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

National Defense Medical Center, Taiwan10 enrolled

Overview

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 Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Long COVID Symptoms

Outcomes

Primary Outcomes

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.

Time frame: Baseline and within 1 week after completion of the 35-hour EECP intervention (approximately 4-7 weeks).

Secondary Outcomes

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.

Time frame: 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.

Time frame: 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.