Background: High-sensitive (hs-) cardiac troponin assays provide prognostic information in atrial fibrillation (AF) patients. Few studies have explored the impact of long-term rate control therapy on levels of troponin in AF patients without coronary heart disease and heart failure. This substudy of the RATe control in Atrial Fibrillation (RATAF) II study aimed to compare the effects of six months' treatment with diltiazem and metoprolol on hs-troponin I (TnI) levels both at rest and during exercise testing in patients with permanent AF.
Methods: This was a parallel-group, randomized, investigator-blinded clinical trial. The cohort consisted of 93 patients (28 women, mean age 71 ± 7 years) with symptomatic, permanent AF with preserved left ventricular systolic function and no coronary heart disease. Participants were randomized in a 1:1 ratio to receive either diltiazem 360 mg (n = 49) or metoprolol 100 mg (n = 44) once daily for six months. Blood tests were drawn at rest and during peak exercise testing at baseline, one month and six months' treatment. This research has been supported by grants from the South-Eastern Norway Regional Health Authority and Vestre Viken Hospital Trust.
Results: Six months' treatment with diltiazem and metoprolol significantly lowered the heart rate at rest and peak exercise. Both treatment groups exhibited a decrease in hs-TnI levels at rest (diltiazem p = 0.008, metoprolol p = 0.03) and peak exercise (diltiazem p < 0.001, metoprolol p = 0.004) at six months compared to baseline levels, with no significant differences observed between the groups.
Conclusions: In patients with permanent AF, six months of rate control therapy with diltiazem or metoprolol lowered levels of hs-TnI. Further research is warranted to determine whether this reduction translates into an improved prognosis.
Trial registration: NCT02695992. Registration date: 2015-04-28.
Keywords: Atrial fibrillation; Beta-blockers; Biomarkers; Calcium channel blockers; Cardiac troponins; Rate control.
© 2025. The Author(s).