The Snapshot ACS (acute coronary syndrome) Study is today released by the George Institute for Global Health, supported by a number of groups including the Cardiac Society of Australia and New Zealand.
More than 4000 people were surveyed in hospitals in New Zealand and Australia over two weeks in May, 2012.
Study leader Associate Professor Julie Redfern said the figures were not good, given the risk of other cardiac events happening later.
"It's not good enough that the majority of patients leaving hospital miss out on the most basic care they need to avoid repeat heart attacks down the line."
A breakdown of results showed a similar situation in Australia, with only 28 per cent of patients there receiving optimal preventive care before leaving hospital.
Forty-three per cent of Kiwi patients were given lifestyle advice - compared to 47 per cent in Australia - and 41 per cent of people here were referred to cardiac rehabilitation, compared to 48 per cent across the Tasman.
Auckland cardiologist Dr Chris Ellis, who works at Auckland City Hospital, said the latest audit indicated more needed to be done to ensure patients were fully informed.
"Essentially, it's a combined issue - the services have got to be in place, the hospitals have got to pay for rehabilitation nurses to run the services that we want patients to get."
Dr Ellis said there were a number of issues that sometimes did not allow medical staff to pass on all advice such as a shortage of staff or time.
"You can't expect patients to be given cardiac rehabilitation unless you've got someone to give it to them. Right across New Zealand and Australia, this has been a reminder that those need to be put in place.
"If we can get those services in place and you can use the medications and the education for patients who've had a heart attack, they will do better long term."
Ministry of Health statistics show that cardiovascular disease - which includes heart, stroke and blood vessel diseases - is the leading cause of death in New Zealand.
The Heart Foundation said optimal care was crucial as many cardiac patients went on to have a second, third and even fourth heart attack.
Manager Kim Arcus said: "We look forward to hospitals using this data to help improve the care provided."
After triple bypass, father takes health tips seriously
Last month, Peter Ingham's life changed forever.
The 57-year-old had come inside after working on his rural property in Warkworth, north of Auckland, and was on the phone to his father when an odd feeling came over him.
Peter Ingham is grateful for the information hospital staff have given him since his heart attack.
"As soon as I hung up, I felt a pain in my arm. I thought it was weird but maybe because I'd been doing a lot of digging ... and then I felt a tightness of the chest. Not longer after that we called the ambulance."
The father of four - who has never had high cholesterol or blood pressure problems - had suffered a heart attack.
He has spent the past few weeks in hospital and last week had a triple bypass operation. He said the experience had opened his eyes to his health.
Since he had been admitted - first to North Shore Hospital and then to Mercy Ascot - he had been given "loads of information".
"They've given me literature on how to get my fitness back over the recovery period. I have to do a bit of walking, I've got rehabilitation and they want my wife here with me too."
Mr Ingham said he particularly appreciated hospital staff's willingness to give him as much information as they could, given he had never had cardiac problems in the past.
"All the information they're giving me, I'm really taking to heart - pardon the pun. I want to hang around for as long as I can."
The advice
What you should be advised on after suffering a heart attack
*Lifestyle advice - healthy eating and the importance of keeping active. Smokers advised on the importance of giving up.
*Referral to a preventive service like cardiac rehabilitation.
*When discharged from hospital, patients should be on at least four kind of medications (most people have five).
The stats
26% of cardiac patients in NZ received optimal care (given all advice that should be given to patients).
41% were referred to a cardiac rehab facility.
43% were given lifestyle advice.
74% were discharged with at least four kinds of medication.