The pensioner had just sold his home and put the pain in his chest and arm down to a pulled muscle from moving boxes.
But by the time he arrived at Curry's house at 6.45am Rendle was worse for wear, backing over the lawn and only just missing the fence three times.
Inside, Curry instantly knew something was amiss as Rendle "looked pinched" and continuously rubbed at his chest.
Curry, 71, who has played bowls with Rendle since she was 16 and said he is like a big brother to her, suggested the symptoms could be a heart attack but Rendle was unconvinced.
"I was hot and sweaty. I had pain up the left arm which was not normal. My chest was heaving a bit. But I just wanted my breakfast."
He and Curry's husband Joe dismissed the idea but Curry stuck to her instincts and ordered Rendle into the car.
"He kept pulling faces with the pain. A pulled muscle is more a constant pain I thought," Curry said.
She drove him to Waikato Hospital's emergency department where nurses immediately began tests.
When the pain suddenly intensified Rendle realised Curry had been right. A Catholic, Rendle tried to say a Hail Mary as he began losing consciousness.
As her friend was rushed to resuscitation Curry called Rendle's wife, Ingrid, in Raglan to break the news.
"When they go into resus [on Shortland Street] it's serious so I panicked."
Ingrid, 68, a former nurse, rushed to the hospital where Rendle underwent immediate surgery to insert a stent into an artery that was 90 per cent blocked.
A second stent could not be inserted into another artery that remains 50 per cent blocked and Rendle is not allowed to drive, over-exercise, travel, do any heavy lifting, or have sex for the next few weeks at least.
Rendle, a father-of-four, said it was only a family history - his father and brother died of heart attacks and two sisters already have stents - that predisposed him to heart problems.
Otherwise, as a non-smoker with normal weight, cholesterol, blood pressure, diet and a person who exercises regularly, Rendle was not a likely candidate.
He and Curry said the Heart Foundation ad urging Kiwis to put aside their "she'll be right attitude" and call 111 if they suspect they or another person is having a heart attack had put the symptoms in the forefront of their minds and was crucial in Curry recognising the situation.
The advertisement was launched five days before Rendle's heart attack.
Heart Foundation medical director Dr Gerry Devlin, who treated Rendle, said many New Zealanders were placing themselves at increased risk of death or permanent heart damage by ignoring warning signs.
Devlin, an interventional cardiologist at Waikato Hospital, said it was vital people acted with urgency if they suspected a heart attack.
"Speed is critical. When a heart attack happens, life-threatening rhythm problems are common. Early access to a defibrillator is really important to save lives."
He said any delay in calling an ambulance can increase the risk of death or permanent damage to the heart.
Devlin said many deaths could be prevented if people recognised the symptoms and called 111.
Heart of the matter
• Heart attacks are New Zealand's biggest killer, claiming more than one life every 90 minutes.
• An attack happens when blood stops flowing to part of the heart.
• Symptoms typically include chest discomfort lasting 10 minutes or more; pain that spreads to the jaw, shoulders or back; sweating; shortness of breath; and nausea.
• Women can also experience other less obvious symptoms including discomfort in the upper back; nausea; sweating; and unusual fatigue.
• Risk factors include smoking, high cholesterol, high blood sugar (diabetes), high blood pressure, weight, physical inactivity, diet, mental health and wellbeing.
