Cox, 24, told the Daily Mirror that she had been dancing with a friend who complained of faintness and then collapsed.
Kylie, a nurse, kneeled down in her wedding dress and gave the man CPR until the paramedics arrived.
“Then me and [my husband] Russell spent the first night of our marriage at the hospital, because we didn’t know whether our friend was going to live or die," Cox said of the harrowing ordeal.
Kylie and Russell said they plan to hold a make-up wedding reception in the future.
2014: The Year in Music [PHOTOS]