evidence: The world’s biggest killer is ischaemic heart disease, responsible for 13% of the world’s total deaths. Since 2000, the largest increase in deaths has been for this disease, rising by 2.7 million to 9.1 million deaths in 2021. As a newly emerged cause of deaths, COVID-19 was directly responsible for 8.8 million deaths in 2021, and consequently, largely pushed down other leading causes of death by one place. Instead of being the second and third leading causes of death as in 2019, stroke and chronic obstructive pulmonary disease became the third and fourth in 2021, responsible for approximately 10% and 5% of total deaths, respectively. [...] Deaths from ischaemic heart disease have increased by more than 1.4 million, the second largest rise in any income group in terms of absolute number of deaths from this cause, just 40 000 lower than the increase in lower-middle-income countries. In 2021, ischaemic heart disease ranked second, closely tracking stroke in total absolute number of deaths and one place ahead of COVID-19. [...] COVID-19 has highlighted the importance for countries investing in civil registration and vital statistics systems to allow daily counting of deaths and direct prevention and treatment efforts. It has also revealed inherent fragmentation in data collection systems in most low-income countries, where policy-makers still do not know with confidence how many people die and of what causes.