Background During the COVID-19 pandemic, decreasing rates of hospitalisations for cardiovascular disease raised concerns for undertreatment, particularly for vulnerable groups. We investigated how the initial COVID-19 public lockdown, impacted the risk of being hospitalised with a major cardiovascular event (MCE: myocardial infarction/stroke/heart failure) according to educational level.

Methods We grouped all Danish residents according to educational attainment level (low, medium, high) and age (40–59, 60–69, ≥70 years). In each group, we calculated the age-standardised and sex standardised risk of MCE hospitalisation in the initial COVID-19 lockdown-period (13 March 2020–3 May 2020) and in the corresponding calendar period in 2019. We calculated age-standardised and sex-standardised risks to investigate whether the COVID-19 lockdown had a differential effect on MCE incidence according to educational level.

Results In the period in 2019, 2700 Danish residents were hospitalised with MCE, compared with only 2290 during the lockdown. During lockdown, the risk of hospitalisation for MCE decreased among residents aged ≥70 with low education (risk difference (RD) −46.2 (−73.2; −19.2) per 100,000) or medium education (RD −23.2 (−50.8; 4.3) per 100 000), but not among residents with high education (RD 5.1 (−32.3; 42.5), per 100 000). The risk of hospitalisation for MCE did not decrease significantly for the younger age groups.

Conclusions The COVID-19 lockdown is associated with a reduced incidence for MCE, especially among low educated, elderly residents. This raises concern for undertreatment that without clinical awareness and action may widen the educational gap in cardiovascular morbidity and mortality.