No racial difference in ACE inhibitor, ARB response in MI

12 May 2008

MedWire News: Analysis of the US subset of VALIANT reveals that outcomes were comparable for African-American and White patients regardless of the treatment assigned.

VALIANT (Valsartan in Acute Myocardial Infarction Trial) included patients with myocardial infarction (MI) complicated by heart failure (HF) or a reduced ejection fraction, who were randomly assigned to treatment with valsartan, captopril, or a combination of the two.

The efficacy of neurohormonal antagonists in hypertension control and prevention and treatment of HF in African Americans has been questioned, based on clinical trials of ACE inhibitors.

L Michael Prisant (Medical College of Georgia, Augusta, USA) and colleagues compared outcomes of the 3390 White and 340 African-American patients in the VALIANT US population according to treatment.

Over a median follow-up of 24.7 months, there were no significant differences between African-American and White patients in the adjusted 3-year rates of all-cause mortality (22.1% and 20.3%, respectively) or cardiovascular mortality (18.4% and 16.7%).

The recurrent MI rate at 3 years was similar between African Americans and Whites. However, there was a trend toward higher rates of HF hospitalizations for African-American compared with White patients (p=0.09), possibly attributable to African Americans being more frequently treated with calcium channel blockers, having more coronary risk factors and worse post-infarction prognostic markers, and/or fewer revascularization procedures.

Further analysis showed that mortality, cardiovascular mortality, hospitalizations for HF, recurrent MI, and stroke rates by race were independent of treatment assignment.

Edward Havranek (Denver Health Medical Center, Colorado, USA) commented on the findings in a related editorial. He said theyare best interpreted by viewing both African-American and White patients as having wide intra-group variation in response to neuorohormonal antagonists.

"Although the mean response between the groups might be slightly different, the individual responses overlap substantially," he noted.

He added that this notion is consistent with data indicating African American and White Americans "are not as different genetically as we might be conditioned to believe."

He concluded: "Differences in response to drug treatments by race are not stark but subtle - not black and white but shades of gray. Until these subtle shadings can be measured more precisely through individual genotyping, race-based therapy should be approached with caution, if at all."

J Am Coll Cardiol 2008; 51: 1865-1871