From the AMERICAN COLLEGE OF CARDIOLOGY and the “anything goes with climate change” department comes this absurd study. What the researchers seem to fail to realize is that just stepping outside from a heated house to the typical outdoor temperatures of any American winter are far more extreme than the 1 degree of climate change we’ve witnessed. In fact, snow shoveling is a major cause of heart attack.
Sudden exertion activities in cold weather can trigger a heart attack or sudden cardiac death. … Shoveling, even pushing a heavy snow blower, can cause sudden increase in blood pressure and heart rate, and the cold air can cause constriction of the blood vessel and decrease oxygen to the heart. – MetroHealth
Of course, they’ll try to tell you that more snow and less snow are signs of climate change too. And then there’s that famous chestnut “snowfalls are now just a thing of the past“. Since that hasn’t happened, now they just go straight for the temperature differential and skip the heart attack snow shoveling risk factor correlation. Although the study isn’t released yet (but this PR fluff is) I can’ say for sure, but it looks like they don’t consider activity during the heart attack at all; then there’s the location of the study, only in Michigan, where lake effect enhanced snowfalls are a common occurrence. The climate change correlation seems pretty darn thin.
Full disclosure, lest anyone accuse me of being insensitive, my father died in the winter of 1969, while walking from a heated car to a dance hall, doctors then said the cold then warm transitions were a trigger factor.
Heart attacks often follow dramatic changes in outdoor temperature
Findings suggest climate change may increase heart attack risk
WASHINGTON (March 1, 2018) — Large day-to-day swings in temperature were associated with significantly more heart attacks in a study being presented at the American College of Cardiology’s 67th Annual Scientific Session. Given that some climate models link extreme weather events with global warming, the new findings suggest climate change could, in turn, lead to an uptick in the occurrence of heart attacks, researchers said.
“Global warming is expected to cause extreme weather events, which may, in turn, result in large day-to-day fluctuations in temperature,” said Hedvig Andersson, MD, a cardiology researcher at the University of Michigan and the study’s lead author.
“Our study suggests that such fluctuations in outdoor temperature could potentially lead to an increased number of heart attacks and affect global cardiac health in the future.”
There is a large body of evidence showing that outdoor temperature affects the rate of heart attacks, with cold weather bringing the highest risk, but most previous studies have focused on overall daily temperatures. This new study is among the first to examine associations with sudden temperature changes.
“While the body has effective systems for responding to changes in temperature, it might be that more rapid and extreme fluctuations create more stress on those systems, which could contribute to health problems,” Andersson said, noting that the underlying mechanism for this association remains unknown.
Along with an overall warming trend, climate change is projected to lead to more extreme events, such as heat waves and cold snaps, depending on where someone lives, the researchers explained.
The research is based on data from more than 30,000 patients treated at 45 Michigan hospitals between 2010-2016. All patients had received percutaneous coronary intervention, a procedure used to open clogged arteries, after being diagnosed with ST-elevated myocardial infarction, the most serious form of heart attack.
The researchers calculated the temperature fluctuation preceding each heart attack based on weather records for the hospital’s ZIP code. Daily temperature fluctuation was defined as the difference between the highest and lowest temperature recorded on the day of the heart attack.
Overall, the results showed the risk of a heart attack increased by about 5 percent for every five-degree jump in temperature differential, in degrees Celsius (9 degrees Fahrenheit). Swings of more than 25 degrees Celsius (45 degrees Fahrenheit) were associated with a greater increase in heart attack rates compared to a smaller increase with temperature swings of 10 to 25 degrees Celsius (18-45 degrees Fahrenheit). The effect was more pronounced on days with a higher average temperature; in other words, a sudden temperature swing seemed to have a greater impact on warmer days.
At the far end of the spectrum, on a hot summer day, nearly twice as many heart attacks were predicted on days with a temperature fluctuation of 35-40 degrees Celsius (63-72 degrees Fahrenheit) than on days with no fluctuation.
“Generally, we think of heart attack risk factors as those that apply to individual patients and we have, consequently, identified lifestyle changes or medications to modify them. Population-level risk factors need a similar approach,” said Hitinder Gurm, MD, professor of medicine and associate chief clinical officer at Michigan Medicine and the study’s senior author.
“Temperature fluctuations are common and [often] predictable. More research is needed to better understand the underlying mechanisms for how temperature fluctuations increase the risk of heart attacks, which would allow us to perhaps devise a successful prevention approach.”
In their analysis, the researchers adjusted for precipitation totals, day of the week and seasonal trends to isolate the effects of daily temperature fluctuations from other potential environmental factors.
Gurm cautioned that the association does not necessarily prove that sudden temperature swings are the cause of the increase in heart attacks; other factors may have contributed to the results. He noted that it remains important to focus on modifiable cardiovascular risk factors such as smoking, high blood pressure and high cholesterol.
Andersson will present the study, “Daily Temperature Fluctuations and Myocardial Infarction: Implications of Global Warming on Cardiac Health,” on Saturday, March 10 at 3:45 p.m. ET in Poster Hall A/B.