MI Care Varies Across Asian Subgroups in the US

Patients of Asian descent who experience MI in the United States are not all treated equally, according to new data. The study, which stratifies patients by seven Asian subgroups, emphasizes the need for population-specific interventions as well as increased representation of diverse patients in clinical research, the researchers say.

Previous studies have identified a heterogeneous mix of risk factors for CVD and diabetes across the population of Asian American adults. For example, people of South Asian descent tend to be at greater risk for developing atherosclerotic cardiovascular disease, but other work has shown that this population is not represented well in large trials.

“Emerging epidemiologic evidence shows us that health status and health outcomes are experienced really quite differently among the different individual Asian ethnic groups in the US,” senior author Nilay S. Shah, MD, MPH (Northwestern University Feinberg School of Medicine, Chicago, IL), told TCTMD. While this is becoming increasingly recognized, he added, the problem remains that “so much of health-related research, when it even includes people who are Asian in the first place, groups everybody together into a singular Asian category.”

A big challenge in tackling this problem is that a solution to improve care for one community might not work for another, Shah added.

“That's not exclusive to people who are Asian,” he said. “We shouldn't assume that what works for one Hispanic community in one place, works for the Black population of another place, works for the Asian population of another place. And there's quite a bit of intersectional factors that are important here, not the least of which are things like socioeconomic position, which obviously influences an individual's ability to access care.”

Commenting on the study for TCTMD, Umesh Khot, MD (Cleveland Clinic, OH), agreed on the need for identifying inconsistencies in treatment and addressing them to achieve better equity. “The biggest thing this highlights is that there's a lot of variability in care,” he said. “Particularly in STEMI care, but also heart attack care in general, you want to eliminate variability and you want people to be treated consistently and in the same way no matter who they are or when or where they present.”

Widespread Outcomes

For the study, published online recently in Circulation: Cardiovascular Quality and Outcomes, Aishwarya Vijay, MD (Northwestern University Feinberg School of Medicine), Shah, and colleagues included 5,691 Asian American patients (1,520 Asian Indian, 422 Chinese, 430 Filipino, 114 Japanese, 283 Korean, 553 Vietnamese, and 2,369 other Asian) as well as 141,271 non-Hispanic white patients from the Get With The Guidelines-Coronary Artery Disease registry. Mean age ranged from 62.9 to 69.4 years among the Asian American groups and was 66.7 years in the non-Hispanic white group. All patients had a STEMI or NSTEMI between 2015 and 2021 and were treated at one of 711 US hospitals.

Baseline characteristics varied across the Asian cohorts. The proportion of female patients ranged from 23.9% in the Asian Indian group to 37.5% in Koreans. Additionally, Filipino patients reported the highest prevalence of diabetes (27.7%), dyslipidemia (36.5%), and hypertension (44.2%), while Chinese patients were the most frequent smokers (28.4%).

So much of health-related research, when it even includes people who are Asian in the first place, groups everybody together into a singular Asian category. Nilay S. Shah

In analyzing process measures and quality of care, investigators adjusted for numerous factors: age, cardiac arrest before arrival, cardiogenic shock on presentation, heart failure on presentation, history of diabetes, history of cerebrovascular disease, baseline serum creatinine, and history of current or prior smoking.

Among the STEMI patients, door-to-ECG time ≤ 10 minutes was less likely in Asian Indian (OR 0.64; 95% CI 0.50-0.82), Chinese (OR 0.65; 95% CI 0.46-0.93), and Korean (OR 0.57; 95% CI 0.33-0.97) men and in other Asian women (OR 0.61; 95% CI 0.41-0.90) compared with their non-Hispanic white peers. Additionally, a door-to-balloon time ≤ 90 minutes was less likely in Asian Indian men (OR 0.71; 95% CI 0.56-0.90) and Filipina women (OR 0.48; 95% CI 0.24-0.98).

In the overall population, Korean men (OR 0.65; 95% CI 0.47-0.90) were less likely to receive optimal medical therapy after MI than non-Hispanic white patients, and Asian Indian men (OR 1.22; 95% CI 1.06-1.40) and women (OR 1.32; 95% CI 1.04-1.67) as well as Filipina women (OR 1.84; 95% CI 1.27-2.67) were more likely to receive it. The odds of referral to cardiac rehab were also lower for Asian Indian (OR 0.87; 95% CI 0.75-1.00), Chinese (OR 0.76; 95% CI 0.58-0.99), Filipino (OR 0.62; 95% CI 0.47-0.81), Vietnamese (OR 0.63; 95% CI 0.50-0.79), and other Asian men (OR 0.68; 95% CI 0.61-0.75) as well as Korean (OR 0.64; 95% CI 0.42-0.98) and other Asian women (OR 0.79; 95% CI 0.66-0.94).

The secondary endpoint of in-hospital mortality was higher among Asian Indian (OR 1.55; 95% CI 1.12-2.16), Chinese (OR 2.12; 95% CI 1.27-3.56), and Filipino men (OR 1.77; 95% CI 1.01-3.10) as well as Vietnamese women (OR 1.86; 95% CI 1.01-3.41) compared with their non-Hispanic white counterparts.

“Objectively there should be no reason why a person's ethnicity should influence whether or not they can meet these quality metrics,” Shah said, acknowledging that the data “also aligned with what we know about cardiovascular disease in the Indian and Filipino populations.”

As such, “this study kind of raises the question of whether quality of care received at the point of having an MI and seeking treatment for an MI was contributing to the disproportionately worse outcomes experienced by patients in these groups,” he added.

Focusing Down

Shah called upon both clinical and administrative leaders to understand the measures needed to optimize quality of care for all patients as well as for specific populations.

“There are factors related to things like health literacy and English language proficiency. There are particular cultural norms around care seeking and adherence to recommendations,” he said. “We have to recognize just that fact that the things that influence quality of care and achieving some of these quality metrics is not necessarily uniform across all populations. . . . If we try to apply a uniform, singular intervention to improve quality of care across an entire health system, it's likely that some people would benefit from that and others wouldn't.”

An important next step should be figuring out why the variations identified in the study exist and what current quality improvement measures are working well, Shah said.

Understanding where in the chain of processes that this is causing problems will help us understand what the solutions are. Umesh Khot

Khot agreed. “Those could be patient-specific or it also could be related to where these people seek care and the types of hospitals they seek care to,” he said. “Understanding where in the chain of processes that this is causing problems will help us understand what the solutions are.”

At this point, Khot continued, improving care for the Asian Indian and Filipino subgroups seems like it would be the most impactful for decreasing mortality based on the data. “Trying to focus on those two populations in particular, especially if you're a hospital that serves a significant number of those patients, I think would be very valuable,” he said.

From there, Shah said, “clinicians and health systems are actually responsible for understanding what the demographics of their patient population are. Because if we don't really know who our patients are, then we can't really best serve them.” Also, pushing for greater representation in clinical research is another priority.

In an accompanying editorial, Robert C. Kaplan, PhD (Albert Einstein College of Medicine, Bronx, NY), and Kwun Chuen Gary Chan, PhD (University of Washington School of Public Health, Seattle), write that the study raises the question of “whether the advantages and disadvantages experienced by the Asian population are consistently found across hospitals and regions of the United States.” It could be that regions with fewer Asian individuals experience poorer quality of care, they suggest, and this is “an important topic for future research.” Studies going forward should also control for socioeconomic status, as Asian subgroups typically represent a range of wealth and poverty in the US, the editorialists note.

The recent launch of the 10,000-person Multi-Ethnic Observational Study in American Asian and Pacific Islander Communities (MOSAAIC) project should help “turn a new page in the story of Asian American health research,” they conclude.

Another recently published study in JAMA Cardiology showed that a culturally-sensitive group lifestyle intervention, while not effective than written health education content at reducing CVD risk factors in a population of South Asian adults in the US, could in fact lead to smaller improvements in things like diet quality and physical activity.