Incident heart failure hospitalisations have increased over the past 15 years in an Australian cohort, while 1-year mortality rates are coming down.

But it is the skew in demographics toward younger patients that has researchers and clinicians concerned.

The study analysed data for 22,476 WA residents 25-94 years of age with a first-ever heart failure hospitalisation between 2001 and 2016.

Prevalent comorbidities (>20%) included AF, hypertension, IHD, valvular heart disease, CKD, cancer, and diabetes.

Published in the International Journal of Cardiology, the results showed incident HF hospitalisation rates rose 7-fold or more with each higher age group 25-54 years, 55-74 years and 75-94 years.

Age-specific rates in both men and women were initially stable or falling, but increased from around 2006 onwards, most notably in the 25-54 years age group.

“The overall age and sex standardised rates of incident HF increased slightly by 0.6% per year (95% CI, 0.3, 0.8; p<.0001) over the entire study period.”

“However, those in the 25-54 year age group demonstrated an average 3.1% (95% CI, 2.2, 4.0) annual increase (trend p<.0001) compared to an average 0.8% (95% CI, 0.3, 1.3; p=0.003) annual increase in the 55-74 year age group and no significant change of -0.02% per year (95% CI, -0.3, 0.4; p=0.93) in the 75-94 year age group.”

The study found 21.8% of patients died within 1-year after incident HF hospitalisation. Most deaths (78.1%) occurred in patients aged 75-94 years.

“The proportion of overall deaths that were cardiovascular disease related decreased from 60.8% (n=160/263) in 2001 to 47.0% (n=190/404) in 2016 (trend p<0.001).”

“Overall, age and sex standardised 1-year mortality rate (per 100 person-years) declined from 23.1 (95% CI, 20.3, 26.0) to 19.6 (95% CI, 17.7, 21.5) between 2001-2016, an annual decline of 1.0% (95% CI, – 0.4, -1.6; p=0.0008).”

The study authors said the finding of rising incident HF hospitalisations was consistent with other studies in Western countries including Denmark, Sweden and Canada.

“This adverse trend is of concern because the increase in HF incident rates in the younger age groups along with an ageing and increasing population in the same high-income countries and declining mortality rates portends to an ever increasing HF burden in the future.”

Lead author, public health researcher Courtney Weber from the University of Western Australia, said the underlying causes for the increasing HF hospitalisations was not clear.

However she noted that young patients who develop HF were also more likely to be obese.

“The prevalence of diabetes mellitus in our HF patients under 55 years was much higher (~28%) than the estimated 4.5% population rate of diabetes mellitus in Australians age 45-54 years, which again emphasises the increasing importance of obesity and diabetes mellitus as population-attributable causes for HF.”

Indigenous Australians were significantly overrepresented in the HF cohort under 55 years of age – 20% compared to 4.5% in the overall cohort.

“Better prevention strategies that focus on comorbidity and lifestyle factors, while considering socio-economic, familial, cultural and historical factors, may be the key to reducing HF in Indigenous Australians,” the study authors said.

Risk factors 

Cardiologist and coauthor Emeritus Professor Joe Hung told the limbic it was concerning to see new cases of hospitalised HF increasing among young people.

“Hospitalised cases are probably just a reflection of the more severe cases …so the concern would be there are more milder cases unrecognised out in the community,” he said.

“But it’s also possible that, particularly with echocardiography as an early diagnostic tool, they are being recognised early.”

Professor Hung said early detection and early intervention to address their risk factors promised a better prognosis in the younger age group.

“What the literature is showing and our data does confirm is that obesity and diabetes rates are much higher than you would expect in the general population.”

“These are the two risk factors which are probably changing in Australia and most Western countries and we think that there is pretty good evidence now linking them to the development of heart failure at a younger age group than previously.”

He said the message has to be to the whole community to lose weight.

“A lot of things arise from the obesity phenomenon. I’d like clinicians to be thinking of this because we all play a role in counselling patients but clearly it is very important from a public health point of view.”

He said it was important to detect HF at any age because there were plenty of good evidence-based therapies.