NEW DELHI: Long-term exposure to air pollution is associated with additional risk of cardiovascular disorders in those already having an underlying heart condition, according to a study.
The research, published recently in the Journal of the American College of Cardiology (JACC), evaluated the association between long-term exposure to small particulate matter 2.5 (PM2.5) and 10 (PM10), and coronary vasomotor disorders in patients with nonobstructive coronary artery disease (NOCAD), which is associated with poor cardiovascular outcomes.
Coronary vasomotor disorders are characterised by impaired ability to adequately adjust coronary blood flow to oxygen demand due to dysfunctional vasomotor function.
The researchers from Catholic University of the Sacred Heart in Rome, Italy and colleagues studied patients with myocardial ischemia and NOCAD undergoing coronary angiography and intracoronary provocation test, an established method for assessment of coronary artery spasm.
Both patients with chronic myocardial ischemia and nonobstructive coronary arteries and myocardial infarction with nonobstructive coronary arteries (MINOCA) were enrolled.
Based on each case's home address, exposure to PM2.5 and PM10 was assessed.
The study included 287 patients with a median age of 62 years. 149 of the participants were male and 161 had myocardial ischemia and nonobstructive coronary arteries while 126 had MINOCA.
Higher exposure to PM2.5 and PM10 in patients with myocardial ischemia and NOCAD is associated with coronary vasomotor abnormalities, the researchers said.
In particular, PM2.5 is an independent risk factor for the occurrence of epicardial spasm and MINOCA as clinical presentation, they said.
''Our study shows for the first time an association between long-term air pollution exposure and the occurrence of coronary vasomotor disorders, suggesting a possible role for pollutants in determining myocardial ischemia in patients with NOCAD,'' the authors of the study noted.
''In particular, we show that PM2.5 and PM10 are independently associated with a positive coronary provocation test in these patients, and that PM2.5 is positively related to the occurrence of epicardial spasm as opposed to microvascular spasm,'' they added.