Using Enhanced External Counterpulsation to Recover Cardiovascular Function for Patient of Chronic Diseases

The goal of this clinical trial is to learn whether enhanced external counterpulsation (EECP) therapy can improve cardiopulmonary function and symptoms in adults with long COVID. It will also evaluate the safety and feasibility of two different EECP treatment schedules.

The main questions it aims to answer are:

• Does EECP therapy improve functional exercise capacity and cardiopulmonary performance in patients with long COVID?
• Do different EECP treatment schedules (standard vs. accelerated sessions) lead to different improvements in symptoms, quality of life, and physiological outcomes?
• What side effects or medical problems occur during EECP therapy?

Researchers will compare two EECP treatment schedules to determine whether a shorter, accelerated program provides similar benefits to the standard schedule.

Participants will:

• Receive EECP therapy either 1 hour per day (5 days per week for 7 weeks) or 2 hours per day (5 days per week for about 4 weeks), both totaling 35 hours of treatment
• Visit the cardiopulmonary rehabilitation clinic regularly for supervised treatment sessions
• Complete physical performance tests (such as the Six-Minute Walk Test and cardiopulmonary exercise testing)
• Have blood pressure and heart rate measured
• Complete questionnaires about symptoms, physical function, sleep quality, and quality of life

Study Overview

• Status: Completed
• Conditions: Long COVID Symptoms
• Intervention / Treatment: Device: enhanced external counterpulsation

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Taiwan
  • Taipei, Taiwan, 114
    • Natioanl Denfense Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 20 years
• Eligible for follow-up ≥3 months
• A confirmed history of COVID-19 (via PCR or antigen test)
• Post-COVID-19 with persistent symptoms ( fatigue, exercise intolerance, dyspnea on exertion, and/or cognitive difficulties) for ≥3 months

Exclusion Criteria:

• Severe peripheral arterial disease or limb ischemia
• Active deep vein thrombosis
• Aortic valve regurgitation,
• Aortic aneurysm requiring surgical repair
• Pregnancy
• Other serious cardiovascular conditions contraindicating EECP
• Unable to ambulate
• Severe neurocognitive impairment precluding consent or cooperation.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Standard EECP Group (1-hour sessions); Participants receive enhanced external counterpulsation (EECP) therapy for 1 hour per session, 5 days per week for 7 weeks, targeting a total treatment dose of 35 hours. EECP is delivered using pneumatic cuffs wrapped around the calves, thighs, and buttocks, with inflation synchronized to the cardiac cycle. Sessions are supervised by rehabilitation staff.	Device: enhanced external counterpulsation; Participants receive enhanced external counterpulsation (EECP) therapy achieving the same total treatment dose of 35 hours.
Experimental: Accelerated EECP Group (2-hour sessions); Participants receive enhanced external counterpulsation (EECP) therapy for 2 hours per session, 5 days per week for approximately 4 weeks, achieving the same total treatment dose of 35 hours. The 2-hour treatment may be delivered as a continuous session or two consecutive 1-hour sessions based on patient tolerance. Sessions are supervised by rehabilitation staff.	Device: enhanced external counterpulsation; Participants receive enhanced external counterpulsation (EECP) therapy achieving the same total treatment dose of 35 hours.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Peak oxygen uptake (Peak VO₂)	Peak oxygen uptake was measured during symptom-limited cardiopulmonary exercise testing (CPET) performed on a cycle ergometer using a ramp protocol (0 W initial workload with increments of 10-15 W per minute). Breath-by-breath gas exchange was continuously recorded using a metabolic cart. Peak VO₂ was defined as the highest 30-second averaged oxygen uptake during the test and expressed in mL·kg-¹·min-¹. Continuous ECG and pulse oximetry monitoring were performed during the test. Exercise was terminated at volitional fatigue or standardized safety criteria.	Baseline and within 1 week after completion of the 35-hour EECP intervention (approximately 4-7 weeks).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Six-Minute Walk Test (6MWT)	The Six-Minute Walk Test (6MWT) was used to assess aerobic capacity and endurance. Participants were instructed to walk at their maximal comfortable pace back-and-forth along a 30-meter corridor for 6 minutes, and the total distance walked (in meters) was recorded. One practice trial was done at baseline to familiarize patients, followed by a measured 6MWT at baseline and again within one week after completing EECP. Standard encouragement and stopping criteria were applied.	Baseline and again within one week after completing EECP
Blood Pressure and Heart Rate	Resting blood pressure (BP) (systolic and diastolic) and resting heart rate were measured after 5 minutes seated, at baseline and post-intervention. We also tracked any change in these vital signs immediately before and after individual EECP sessions to monitor acute effects. For analysis, we focused on the baseline vs post-intervention resting BP and HR changes.	Baseline and weekly, immediately before and after each EECP session, throughout the treatment period.
PROMIS Physical Health score	Physical health status was assessed using the PROMIS Adult Health Profile short form. The Physical Health domain includes items related to fatigue, pain, and physical functioning. Scores were calculated using a summed short-form scale ranging from 4 to 20, with higher scores indicating better physical health.	Baseline and within 1 week after completion of the intervention
PROMIS Mental Health Score	Mental health status was assessed using the PROMIS Adult Health Profile short form. The Mental Health domain includes items related to depression, anxiety, and social role functioning. Scores were calculated using a summed short-form scale ranging from 4 to 20, with higher scores indicating better mental health.	Baseline and within 1 week after completion of the intervention
PROMIS Sleep Disturbance Domain	Sleep disturbance was evaluated using the PROMIS Sleep Disturbance domain. This measure assesses perceived sleep quality and sleep-related problems, with higher scores indicating greater sleep disturbance.	Baseline and within 1 week after completion of the intervention
Seattle Angina Questionnaire-7 (SAQ-7) summary score	Cardiovascular health status was assessed using the Seattle Angina Questionnaire-7 (SAQ-7), a validated instrument evaluating angina frequency, physical limitation, and disease-specific quality of life related to coronary artery disease. Scores range from 0 to 100, with higher scores indicating fewer angina symptoms and better quality of life.	Baseline and within 1 week after completion of the intervention
COPD Assessment Test (CAT) score	Respiratory symptom burden was measured using the COPD Assessment Test (CAT), an 8-item questionnaire evaluating symptoms such as cough, dyspnea, chest tightness, and energy level. Total scores range from 0 to 40, with lower scores indicating fewer respiratory symptoms.	Baseline and within 1 week after completion of the intervention
Rose Dyspnea Scale (RDS)	Breathlessness severity was evaluated using the Rose Dyspnea Scale (RDS), a 4-item scale assessing dyspnea during physical activities. Scores range from 0 to 4, with higher grades indicating more severe dyspnea.	Baseline and within 1 week after completion of the intervention
Pittsburgh Sleep Quality Index (PSQI) global score	Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), a validated questionnaire measuring sleep quality and disturbances over the previous month. The instrument includes seven components that generate a global score ranging from 0 to 21. Higher scores indicate worse sleep quality, and a global score greater than 5 indicates poor sleep quality.	Baseline and within 1 week after completion of the intervention

Collaborators and Investigators

• Sponsor: National Defense Medical Center, Taiwan

Study record dates

Study Major Dates

• Study Start (Actual): December 25, 2023
• Primary Completion (Actual): June 24, 2024
• Study Completion (Actual): June 24, 2024

Study Registration Dates

• First Submitted: March 11, 2026
• First Submitted That Met QC Criteria: March 20, 2026
• First Posted (Actual): March 25, 2026

Study Record Updates

• Last Update Posted (Actual): March 25, 2026
• Last Update Submitted That Met QC Criteria: March 20, 2026
• Last Verified: June 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: TSGHIRB No. C202205103; NSTC-114-2221-E-016-002-MY2 (Other Grant/Funding Number: National Science and Technology Council); MND-MAB-D-115223 (Other Grant/Funding Number: Medical Affairs Bureau, Ministry of National Defense); TSGH-E-115276 (Other Grant/Funding Number: Tri-Service General Hospital)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No