Effects of Diaphragmatic and Abdominal Neuromuscular Electrical Stimulation in Post-PCI Patients

Effects of Diaphragmatic and Abdominal Neuromuscular Electrical Stimulation on Arterial Blood Gases, Pulmonary Function, Ejection Fraction and Functional Capacity in Post-PCI Patients

This study is a randomized controlled trial designed to evaluate the effects of combined diaphragmatic and abdominal neuromuscular electrical stimulation (NMES) on arterial blood gases, pulmonary function, left ventricular ejection fraction, and functional capacity in patients following percutaneous coronary intervention (PCI). A total of 42 participants will be randomly allocated into two groups: an intervention group receiving NMES along with standard cardiac rehabilitation, and a control group receiving standard rehabilitation alone. The intervention will be administered for 30 minutes per session, five days per week, over a period of two weeks. Outcome measures will include arterial blood gas parameters (PaO₂, PaCO₂, SaO₂), spirometry indices (FVC, FEV₁, PEFR), ejection fraction assessed by echocardiography, and functional capacity measured using the 6-minute walk test. Assessments will be conducted at baseline and post-intervention. The study aims to determine whether NMES can serve as an effective adjunct to conventional cardiac rehabilitation in improving respiratory and functional outcomes in post-PCI patients.

Study Overview

• Status: Not yet recruiting
• Conditions: Percutaneous Coronary Intervention
• Intervention / Treatment: Device: Neuromuscular Electrical Stimulation (NMES); Other: Standard Cardiac Rehabilitation

Detailed Description

Percutaneous coronary intervention (PCI) improves coronary blood flow in patients with coronary artery disease; however, many patients continue to experience reduced pulmonary function, impaired gas exchange, decreased cardiac performance, and limited functional capacity after the procedure. These issues are often related to respiratory muscle weakness, immobilization, and altered ventilatory mechanics. Conventional cardiac rehabilitation focuses mainly on aerobic and resistance training, with limited emphasis on respiratory muscle strengthening.

Neuromuscular electrical stimulation (NMES) is a non-invasive technique that induces muscle contractions and may enhance both inspiratory and expiratory muscle function when applied to the diaphragm and abdominal muscles. This study aims to evaluate the effectiveness of combined diaphragmatic and abdominal NMES as an adjunct to standard cardiac rehabilitation in post-PCI patients.

In this randomized controlled trial, 42 hemodynamically stable patients aged 40-75 years will be randomly assigned to either an intervention group (NMES plus standard rehabilitation) or a control group (standard rehabilitation alone). The NMES intervention will be applied for 30 minutes per session, five days per week, for two weeks.

Outcome measures will include arterial blood gases (PaO₂, PaCO₂, SaO₂), pulmonary function (FVC, FEV₁, PEFR), left ventricular ejection fraction, and functional capacity assessed by the 6-minute walk test. Assessments will be conducted at baseline and after the intervention.

This study aims to determine whether NMES can improve respiratory and functional outcomes and serve as an effective adjunct to conventional cardiac rehabilitation in post-PCI patients.

• Study Type: Interventional
• Enrollment (Estimated): 42
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Arjumand Bano, MS; Phone Number: +92 305 9551883; Email: arjumand.bano@riphah.edu.pk

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Patients aged 40-75 years
• Patients who have undergone successful percutaneous coronary intervention (PCI) for stable or acute coronary syndrome
• Hemodynamically stable (no inotropic support, no active arrhythmias)
• Left ventricular ejection fraction (LVEF) ≥ 35%
• Able to perform spirometry and 6-minute walk test (6MWT)
• Willing to participate and provide informed consent

Exclusion Criteria:

• Significant arrhythmias or pacemaker/implantable defibrillator not cleared for NMES
• Severe pulmonary disease (e.g., advanced COPD, pulmonary fibrosis) affecting lung function independently
• Neuromuscular disorders interfering with NMES application
• Recent stroke or severe cognitive impairment limiting participation
• Active infection, sepsis, or systemic inflammatory disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: NMES + Standard Cardiac Rehabilitation; Participants in this group will receive combined diaphragmatic and abdominal neuromuscular electrical stimulation (NMES) in addition to standard cardiac rehabilitation. NMES will be applied using surface electrodes placed over the lower thoracic region (for diaphragmatic stimulation) and abdominal muscles (rectus abdominis and external obliques). The intervention will be delivered for 30 minutes per session, five days per week, for two weeks, along with routine cardiac rehabilitation including aerobic exercise, breathing exercises, and education.	Device: Neuromuscular Electrical Stimulation (NMES); A dual-channel electrical stimulation device will be used to deliver stimulation to respiratory muscles. Surface electrodes will be placed over the lower thoracic region for diaphragmatic stimulation and over the abdominal muscles for expiratory muscle stimulation. Stimulation parameters will include a frequency of 30-50 Hz, pulse width of 300 µs, and a duty cycle of 5 seconds on and 5 seconds off. Intensity will be adjusted to achieve visible muscle contraction without discomfort. Sessions will last 30 minutes, five days per week, for two weeks.; Other Names: Diaphragmatic NMES; Abdominal NMES
Active Comparator: Standard Cardiac Rehabilitation; Participants in this group will receive standard cardiac rehabilitation only, including aerobic exercise, breathing exercises, and patient education as per institutional protocol, without the use of neuromuscular electrical stimulation (NMES).	Other: Standard Cardiac Rehabilitation; A structured cardiac rehabilitation program including aerobic exercise, breathing exercises, and patient education delivered according to institutional protocols, without the use of neuromuscular electrical stimulation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Partial Pressure of Oxygen (PaO₂)	Measurement of arterial partial pressure of oxygen using arterial blood gas analysis.	Baseline and after 2 weeks of intervention
Partial Pressure of Carbon Dioxide (PaCO₂)	Measurement of arterial partial pressure of carbon dioxide using arterial blood gas analysis.	Baseline and after 2 weeks of intervention
Arterial Oxygen Saturation (SaO₂)	Measurement of arterial oxygen saturation using arterial blood gas analysis.	Baseline and after 2 weeks of intervention
Forced Vital Capacity (FVC)	Assessment of forced vital capacity using spirometry.	Baseline and after 2 weeks of intervention
Forced Expiratory Volume in 1 Second (FEV₁)	Assessment of forced expiratory volume in 1 second using spirometry.	Baseline and after 2 weeks of intervention
Peak Expiratory Flow Rate (PEFR)	Assessment of peak expiratory flow rate using spirometry.	Baseline and after 2 weeks of intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Left Ventricular Ejection Fraction (LVEF)	Measurement of cardiac function using echocardiography (Simpson's biplane method).	Baseline and after 2 weeks

Collaborators and Investigators

• Sponsor: Riphah International University
• Investigators: Principal Investigator: Arjumand Bano, MS, Riphah International University

Study record dates

Study Major Dates

• Study Start (Estimated): May 28, 2026
• Primary Completion (Estimated): June 28, 2026
• Study Completion (Estimated): June 29, 2026

Study Registration Dates

• First Submitted: April 2, 2026
• First Submitted That Met QC Criteria: June 1, 2026
• First Posted (Actual): June 5, 2026

Study Record Updates

• Last Update Posted (Actual): June 5, 2026
• Last Update Submitted That Met QC Criteria: June 1, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: Cardiac Rehab Coronary Stent
• Other Study ID Numbers: REC/RCR & AHS/25/0322

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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