NEW YORK (360Dx) – With clinicians increasingly looking for earlier signs of cardiovascular disease, a principal investigator of a new study said this week that measuring troponin levels using Abbott's High Sensitive Troponin-I blood test could help predict the chance of having a cardiac event when the person shows no symptoms.
The study findings support adding high sensitivity troponin-I blood tests to current cardiovascular risk assessments, Christie Ballantyne, a professor of medicine and director of the center for cardiometabolic disease prevention at Baylor College of Medicine, said in an interview.
Ballantyne, the corresponding author of the study — which was published this week in the journal Circulation — said that high sensitivity troponin I measurements should be combined with levels of cholesterol and blood pressure, among other standard indications of heart health, to better identify patients who might benefit from an improved diet and exercise.
Adding measurements of troponin-I provides a better view of when a person could develop cardiovascular problems later in life if they don't take measures to mitigate health risks, he said.
That’s important because at present "we tend to not treat cardiovascular disease until someone has symptoms," and treatment often comes too late for patients, especially when there is heart failure, Ballantyne noted.
Using data from the Atherosclerosis Risk in Communities (ARIC) study, which has been ongoing since 1987, the investigators reported that elevated troponin-I levels using Abbott's Architect High Sensitive Troponin-I blood test are associated with a range of future cardiac events, including heart attack, coronary heart disease, stroke, hospitalization from heart failure, and death.
Adults who had elevated levels of troponin-I were more than twice as likely to have a cardiac disease event, such as a heart attack; nearly three times more likely to have ischemic stroke; and more than four times as likely to be hospitalized with heart failure.
The study findings align with those of other large cardiovascular studies, Tom Kaier, a clinical research fellow in the department of cardiovascular research at King's College London, said in an interview. "Among the increasing level of evidence, the bigger question for physicians and patients is [whether we should] use cardiac troponin in primary prevention to identify cardiovascular risk."
The King's College researcher is developing a point-of-care test for detecting cardiovascular events but did not participate in the Circulation study.
"The authors correctly observed a positive correlation between troponin and established risk factors — the older, more hypertensive, more likely diabetic patient is likely to have a higher cardiac troponin level," he said. "This translates into higher cardiovascular risk, even when corrected for some demographics."
However, before the findings can be incorporated into clinical practice, "we ought to have an actionable result," Kaier said. "At this stage, it is actionable to treat hyperlipidemia, hypertension, and diabetes with drug therapy. But I do not foresee a future where we blindly start medical therapy for individuals based on a hs-cTnI concentration that falls into the 4th quintile as per this analysis, without measuring blood pressure, heart rate, and HbA1c."
Ballantyne agrees that if biomarkers of cardiovascular risk used in routine testing are normal, it may not be necessary to test levels of troponin. However, what constitutes normal has been continuously evolving, he noted.
Based on current levels for routine biomarkers, most people are not testing in normal ranges, Ballantyne said. "For example, two thirds of the public has hypertension. We could really do a better job of determining who is at risk so that we can tailor therapy in a more precise manner."
Kaier noted that in clinical practice, one option could be to use high-sensitivity biomarkers to "identify a subgroup of drugs, such as expensive PCSK9 inhibitors," which modulate risk but could be paired with use of a diagnostic test to justify the investment and provide a more personalized approach to treating most patients with an elevated risk profile.
The ARIC study is a prospective population study of cardiovascular disease incidence in adults who were aged 45 to 64 years when they were recruited from US communities from 1987 to 1989.
In the portion of the study presenting the high-sensitivity troponin findings, the investigators began evaluating the participants from their fourth visit for a cardiovascular evaluation, from 1996 through 1998.
They analyzed the clinical background and test results of 8,121 people. The investigators measured blood pressure, lipid levels, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, diabetes mellitus, and triglycerides, among other indicators of cardiovascular health. For measurements of troponin I, they used the Abbott Architect Stat Troponin-I chemiluminescent immunoassay running on the Abbott Park, Illinois firm's automated Architect i2000sr chemistry analyzer. The investigators also implemented other cardiovascular biomarker measurements, including for high sensitivity troponin T, N-terminal pro–B-type natriuretic peptide, and high-sensitivity C-reactive protein.
"Of these markers, the one that's most widely used is high-sensitivity C reactive protein, but it turns out that it's probably the weakest of these markers in regard to predicting cardiovascular events," Ballantyne said.
High-sensitivity troponin I and high-sensitivity troponin T were only modestly correlated and were complementary in prediction of cardiovascular disease events, he said.
The use of troponin for cardiovascular health testing has been growing and is reflected by clinical studies and recent regulatory clearances.
For example, European researchers reported last year that the diagnostic accuracy and clinical utility of a new Siemens high-sensitivity Advia Centaur troponin I assay are comparable to that of established high-sensitivity troponin assays developed by Abbott and Roche.
Also in Europe, Kaier and his colleagues are developing a point-of-care blood test to diagnose heart attacks that uses cardiac myosin-binding protein C as an alternative biomarker to high-sensitivity troponin used in laboratory testing.
In North America, clinicians at the Mayo Clinic in Rochester, Minnesota, said the number of elevated troponin readings in the emergency room nearly doubled when the hospital began using Roche's Elecsys Troponin T Gen 5 Stat test, a high-sensitivity troponin T test.