Patients’ age, surgical risk, anatomy and procedural preference are typically the driving factors in therapeutic choice for the treatment of aortic stenosis, but a study published this month in the European Heart Journal considers whether a new aspect—the environmental impact of the available treatment options—should be taken in to consideration.
The study, authored by David Blitzer, Isaac George and colleagues (Columbia University Irving Medical Center, New York, USA) compares the total life cycle carbon footprint of surgical aortic valve replacement (SAVR) to transcatheter aortic valve implantation (TAVI) performed in operating room (OR) or cath lab settings, taking into account material and energy usage in the preoperative, operative and postoperative stages.
What the investigators were able to show was that the carbon footprint of the surgical approach was likely to be around twice as high as that of TAVI, performed in either setting, something they say should potentially be taken into consideration when making population level decisions and treatment guidelines moving into the future.
“Climate change is increasingly recognised as a public health issue, with the World Health Organization estimating an excess of 250,000 mortalities per year, and ultimately accounting for 8 million deaths worldwide between 2030 and 2050 and increasing evidence for the role of environmental factors in cardiovascular morbidity and mortality,” Blitzer and colleagues write in their European Heart Journal paper.
The healthcare sector, they acknowledge, is a major contributor to greenhouse gas emissions, accounting for an estimated 4–10% of total emissions. However, the authors note that literature quantifying the greenhouse gas emissions of cardiothoracic surgery procedures are limited, whilst there has been no such attempt for transcatheter therapies.
Using a life cycle assessment (LCA) methodology, the study’s authors compared the approaches using data from procedures performed from March to September 2023.
Parameters assessed included the raw materials, manufacturing, transportation, use, and end-of-life treatment of surgical instruments, personal protective equipment, and the implanted prostheses, as well as pre-operative imaging and interventions, including computed tomography, echocardiography, catheterisations, and blood work related to the procedures. A model for carbon footprints, measured in kilograms of CO2 equivalents (kg CO2e) was created, based on the primary data.
The researchers showed that total life cycle carbon footprint for TAVI performed in the OR (280–340kg CO2e) and cath lab (290–360kg CO2e) were significantly lower than for SAVR (620–750kg CO2e).
Postoperative intensive care unit and floor care accounted for the largest portion of the carbon footprint, including ∼170kg CO2e for OR-TAVI (55% of total), 170kg CO2e for cath lab–TAVI (52% of total), and 405kg CO2e for SAVR (59% of total).
Of the total, intensive care unit length of stay was a large contributor to the carbon footprint, comprising ∼27% of OR–TAVI, 25% of cath lab–TAVI, and 43% of the SAVR footprint.
“Our periprocedural analysis demonstrates that SAVR is associated with twice the carbon footprint of TAVI regardless of the location of where TAVI was performed. Surgical aortic valve replacement was associated with significantly more waste intraoperatively, as well as post-operatively due to the significantly longer intensive care unit (ICU) and total lengths of stay,” Blitzer and colleagues write in their European Heart Journal paper.
“While carbon emissions should not be the deciding factor in the treatment strategy for individual patients, relative emissions should play a role in the future when deciding between differing treatment options,” they go on to write. They note that some literature already exist regarding the ethical principles that might guide decisions surrounding healthcare rationing should that become necessary as a result of climate change, similar to approaches adopted during the pandemic.
“If climate change is not curtailed, such policies may have to be implemented on a wider scale and for longer periods of time. Regardless, data acquisition, analysis, and provider education will be critical to informing this decision-making process and to hopefully implementing policies that help avoid the need to ration or limit care based on environmental limitations.”
Steps such as minimising unnecessary plastic packaging and properly utilising independent waste streams could go some way to addressing some of the issues highlighted in their paper, the authors state. “Developing sustainable and meaningful practices today will pay dividends for the medical community and society for the future,” they conclude.
