Based on the best available evidence, this report describes the annual burden of hospital admissions linked to a primary diagnosis of cardiovascular disease (CVD) and heart failure through the prism of Seasonality. On this basis, the authors describe the differential burden of disease across Australia according to the four distinct seasons that most Australians are exposed to.

Key findings:

• Despite living on a continent where icy conditions and snow are rare, paradoxically, Australians are vulnerable to weather extremes; particularly exposure to Winter weather conditions.
• Although almost every Australian is at risk of experiencing Seasonality, key contributors to this phenomenon are poor lifestyle choices, pre-existing CVD, older age, exposure to climate extremes and/or high levels of pollution and fewer economic resources to maintain thermoregulatory control.
• Compared to lower levels of hospitalisation during Summer, overall, there is a 32% increase in the number of hospital admissions linked to CVD and Heart Failure during Winter.
• On this basis, among the estimated 593,000 admissions for CVD in Australia in 2019, 41,500 (>450 per day) more CVD admissions will occur in Winter than in Summer.
• Overall, when considering the excess number of admissions occurring in Autumn, Winter and Spring combined compared to Summer, Seasonality resulted in 71,000 more CVD admissions at a cost of $360 million.
• Given that Seasonality is also a major contributor to premature mortality in those affected by Heart Failure (up to 10% of patients die within 30-days of admission), in addition to significant cost-savings, hundreds of lives will also be saved each year by preventing this deadly phenomenon.
• On a regional basis, individuals living in South Australia and Tasmania are at particular risk of Seasonality. However, so are individuals living in the milder climes of Queensland.
• By 2030, the total number of CVD-related admissions will have risen to 645,000. Of these, an additional 45,000 will occur in Winter compared to Summer of 2030.
• Without action, every State and Territory in Australia will experience a rise in the burden of Heart Failure and an increasing burden imposed by Seasonality; but this will vary. For example, in South Australia by 2030 the number of Heart Failure admissions will have increased (in absolute terms) by 8.2% and the Winter Peak by 9.8%. In NSW, the equivalent figures will be 8.6% and 9.9%, respectively.