An Uneven Playing Field: Demographic and Regionalized Disparities in Access to Device-Based Therapies for Cardiogenic Shock

Racial, Ethnic, Socioeconomic, and Geographic Inequities in Access to Mechanical Circulatory SupportJournal of the Society for Cardiovascular Angiography & Interventions101193PreviewHospital admissions for cardiogenic shock have increased in the United States. Temporary mechanical circulatory support (tMCS) can be used to acutely stabilize patients. We sought to evaluate the presence of racial, ethnic, and socioeconomic inequities in access to MCS in the United States among patients with cardiogenic shock. Full-Text PDF Open Access With advances in primary percutaneous coronary intervention and the integration of regionalized systems of care networks, in-hospital mortality following acute myocardial infarction (AMI) has dropped to <5%1McNamara R.L. Kennedy K.F. Cohen D.J. et al.Predicting in-hospital mortality in patients with acute myocardial infarction.J Am Coll Cardiol. 2016; 68: 626-635https://doi.org/10.1016/j.jacc.2016.05.049Crossref PubMed Scopus (158) Google Scholar; however, in the 5% to 12% of AMI complicated by circulatory collapse due to cardiogenic shock (CS), short-term mortality rates remain >40%.2Hochman J.S. Sleeper L.A. Webb J.G. et al.Early revascularization in acute myocardial infarction complicated by cardiogenic shock. SHOCK investigators. Should we emergently revascularize occluded coronaries for cardiogenic shock.N Engl J Med. 1999; 341: 625-634https://doi.org/10.1056/NEJM199908263410901Crossref PubMed Scopus (2377) Google Scholar, 3Kolte D. Khera S. Aronow W.S. et al.Trends in incidence, management, and outcomes of cardiogenic shock complicating ST-elevation myocardial infarction in the United States.J Am Heart Assoc. 2014; 3e000590https://doi.org/10.1161/JAHA.113.000590Crossref Scopus (420) Google Scholar, 4Sterling L.H. Fernando S.M. Talarico R. et al.Long-term outcomes of cardiogenic shock complicating myocardial infarction.J Am Coll Cardiol. 2023; 82: 985-995https://doi.org/10.1016/j.jacc.2023.06.026Crossref Scopus (1) Google Scholar In response to these discouraging outcomes, an increasing number of patients with CS due to AMI or acutely decompensated heart failure undergo implantation of temporizing mechanical circulatory support (tMCS) devices to support hemodynamics and end-organ perfusion as a bridge to myocardial recovery or advanced cardiac replacement therapies.5Shah M. Patnaik S. Patel B. et al.Trends in mechanical circulatory support use and hospital mortality among patients with acute myocardial infarction and non-infarction related cardiogenic shock in the United States.Clin Res Cardiol. 2018; 107: 287-303https://doi.org/10.1007/s00392-017-1182-2Crossref PubMed Scopus (182) Google Scholar,6Schrage B. Becher P.M. Goßling A. et al.Temporal trends in incidence, causes, use of mechanical circulatory support and mortality in cardiogenic shock.ESC Heart Fail. 2021; 8: 1295-1303https://doi.org/10.1002/ehf2.13202Crossref PubMed Scopus (42) Google Scholar More recently, this surge in CS device-based therapy has been fueled by an increase in the deployment of microaxial left ventricular assist devices (mLVAD) and extracorporeal membrane oxygenation (ECMO), given their enhanced hemometabolic support capabilities compared with conventional intraaortic balloon pump (IABP).7Thiele H. Jobs A. Ouweneel D.M. et al.Percutaneous short-term active mechanical support devices in cardiogenic shock: a systematic review and collaborative meta-analysis of randomized trials.Eur Heart J. 2017; 38: 3523-3531https://doi.org/10.1093/eurheartj/ehx363Crossref PubMed Scopus (238) Google Scholar, 8Amin A.P. Spertus J.A. Curtis J.P. et al.The evolving landscape of Impella use in the United States among patients undergoing percutaneous coronary intervention with mechanical circulatory support.Circulation. 2020; 141: 273-284https://doi.org/10.1161/CIRCULATIONAHA.119.044007Crossref PubMed Scopus (242) Google Scholar, 9Syed M. Khan M.Z. Osman M. et al.Sixteen-year national trends in use and outcomes of VA-ECMO in cardiogenic shock.Cardiovasc Revasc Med. 2022; 44: 1-7https://doi.org/10.1016/j.carrev.2022.06.267Crossref Scopus (6) Google Scholar This trend continues despite an absence of randomized clinical trial (RCT) data demonstrating improvement in short-term survival with tMCS devices compared with medical therapy or IABP, and with clinical guidelines assigning their routine use in AMI-CS only a Class IIb (Level of Evidence: C) recommendation.10Karami M. Eriksen E. Ouweneel D.M. et al.Long-term 5-year outcome of the randomized IMPRESS in severe shock trial: percutaneous mechanical circulatory support vs. intra-aortic balloon pump in cardiogenic shock after acute myocardial infarction.Eur Heart J Acute Cardiovasc Care. 2021; 10: 1009-1015https://doi.org/10.1093/ehjacc/zuab060Crossref PubMed Scopus (24) Google Scholar, 11Thiele H. Zeymer U. Akin I. et al.Extracorporeal life support in infarct-related cardiogenic shock.N Engl J Med. 2023; 389: 1286-1297https://doi.org/10.1056/NEJMoa2307227Crossref Google Scholar, 12Levine G.N. Bates E.R. Blankenship J.C. et al.ACC/AHA/SCAI Focused Update on Primary Percutaneous Coronary Intervention for Patients with ST-elevation myocardial infarction: an update of the 2011 ACCF/AHA/SCAI guideline for percutaneous coronary intervention and the 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction.Circulation. 2016; 133: 1135-1147https://doi.org/10.1161/CIR.0000000000000336Crossref PubMed Scopus (339) Google Scholar Perhaps, the increased use of tMCS devices is fueled by data from dedicated North American CS registries that show that the early use of hemodynamically tailored tMCS at institutions with appropriate levels of expertise is associated with improved survival.13Basir M.B. Kapur N.K. Patel K. et al.Improved outcomes associated with the use of shock protocols: updates from the national cardiogenic shock initiative.Catheter Cardiovasc Interv. 2019; 93: 1173-1183https://doi.org/10.1002/ccd.28307Crossref PubMed Scopus (271) Google Scholar, 14Tehrani B.N. Truesdell A.G. Sherwood M.W. et al.Standardized team-based care for cardiogenic shock.J Am Coll Cardiol. 2019; 73: 1659-1669https://doi.org/10.1016/j.jacc.2018.12.084Crossref PubMed Scopus (277) Google Scholar, 15Papolos A.I. Kenigsberg B.B. Berg D.D. et al.Management and outcomes of cardiogenic shock in cardiac ICUs with versus without shock teams.J Am Coll Cardiol. 2021; 78: 1309-1317https://doi.org/10.1016/j.jacc.2021.07.044Crossref PubMed Scopus (62) Google Scholar To muddy the waters in this field even further, there is marked regional variation in the expertise, access to, and use of tMCS devices for CS patients who remain unresponsive to conventional treatment strategies.8Amin A.P. Spertus J.A. Curtis J.P. et al.The evolving landscape of Impella use in the United States among patients undergoing percutaneous coronary intervention with mechanical circulatory support.Circulation. 2020; 141: 273-284https://doi.org/10.1161/CIRCULATIONAHA.119.044007Crossref PubMed Scopus (242) Google Scholar,16Shaefi S. O’gara B. Kociol R.D. et al.Effect of cardiogenic shock hospital volume on mortality in patients with cardiogenic shock.J Am Heart Assoc. 2015; 4e001462https://doi.org/10.1161/JAHA.114.001462Crossref Scopus (120) Google Scholar, 17Geller B.J. Sinha S.S. Kapur N.K. et al.Escalating and de-escalating temporary mechanical circulatory support in cardiogenic shock: a scientific statement from the American Heart Association.Circulation. 2022; 146: e50-e68https://doi.org/10.1161/CIR.0000000000001076Crossref PubMed Scopus (35) Google Scholar, 18Elbadawi A. Elgendy I.Y. Omer M.A. et al.Hospital volume and in-hospital outcomes with Impella guided percutaneous coronary interventions: insights from a national database.Am J Cardiol. 2020; 125: 1753-1754https://doi.org/10.1016/j.amjcard.2020.03.007Abstract Full Text Full Text PDF Scopus (2) Google Scholar How tMCS use is influenced by patient demographic characteristics, such as race, ethnicity, and social determinants of health has not been well studied. In this issue of JSCAI, Nathan et al19Nathan A.S. Reddy K.P. Eberly L.A. et al.Racial, ethnic, socioeconomic, and geographic inequities in access to mechanical circulatory support.J Soc Cardiovasc Angiogr Interv. 2023; Google Scholar examined racial, ethnic, and socioeconomic disparities in access to tMCS in Medicare beneficiaries with an admission or diagnosis discharge of CS who were treated with IABP, mLVAD, or ECMO at 1829 percutaneous coronary intervention-capable acute care facilities at the 25 largest core-based statistical areas in the United States. These authors should be commended for performing an in-depth analysis that provides insight into this device-related health care disparity. Using Medicare demographic characteristics to identify race and ethnicity, and individual assessments of median household income, Medicaid dual-eligibility, and distressed community index scores to categorize socioeconomic status, the authors (1) compared patient socioeconomic and hospital characteristics of institutions with and without mLVAD or ECMO programs; (2) determined the likelihood of mLVAD or ECMO use based on race, ethnicity, and socioeconomic status; and (3) described variations in ZIP code-level age-adjusted rates of mLVAD utilization. The findings were sobering; widespread disparities in access to these cutting-edge therapies were observed based on race and ethnicity. More than 90% of sites with mLVAD and ECMO programs were located in metropolitan areas, and these hospitals were more likely to treat patients with high median household incomes. Only 3 centers with mLVAD and 1 with ECMO capabilities were identified in rural areas. Racial and ethnic disparities were equally stark, with <10% of all patients receiving an mLVAD self-identifying as African American. Using generalized linear mixed effects models, they elucidated associations between socioeconomic status, race, ethnicity, and the likelihood of receiving an mLVAD. African American and dual Medicaid-eligible CS patients were at significant disadvantages, with the odds of receiving these advanced device-based treatment strategies reduced by 37% and 20%, respectively. More pronounced findings were noted with ECMO, such that for each $1000 decrement in median household income there was a 35% reduction in the likelihood of receiving this form of cardiopulmonary support. Again, African Americans and dual Medicaid eligible patients fared most poorly, as their odds of undergoing cannulation for refractory circulatory collapse were reduced by 36% and 62%, respectively. Chloropleth maps of the core-based statistical areas in question graphically reinforced these study findings by demonstrating that African Americans, Hispanics, and patients who were dual Medicaid eligible had markedly attenuated rates of implantation of these devices. There is precedent for demographic and geographic variations in access to cutting-edge technologies across the spectrum of interventional cardiology.20Damluji A.A. Fabbro M. Epstein R.H. et al.Transcatheter aortic valve replacement in low-population density areas: assessing healthcare access for older adults with severe aortic stenosis.Circ Cardiovasc Qual Outcomes. 2020; 13e006245https://doi.org/10.1161/CIRCOUTCOMES.119.006245Crossref Scopus (11) Google Scholar, 21Steitieh D. Zaidi A. Xu S. et al.Racial disparities in access to high-volume mitral valve transcatheter edge-to-edge repair centers.J Soc Cardiovasc Angiogr Interv. 2022; 1100398https://doi.org/10.1016/j.jscai.2022.100398Abstract Full Text Full Text PDF Scopus (2) Google Scholar, 22Kupsky D.F. Wang D.D. Eng M. et al.Socioeconomic disparities in access for watchman device insertion in patients with atrial fibrillation and at elevated risk of bleeding.Struct Heart. 2019; 3: 144-149https://doi.org/10.1080/24748706.2019.1569795Abstract Full Text Full Text PDF Google Scholar, 23Maknojia A. Gilani A. Ghatak A. Racial disparity in patients with chronic coronary total occlusion undergoing interventions.J Soc Cardiovasc Angiogr Interv. 2022; 1: E-21Google Scholar Using health care administrative inpatient claims data, Damluji et al20Damluji A.A. Fabbro M. Epstein R.H. et al.Transcatheter aortic valve replacement in low-population density areas: assessing healthcare access for older adults with severe aortic stenosis.Circ Cardiovasc Qual Outcomes. 2020; 13e006245https://doi.org/10.1161/CIRCOUTCOMES.119.006245Crossref Scopus (11) Google Scholar reported a nearly 7-fold difference in transcatheter aortic valve replacement utilization rates in the state of Florida, with the majority of dedicated valve centers located in high population density areas, and those residing in low population density areas having marked increases in travel time/distance and >6 fold higher procedural mortality. Parallel findings were noted in a contemporary analysis of 1567 hospital discharges following transcatheter edge-to-edge repair for severe mitral valve regurgitation from the Arizona, Colorado, Florida, Maryland, North Carolina, New Jersey, New York, and Virginia State Inpatient Databases. Specifically, there were significant racial disparities in access to high-volume mitral valve institutions, with African Americans and Hispanics being afforded 59% and 51% lower chances of access to transcatheter mitral valve repair at high-volume centers, respectively.21Steitieh D. Zaidi A. Xu S. et al.Racial disparities in access to high-volume mitral valve transcatheter edge-to-edge repair centers.J Soc Cardiovasc Angiogr Interv. 2022; 1100398https://doi.org/10.1016/j.jscai.2022.100398Abstract Full Text Full Text PDF Scopus (2) Google Scholar Hispanics were also 3 times more likely to experience in-hospital mortality post-procedure.21Steitieh D. Zaidi A. Xu S. et al.Racial disparities in access to high-volume mitral valve transcatheter edge-to-edge repair centers.J Soc Cardiovasc Angiogr Interv. 2022; 1100398https://doi.org/10.1016/j.jscai.2022.100398Abstract Full Text Full Text PDF Scopus (2) Google Scholar Unlike valve therapies, tMCS devices have not been associated with improved survival, and they are often implanted under emergency circumstances, in which the rates of major bleeding complications and acute limb ischemia may be as high as 40%.24Pahuja M. Ranka S. Chehab O. et al.Incidence and clinical outcomes of bleeding complications and acute limb ischemia in STEMI and cardiogenic shock.Catheter Cardiovasc Interv. 2021; 97: 1129-1138https://doi.org/10.1002/ccd.29003Crossref PubMed Scopus (26) Google Scholar, 25Cheng R. Hachamovitch R. Kittleson M. et al.Complications of extracorporeal membrane oxygenation for treatment of cardiogenic shock and cardiac arrest: a meta-analysis of 1,866 adult patients.Ann Thorac Surg. 2014; 97: 610-616https://doi.org/10.1016/j.athoracsur.2013.09.008Abstract Full Text Full Text PDF PubMed Scopus (610) Google Scholar, 26Stone G.W. Abraham W.T. Lindenfeld J. et al.Five-year follow-up after transcatheter repair of secondary mitral regurgitation.N Engl J Med. 2023; 388: 2037-2048https://doi.org/10.1056/NEJMoa2300213Crossref PubMed Scopus (30) Google Scholar, 27Mack M.J. Leon M.B. Thourani V.H. et al.Transcatheter aortic-valve replacement with a balloon-expandable valve in low-risk patients.N Engl J Med. 2019; 380: 1695-1705https://doi.org/10.1056/NEJMoa1814052Crossref PubMed Scopus (2900) Google Scholar There exist well-established relationships between volume and outcomes in CS.16Shaefi S. O’gara B. Kociol R.D. et al.Effect of cardiogenic shock hospital volume on mortality in patients with cardiogenic shock.J Am Heart Assoc. 2015; 4e001462https://doi.org/10.1161/JAHA.114.001462Crossref Scopus (120) Google Scholar Therefore, another unwanted impact of the low use of tMCS devices in nonmetropolitan hospitals is that these facilities may experience worse outcomes and higher complication rates with the infrequent use of devices. In the context of recent observational data suggesting the potential for improved outcomes when tMCS devices are implanted using standardized team-based protocols, one may argue that the demographic and geographic differences in outcomes with CS seen today are in part due to the nonuniform patterns of patient selection seen in real-world clinical practice.13Basir M.B. Kapur N.K. Patel K. et al.Improved outcomes associated with the use of shock protocols: updates from the national cardiogenic shock initiative.Catheter Cardiovasc Interv. 2019; 93: 1173-1183https://doi.org/10.1002/ccd.28307Crossref PubMed Scopus (271) Google Scholar Notwithstanding the absence of professional societal guideline support for the broad use of tMCS devices in CS, the findings of Nathan et al highlight pervasive racial and ethnic barriers to the use of advanced medical device therapies present in the US health care system. These inequities have historically and disproportionately affected segments of our society who not only have the greatest burden of health and social risk factors but who are also underrepresented in clinical trials and whose voices are often not heard28Caraballo C. Ndumele C.D. Roy B. et al.Trends in racial and ethnic disparities in barriers to timely medical care among adults in the US, 1999 to 2018.JAMA Health Forum. 2022; 10 (3)e223856https://doi.org/10.1001/jamahealthforum.2022.3856Crossref Scopus (7) Google Scholar, 29Epps K. Goel R. Mehran R. et al.Influence of race/ethnicity and sex on coronary stent outcomes in diabetic patients.J Soc Cardiovasc Angiogr Interv. 2023; 2https://doi.org/10.1016/j.jscai.2023.101053Abstract Full Text Full Text PDF Scopus (1) Google Scholar, 30Ortega R.F. Yancy C.W. Mehran R. Batchelor W. Overcoming lack of diversity in cardiovascular clinical trials: a new challenge and strategies for success.Circulation. 2019; 140: 1690-1692https://doi.org/10.1161/CIRCULATIONAHA.119.041728Crossref PubMed Scopus (33) Google Scholar within the cacophony of health care discussions. In the case of tMCS, further research is needed in the form of pragmatic and adequately powered RCT enriched with broad patient subsets and prespecified definitions and protocols. Coupled with multicenter collaborations such as the American Heart Association’s Cardiogenic Shock Registry31Cardiogenic Shock Registryhttps://www.heart.org/en/professional/quality-improvement/cardiogenic-shock-registryDate accessed: October 12, 2023Google Scholar and regionalized shock networks, these efforts may provide further insight into the utilization and outcomes associated with advanced device-based interventions for CS across race, ethnicity, sex, rurality, and socioeconomic status. However, at their core, the findings of Nathan et al are disturbingly emblematic of a much more complex and challenging sociopolitical problem that is deeply rooted in the world’s richest health care system. Therefore, to truly level the “device therapy playing field” will require not only more targeted health-related outcomes research but a national commitment to improve health care access and quality, in general, and especially for those most in need of acute lifesaving therapies. Behnam Tehrani has received research grant funding support from Boston Scientific, and he is an advisor to Abbott Medical. Kelly Epps has no disclosures. Wayne Batchelor has served as a consultant for Boston Scientific, Abbott, Medtronic, and V-Wave. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.