When the heart’s function is impaired and it can no longer pump blood in sufficient quantities through the body (heart failure), its effects on human health and longevity were held to be equally dire, irrespective of how the heart malfunctioned.
This was the decade-long accepted view in the medical field regarding two kinds of heart failure, which were thought to be similar in prevalence and clinical outcomes.
Now, a joint study led by researchers from New Zealand and Singapore has shown that ‘how’ the heart malfunctions has very distinct implications for patients’ prognosis and survival.
The research, recently published in the European Heart Journal, was based on a 7-year collaborative study of 2039 patients from both Singapore and New Zealand. The study focused on two classes of heart failure.
In one type, the heart muscles were weakened and their pumping power was affected, thereby reducing the volume of blood pumped out (called HFrEF for heart failure with reduced ejection fraction). In the other, the walls of the heart were thickened, and the heart couldn’t fill properly with incoming blood between beats, though the pumping function was near normal (HFpEF or heart failure with preserved ejection fraction).
Previous research on heart failure has been contentious, with survival outcomes predicted to be the same for both types. However, the current multi-ethnic cohort study demonstrated that patients with HFpEF are more likely to have better survival and health outcomes. The incidence of HFpEF is also lower than was previously thought.
These findings show that the approach and treatment of patients with heart failure will need to be revised, here and in other parts of the world.
“This information will influence clinical thought and health-care planning of heart failure around the world, and provide more precise treatment,” said Professor Rob Doughty, the NZ Heart Foundation Chair of Heart Health at the University of Auckland.
“Our 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.”
In Singapore, nearly 1 out of 3 deaths is due to either heart disease or stroke. In New Zealand, two percent of the population is living with heart failure.
Professor Mark Richards, Joint international leader of the study and Director of Singapore’s Cardiovascular Research Institute of the National University Health System of Singapore, says, “Our findings are pivotal to the understanding of the occurrence, death rates and risk prediction within different classes of heart failure.”
“We are particularly proud to have proven these findings, with identical procedures executed simultaneously in two countries, 5000 miles apart.”
The study also underscored that the most successful global cardiac biomarker- NT proBNP (which was found and validated in the Christchurch Heart Institute)- was a powerful prognostic indicator in both types of heart failure.
Professor Richards, who is also Director of Christchurch Heart Institute and Heart Foundation Chair of Cardiovascular Studies in New Zealand, concludes that “Overall, this will exert a major influence on clinical thinking and planning.”