Extreme temperatures increase the risk of death from heart failure

According to a new study done, exposure to extremely hot or cold temperatures increases a heart patient’s risk of death.

This graph shows the temperature percentiles and the relative risk (RR) of dying from heart disease in 567 cities around the world. The dotted line represents the temperature associated with the lowest risk of death. The dotted lines represent the 1st percentile (extreme cold) and the 99th percentile (extreme heat). Image credit: broadcast

The study was recently reported in the Journal of the American Heart Association Traffic.

The global analysis of more than 32 million cardiovascular deaths over four decades showed a high number of deaths on days with the highest or lowest temperatures compared to days with temperate climates.

It highlights the urgent need to develop measures that will help our society mitigate the impact of climate change on cardiovascular disease.”

Haitham Khraishah, MD, study co-author and cardiovascular disease researcher, School of Medicine, University of Maryland

Among the types of cardiovascular disease, people with heart failure were the most likely to be negatively affected by very cold and very hot days, facing a 12% higher risk of death on extremely hot days than on very hot days. optimum temperature days in a given city. Extreme cold increased the threat of death from heart failure by 37%.

The findings depended on an analysis of health data from more than 32 million cardiovascular deaths that occurred in 567 cities in 27 countries on 5 continents between 1979 and 2019. The explanation for the extreme weather varied from city to city. other.

It was specified as the upper 1% or lower 1% of the so-called “minimum mortality temperature”, which is the temperature at which the lowest mortality rate was obtained.

For every 1,000 cardiovascular deaths, the researchers found that:

• Extremely hot days (above 86°F in Baltimore) are available for an additional 2.2 deaths.
• Extreme cold days (below 20°F in Baltimore) reported 9.1 additional deaths.
• Among the types of heart disease, the highest number of excess deaths was found in people with heart failure (2.6 excess deaths on extremely hot days and 12.8 on extremely cold days).

Although we don’t know why the effects of temperature were more pronounced in patients with heart failure, it could be due to the progressive nature of heart failure as a disease.. One in four people with heart failure are readmitted to hospital within 30 days of discharge, and only 20% of heart failure patients survive 10 years after diagnosis..”

Haitham Khraishah, MD, study co-author and cardiovascular disease researcher, School of Medicine, University of Maryland

Climate change has been found to cause extreme weather conditions at both ends of the spectrum. A 2021 study published in the journal Science discovered that the warming of the Arctic caused a change of events resulting in an interruption of the polar vortex creating periods of extreme cold in the Northern Hemisphere.

Barrak Alahmad, MD, Ph.D., a researcher at Harvard TH Chan School of Public Health at Harvard University in Boston and a faculty member at the College of Public Health at Kuwait University in Kuwait City, was the corresponding author of the study.

Dr. Khraishah and Dr. Alahmad have taken steps over the past four years to build the heart disease mortality database for this study with collaborators from more than 35 institutions worldwide.

The team created and expanded the Heart Disease Mortality Database as part of the Multi-Country Multi-City (MCC) Collaborative Research Network. It is a consortium of biostatisticians, epidemiologists and climatologists learning about the effects of climate on health and the associated environmental stressors on mortality rates.

This study provides an indisputable link between extreme temperatures and heart disease mortality from one of the largest multinational datasets ever assembled.. Data can be extracted more deeply to learn more about the role of health disparities and genetic predispositions that make some populations more vulnerable to climate change.”

Mark T. Gladwin, MD, Dean, School of Medicine, University of Maryland

Additionally, Gladwin is the Vice President of Medical Affairs, University of MarylandBaltimore, and Professor Emeritus John Z. and Akiko K. Bowers.

According to Dr. Khraishah, these questions will be answered in future research.

Some limitations of the study are the under-representation of data from South Asia, the Middle East and Africa.

The scientists also took into account humidity and atmospheric pollutants, which could have explained the excess of deaths in places with extreme temperatures. In addition, they regulated the delayed effect of temperature on climatic zones and human health (delay effect).

“This historic document is a call to consider climate change as a growing public health problem and underlines the need to study it as a potential cause of health disparitiessaid Stephen N. Davis, MBBS, chair of the UMSOM Department of Medicine and UMMC Chief Medical Officer.

This study was financially supported by the Kuwait Foundation for the Advancement of Science.