deposit of at least $150,000 to be evaluated and placed on a waiting list. The total cost for the transplant and subsequent hospital care, as well as antirejection drugs, would be nearly $1 million, payable in advance.

To exert public pressure and raise money, Ms. De La Cruz began sending out messages on Twitter, with daily tweets about her brother’s health, his dog, Chance, and the red tape she was trying to cut. She gained a following of more than 6,300 people, whom she began calling Eric’s Twitter Army.

The troops included Trent Reznor of the band Nine Inch Nails, which said it would award donors backstage passes and time with the band; the famed Tony Hawk auctioned autographed skateboards. Supporters bombarded Nevada legislators with calls, faxes and e-mail. The Medicare hearing was rescheduled, and by June, Mr. De La Cruz had won his long-awaited coverage, opening the door to a heart transplant center.

Elated, Ms. De La Cruz contacted U.C.L.A. Medical Center’s heart transplant program, but now the hospital insisted that her brother get a secondary insurance policy  even though Mr. Reznor told me the band raised nearly $1 million in less than two weeks. A hospital spokeswoman declined to comment on the case, citing patient privacy, but said the hospital “had been working with” the family.

Eventually, Ms. De La Cruz arranged for her brother to be seen by doctors at the University of Southern California Medical Center. There, he spent a week on the “high-priority transplant” list.

But his condition had deteriorated so much that he soon became too sick for the procedure. On July 4, Eric De La Cruz died, at age 31.

Ms. De La Cruz says a surgeon told her he could have helped her brother, but he arrived “two years too late.” If not for all the delays and denials, she says, her brother would be alive today.