Statins for Coronary Patients Exposed to Wildfire-Related Air Pollution: An Opportunity to Reduce the Increased Risk of Coronary Events

Large-scale wildfires like those in Australia during the “Black Summer” 2019-2020 and currently those in Canada have become more frequent because of climate change. Wildfire smoke is globally the key contributor of fine particulate matter air pollution and especially of the very small particles with an aerodynamic diameter ≤ 2.5 μm (PM2.5).1Hadley M.B. Henderson S.B. Brauer M. Vedanthan R. Protecting cardiovascular health from wildfire smoke.Circulation. 2022; 146: 788-801Crossref PubMed Scopus (4) Google Scholar Even very short-term exposure to ambient fine particulate pollution caused by PM2.5 does associate with increased cardiovascular morbidity.1Hadley M.B. Henderson S.B. Brauer M. Vedanthan R. Protecting cardiovascular health from wildfire smoke.Circulation. 2022; 146: 788-801Crossref PubMed Scopus (4) Google Scholar Mechanistically, the inhaled particles enter the circulation and then cause low-degree inflammation, systemic endothelial dysfunction, and deterioration of vascular health. Hypercholesterolemic patients with atherosclerotic cardiovascular disease suffer from endothelial dysfunction. This particularly applies to patients with the autosomal dominant disorder familial hypercholesterolemia (FH). On the basis of the prevalence of 1:250 for FH, there are approximately 150,000 FH patients in Canada alone. In these patients, the lifelong strong elevation of low-density lipoprotein cholesterol, if left untreated, causes lifelong systemic endothelial dysfunction, which is especially severe in the inflamed atherosclerotic coronary segments.2Vuorio A. Budowle B. Kovanen P.T. Airborne particles and cardiovascular morbidity in severe inherited hypercholesterolemia: vulnerable endothelium under multiple attacks.Bioessays. 2022; 44e2100273Crossref PubMed Scopus (1) Google Scholar Unfortunately, most of the FH patients are not treated effectively and many are not treated at all. Consequently, most FH patients are suffering from either a full-blown or residual endothelial dysfunction, which can be then worsened by PM2.5 pollution.2Vuorio A. Budowle B. Kovanen P.T. Airborne particles and cardiovascular morbidity in severe inherited hypercholesterolemia: vulnerable endothelium under multiple attacks.Bioessays. 2022; 44e2100273Crossref PubMed Scopus (1) Google Scholar In a very recent retrospective observational study of 674 patients with acute coronary syndrome, 264 (40%) had endothelial dysfunction.3Yoshii T. Matsuzawa Y. Kato S. et al.Endothelial dysfunction predicts bleeding and cardiovascular death in acute coronary syndrome.Int J Cardiol. 2023; 376: 11-17Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar In the follow-up (median, 6.1 years), the multivariable analysis revealed an independent predictive value for major adverse cardiovascular events (hazard ratio, 2.04; 95% confidence interval, 1.43-2.89; P < 0.001). Additionally, the patients with endothelial dysfunction had a 2.5-fold greater risk for cardiovascular death. Simvastatin rapidly restores the function of cultured endothelial cells and also of the endothelial layer in the aortic wall of Watanabe heritable rabbits, the animal counterpart of FH.4van Nieuw Amerongen G.P. Vermeer M.A. Nègre-Aminou P. Lankelma J. Emeis J.J. van Hinsbergh V.W. Simvastatin improves disturbed endothelial barrier function.Circulation. 2000; 102: 2803-2809Crossref PubMed Google Scholar Because statins are effective in the secondary prevention of cardiovascular events, the endothelial function-enhancing effect also applies to atherosclerotic coronary arteries of secondary prevention patients, particularly those at very high cardiovascular risk, such as undertreated FH patients. When they, or any high-risk secondary prevention coronary patients, are exposed to wildfire-derived PM2.5, they need to continue effective statin medication as a part of their lipid-lowering regimen for the prevention of cardiovascular events. Checking this at the reception is an opportunity that should not be missed. None.