Parag Joshi, MD: High Blood Pressure Risk Biomarker

A new blood test from investigators at UT Southwestern Medical Center may give physicians the confidence to assess for even earlier heart disease risk through a pair of biomarkers.

But questions remain as to who should be tested, and how such biomarker readings will influence a patients decision to manage their blood pressure risk.

In an interview with MD Magazine® while at the American Heart Association (AHA) 2019 Scientific Sessions in Philadelphia, presenting author Parag Joshi, MD, preventive cardiologist at UT Southwestern Medical Center, explained the team’s new biomarker assessment findings, and how he thinks borderline hypertension risk assessment has been thus treated among physicians and patients.

MD Mag: What were the findings of the blood pressure biomarker assessment?

Joshi: Yeah so, we were excited to present our results today. We looked at blood pressure guidelines and who qualifies for blood pressure treatment, and who doesn't based on the most recent guidelines from 2017.

And what was unique to those guidelines was a stronger incorporation of estimating risk for heart attack, strokes, heart failure. And so, our question was, can we do better with estimating risk using some blood-based tests and biomarkers that measure damage or wear and tear or stress on the heart muscle?

And so those 2 blood tests that we used were a high-sensitivity troponin assay and an NT-ProBNP. And these are blood tests that we use in acutely ill patients, so people that come into the hospital sick with a heart attack or heart failure.

But we also know that about 25% of people walking around who are otherwise feeling fine have subtle elevations in those markers—not to the level of a heart attack or heart failure exacerbation, but detectable with these assays.

So, we employed those in large-population studies according to the blood pressure guidelines. And we basically stratified people—do they have an abnormal biomarker, or was it totally normal? And we found a nice degradation of risk by those biomarkers, such that the people who were in the same category—not recommended for treatment—about 30% of them had an elevation in one of those biomarkers. And their risk for events was two-fold higher than those who did not.

So, by all other measures they were at similar risk. But this biomarker actually identified people who are at higher risk than we thought, and potentially then may benefit from more aggressive blood pressure treatment, medications, or intensive lifestyle modifications.

MD Mag: Have we not yet adequately put in strategy to address borderline-risk cardiovascular patients?

Joshi: I think you raise a great point—who's the right population for this? Have we really tapped into this test, and the research, the information that you can get glean from this test? Specifically, the troponin assay, which we've all become very comfortable using in the acute setting. Someone who comes in with chest pain—it helps us decide, ‘Do we think it's a heart attack or not?’

But now the concept of measuring this in healthy people who are walking around, not presenting with any symptoms, what's the right group to use a test like this? That's not something we can fully commit an answer to with our study.

I think about my own clinical practice with the data that we've generated. Oftentimes, I'll have patients who are unsure about starting medication for a risk factor—blood pressure. In that discussion, and in sort of motivating that patient to how aggressively they need to be with their treatment, this is one of the tools now that I think we can incorporate into that discussion and say, “Listen, I think you should be on blood pressure medicine. You don't think you should be on it. Maybe we should check to see if there's any subtle wear and tear that we're seeing the early signs with one of these markers, and if it's there, then we really need to be more aggressive.”

Alternatively if you have someone that you may think needs to be on blood pressure medicine and they're not quite ready or sure, and we test this, and it's a little bit high, that can really identify, “We may be underestimating your risk, but now we're seeing some actual consequences of these risk factors.”

And not only blood pressure—which is what our focus was in—but certainly treating the whole patient: the lifestyle modifications, exercise, motivating dietary changes, weight loss, all of those things I think can be achieved if you have this kind of result.

But deciding in whom to measure it in is still a question. It's not one that we would say, ‘Measure in everybody,’ because we don't have the data to suggest that there couldn't be harms from that. So you really want to understand, have a discussion with patients about what you're going to do with the results before you test.