Prolonged toxic air exposure can lead to heart attack: Study

New Delhi: Higher exposure to air pollutants can cause narrowing of blood vessels in those already having an underlying heart condition, thus exposing them to serious health risks, including a heart attack, according to a study published in the Journal of the American College of Cardiology (JACC).

The study says prolonged exposure to PM2.5 or fine particulate matter can lead to a sudden, temporary squeezing of the arteries which can lead to heart attack. The findings are based on an analysis of test reports of 287 patients suffering from NonObstructive Coronary Artery Disease or NOCAD (defined as < 50% diameter stenounderwent sis) who coronary angiography followed by a coronary provoca tion test at a hospital in Rome in which a drug in injected to check whether the coronary arteries are hyper-responsive.

The researchers found 176 (61%) patients suffering from NOCAD had a positive provocation test. It was also revealed in the study that patients with a positive provocation test were exposed to higher levels of PM2.5 and PM10 compared to patients with a negative provocation test.

“Our study shows for the first time an association between long-term air pollution and occurrence of coronary vasomotor disorders (constriction or dilation of the heart’s blood vessels), suggesting a possible role for pollutants in determining myocardial ischemia (lack of blood flow to the heart muscles) in patients with NOCAD,” the JACC study says. It adds: “..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.”

Dr, professor of cardiology said prolonged exposure to the fine particulate matter is known to cause cardiovascular deaths. “The problem is that sudden rise in the pollutants can lead to more deaths in a short interval,” he said. Dr.Gupta added that in cities like Delhi that are already having chronic elevation of air pollution, it predisposes people at high risk to develop heart disease. “While urgent systematic steps are the need of hour, individuals’ choices that are environmentally he althy are important. For example, people should wear masks while going out on days when the pollution levels are very high. Keeping yourself hydrated can also help,” the cardiologist said.