As expected, traffic during the holiday season is getting worse as Christmas approaches. What used to be a 30-40 minute leisurely drive from the office to the house during peak hours can become a stress-filled, two-hour ordeal.

The amount of stress getting stuck in a traffic jam could be sufficient to trigger a heart attack in high-risk individuals. This is why we advise our high-risk patients to avoid driving during the holiday season. Aside from the alcohol-binging, traffic-related stress may be another major risk factor for the so-called holiday heart syndrome, or an increase in heart attacks during the holiday season.When you look at the big picture, that is, analyzing the data on a population level, traffic-related stress—aggravated by the exposure to traffic noises and air pollution—apparently triggers more heart attacks than cocaine, caffeine, anger or sex. This is based on data from a group of European researchers published in the prestigious journal, The Lancet, several years ago.

If you have a good heart with patent heart arteries adequately supplying the heart muscles with oxygenated blood, traffic-related factors pose only a minuscule risk. There should be nothing to worry about. But if you already have coronary artery disease or clogging of the heart arteries, the risk is tilted to a precarious level, with a tripling of the risk to develop a heart attack or a life-threatening arrhythmia or irregular heartbeat that could cause cardiac arrest.

Various risk factors

We all know the various risk factors for why the heart arteries get clogged. These consist of smoking, high blood pressure, diabetes, obesity, high cholesterol and sedentary living. But there are other sets of risk factors that could trigger the final heart attack event. Exposure to traffic and air pollution are among these.

It’s not only the stress caused by driving in heavy traffic that could be the trigger, but exposure to traffic-related noises like the honking of horns and revving up of engines, and the air pollution as well. Come to think of it, policemen and traffic enforcers could be at high risk and should be provided the necessary protection for these environmental triggering factors.

In The Lancet study, the researchers headed by Tim Nawrot, a professor at Hasselt University in Belgium, used a comparative risk assessment analysis based on 36 previously published studies of nonfatal heart attack. They analyzed the relative risk of each of 13 suspected triggers to both individual and overall public health.

“One of the contributions of our paper, besides ranking the trigger factors, is that this is really an exercise in demonstrating the discrepancies between individual and population-based risks,” explained Nawrot, who is an expert on environmental epidemiology.

The authors reported that analyzing the impact of the risk factors on a population level, exposure to traffic-related factors was associated with a bigger number of total heart attacks.

The following are the percentages of heart attacks preceded by each of 13 trigger events on a population level: traffic exposure (7.4 percent), physical exertion (6.2 percent), alcohol excess (5 percent), coffee excess (5 percent), negative emotions (3.9 percent), anger (3.1 percent), heavy metal (2.7 percent), extreme positive emotions (2.4 percent), sexual activity (2.2 percent), cocaine use (0.9 percent), marijuana use (0.8 percent) and respiratory infection (0.6 percent).

Adverse effect on the heart

Although the percentages may be relatively small—giving the impression that the risk is not that high—the actual numbers of affected individuals may be big, considering the size of the population exposed to the environmental triggering factors such as traffic and air pollution. This explains why the public health risk can be still significant, explained professor Joel Kaufman, environmental and occupational medicine expert from the University of Washington.

Traffic-related risk factors triggering a heart attack or stroke do not only affect the drivers or passengers stuck in a jam. Those living in neighborhoods with constant traffic noise should also be warned that their risk of hospitalization for heart attacks is higher compared with those who live in quieter areas with a safe distance from traffic-congested roads. This was the finding of another study from Rutgers University in the United States, which was published earlier this year in the Journal of the American College of Cardiology (JACC). This study on a North American population corroborates the earlier European data documenting similar adverse effect on the heart by transportation-related noise pollution.

According to Dr. Abel Moreyra, a professor of medicine at Rutgers and the lead author of the study, studies like this are important so the public should not only be concerned about the conventional risk factors such as smoking, hypertension, diabetes, obesity and cholesterol problems, but these nontraditional risk factors as well, like traffic, air and noise pollution.

Environmental hazards, including noise pollution, have been associated in previous studies with hearing loss, sleep disorders, chronic stress and high blood pressure. Because of this, it’s fair to assume that prolonged exposure to these could lead to higher rates of heart disease and heart attacks.

Loud noise levels

In the JACC paper, Moreyra and his colleagues at Rutgers analyzed the heart attack risk factors for 15,846 residents in New Jersey who suffered from a heart attack in 2018. The New Jersey population was chosen since it’s the densest state in the US, with many residents near busy roadways, train lines and big airports.

The study found that one in 20 heart attacks was associated with exposure to loud noise levels, and the risk was 72 percent higher compared to those living in quieter areas. Measuring the noise exposure by decibel levels, the heart attack risk for those exposed to an average noise level of 65 decibels or higher was 3336.5 per 100,000 people, while those whose exposure to noise level was below 45 decibels had a rate of 1938.6 per 100,000. The noise level of city traffic is around 85 decibels.

As in similar previous studies, the researchers attributed the increased risk to the chronic stress, sleep disturbances and anxiety. They were identified as the culprits for the detrimental impact on heart health. It is well known that chronic stress induces the release of hormones linked to inflammation and progressive blockage of the arteries and blood vessels.

The authors concluded: “ … that 5 percent of all acute [myocardial infarctions or heart attacks] hospitalizations were attributable to high noise levels indicates the significance of the exposure, and the findings underscore the importance of stricter noise regulations and enforcement by the transportation authorities.”

A key regulation should be penalizing the unnecessary honking of horns. There should also be mandatory policies for better noise insulation or cancellation for buildings and residences exposed to higher levels of traffic- or transportation-related noises.

The authors also proposed more considerate rules and schedules for airport landings and take-offs to minimize noise disturbances at night, and tire manufacturers should develop tires producing less noise from the friction between the tires and the road during sudden brakes.

Several guidelines now include air pollution as a trigger factor for heart attack. We’re quite certain that other traffic-related factors like noise pollution can also be considered in this list, so the medical community and the public could be properly warned and guided on how to reduce such risk.

Wishing everyone a joyous and traffic-free Christmas. INQ