Routine exercise-based cardiac rehabilitation does not increase aerobic fitness: A CARE CR study

Area of Science:

• Cardiology
• Exercise Physiology
• Rehabilitation Medicine

Background:

• Recent studies question the efficacy of routine exercise-based cardiac rehabilitation (CR) in significantly increasing peak oxygen uptake (V̇O_2peak).
• This potential lack of improvement may explain why CR is no longer associated with improved patient survival in contemporary research.
• The adequacy of the exercise training stimulus in CR programs needs further investigation.

Purpose of the Study:

• To determine if routine exercise-based CR increases V̇O_2peak using maximal cardiopulmonary exercise testing (CPET).
• To quantify the exercise training stimulus provided during a standard CR program.
• To assess the impact of CR on secondary physiological and body composition markers.

Main Methods:

• A randomized controlled trial comparing 8 weeks of twice-weekly exercise-based CR (intervention) against no supervised exercise (control) in coronary heart disease patients.
• Primary outcome: V̇O_2peak measured by CPET.
• Secondary outcomes: body composition (DXA), carotid intima-media thickness, hs-CRP, NT-proBNP, and 5-year mortality risk score.

Main Results:

• Seventy patients (86% male, mean age 63 years) were enrolled (48 intervention, 22 control).
• Mean exercise duration was 23 minutes per session at 45.9% heart rate reserve.
• No significant changes in V̇O_2peak or any secondary outcomes were observed between the CR and control groups at any time point.

Conclusions:

• Routine, standard exercise-based cardiac rehabilitation does not lead to a significant increase in V̇O_2peak.
• Current CR protocols are unlikely to yield substantial long-term physiological benefits for patients with coronary heart disease.