Coughlin SS, Gottdiener JS, Baughman KL, Wasserman A, Marx ES, Tefft MC, Gersh BJ.
Black-white differences in mortality in idiopathic dilated cardiomyopathy: the Washington, DC, dilated cardiomyopathy study.
J Natl Med Assoc 1994;86(8):583-91.

The primary purpose of this case control study was to examine if black patients with idiopathic dilated cardiomyopathy experience greater mortality as compared with whites and if these differences were accounted for by differences in SES or previously identified prognostic factors. Patients were interviewed by telephone for baseline information and were contacted again approximately one year later to determine their vital status and to obtain information about health insurance coverage and referral for cardiac transplantation.

Among other clinical findings, the authors note that “black patients were less likely to have undergone coronary angiography and more likely to have electrocardiographic evidence of left ventricular hypertrophy.” Data on survival rates revealed that the “cumulative survival among black patients at 12 and 24 months was 71.5% and 63.6% respectively, compared with 92% and 86.3% among whites.” Of those patients 60 years or older, “the cumulative survival among black patients at 12 and 24 months was 58.8% and 42.1% respectively, compared with 86.7% and 77% among older white patients.” Coronary angiography, “which was performed less frequently among older persons and among blacks in this sample of patients,” was positively associated with survival (p<.003). Furthermore, the “racial difference in survival was not diminished by adjustment for level of educational attainment, which may be associated with patient delays in seeking health care or poor patient compliance with treatment regimens.” And “although racial differences in comorbid conditions could account for the poorer survival of black patients with dilated cardiomyopathy, the association with black race persisted after adjustment for hypertension, diabetes, and Quetelet index, and these factors were not significantly associated with survival.”

The authors suggest that “the poorer survival among blacks may be due to a delay in diagnosis and greater severity of disease at the time of diagnosis, or to racial differences in cardiac care” and that “there may be significant barriers to surgical intervention affording survival among black patients with idiopathic dilated cardiomyopathy.” In conclusion, the findings of this study “underscore the need for effective strategies for the primary, secondary, and tertiary prevention of premature disability and death from idiopathic cardiomyopathy in blacks.”