PMID 29560335

Research
All papers

Superior Effects of High-Intensity Interval Training Compared to Conventional Therapy on Cardiovascular and Psychological Aspects in Myocardial Infarction

Choi HY, Han HJ, Choi JW, Jung HY, Joa KL

Question

The study compared the effects of high-intensity interval training and conventional moderate-intensity continuous training on cardiovascular function, psychological symptoms, and activity state in low- and moderate-risk phase II myocardial infarction patients.

Summary

In low- and moderate-risk patients beginning phase II cardiac rehabilitation soon after first STEMI treated with PCI, an 18-session supervised 4 x 4-minute HIIT program improved VO2max, METs, 6-minute walk distance, activity score, depression score, and fatigue score more than matched-duration moderate-intensity continuous training. The authors reported that all 44 analyzed patients completed 18 sessions without adverse events.

Methodology

  • Low- and moderate-risk phase II cardiac rehabilitation patients after first-time STEMI treated with primary PCI.
  • 44 participants.
  • Aerobic interval training.
  • Work intervals: 4 minutes.
  • Recovery: 3 minutes.
  • Intensity: 85%-100% HRmax during work intervals; 50%-60% HRmax during recovery.
  • 48 minutes total: 10 minutes stretching, 5 minutes warm-up, 28 minutes main exercise, 5 minutes cool-down.
  • Average 1-2 sessions per week.
  • 18 sessions over 9-10 weeks on average.
  • Prospective, non-blinded randomized controlled trial comparing 18 sessions of HIIT with moderate-intensity continuous training.
  • VO2max, METs, 6-minute walk distance, and Korean Activity Scale/Index were tracked.

Outcomes

VO2max

VO2max improved more in HIIT than MICT.

Abstract reports VO2max improved by 7.58 mL/kg/min in HIIT compared with 2.42 mL/kg/min in MICT, p<0.005.

Improved

Cardiovascular and functional state

METs, 6MWT, and KASI improved significantly more after HIIT than after MICT.

Reported as significant between-group improvements after 18 sessions; p<0.05 threshold.

Improved

Depression

HADS depression improved in HIIT and decreased in MICT; PHQ-9 tended to favor HIIT without statistical significance.

HADS-D improved by 1.89 in HIIT compared with decrement of 0.47 in MICT; PHQ-9 p=0.068.

Improved

Fatigue

FSS improved more after HIIT than after MICT.

FSS improved by 6.38 in HIIT compared with decrement of 0.77 in MICT; p<0.005.

Improved

Anxiety and insomnia

HADS anxiety and Insomnia Severity Index did not differ significantly between HIIT and MICT.

No clear change

Adverse events

All 44 analyzed patients completed 18 sessions without adverse events.

No clear change

Insights

  • A 4 x 4-minute HIIT structure at 85%-100% HRmax can be effective in clinically screened post-MI cardiac rehabilitation.
  • The study supports matching total session duration when comparing HIIT to continuous training; the interval intensity pattern was associated with larger gains.
  • For post-MI users, HIIT programming requires clinical risk stratification and should not be generalized to high-risk or unsupervised settings.

Limitations

  • Small sample size.
  • High-risk patients were excluded.
  • The sample was predominantly male.
  • Non-blinded trial design.
  • Social support and other unmeasured factors could have affected psychological outcomes.
  • No long-term follow-up or clinical event endpoint was reported.

Safety

  • All 44 analyzed patients completed 18 sessions without any adverse event.
  • One patient assigned to HIIT and one assigned to MICT did not finish all sessions because of ankle injury and occupational reasons.
  • High-risk patients were excluded because the authors were not sure of HIIT safety for those patients.