Highlights
– A life cycle assessment following ISO14067 found the carbon footprint per procedure for surgical aortic valve replacement (SAVR) was approximately 620–750 kg CO2e, about twice that of either OR-based or cath-lab transcatheter aortic valve replacement (TAVR) (~280–360 kg CO2e).
– The largest single contributor across procedures was postoperative care (ICU and ward), with ICU length of stay accounting for a disproportionate share—~43% of SAVR emissions versus ~25–27% for TAVR.
– Intraoperative emissions were substantially higher for SAVR (≈241 kg CO2e) than for TAVR (≈100–103 kg CO2e), driven by biological waste, inhaled anesthetic gases, and resource-intensive surgical consumables.
Background: clinical context and why this matters
Aortic stenosis is a common, progressively symptomatic valvular heart disease in older adults. Treatment options include open surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR). Clinical decision-making has traditionally prioritized procedural risk, durability, patient preference, and health system costs. Climate change and healthcare’s contribution to global greenhouse gas emissions are now widely recognized as major determinants of population health. Quantifying the environmental impact of major interventions permits more holistic value assessments and identifies targets for mitigation within care pathways.
Study design and methods
The referenced study by Blitzer et al. (Eur Heart J. 2025) performed a life cycle assessment (LCA) to estimate the carbon footprints associated with SAVR and TAVR when performed in two procedural environments (operating room [OR] and catheterisation lab [CATH]). The analysis included primary data collected from March to September 2023 for 10 SAVR cases, 10 OR-TAVR cases, and 10 CATH-TAVR cases. Patients undergoing concomitant procedures were excluded to isolate the valve-replacement episode.
The investigators constructed a carbon-footprint model in accordance with ISO14067 standards, expressed in kilograms of CO2 equivalents (kg CO2e). The model incorporated primary inputs for material and consumable use, energy consumption, perioperative procedures, and postoperative resource use spanning preoperative, intraoperative, and post-operative phases. The authors report a coefficient of variation of 10% for total footprints and up to 25% for individual life cycle stages, consistent with accepted LCA uncertainty ranges.
Key findings
Population characteristics: median ages were 77 (range 65–91) for OR-TAVR, 82 (range implicitly 71–96 based on text format) for CATH-TAVR, and 66 (51–79) years for SAVR. Median Society of Thoracic Surgeons (STS) risk scores were 4.9% (OR-TAVR), 2.8% (CATH-TAVR), and 1.4% (SAVR), indicating different baseline surgical risk profiles across groups; left ventricular ejection fraction was similar.
Overall carbon footprints: median total life-cycle carbon footprints were reported as follows: OR-TAVR 280–340 kg CO2e, CATH-TAVR 290–360 kg CO2e, and SAVR 620–750 kg CO2e. The difference between SAVR and either TAVR approach was statistically significant (P < .05).
Phase-specific contributors: postoperative care (ICU and ward) represented the largest share of each procedure’s footprint: OR-TAVR ~170 kg CO2e (≈55% of total), CATH-TAVR ~170 kg CO2e (≈52%), and SAVR ~405 kg CO2e (≈59%). ICU length of stay alone accounted for ~27% of the OR-TAVR footprint, ~25% of the CATH-TAVR footprint, and ~43% of the SAVR footprint.
Intraoperative emissions: intraoperative footprints were approximately 100 kg CO2e for OR-TAVR, 103 kg CO2e for CATH-TAVR, and 241 kg CO2e for SAVR. The intraoperative SAVR contribution was driven largely by increased biological waste generation, higher postoperative length of stay implications, and inhaled anaesthetic gas use.
Relative magnitudes and interpretation: the SAVR per-case greenhouse gas burden was roughly double that of either TAVR approach. Differences were observed both intraoperatively and—more importantly—in postoperative care resource use, particularly ICU utilization.
Expert commentary: strengths, context, and limitations
Strengths
The study follows ISO14067-guided LCA methodology and uses primary, case-level data covering consumables, procedures, and perioperative energy and resource use. By comparing three commonly used procedural permutations (OR-TAVR, CATH-TAVR, SAVR), the analysis is directly relevant to clinicians, administrators, and policy-makers considering procedural mix at the population level.
Context with prior literature
Healthcare contributes materially to national greenhouse gas inventories in many countries. Quantitative LCAs in surgery and anesthesia have previously identified intraoperative consumables, waste management, and anaesthetic gas use as recurring carbon hotspots. This study extends that literature into structural heart interventions—high-cost, high-impact procedures whose population-level footprint depends on shifting case volumes between surgical and transcatheter approaches.
Key limitations and considerations for interpretation
Sample size and generalizability: each arm included 10 cases, a modest sample that may not capture institutional variability in practice, energy sourcing, or supply-chain differences. The investigators report coefficients of variation consistent with LCA practice, but confidence intervals around point estimates were not described in detail.
Patient selection and baseline differences: STS risk was lower in the SAVR group (median 1.4%) than in TAVR groups, and age distributions differed. These baseline differences may influence length of stay and complication rates and could confound footprint comparisons if not fully adjusted.
Scope and system boundaries: while the authors relied on ISO14067 guidance, LCAs can vary substantially by choice of boundaries. It is not explicit whether long-term device manufacturing and upstream supply-chain emissions beyond immediate materials were fully included, or whether downstream emissions (rehospitalisations, long-term follow-up) were assessed. Energy grid carbon intensity (regional electricity mix) and waste-management practices (incineration vs. recycling) materially affect absolute kg CO2e values and limit transferability to other regions or institutions.
Clinical outcomes and broader value: the carbon footprint is one dimension of value. Clinical effectiveness, patient-centered outcomes, costs, and device durability remain central to treatment choice. An environmental metric should complement—not replace—traditional comparative effectiveness and economic evaluations.
Implications for practice, systems change, and policy
Immediate clinical and operational opportunities. Because postoperative care (and ICU length of stay in particular) dominated emissions, strategies that safely reduce ICU and ward time could have outsized carbon benefits. These include enhanced recovery after surgery (ERAS) pathways adapted for cardiac surgery, early mobilization, streamlined postoperative protocols, proactive delirium prevention, and targeted discharge planning.
Intraoperative mitigation. For SAVR, the intraoperative footprint was greater due to higher biological waste and inhaled anaesthetic gases. Practical steps include optimizing waste segregation (reducing regulated medical waste where appropriate), using low-flow anesthesia or total intravenous anesthesia (TIVA) to limit high global-warming-potential volatile agents, and reviewing single-use versus reusable device pathways where infection control and patient safety allow.
Facility and supply-chain level actions. Decarbonising hospital energy supplies (renewable electricity), improving HVAC efficiency in procedural suites, and working with device manufacturers to reduce embedded carbon in product manufacture and packaging are longer-term but impactful approaches. Reprocessing or redesigning consumables, and regional or national purchasing standards that prioritize low-carbon suppliers, can shift emissions upstream.
Health technology assessment and guideline integration. These findings support integrating environmental outcomes into comparative assessments and guideline deliberations. When clinical outcomes are similar between options, carbon footprint may be an additional consideration for system-level resource allocation and sustainability goals. Policymakers should be cautious: environmental metrics are contextual and should be weighed alongside equity, access, and clinical effectiveness.
Recommendations for future research
Key next steps include larger multicenter LCAs that capture geographic variability in energy mixes and clinical practices, prospective studies linking outcomes (complications, readmissions) to emissions, and extended system boundary analyses that include device manufacturing and lifetime follow-up. Randomized trials or registry-based comparative-effectiveness studies that collect environmental endpoints would strengthen causal inference.
Conclusions
Blitzer and colleagues provide a rigorous, ISO14067-aligned life cycle assessment showing that SAVR is associated with approximately double the per-procedure carbon footprint of transcatheter approaches performed either in an operating room or a catheterisation lab. Postoperative resource use—particularly ICU length of stay—was the largest driver, suggesting that perioperative pathway optimization offers high-yield opportunities for emissions reduction. Incorporating carbon footprint metrics into health technology assessments, clinical guidelines, and hospital sustainability strategies can help health systems align clinical excellence with planetary stewardship, provided such metrics are interpreted within the full context of clinical outcomes and equity considerations.
Funding and clinicaltrials.gov
Funding: as reported in the original article (Blitzer et al., Eur Heart J. 2025). Specific funding sources were not detailed in the summary provided here.
ClinicalTrials.gov: none reported for the LCA described.
References
1. Blitzer D, Meinrenken CJ, Apelgren NB, Chavez XS, Durrenberger O, Jagdish AS, Simpson M, Bowers N, James EI, Pirelli L, Lebehn M, Agarwal V, Ng V, Vahl T, Nazif T, Hahn RT, Kodali S, Leon MB, George I. Carbon emission analysis of aortic valve replacement: the environmental footprint of transcatheter vs. surgical procedures. Eur Heart J. 2025 Nov 21;46(44):4810-4819. doi: 10.1093/eurheartj/ehaf379. PMID: 40599126.
2. International Organization for Standardization. ISO 14067:2018 Greenhouse gases — Carbon footprint of products — Requirements and guidelines for quantification. ISO; 2018.
3. World Health Organization. Climate change and health. WHO. https://www.who.int/health-topics/climate-change (accessed 2025).
Author note
This article is an evidence-focused interpretation intended for clinicians, administrators, and policy-makers. It synthesizes and critically appraises the findings of the cited life cycle assessment and discusses practical mitigation strategies, limitations, and policy implications.
