In a recent study which revealed higher readmission and mortality rates among Black patients following percutaneous coronary intervention (PCI), stark disparities affected by the structural barriers to health equity in Michigan were emphasised, Stephanie Spehar (University of Michigan, Ann Arbor, USA) tells Cardiovascular News. In this interview, Spehar elaborates further on the rationale behind their retrospective analysis of data collected from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2), to address the socioeconomic gaps in post-PCI pathways to care between Black and white patients.
Can you please summarise the significance of the findings?
Firstly, to give an overview of the findings, when looking at long-term outcomes like readmission and mortality, we found that […] Black patients following PCI were more likely to be readmitted within 90-days and were more likely to die than white patients in long-term follow-up. In general, we found minimal differences in in-hospital process measures and outcomes between Black and white patients following PCI.
Another piece of our study that is important was trying to understand exactly why those disparities occur—some of the big drivers or mediators we saw were personal wealth and economic status of the patient’s community, as well as patients’ underlying comorbid conditions. This is significant as we know these differences still exist and it shows that there is some disparity of care outside of the hospital setting. We are doing a better job of adhering to guidelines and making sure everyone gets high-quality care, but once a patient leaves the hospital, we know that there are a number of important factors and structural barriers that may be driving long-term disparities in outcomes. It is challenging but important, and it highlights the need for our providers to care not only about the immediate procedure and what is happening in the acute hospital setting, but also overseeing the post-discharge pathways as well. Moreover, as a health care system, we must attempt to make improvements in preventive care to delay the onset of coronary artery disease and other comorbid conditions.
Do the common risk factors for coronary heart disease differ among ethnic groups?
In our research we were able to identify many baseline characteristics that may indicate differences in the severity of cardiovascular disease and could impact long-term outcomes. Black patients were more likely to have diabetes, hypertension, and had higher rates of chronic kidney disease necessitating dialysis. It is well established that such conditions not only put one at risk for cardiovascular disease but may also impact long-term outcomes.
Underlying conditions are certainly one of the most important factors that may explain the differences in post-PCI long-term outcomes between Black and white patients, but that is not to say there are not other things happening too, particularly concerning are personal wealth and the economic wellbeing of the community. Moreover, the relationship between personal wealth, economic wellbeing of the community, and underlying conditions or comorbidities are complex and interconnected.
What would you say are the most significant risk factors contributing to mortality among Black patients post-PCI?
It is hard to know because we do not necessarily have a grasp on what is specifically happening, or not happening, in the outpatient setting. One of our important findings was that Black patients were less likely to be referred to cardiac rehabilitation. We know that cardiac rehabilitation is a guideline-recommended therapy after heart attacks and stenting. We believe a very tangible thing that can come from this study is focusing on cardiac rehabilitation referrals and understanding why Black patients are not being referred. This disparity is important as it is something we have already begun targeting within our state-wide quality improvement collaborative. Other than that, it is really hard to know exactly what is happening in the outpatient setting and we definitely need more research in terms of post-acute care pathways and care coordination. Patient navigation assistance has been used in different populations, like the oncology population, and may be helpful after PCI. Again, working through some of the socioeconomic barriers like transportation, having access to healthcare, which a lot of folks do not have here, is really critical. These are not necessarily measures that we are tracking as physicians, but they are extremely important in terms of outcomes. Finally, optimal management of risk factors in terms of underlying conditions—so better management of hypertension and diabetes—will continue to improve long-term outcomes following heart attacks as well.
You mention having conducted a state-wide quality improvement collaborative to discuss improvements that can be made concerning patient care—what were the outcomes of this? How can post-PCI disparities between Black and white patients be reduced?
Michigan has a state-wide collaborative which collects data on all PCIs performed at 48 hospitals across the state. It is a robust body of data that we can use to understand care here. The group meets regularly to debrief and understand these outcomes and we have begun to try to understand these observed disparities
I think cardiac [rehabilitation] cannot be understated. Why is it that people are being referred less for cardiac [rehabilitation] and how, as a system, can we make sure that this stops happening? And so it is a really strong collaborative group that comes together and thinks through different strategies for how we can attempt to reduce these disparities.
Within our state-wide quality collaborative we have focused on improving the use of cardiac rehabilitation after cardiovascular procedures such as PCI with a specific goal of improving the rate of referral to cardiac rehabilitation prior to discharge. Our hope is that through collaboration across the state with health care facilities and providers, we can improve upon this disparity.
Lastly, understanding the root cause of many of these structural barriers to health equity remains critical.
What do the results tell us about racial disparities more generally in the USA? Does the study raise questions that may lead to further study? Are there broader questions that can be answered by this research?
That is one of the limitations of our study—it is based in the state of Michigan and so certainly the patient population and the economic landscape may be different than in other states. So, I think it is hard to generalise across the entire USA, although we are a racially, socioeconomically diverse state, and we saw that in our data. And so again, I think it is hard to generalise, but I do not think anyone would be surprised if these same disparities were true at a more national level.
How generalisable are the results to the other ethnic groups that were excluded from the study? Are you able to extend these findings?
I cannot comment on other races or ethnic groups—we specifically focused on Black and White patients as they were the largest racial/ethnic groups. Patients who identify as multiple races were around 2.9% of our entire population. I do not know that we would be able to generalise, although when you look at what mediated the difference in outcomes, again it was personal wealth, community socioeconomic status, and comorbid conditions. Race is a social construct not a biological one.
I think one big takeaway for us is post-procedure routes to care and the options that are available so that we can better support patients and make sure they are getting the follow-up care they need and are not being readmitted and having bad outcomes. And more broadly, we as a society need to focus on understanding the root causes of many of the structural barriers to health equity such as ensuring economic mobility and affordable and adequate health insurance coverage, to name a few.
