WSU study finds overwhelming evidence of hidden heart disease in hypertensive African-Americans

A Wayne State University School of Medicine study has found that an overwhelming majority of African-American patients with hypertension also suffered hidden heart disease caused by high blood pressure even though they displayed no symptoms.

The study – "Subclinical Hypertensive Heart Disease in African-American Patients with Elevated Blood Pressure in an Inner-City Emergency Department" – was conducted by Phillip Levy, M.D., M.P.H., associate professor of Emergency Medicine, and was recently published online in Annals of Emergency Medicine.

Nine of every 10 patients tested suffered hidden heart damage caused by high blood pressure, the study found. While slightly more than 93 percent of 161 patients in the study had a history of hypertension, 90.7 percent tested positive for hidden hypertensive heart disease. None of them knew their high blood pressure was affecting their hearts and did not show any symptomatic signs of heart disease.

"These results present a tremendous opportunity to screen for heart disease before it becomes symptomatic, especially in a population with high rates of hypertension," Levy said. "If we can detect incipient heart disease early, we have a better shot at treating it before it turns into a full-blown health emergency. Our study is also a strong reminder that emergency patients with chronic disease – in this case, hypertension – are generally a high-risk group."

The patients were enrolled in the study after appearing at the emergency room of Detroit Receiving Hospital. They did not come to the hospital for heart disease symptoms. Once enrolled in the study, they underwent echocardiograms, which revealed the hypertensive heart disease. Of the total 161 patients, 93.8 percent were inner-city African-Americans; 51.6 percent were male. The mean age of the patients enrolled was 49.8 years.

Most of the patients (93.8 percent) had a history of high blood pressure and were aware that they had the condition, but only 68.3 percent were receiving treatment.

Of those found to have hidden heart disease, the majority were diagnosed with diastolic dysfunction, defined as the heart's inability to adequately pump blood. Levy said the echocardiograms found the presence of subclinical hypertensive heart disease "ubiquitous."

He noted that hypertension is commonplace in the United States, and affects more than 76 million adults. The prevalence of the condition is higher in African-Americans, who are at "tremendous risk" for pressure-related consequences of hypertension, especially the premature onset of damage to and impairment of heart function.

According to the U.S. Centers for Disease Control and Prevention, 228.3 in every 100,000 Michigan residents 35 and older died of hypertension-related causes in 2009. In African-Americans, the rate was 381.9 deaths for every 100,000, and in whites it was 211. All Michigan rates were higher than national statistics. In rates of hypertension hospitalizations of Michigan residents 65 and older who are Medicare beneficiaries, African-Americans had higher rates (14 hospitalizations per 1,000 Medicare beneficiaries) than whites (3.6 per 1,000). Again, both rates were higher than national numbers.