ImportanceThe healthcare sector is essential to human health and well-being, yet its significant carbon footprint contributes to climate change-related threats to health.ObjectiveTo review systematically published studies on environmental impacts, including carbon dioxide equivalent (CO2e) emissions, of contemporary cardiovascular healthcare of all types, from prevention through to treatment.Evidence reviewWe followed the methods of systematic review and synthesis. We conducted searches in Medline, EMBASE and Scopus for primary studies and systematic reviews measuring environmental impacts of any type of cardiovascular healthcare published in 2011 and onwards. Studies were screened, selected and data were extracted by two independent reviewers. Studies were too heterogeneous for pooling in meta-analysis and were narratively synthesised with insights derived from content analysis.FindingsA total of 12 studies estimating environmental impacts, including carbon emissions (8 studies), of cardiac imaging, pacemaker monitoring, pharmaceutical prescribing and in-hospital care including cardiac surgery were found. Of these, three studies used the gold-standard method of Life Cycle Assessment. One of these found the environmental impact of echocardiography was 1%–20% that of cardiac MR (CMR) imaging and Single Photon Emission Tomography (SPECT) scanning. Many opportunities to reduce environmental impacts were identified: carbon emissions can be reduced by choosing echocardiography as the first cardiac test before considering CT or CMR, remote monitoring of pacemaker devices and teleconsultations when clinically appropriate to do so. Several interventions may be effective for reducing waste, including rinsing bypass circuitry after cardiac surgery. Cobenefits included reduced costs, health benefits such as cell salvage blood available for perfusion, and social benefits such as reduced time away from work for patients and carers. Content analysis revealed concern about the environmental impact of cardiovascular healthcare, particularly carbon emissions and a desire for change.Conclusions and relevanceCardiac imaging, pharmaceutical prescribing and in-hospital care including cardiac surgery have significant environmental impacts, including CO2e emissions which contribute to climate-related threats to human health. Importantly, many opportunities to effectively reduce environmental impacts exist within cardiac care, and can provide economic, health and social cobenefits.