ABSTRACT
Objectives There are concerns about the potential effect of social distancing used to control coronavirus disease 2019 (COVID-19) on the incidence of cardiovascular diseases (CVD). Study design Retrospective cohort study. Methods We examined the association between lockdown and CVD incidence in a Zero-COVID country, New-Caledonia. Inclusion criteria was defined by a positive troponin sample during hospitalization. Study period lasted for two months starting the 20th of March 2020 (strict lockdown: first month;loose lockdown: second month) compared to the same period of the three previous years to calculate incidence ratio (IR). Demographic characteristics and main CVD diagnoses were collected. Primary endpoint was the change in incidence of hospital admission with CVD during lockdown compared to the historical counterpart. Secondary endpoint included influence of strict lockdown, change in incidence of the primary endpoint by disease and outcome incidences (intubation or death) analysed with inverse-probability-weighting method. Results 1215 patients were included: 264 in 2020 versus 317 (average of the historical period). CVD hospitalizations were reduced during strict lockdown (IR 0.71 [0.58-0.88]), but not during loose lockdown (IR 0.94 [0.78-1.12]). The incidence of acute coronary syndromes was similar in both periods. The incidence of acute decompensated heart failure (AHF) was reduced during strict lockdown (IR 0.42 [0.24 -0.73]) followed by a rebound (IR 1.42 [1–1.98]). There was no association between lockdown and short-term outcomes. Conclusions Our study showed that lockdown was associated with a striking reduction in CVD hospitalizations, independently from viral spread, and a rebound of AHF hospitalizations during looser lockdown.