Stock volatility may trigger the onset of acute coronary syndrome: A nationwide case-crossover analysis

Stock volatility, an adverse psychological stressor, has been linked to cardiovascular mortality or hospitalization. However, no studies had quantified the risk of acute coronary syndrome (ACS) onset from stock market fluctuation. Using the time-stratified case-crossover design, which could control for the potential confounding from time-invariant, we conducted the analysis based on a nationwide registry comprising of 2,113,728 ACS patients in China from January, 2015 to December, 2021. We obtained daily returns (%) of three main stock indexes in Chinese Mainland, and matched the case and control days of ACS onset on hourly level. The data were analyzed using conditional logistic regression models. The associations between daily stock returns and ACS onset were U-shaped with stock rise and fall both increasing the risk of ACS onset. The excess risks associated with each 1%-decrease of daily stock returns for Shanghai, Shenzhen and ChiNext index were 0.96% (95%CI: 0.40,1.51), 0.65% (95%CI: 0.27,1.03) and 0.87% (95%CI: 0.52,1.21) at the concurrent day, respectively; and a 1%-increase of daily stock returns was associated with 1.06% (95%CI: 0.61,1.52), 0.45% (95%CI: 0.11,0.80) and 0.17% (95%CI: -0.08,0.41) increases of ACS onset, respectively. Thereafter, most of the associations gradually attenuated, disappeared after 3 days. The associations were significant for unstable angina and ST-segment-elevation myocardial infarction, but not for non-ST-segment-elevation myocardial infarction. This nationwide study provides novel and robust evidence that both stock rise and fall could increase the risk of ACS onset, highlighting the importance of heart care and psychological support during fluctuations of stock market.