Impact of environmental pollution and weather changes on the incidence of ST-elevation myocardial infarction.

BACKGROUND: Environmental pollution and weather changes unfavorably impact on cardiovascular disease. However, limited research has focused on ST-elevation myocardial infarction (STEMI), the most severe yet distinctive form of acute coronary syndrome. METHODS AND RESULTS: We appraised the impact of environmental and weather changes on the incidence of STEMI, analysing the bivariate and multivariable association between several environmental and atmospheric parameters and the daily incidence of STEMI in two large Italian urban areas. Specifically, we appraised: carbon monoxide (CO), nitrogen dioxide (NO2), nitric oxide (NOX), ozone, particulate matter smaller than 10 µm (PM10) and than 2.5 µm (PM2.5), temperature, atmospheric pressure, humidity and rainfall. A total of 4285 days at risk were appraised, with 3473 cases of STEMI. Specifically, no STEMI occurred in 1920 (44.8%) days, whereas one or more occurred in the remaining 2365 (55.2%) days. Multilevel modelling identified several pollution and weather predictors of STEMI. In particular, concentrations of CO (p = 0.024), NOX (p = 0.039), ozone (p = 0.003), PM10 (p = 0.033) and PM2.5 (p = 0.042) predicted STEMI as early as three days before the event, as well as subsequently, and NO predicted STEMI one day before (p = 0.010), as well as on the same day. A similar predictive role was evident for temperature and atmospheric pressure (all p < 0.05). CONCLUSIONS: The risk of STEMI is strongly associated with pollution and weather features. While causation cannot yet be proven, environmental and weather changes could be exploited to predict STEMI risk in the following days.

Impact of temporary traffic bans on the risk of acute coronary syndromes in a large metropolitan area.

BACKGROUND: Strong epidemiologic evidence has highlighted the role of pollution, on top of adverse climate features, as a novel cardiovascular risk factor. However, mechanistic proof that reducing pollution may be beneficial to prevent atherothrombotic events is limited. We aimed at appraising the impact of temporary traffic bans in a large metropolitan area on the risk of acute coronary syndromes. METHODS: Aggregate and anonymized data from 15 tertiary cardiac care centers were obtained detailing precoronavirus disease 2019 (COVID-19) daily cases of ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI), including those treated with percutaneous coronary intervention (PCI). Data on pollutants and climate were sought for the same days. Mixed level regression was used to compare the week before vs after the traffic ban (Fortnight analysis), the 3 days before vs. after (Weekly analysis) and the Sunday before vs. after (Sunday analysis). RESULTS: A total of 8 days of temporary traffic bans were included, occurring between 2017 and 2020, totaling 802 STEMI and 1196 NSTEMI in the Fortnight analysis, 382 STEMI and 585 in the Weekly analysis, and 148 STEMI and 210 NSTEMI in the Sunday analysis.Fortnight and Sunday analyses did not disclose a significant impact of traffic ban on STEMI or NSTEMI (all P>0.05). Conversely, Weekly analysis showed non-significant changes for STEMI, but a significant decrease in daily NSTEMI when comparing the 3 days before the traffic ban with the ban day (P=0.043), as well as the 3 days before vs. the 3 days after the ban (P=0.025). No statistically significant effect of traffic ban was found at Fortnight, Weekly or Sunday analyses for daily mean concentrations of benzene, carbon monoxide, nitric oxide, nitrogen dioxide, ozone, sulfur dioxide, particulate matter (PM) <2.5 µm or PM <10 µm (all P>0.05). However, minimum daily concentrations showed a significant reduction of ozone during the ban in comparison to the week preceding it (P=0.034), nitric oxide during the ban in comparison to the 3 days preceding it (P=0.046), and an increase in benzene during the ban in comparison to the Sunday before (P=0.039). CONCLUSIONS: Temporary traffic ban may favorably reduce coronary atherothrombotic events, and in particular NSTEMI, even if not globally and immediately impacting on environmental pollution. Further controlled studies are required to confirm and expand this hypothesis-generating results.