Worse CVD outcomes persisted after adjustment for risk factors

Black patients undergoing coronary angioplasty with stenting had significantly higher rates of cardiac death and other poor outcomes compared to whites in pooled data from major randomized coronary stenting trials.

After adjusting for multiple clinical risk factors, Black patients had roughly a 30% higher risk for major adverse cardiovascular events, including cardiac death, myocardial infarction (MI), and ischemia-driven lesion revascularization, at all time points examined, reaching statistical significance at 1- and 5-years.

Racial disparities in cardiovascular disease outcomes have been recognized for 3 decades, with numerous studies showing Black patients to have lower rates of coronary revascularization and higher cardiovascular mortality compared to whites, even after controlling for socioeconomic and other factors that impact these outcomes.

But these studies had significant limitations — including reliance on registry data and single-center design — and the impact of race and ethnicity on cardiovascular outcomes remains the subject of debate.

In an effort to address these limitations, researcher Mordechai Golomb, MD, of the Cardiovascular Research Foundation, New York City, and colleagues, pooled data from 10 randomized controlled trials to examine race-based differences in outcomes among patients undergoing percutaneous coronary intervention (PCI).

Their findings were published in the journal JACC: Cardiovascular Interventions.

Golomb and colleagues assessed baseline characteristics and outcomes at 30-days, 1-year and 5-years following PCI by race.

Major endpoints included death, MI, and major adverse cardiac events (MACE). Multivariate Cox proportional hazards regression was performed to assess associations between race and outcomes, controlling for differences in 12 baseline covariates.

The 10 pooled studies included 22,638 patients, including 20,585 (90.9%) who were white, 918 (4.1%) who were Black, 404 (1.8%) who were Asian, and 473 (2.1%) who were Hispanic.

Baseline characteristics differed among the groups, with Black and Hispanic participants more likely to be female, with higher BMIs and a higher prevalence of diabetes and hypertension.

Among the main findings:

  • Five-year major adverse cardiac event rates were 18.8% in white patients (reference group), compared with 23.9% in Black patients (P=0.0009), 11.2% in Asian patients (P=0.0007), and 21.5% in Hispanic patients (P=0.07).
  • At 30 days post-procedure, Black and white patients had similar rates of death (0.5% versus 0.7%, respectively; P=0.62), but Black patients had higher rates of MI (4.9% versus 3.3%; P=0.009) and major adverse cardiovascular events (MACE) (6% vs. 4.2%; P=0.008). These differences were consistent at 1 and 5 years.
  • Multivariate analysis demonstrated an independent association between Black race and 5-year risk for major adverse cardiac events (hazard ratio: 1.28; 95% CI, 1.05-1.57; P=0.01).
  • By multivariate analysis, black race was associated with increased adjusted risks for death (hazard ratio [HR]: 2.06; 95% CI, 1.26-3.36; P=0.004) and MI (HR: 1.45; 95% CI, 1.01-2.10; P=0.045) at 1 year and increased adjusted risks for MI (HR: 1.55; 95% CI: 1.15-2.09; P=0.004) and MACE (HR: 1.28; 95% CI; 1.05-1.57; P=0.01) at 5 years.

“The results of multivariate analysis from our study suggest that for Hispanic patients, the excess risk for adverse clinical outcomes may have been attributable to a higher prevalence of risk factors. In contrast, the excess risk for adverse clinical outcomes for Black patients persisted even after adjustment for baseline risk factors.”

Golomb and colleagues noted that this observed increase “may be explained by differences that are not fully captured in traditional cardiovascular risk factor assessment, including socioeconomic differences and education, treatment compliance rates and yet-to-be-elucidated genetic differences and/or other factors.”

In an accompanying editorial, Michael Nanna, MD, and Eric D. Peterson, MD, of the Duke University School of Medicine, Durham, North Carolina, wrote that while the study addresses some of the limitations of prior trials assessing racial differences in CVD outcomes, it had limitations of its own.

“Those enrolled in RCTs are typically healthier, receive better care, and as a result, have better outcomes than those in the community,” they wrote. “The trials also enrolled a low proportion of Black patients, which increases the risk of selection bias. Additionally, the trials classified those of Hispanic ethnicity as a separate race category, which is not consistent with current standards.”

Despite these limitations, the editorial writers noted that “the bottom-line conclusions from the Golomb et al. analyses are strikingly similar to those from multiple studies conducted over the past several decades.”

“Relative to whites, Black patients with CVD have significantly worse longitudinal outcomes,” they wrote.

Nanna and Peterson wrote that the study should be viewed “as part of a broader and consistent message of widespread racial disparities in America.”

“The most recent example can be found in the current news headlines, where Black patients have dramatically higher risk for Covid-19 infection and death relative to whites,” they wrote. “Although less well studied to date, the underlying causes for these differences in the Covid-19 pandemic are likely to mirror those in the CVD disparities published reports.”

They concluded that the study by Golomb and colleagues “remind us just how large the racial gaps in CVD care and outcomes continue to be.”

“Yet, rather than merely observe these differences over and over again for the next 30 years, there is an urgent need for action to address these, both locally and nationally. The recent unfortunate death of George Floyd has helped awaken the nation’s consciousness to urgently address longstanding racial injustice.

“The medical profession too should seize this moment and find ways of reversing racial disparities in health and healthcare. Talking is no longer enough; it is our responsibility to finally deliver effective solutions.”

  1. After adjusting for multiple clinical risk factors, Black patients had roughly a 30% higher risk for major adverse cardiovascular events, including cardiac death, myocardial infarction (MI) and ischemia-driven lesion revascularization, at all time points examined.

  2. By multivariate analysis, Black race was associated with increased adjusted risks for death at 1-year post PCI.

Salynn Boyles, Contributing Writer, BreakingMED™

Funding for this study was provided by Abbott Laboratories.

Principle researcher Gregg Stone reported holding equity options in Ancora, Qool Therapeutics, Cagent, Applied Therapeutics, the Biostar family of funds, SpectraWave, Orchestro Biomed, Aria, Cardiac Success, the MedFocus family of funds, Valfix and receiving consulting fees from Valfix, TherOx, Vascular Dynamics, Robocath, HeartFlow, Gore Ablative Solutions, Miracor, Neovasc, W-Wave, Abiomed, and others.

Researcher Pieter Smits reported receiving institutional research grants from Abbott Vascular, Terumo, and St. Jude Medical and speaker fees from Abbott Vascular, St. Jude Medical and Terumo. Researcher Patrick Serruys reported receiving consulting fees from Biosensors, SINOMED, Balton sp, Philips/Volcano, Xeltis, and HeartFlow.

Editorial writers Eric Peterson reported being a consultant and/or serving on advisory boards for Amgen, AstraZeneca, Merck, Novartis, Pfizer, Janssen and Sanofi.

Cat ID: 306

Topic ID: 74,306,585,730,306,308,914,192,925