According to a new study published in Scientific Reports, the risk of sudden cardiac death was significantly increased during prolonged episodes of cold weather known as cold spells (Odds Ratio 1.49, 95% Confidence Interval 1.06-2.09). Patients who had been diagnosed with ischemic heart disease were at a lower risk of sudden cardiac death during cold spells than patients whose diagnosis of ischemic heart disease was delayed until autopsy. The use of aspirin, beta-blockers and nitrates decreased the risk of sudden cardiac death during cold spells.
Cold weather is known to increase blood pressure, change blood composition, autonomic nervous system function, and oxygen demand of the heart. Because aspirin, beta-blockers, and nitrates influence these same processes in the human body, it was hypothesized that the risk of sudden cardiac death caused by cold weather would be smaller in patients using these medications. It was also hypothesized that the timely setting of the diagnosis of ischemic heart disease, which might lead to changes in health attitudes, behavior, and the use of medications, could protect patients during cold weather. The study results were consistent with the hypotheses.
Sudden cardiac death is an unexpected event, and it commonly affects the seemingly healthy and those in the prime of life. Only 32% of the 2572 patients suffering ischemic sudden cardiac death had a prior diagnosis of ischemic heart disease. The rest were diagnosed with the condition during medico-legal autopsy.
The study was conducted in collaboration with Dr. Niilo Ryti M.D., Professor Heikki Huikuri M.D. PhD, and Professor Jouni Jaakkola M.D. PhD along with a group of scientists and medical doctors at the Center for Environmental and Respiratory Health Research (CERH) in the University of Oulu in Finland. CERH is a WHO Collaboration Centre in Global Change, Environment and Public Health, and one of its focus areas is investigating the associations between weather and health. The researchers remind that seeking help for cardiologic symptoms during cold weather and adhering to the recommendations and medications administered by medical doctors might be life-saving.
The article titled Cold spells and ischaemic sudden cardiac death: effect modification by prior diagnosis of ischaemic heart disease and cardioprotective medication is available online at http://www.nature.com/articles/srep41060
Niilo R. I. Ryti, Elina M. S. Mäkikyrö, Harri Antikainen, M. Juhani Junttila, Eeva Hookana, Tiina M. Ikäheimo, Marja-Leena Kortelainen, Heikki V. Huikuri & Jouni J. K. Jaakkola. Cold spells and ischaemic sudden cardiac death: effect modification by prior diagnosis of ischaemic heart disease and cardioprotective medication. Sci. Rep. 7, 41060; doi: 10.1038/srep41060 (2017)
CERH Online: http://www.oulu.fi/cerh/
Photo: Jokke Jantunen/Plugi
Last updated: 7.2.2017