Annan was an ironman, a marathon swimmer and had completed around 15 Round Taupo cycle races when in 2015 he unexpectedly had a heart attack which killed part of his heart tissue.
"I thought I was recovering when, in early 2017, I was referred for a heart transplant because my heart had given up the ghost and I deteriorated pretty quickly. In September 2017, I managed to get a donor heart and off we went again.
"What you end up with is a new normal," he said, of the daily medication and diet schedule. "But it's wonderful to get a second chance and I am very, very thankful to donors and the donor family that makes the decision.
"Most people think, if they put donor on their driver's license that that is it, but that's not the case at all. It's up to the next-of-kin whether they consent or decline.
"A lot say no initially and then come back and say they've changed their mind and agree to it, but it's often too late by then because you have a six-hour timeframe for a heart from the time a machine is turned off. It's a big logistical exercise."
Annan set himself a goal to enter Auckland's Bike the Bridge event in February after his transplant and, at this event, his wife Pauline Mills won an electric bike.
"I was a bit dubious at first, calling it a cheating bike, but with the e-bike I found I could do a whole lot of stuff I otherwise couldn't do."
He cycles 30km return from work three days a week and 80km to 100km on the weekend, to a total of 200km a week.
Several competitors in the K2 cycle race have survived life threatening illnesses and were competing at the Coromandel race. Others, such as group of 27 from the BNZ, used the event to fundraise for causes such as cancer research. The BNZ staff raised $44,000 for this cause.
Craig Brant is another heart transplant recipient who completed the event - in the K1 division which is 100km.
The 17th Flight Centre K2 Road Cycle drew 1050 riders including more than 50 who completed the circuit around the Coromandel Peninsula twice. Known as the K4, riders started pedalling at 10pm Friday and most did not finish until late on Saturday in Coromandel Town.