These two types of heart failure were previously thought to be equal in occurrence and risk of death, said Professor Rob Doughty, the NZ Heart Foundation Chair of Heart Health at the University of Auckland.
"However, our new findings reveal that the stiff heart muscle is less common than originally thought, affecting about three out of every 10 heart failure patients, and there is less risk of dying from this type compared with heart failure where the heart is not pumping properly."
Two percent of our population live with heart failure, and the study's findings provided greater accuracy about their risk of dying.
"Based on our new findings from this study, the global approach and treatment of patients with heart failure, based on measures of heart pump function, may need to be reviewed," Doughty said.
"This information will influence clinical thought and health-care planning of heart failure around the world, and provide more precise treatment."
Christchurch Heart Institute director Professor Mark Richards said the findings were "pivotal" to understanding occurrence, death rates and risk prediction within different classes of heart failure.
Richards won research funding and supervised the study in Singapore, where he was also director of the Cardiovascular Research Institute of Singapore.
Sixteen distinguished heart doctors and researchers had been involved, including Professor Carolyn Lam of the National Heart Centre in Singapore and Professor Richard Troughton of the Christchurch Heart Institute.
"We are particularly proud to have proven these findings, with identical procedures executed simultaneously in two countries, 5000 miles apart," Richards said.
Further, the researchers had demonstrated that the world's most successful-ever cardiac biomarker – named NT-proBNP and discovered and validated in the Christchurch Heart Institute – was a powerful indicator in both types of heart failure in both Singapore and New Zealand.
"Overall, this will exert major influence on clinical thinking and planning."
