Progression of coronary atherosclerosis in African-American patients

Posted On 2013-12-03 17:50:05

Ozgur Bayturan MD

Associate Professor of Medicine, Celal Bayar University Department of Cardiology, Manisa, Turkey. Email:

African-Americans have higher rates of vascular events compared to whites (1-2). This higher event rates increases the attention to the determinants of atherosclerosis progression and its morphological features in African-Americans. Intravascular ultrasound (IVUS), multislice computed tomography, optical coherence tomography, and magnetic resonance are the imaging tools that employed in clinical practice and research studies.

In this issue of the Journal, Kataoka et al focus on one of the interesting questions of atheresclerosis. They investigated the potential impact of race on atherosclerosis progression. Employing serial intravascular ultrasound (IVUS) measurements, they report more atheroma progression in patients with African-American descent. The authors investigated 3,479 patients with atherosclerosis. Risk factor control and atheroma progression were compared between African-Americans (n=170) and Caucasians (n=3,309). They report a subtle increase in total atheroma volume (TAV) in African Americans after an 18 to 24 months follow-up. Moreover, this progression occurs despite a complete medical therapy under a clinical trial. On the other hand, their data demontrates a significant decrease in white patients TAV compared to baseline. Including percent atheroma volume data could have been given a better understanding to the present study.

The current article reports significant differences in risk factors between these two population. African-Americans had higher HbA1c, obesity and greater prevalence of diabetes compared to whites. In additon, lower high-density lipoprotein (HDL) values were reported in African-Americans. Not unexpectedly, blood pressure in African-Americans exceeded that in whites as in previous studies (3-4). Clustering of multiple risk factors is more common in the African-American population. Which all these findings confirm the current literature with an IVUS standpoint.

This data show that diabetes is a more challenging risk factor for African-Americans compare to whites. The higher prevalance and higher HbA1c levels are striking in African-American patients. The present study may suggest that African-Americans have more intractable and complicated diabetes compared to whites.

Another finding of the current study is regarding the coronary artery calcification. The authors report more baseline coronary calcification (CC) in whites compare to African-Americans. Moreover, less progression of CC in African-American patients has been demonstrated in the current report. These findings are in line with CT angiography studies (5-6). CT studies demonstrated that African-Americans have less calcified disease compare to white individuals. Indeed this finding is also confirmed by autopsy studies (7-8), that demonstrated whites have higher prevalance of coronary artery calcification compared to African-Americans. Combining the less CC pattern with the higher rates of vascular events in African-Americans suggest that calcification is not playing the same biological role in African-Americans as higher CC is related with higher vascular events in whites (9-10).

In addition to the presence of coronary calcification, investigating the spotty calcification pattern might be another research topic in different races because of its relation to higher vascular event rates (11).

Despite our limited understanding regarding the effect of race on cardiovascular disease, the present paper confirms some of the previous published studies. In addition, it suggest that we may have to pay more attention on diabetes control, increased BMI, low HDL, and hypertesion control in African-Americans.


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