Aerobic Training in Post-MI Patients With DPN
Condition: Myocardial Infarction; Diabetes Mellitus, Type 2; Diabetic Peripheral Neuropathy
MeSH terms: Peripheral Nervous System Diseases; Myocardial Infarction; Diabetes Mellitus; Diabetes Mellitus, Type 2; Infarction
Study type: Interventional

Summary: 
      Cardiac rehabilitation (CR) is categorized by the American College of Cardiology "class IA
      recommendation" in the management of patients with cardiovascular disease (CVD) including
      post-myocardial infarction (MI) patients, who have reduced functional capacity and impaired
      quality of life. Studies have reported that post-MI patients enrolled in exercise-based CR
      (EB-CR) show improved functional capacity, significant decrease risk of re-infarction, and
      25% reduction in mortality. Aim: To define the effect of diabetic peripheral neuropathy (DPN)
      on the outcome measures of exercise based-cardiac rehabilitation (EB-CR) program in
      post-myocardial infarction (MI) patients with type-II diabetes mellitus (DM).

      Methods: Thirty-seven post-MI patients with type-II DM were enrolled in the study within 1-6
      months of MI from those referred for cardiac rehabilitation in the cardiac rehabilitation
      unit, Alexandria Teaching Hospital. Seven patients were lost. Fifteen patients attended 8
      weeks of aerobic training program (exercise group; 12 men and 3 women) while 15 patients did
      not (control group; 11 men and 4 women). The exercise group was assessed for the presence of
      peripheral neuropathy and patients were accordingly subdivided into those with DPN "group A"
      and those without "group B". All groups were evaluated at baseline and at the end of the
      study. Evaluation included Duke Activity Status Index (DASI) questionnaire, 6-minute walk
      test, and symptom-limited treadmill exercise stress test (EST).

      Outcome measures included: DASI score; 6-minute walk test distance (6MWD); and heart rate
      (HR), blood pressure (BP), rate pressure product (RPP), and functional capacity in metabolic
      equivalents (METs) measured during EST.
    

Detailed description: 
      The study population included post-MI patients with type-II DM within 1 to 6 months from
      onset of MI from those referred for cardiac rehabilitation in the cardiac rehabilitation
      unit, Alexandria Teaching Hospital. Patients were diagnosed as having MI according to the
      Joint ESC/ACCF/AHA/WHF Task Force for the Universal Definition of MI and DM according to the
      2016 American Diabetes Association guidelines.

      All patients were assessed by a cardiologist by clinical examination, electrocardiogram and
      echocardiography. Patients were excluded if they had any contraindication to exercise stress
      test (EST) or CR,systemic illness other than DM or hypertension, neurological disorders other
      than DPN, or had loss of protective sensation (anesthesia) and/or ulcerations in the lower
      limbs.

      All patients were informed about the nature of the study and an informed consent was obtained
      from all of them. The protocol was approved by the ethics committee.

      Patients were divided into 2 groups; those enrolled in EB-CR program "exercise group" and
      those not enrolled in EB-CR program "control group".

      Baseline evaluation for both groups included: demographic data collection, history taking,
      clinical examination, electrophysiological studies to confirm the presence or absence of
      neuropathy (sural sensory, posterior tibial and deep peroneal motor conduction studies),
      total neuropathy score to assess the clinical severity of DPN, Duke Activity Status Index
      questionnaire (DASI) to assess patients' physical activity level, Six-Minute Walk Test, and
      symptom-limited treadmill EST using Bruce protocol. All patients were on their regular
      medications including B-blockers during the EST.

      The exercise group underwent an outpatient EB-CR program (phase II) according to the American
      College of Sports Medicine guidelines for exercise prescription for cardiac patients.Sessions
      were 3 days/week for 8 weeks. The program included: Warm up (10 minutes): stretching
      exercises. Aerobic exercise training using treadmill (30 - 60 minutes/session): with target
      heart rate (HR) at 45 - 75% of HR reserve. The maximal HR (HR max) was derived from that
      obtained during EST. Patients who had ischemic/arrhythmic manifestations during EST, exercise
      intensity was prescribed at a HR below the ischemic threshold (10 beats below). Cool down (10
      minutes): light intensity treadmill walking. Supervision was provided according to the risk
      status of each patient that was determined according to the American Association of
      cardiovascular and Pulmonary Rehabilitation criteria for risk stratification. Controls were
      advised to maintain their medications and regular activities of daily living.

      The follow-up evaluation included: DASI, Six Minute Walk Test and symptom limited EST. The
      Outcome measures were DASI score, Six-minute walk test distance (6MWD), functional capacity
      in metabolic equivalents (METs), HR, blood pressure (BP) and rate pressure product (RPP) at a
      given workload.
    

Intervention name(s): Exercise based-cardiac rehabilitation (EB-CR) program
Intervention type(s): Other
Intervention description(s): The exercise group underwent an outpatient EB-CR program (phase II) according to the American College of Sports Medicine guidelines for exercise prescription for cardiac patients.[19] Sessions were 3 days/week for 8 weeks. The program included: (1) Warm up (10 minutes): stretching exercises. (2) Aerobic exercise training using treadmill (30 - 60 minutes/session): with target heart rate (HR) at 45 - 75% of HR reserve. The maximal HR (HR max) was derived from that obtained during exercise stress test (EST). Patients who had ischemic/arrhythmic manifestations during EST, exercise intensity was prescribed at a HR below the ischemic threshold (10 beats below). (3) Cool down (10 minutes): light intensity treadmill walking. Supervision was provided according to the risk status of each patient that was determined according to the American Association of cardiovascular and Pulmonary Rehabilitation criteria for risk stratification.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Supportive Care