Impact of lockdown on cardiovascular disease hospitalizations in a Zero-COVID-19 country

OBJECTIVES: There are concerns about the potential effect of social distancing used to control 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 were defined by a positive troponin sample during hospitalization. The study period lasted for 2 months, starting March 20, 2020 (strict lockdown: first month; loose lockdown: second month) compared with the same period of the three previous years to calculate incidence ratio (IR). Demographic characteristics and main CVD diagnoses were collected. The primary endpoint was the change in incidence of hospital admission with CVD during lockdown compared with the historical counterpart. The secondary endpoint included influence of strict lockdown, change in incidence of the primary endpoint by disease, and outcome incidences (intubation or death) analyzed with inverse probability weighting method. RESULTS: A total of 1215 patients were included: 264 in 2020 vs 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 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 acute decompensated heart failure hospitalizations during looser lockdown.