Noise pollution in cities can affect the prediction and prognosis of cardiovascular risk after a heart attack

Research from two studies in different European cities shows that noise pollution in cities has a significant negative impact on heart health, according to data presented at the ESC Congress 2024.

The DECIBEL-MI study shows that young patients aged 50 or younger who had suffered a heart attack were exposed to higher noise levels than the general population. The study shows that noise in cities can significantly increase the risk of early heart attack in young people with low traditional risk factors. Taking noise exposure into account in risk prediction models helps to accurately identify people at risk, leading to more targeted prevention.

The DECIBEL-MI study included 430 consecutive patients from Bremen, Germany, who were 50 years or younger and suffered from an acute heart attack and were admitted to a local heart center. When noise exposure was calculated in residential areas, the researchers found that noise exposure was higher compared to the general population in the same region.

Patients with a heart attack and a low LIFE-CVD score (≤ 2.5%), which indicates low levels of traditional risk factors such as smoking or diabetes, had significantly higher noise exposure than patients with a high LIFE-CVD score. This is crucial because traditional risk assessment models may underestimate cardiovascular risk in young people who are otherwise considered low risk. By taking noise exposure into account in these models, it is possible to more accurately identify individuals at increased risk of heart attack, allowing for more targeted prevention measures and interventions.

A separate study in France examined the influence of noise exposure on the prognosis after a first heart attack. “In the ENVI-MI study, we found a strong association between noise exposure in the city, especially at night, and a worse prognosis one year after a first heart attack,” explained study leader Professor Marianne Zeller from the University of Burgundy and Dijon Hospital in France.

Data from the French observational database (RICO) were collected for 864 patients hospitalized for acute myocardial infarction and surviving at least 28 days after the myocardial infarction. At one-year follow-up, 19% experienced a major cardiovascular event (MACE; cardiac death, rehospitalization for heart failure, recurrent myocardial infarction, emergency revascularization, stroke, angina, and/or unstable angina).

The daily measured noise levels at each patient’s home address (average noise level in A-weighted decibels) [dB(A)]: 56.0 over 24 hours and 49.0 at night) were considered moderate and representative of a large part of the European population.

Notably, for every 10 dB(A) increase in noise during the night, the risk of MACE increased by 25% (hazard ratio 1.25; 95% confidence interval 1.09–1.43), regardless of air pollution, socioeconomic level, and other confounding factors.

“These data provide initial evidence that noise exposure can influence prognosis. If confirmed by larger prospective studies, our analysis could help identify new opportunities for environmental secondary prevention strategies, including noise barriers for high-risk MI patients,” added Professor Zeller.