PMID 38268237

Research
All papers

Exercise training and high-sensitivity cardiac troponin-I in patients with heart failure with reduced ejection fraction

Riveland E, Valborgland T, Ushakova A, Skadberg Ø, Karlsen T, Hole T, Støylen A, Dalen H, Videm V, Koppen E, Linke A, Delagardelle C, Van Craenenbroeck EM, Beckers P, Prescott E, Halle M, Omland T, Ellingsen Ø, Larsen AI, SMARTEX‐HF Study Group

Question

Does a 12-week structured exercise training program reduce serum high-sensitivity cardiac troponin I in patients with stable symptomatic heart failure with reduced ejection fraction, and are troponin changes associated with left ventricular remodeling, VO2peak, and NT-proBNP?

Summary

This SMARTEX-HF substudy analyzed whether 12 weeks of exercise training changed high-sensitivity cardiac troponin I in people with stable heart failure with reduced ejection fraction. Patients were randomized to HIIT, moderate continuous training, or recommendation of regular exercise, but HIIT and moderate groups were combined because actual training intensities overlapped. Structured exercise modestly reduced troponin I within the intervention group, but the main comparison versus control was not statistically significant. In patients without selected additional comorbidities, structured exercise showed a significant between-group troponin I reduction. Exercise also improved VO2peak versus control.

Methodology

  • 196 stable symptomatic HFrEF patients from SMARTEX-HF with hs-cTnI samples; NYHA II-III, median LVEF about 30%, mostly male and mostly ischemic heart failure.
  • 196 participants.
  • Treadmill or bicycle.
  • Intensity: HIIT target 90-95% HRmax; MCT target 60-70% HRmax; groups pooled because actual intensities overlapped.
  • HIIT approximately 38 minutes including warm-up and cool-down; MCT approximately 47 minutes.
  • 3 supervised sessions per week.
  • 12 weeks.
  • Multicentre randomized SMARTEX-HF substudy using available hs-cTnI blood samples; HIIT and MCT arms were merged into a structured exercise training group because achieved intensities overlapped.
  • High-sensitivity cardiac troponin I, Left ventricular end-diastolic diameter, NT-proBNP, and VO2peak were tracked.

Outcomes

hs-cTnI in full population

SET had a modest within-group hs-cTnI reduction, but the between-group comparison versus control was not statistically significant.

SET median 11.9 to 11.5 ng/L, P = 0.030; SET versus control P = 0.116. Table delta SET -0.7 ng/L versus control -0.2 ng/L; relative-change comparison P = 0.184.

Mixed

hs-cTnI in patients without selected comorbidities

Among patients without atrial fibrillation, hypertension, diabetes mellitus, and COPD, SET showed a greater reduction in hs-cTnI than control.

SET 10.9 to 9.2 ng/L, P = 0.002; control 6.4 to 5.8 ng/L, P = 0.64; delta SET -1.2 ng/L versus control -0.1 ng/L, P = 0.007.

Improved

VO2peak

VO2peak improved in SET and differed from control at 12 weeks.

Whole group 17.1 to 17.3 mL/kg/min, P = 0.003; SET 16.8 to 17.3 mL/kg/min, P < 0.0001; control did not change, P = 0.44; delta between SET and control P = 0.001.

Improved

LVEDD

LVEDD was associated with hs-cTnI levels; the model predicted lower hs-cTnI with lower LVEDD, but group delta results were not consistently significant.

Each 1 mm LVEDD decrease associated with 1.2% lower hs-cTnI (95% CI 0.6% to 1.9%, P < 0.001). Table full-population delta SET -2.0 mm versus control 0.0 mm, P = 0.015.

Mixed

NT-proBNP

NT-proBNP did not change significantly and delta values did not differ between SET and control.

Whole group P = 0.26; delta SET versus control P = 0.80. Model predicted 3.0% lower hs-cTnI for each 10% lower NT-proBNP, 95% CI 2.4% to 3.5%, P < 0.0001.

No clear change

Insights

  • This article should be coded as structured clinical exercise evidence, not pure HIIT evidence, because HIIT and MCT arms were pooled.
  • Prescribed intensity and achieved intensity can diverge substantially in clinical interval training.
  • For HFrEF, exercise evidence is safety-sensitive and depends on stable disease, medical therapy, supervision, and clinical testing.
  • VO2peak improved with structured exercise, but biomarker improvements were modest and not significantly different versus control in the full population.

Limitations

  • HIIT and MCT were pooled because actual training intensities overlapped.
  • Pooling limits concrete recommendations about which intensity level to use.
  • Control group physical activity and intensity data were limited.
  • Subgroup findings may be affected by baseline differences in NT-proBNP and hs-cTnI.
  • Potential influence of haemoconcentration on hs-cTnI changes.
  • Exact HIIT work-rest protocol was not reported in this article.
  • The study context predates contemporary HFrEF therapy with sacubitril-valsartan and SGLT2 inhibitors.

Safety

  • Safety and adherence details were not reported in the paper.