Two different antihypertensive regimens had the effect of lowering blood pressure levels in patients while reducing both cardiac troponin levels measured by a high-sensitivity assay (hs-cTn) and B-type natriuretic peptide (BNP) concentrations. Investigators reported in Clinical Chemistry on the results of the TElmisartan and AMlodipine STudy to Assess the cardiovascular PROTECTive effects (TEAMSTA).
Investigators in this prospective, randomized trial wanted to see how different combinations of antihypertensive treatment strategies would impact the levels of cardiovascular biomarkers, as few studies have looked at this issue. “The primary objective was to show effects of antihypertensive treatment beyond [blood pressure] reduction,” they explained. They looked at several combinations: an angiotensin-receptor blocker plus a calcium-channel blocker, and an angiotensin-receptor blocker plus a diuretic.
TEAMSTA investigators randomized into two cohorts 481 hypertensive patients at one healthcare center. In one group, 251 individuals received 80-mg telmisartan and 5-mg amlodipine, while in the other, 230 received 40-mg olmesartan and 12.5-mg hydrochlorothiazide. Patients prior to randomization and after 6 months had measurements of their blood pressure, hs-cTn I and T, BNP, and N-terminal-pro-BNP (NT-proBNP). Various assays from manufacturers Roche and Abbott were used to measure the cardiovascular biomarkers.
Investigators after half a year’s treatment saw a drop in systolic and diastolic blood pressure in both groups. Measurability varied among the subcategories of hs-cTn. In the case of hs-cTnI, concentrations were measurable in more than 98% of the study participants. Through the treatment interventions, hs-cTnI concentrations declined markedly in both study groups and in the overall population dropped from from 4.6 to 4.2 ng/L. In a subgroup analysis, the investigators discovered that male patients experienced a much higher reduction in hs-cTnI concentrations than their female counterparts. By comparison, hs-cTnT’s measurability was just 26.2% in the overall study population. Concentrations for this biomarker didn’t change after the intervention. BNP and NT-proBNP concentrations also were reduced after 6 months: from 15.0 to 12.4 ng/L and from 64.8 to 53.3 ng/L, respectively.
Overall, investigators determined that reducing blood pressure in patients led to a reduction in hs-cTnI, BNP, and NT-proBNP concentrations after half a year’s treatment with antihypertensive therapies. “This effect was stronger when the combination of an angiotensin-receptor blocker with a calcium-channel blocker was used as compared to an angiotensin-receptor blocker and a diuretic,” they further observed.
“The TEAMSTA study extends and corroborates other recent pilot studies highlighting the enormous potential of well-characterized cardiac biomarker assays, particularly hs-cTn, beyond their established and approved indication,” Patrick Badertscher, MD, and Christian Mueller, MD, FESC, wrote in a related editorial.
hs-cTn assays have given clinical researchers additional insights into how the heart works, they wrote. While they’re not as definitive as hard clinical end points in ascertaining intervention measures, cardiovascular biomarkers “nicely complement clinical assessment and cardiac imaging. The investigators of the TEAMSTA study must be congratulated for their important contribution to this emerging field,” Badertscher and Mueller wrote.
Why cTnT and cTnI yielded such different results should be explored in further studies, they suggested. “It is unknown and a matter of ongoing research to what extent these discrepancies relate to differences in the nature of the analytes cTnT and cTnI, the antibody combination of the hs-cTn assay used, or the analytical sensitivity achieved.”
Pick up the latest issue of Clinical Chemistry to get more details on this study and the related editorial that addresses the impact of antihypertensive treatments on cardiovascular biomarkers.