Dr. Tariq Shafi, Professor of Medicine and Director of the Nephrology Division, recently published the article “Resistant Hypertension and Cardiovascular Disease Mortality in the US: Results From the National Health and Nutrition Examination Survey (NHANES)” in BMC Nephrology.

Read the full article here.

Here, Dr. Shafi tells us about the article, its findings, and its potential impact on the US adults with hypertension.

Tell us about your study.

We were interested in gathering more information about people with apparent treatment-resistant hypertension (aTRH), which refers to hypertension that is either uncontrolled on 3 antihypertensive medications or controlled but requiring 4 or more antihypertensive medications. We wanted to know how common is aTRH in the U.S. (prevalence) and what is the contribution of aTRH to cardiovascular disease (CVD) mortality in the U.S. (outcomes).

What did your study find?

To answer these questions, we used data from the 1988-2010 National Health and Nutrition Examination Survey (NHANES). NHANES is a nationally representative survey, and its results reflect disease burden in the entire U.S. population. We found that 7.6 million U.S. adults have aTRH, and it is more common in older individuals, African Americans, and among those with a history of diabetes, kidney disease, or CVD. We also found that aTRH identifies patients at higher risk of CVD mortality; those with aTRH had a 47% higher risk of CVD mortality compared to those without aTRH. Furthermore, even for those individuals with BP controlled on 4 or more medications (controlled aTRH), the CVD mortality was 66% higher compared to those without aTRH.

What gaps in knowledge do these findings fill? What gaps still persist?

These results tell us that there are a substantial number of adults in the U.S. (7.6 million) with aTRH and that these individuals are at high risk for CVD death. We don’t fully understand the reasons for increased CVD risk, and this needs further investigation.

Were these findings surprising to you?

The most surprising finding was the 66% higher risk of CVD death among people with BP controlled with 4 or more medications (controlled aTRH). In clinical practice, we generally do not consider patients at high risk if their BP is well-controlled with multiple medications.

What additional research is needed?

We need to understand why people with aTRH, particularly those with controlled aTRH, are at such high risk for CVD death. We need mechanistic studies and population health strategies to simultaneously understand the mechanisms of increased risk while ensuring that our patients receive the best care possible.