Cardiovascular Diseases

temperature, air pollution and particulate matter and cardiovascular illnesses

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and a major risk factor for ischemic stroke. We aimed to evaluate the effect of air pollution on the new AF onset requiring (Yitshak Sade et al, 2015a). A case-crossover analysis was performed on a population of patients hospitalized between 2006-2010 with first time occurrence of atrial fibrillation. AF onset was associated with an interquartile range elevation of carbon monoxide concentrations during the winter season (odds ratio (OR) 1.15, p = 0.040) and sulfur dioxide concentrations during the fall season (OR 1.21, p = 0.028). An interquartile range elevation in nitric dioxide concentration was associated with AF onset only among patients younger than 65 years of age (OR 1.08, p = 0.025). Patients with diabetes mellitus or chronic obstructive pulmonary disorder had higher susceptibility for carbon monoxide-associated AF development.

Ischemic stroke (IS) is a multifactorial disorder, a leading cause of long-term disability or death. We aimed to investigate the association between changes in ambient temperature and risk of IS (Yitshak Sade et al, 2015b). We used a time-stratified case-crossover design including all patients admitted to Soroka University Medical Center in southern Israel between 2012 and 2014 due to IS. Exposure windows of 6, 12, 24, 48, 72, and 96 hours were examined. IS incidence was associated with increase in temperature during the summer and autumn season over the 96 hours preceding symptoms onset; the odds ratio (OR) for an increase of 5°C was 3.10 (95% CI, 1.45–6.61) during the summer and 1.86 (95% CI, 1.15–2.99) in autumn. In winter, the increased temperature over 96 hours was associated with lower risk of stroke (OR, 0.68; 95% CI, 0.48–0.97). Men were more sensitive to temperature fluctuations (OR, 1.35; 95% CI, 1.01–1.80) than women (OR, 0.96; 95% CI, 0.68–1.36).

In the next study we evaluated the association between stroke incidence and exposure to PM (Vodonos et al, 2017). We performed case-crossover analysis, stratified by personal characteristics and distance from main roads. Associations between ischemic stroke and increases of interquartile range average concentrations of PM10 and PM2.5 at the day of the event were observed among subjects <55 years (OR [95% CI], 1.11 [1.02–1.20] and 1.10 [1.00–1.21]). Stronger associations were observed in subjects living within 75 m from a main road (1.22 [1.03–1.43] and 1.26 [1.04–1.51]).

In another retrospective analysis, we assessed the contribution of neighborhood greenness and particulate matter to the development of CVD by analyzing the change in prediction abilities (Yitshak-Sade et al, 2017). We included members of Clalit HMO, and who had at least one cardiovascular risk factor (dyslipidemia, diabetes, hypertension, or smokers). PM exposure and neighborhood greenness (Normalized Difference Vegetation Index-NDVI) were assessed by satellite-based models. Coarse-PM exposure was associated with stroke and Myocardial Infarction (MI) (OR 1.02,p < 0.01 for both). NDVI was associated with MI: OR 0.72(p < 0.01) for NDVI 0.1–0.2; and OR 0.52(p = 0.270) for NDVI > 0.2.

We further evaluated whether high levels of non-anthropogenic PM from dust storms constitute a health risk and  whether these health risks are exacerbated in a particular demographic. In the analysis we included all patients above 18 years old admitted to Soroka hospital with a primary diagnosis of acute coronary syndrome (ACS)(Vodonos et al, 2015). Using a case crossover design, the estimated odds of hospitalization due to ACS were significantly higher with higher PM10 during non-dust storm days on the same day (lag0); OR = 1.014 (95%CI 1.001–1.027) for a 10 μg/m3 increase. The effect size for the dust exposure association was larger for older (above the age of 65), female or Bedouin patients.

In a recent nationwide analysis (Kranc et al, 2021), we assessed the incidence of the Out-of-hospital-cardiac arrest (OHCA) events attended by emergency medical services (EMS), in relation to meteorological conditions: temperature, humidity, heat index and solar radiation.  We analyzed all adult cases of OHCA in Israel attended by EMS during 2016–2017. In the case-crossover design, we focused at ambient exposure within 72 h prior to the OHCA event. Exposure to 90th and 10th percentile of temperature adjusted to humidity were positively associated with the OHCA although with borderline significance.