Cardiac patients living in high pollution areas were found to be over 40 per cent more likely to have a second heart attack when compared to patients living in low pollution areas, according to Doctor Yariv Gerber. "We know that like smoking cigarettes, pollution itself provokes the inflammatory system. If you are talking about long-term exposure and an inflammatory system that is irritated chronically, pollution may well be involved in the progression of atrial sclerosis that manifests in cardiac events," explains Gerber.
Air pollution has previously been acknowledged as a factor in heart attack risk, as well as other health risks. The goal of this study, says Gerber, was to quantify that association and determine the long-term effects of air pollution on myocardial infarction (MI) patients. Their study followed 1,120 first-time MI patients who had been admitted to one of eight hospitals in central Israel between 1992 and 1993, all of whom were under the age of 65 at the time of admittance. The patients were followed up until 2011, a period of 19 years.
Air quality was measured at 21 monitoring stations inareas where the patients lived, and analysed by a group of researchers at the Technion in Haifa. After adjusting for other factors such as socio-economic status and disease severity, the researchers identified an association between pollution and negative clinical outcomes, including mortality and recurrent vascular events such as heart attack, stroke and heart failure.
Compared to patients who lived in areas with the lowest recorded levels of pollution, those in the most polluted environment were 43 per cent more likely to have a second heart attack or suffer congestive heart failure and 46 per cent more likely to suffer a stroke. The study also found that patients exposed to air pollution were 35 per cent more likely to die in the almost 20 year period following their first heart attack than those who were exposed to lower levels of pollution.
According to Gerber, the true impact of air pollution might be even stronger than this study shows. "Our method of assessing exposure does have limitations. Because we are using data from monitoring stations, it is a crude estimate of exposure, which most likely leads to an underestimation of the association," he warns. He estimates that air pollution could have double the negative impact with more precise measurement.
MEDICA.de; Source: Tel Aviv University