Carbon emission analysis of aortic valve replacement: the environmental footprint of transcatheter vs. surgical procedures

Abstract

Background and aims: The impact of climate change is increasingly recognized as a major public health determinant. A life cycle assessment to determine the carbon emissions associated with open surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) in the operating room (OR), and the cath lab (CATH) was performed.

Methods: Total carbon footprint from SAVR (n = 10) and TAVR (n = 10 OR-TAVR, n = 10 CATH-TAVR) from March to September 2023 was calculated. Patients undergoing any other procedure at the time of SAVR or TAVR were excluded. A model for carbon footprints, measured in kilograms of CO2 equivalents (kg CO2e) was created following ISO14067 standards, based on primary data (materials, procedures, energies, in the pre-operative, operative, and post-operative setting). Reported footprints carry a coefficient of variation of 10% for totals and up to 25% for individual life cycle stages, as standard in carbon footprinting analysis.

Results: Median age for OR-TAVR, CATH-TAVR, and SAVR was 77 (range 65-91), 82 (7196), and 66 (51-79) years, respectively. Median Society of Thoracic Surgeons risk for same was 4.9, 2.8, and 1.4%, respectively. Ejection fraction was similar across groups. Total life cycle carbon footprint for OR-TAVR, CATH-TAVR, and SAVR was 280-340 kg CO2e, 290-360 kg CO2e, and 620-750 kg CO2e, respectively (P < .05 SAVR vs either TAVR). Post-operative intensive care unit and floor care accounted for the largest portion of the carbon footprint, including ∼170 kg CO2e for OR-TAVR (55% of total), 170 kg CO2e for CATH-TAVR (52% of total), and 405 kg CO2e for SAVR (59% of total) (P < .05 SAVR vs either TAVR). Of the total, intensive care unit length of stay was a large contributor to the carbon footprint, comprising ∼27% of OR-TAVR, 25% of CATH-TAVR, and 43% of the SAVR footprint. Approximate intraoperative carbon footprint was 100 kg CO2e for OR-TAVR, 103 kg CO2e for CATH-TAVR, and 241 kg CO2e for SAVR. The intraoperative footprint of SAVR was driven by biological waste, post-operative length of stay, and inhaled anaesthetic gases.

Conclusions: The carbon footprint of SAVR is about twice as high as those from OR-TAVR or CATH-TAVR. These findings should potentially be considered when making population level decisions and guidelines moving into the future.

Keywords: AVR; SAVR; TAVR; aortic valve; emissions.