A standard blood test used to verify heart muscle damage from heart attacks could also identify people at risk of hypertension well before the silent killer shows up on a blood pressure machine, a new study has found.
Researchers found that people with subtle elevations in cardiac troponin were more likely to be diagnosed with hypertension within a few years.
High blood pressure is a leading cause of heart attacks and strokes and claims more than 9 million lives worldwide each year, according to the World Health Organisation.
“Identifying those at risk for hypertension as well as those in the earliest stages of the disease would allow us to intervene much sooner, either with lifestyle changes or medication, before the condition develops fully and has had a chance to damage organs,” said lead investigator Bill McEvoy, assistant professor of medicine at the Johns Hopkins University School of Medicine.
Researchers said the standard troponin test, already the gold-standard screen for cardiac muscle damage from ongoing or recent heart attacks, works great for figuring out whether someone with chest pain or other cardiac symptoms is having a heart attack, but results often come back “normal” for many with other forms of cardiac damage unrelated to heart attacks.
The high-sensitivity test used in the study can identify these people, the researchers add, because it detects even trace amounts of troponin released by heart cells injured by spikes in blood pressure that come and go unnoticed.
For their study, McEvoy and colleagues analysed blood samples obtained in the late 1980s and early 1990s from 5,479 people enrolled in a long-term multicentre research known as the Atherosclerosis Risk in Communities Study.
Designed to track heart disease risk over time, the study followed people for an average of 12 years.
None of the participants had clinical diagnosis of hypertension at the beginning of the study although about 27 per cent had high-normal blood pressures, a condition that often heralds the onset of full-blown hypertension later on.
Compared with people whose troponin levels were undetectable, less than 5 nanogrammes per decilitre, those with mild elevations, 5 to 8 nanogrammes per decilitre, had a 13 per cent higher rate of hypertension during the follow-up.
Those with notably elevated troponin levels, 9 to 13 nanogrammes per decilitre, were 24 per cent more likely to have developed hypertension, and those with troponin levels above 13 nanogrammes per decilitre had a nearly 40 per cent higher risk of hypertension.
Similarly, compared with people whose troponin levels were undetectable, participants with slightly elevated troponin levels were twice as likely to develop heart muscle thickening within six years after the initial testing.
Those with notably elevated troponin levels were three times more likely to have thickened heart muscle within six years, while participants with high levels of troponin had a fivefold risk of such heart muscle abnormalities.
The research was published in the journal Circulation.