Trends in cardiovascular disease in Australia and in the world

Cardiovascular disease (CVD) is the leading cause of death globally, despite recent declines in cardiovascular mortality, and its contemporary burden remains to be adequately addressed. Metabolic syndrome (MetS) is a cluster of major risk factors for CVD, ¹ and thus an ideal target for intervention.^1–7

In this issue of the journal, Sarink and collaborators report on 787,115 subjects from Western Australia, aged 35 to 84 years, highlighting that most CVD events, distinguished as coronary heart disease (CHD), cerebrovascular disease (CeVD) and peripheral arterial disease (PAD), occurred in older adults. They also observed a trend towards worsening prevalence in young adults for most CVD subtypes. CHD was defined as acute myocardial infarction (AMI), unstable angina, stable angina or other chronic forms of ischaemic heart disease; CeVD included cerebral infarction, transient ischaemic attack, precerebral or cerebral artery disease without infarction, or unspecified stroke or intracerebral haemorrhage; and PAD as atherosclerosis of the aorta, renal arteries or arteries of the extremities, unspecified peripheral vascular disease. ⁸ Intriguingly, they found that the incidence of CVD subtypes was decreasing in middle-aged and elderly adults, but was stable or increasing among younger adults less than 55 years of age. This can potentially be explained by a higher prevalence of diabetes and obesity in the younger population. A key limitation of this study was that whilst it examined temporal trends in these important adverse outcomes, it did not report on the burden of different co-morbidities driving such outcomes, including MetS, atrial fibrillation, aortic aneurysm, cardiomyopathy, myocarditis, hypertensive heart disease, endocarditis and autoimmune disease.

Reports exploring the temporal changes of cardiovascular disease burden for other countries have also been published. For instance, In China, a rising prevalence of different cardiovascular risk factors was observed among rural residents and in women, groups that have traditionally been neglected in health policy decisions. ⁹ In the United States, even with the significant decline in cardiovascular and stroke-related mortality, we continue to note a national improvement gap among those aged under 65 when compared with an integrated health care delivery system. ¹⁰

In Italy, overall improvements were reported for several cardiovascular risk factors, but these translated into a reduced prevalence of stroke but not AMI. In addition, worrying inequalities in risk factor prevalence and management were apparent when comparing different educational classes. In a study in Norway with 69,732 patients, it was found that the majority of cases of heart failure occurred during hospitalization due to AMI. ¹¹

In Germany, recent trends suggest absolute improvements in the prevalence and burden of cardiovascular disease, despite this being still the major source of death and disability, especially in men. Notably, most of such burden was due to sanctionable risk factors, such as diet, overweight/obesity, hypertension, smoking, inactivity, diabetes, dyslipidaemia and pollution. Already in the Finnish AMI registry the prognosis of survivors of acute coronary syndrome improved during the 18-year period, but even so it was considered to be much worse than in the comparable general population. ¹² In another study in Western Europe, it was found that despite the increase in body weight, the total burden of cardiovascular risk factor had decreased in men aged 50 years in the last half century. ¹³

In conclusion, the article by Sarink and colleagues provides us with the important findings that most CVD occurs in the elderly and with worsening prevalence trends in young adults. Public health interventions to improve cardiovascular mortality in the vulnerable young adult population can play a key role in closing this gap. Further research is needed to determine the economic implications of implementing such programmes.