UMIN-ICDS Clinical Trial

Public title

A study using non-contact millimeter-wave radar to continuously assess respiratory patterns in patients with cardiovascular diseases and patients newly starting CPAP therapy

Acronym

MWR Respiratory Monitoring Study

Scientific Title

A prospective observational study of continuous monitoring of respiratory patterns and sleep-disordered breathing using millimeter-wave radar in patients with cardiovascular diseases

Scientific Title:Acronym

MWR-CARDIO Study

Region

Japan

Condition

Cardiovascular diseases and sleep apnea syndrome
The cardiovascular conditions include angina pectoris or arrhythmia requiring elective percutaneous coronary intervention or catheter ablation, acute heart failure, and acute coronary syndrome. Patients with moderate-to-severe sleep apnea syndrome who are newly initiating continuous positive airway pressure therapy are also included.

Classification by specialty

Cardiology

Pneumology

Classification by malignancy

Others

Genomic information

NO

Narrative objectives1

Respiratory rate and respiratory patterns are important physiological parameters that reflect changes in the clinical condition of patients with cardiovascular diseases. However, continuous and objective assessment, especially during sleep, remains difficult in routine clinical practice.

Millimeter-wave radar (MWR) enables non-contact and unconstrained monitoring of respiratory activity by detecting subtle body surface movements without attaching sensors.

The primary objective of this prospective observational study is to evaluate the agreement between respiratory parameters measured using MWR, including respiratory rate, sleep apnea and hypopnea events, and periodic breathing, and those obtained using conventional monitoring methods in routine clinical practice. Study participants include patients undergoing elective percutaneous coronary intervention or catheter ablation, patients hospitalized for acute heart failure or acute coronary syndrome, and patients newly initiating continuous positive airway pressure (CPAP) therapy.

Secondary objectives are to investigate longitudinal changes in respiratory patterns before and after treatment, during the transition from the acute phase to the recovery phase, before and after cardiac rehabilitation, and their associations with clinical deterioration, treatment response, and recurrent cardiovascular events. In patients newly initiating CPAP therapy, the occurrence and longitudinal course of central sleep apnea, treatment-emergent central sleep apnea, and periodic breathing will also be explored.

No treatment modification, CPAP setting adjustment, or other research-specific intervention will be performed based on MWR measurements.

Basic objectives2

Others

Basic objectives -Others

Assessment of agreement between a non-contact respiratory monitoring device and conventional assessment methods, and exploratory evaluation of associations between longitudinal respiratory pattern changes and clinical outcomes

Trial characteristics_1

Exploratory

Trial characteristics_2

Others

Developmental phase

Not applicable

Primary outcomes

Agreement between respiratory parameters measured using conventional monitors or assessment methods and those measured using millimeter-wave radar (MWR).

The main respiratory parameters evaluated will include:

Respiratory rate

Number or index of sleep apnea and hypopnea events

Periodic breathing variation

Conventional assessment methods will include visual observation, bedside monitors, pulse oximetry, portable sleep apnea monitoring, or polysomnography used as part of routine clinical care.

Agreement between measurement methods will be evaluated using correlation coefficients, mean differences and 95% limits of agreement obtained from Bland-Altman analysis, and intraclass correlation coefficients where appropriate.

Key secondary outcomes

1. Association between changes in respiratory patterns and clinical deterioration or improvement.

2. Changes in respiratory rate, sleep apnea and hypopnea events, and periodic breathing before and after elective percutaneous coronary intervention or catheter ablation.

3. Changes in respiratory patterns before and after cardiac rehabilitation.

4. Associations between respiratory patterns and clinical events, including worsening heart failure, rehospitalization, and recurrence of atrial fibrillation.

5. Continuous changes in respiratory patterns from the acute phase to the recovery phase in patients with acute heart failure or acute coronary syndrome.

6. Associations of respiratory rate, sleep apnea and hypopnea events, and periodic breathing measured using MWR with blood pressure, pulse rate, oxygen saturation, body temperature, physical findings, blood test results, electrocardiographic findings, echocardiographic findings, sleep study results, and clinical course.

7. Incidence of central sleep apnea or periodic breathing in patients newly initiating CPAP therapy.

8. Longitudinal changes in the central apnea index, residual apnea-hypopnea index, oxygen saturation variation, and respiratory patterns in patients newly initiating CPAP therapy.

9. Associations between respiratory patterns and CPAP usage parameters, including usage time, air leakage, and prescribed pressure.

10. Comparison of age, body mass index, baseline apnea-hypopnea index, presence of cardiovascular diseases, and CPAP usage parameters between patients with and without treatment-emergent central sleep apnea.

Study type

Observational

Basic design

Randomization

Randomization unit

Blinding

Control

Stratification

Dynamic allocation

Institution consideration

Blocking

Concealment

No. of arms

Purpose of intervention

Type of intervention

Interventions/Control_1

Interventions/Control_2

Interventions/Control_3

Interventions/Control_4

Interventions/Control_5

Interventions/Control_6

Interventions/Control_7

Interventions/Control_8

Interventions/Control_9

Interventions/Control_10

Age-lower limit

18

years-old

<=

Age-upper limit

Not applicable

Gender

Male and Female

Key inclusion criteria

1. Age 18 years or older.
2. Patients scheduled to undergo elective percutaneous coronary intervention or catheter ablation for angina pectoris or cardiac arrhythmias.
3. Patients hospitalized for acute heart failure or acute coronary syndrome.
4. Patients scheduled to initiate CPAP therapy for sleep apnea syndrome.
5. Patients who provide written informed consent after receiving a full explanation of the study.

Key exclusion criteria

1. Pregnant women or women with possible pregnancy.
2. Patients who refuse study participation or MWR monitoring.
3. Patients considered unsuitable for study participation by the principal investigator.

Target sample size

90

Name of lead principal investigator

1st name	Hiroyuki
Middle name
Last name	Takenaka

Organization

Hirakata Kohsai Hospital, Federation of National Public Service Personnel Mutual Aid Associations

Division name

Department of Cardiology

Zip code

573-0153

Address

1-2-1 Fujisaka Higashimachi, Hirakata, Osaka, Japan

TEL

072-858-8233

Email

h-takenaka@kkr-hirakoh.jp

Name of contact person

1st name	Mitsunori
Middle name
Last name	Miho

Organization

Hirakata Kohsai Hospital, Federation of National Public Service Personnel Mutual Aid Associations

Division name

Department of Cardiology

Zip code

573-0153

Address

1-2-1 Fujisaka Higashimachi, Hirakata, Osaka, Japan

TEL

072-858-8233

Homepage URL

Email

m-miho@kkr-hirakoh.jp

Institute

Hirakata Kosei Hospital, Federation of National Public Service Personnel Mutual Aid Associations

Institute

Department

Personal name

Organization

MaRI Co., Ltd.

Organization

Division

Category of Funding Organization

Profit organization

Nationality of Funding Organization

Co-sponsor

Name of secondary funder(s)

Organization

Hirakata Kosei Hospital, Federation of National Public Service Personnel Mutual Aid Associations

Address

1-2-1 Fujisaka Higashimachi, Hirakata, Osaka, Japan

Tel

072-858-8233

Email

m-miho@kkr-hirakoh.jp

Secondary IDs

NO

Study ID_1

Org. issuing International ID_1

Study ID_2

Org. issuing International ID_2

IND to MHLW

Institutions

国家公務員共済組合連合会 枚方公済病院

Date of disclosure of the study information

2026

Year

07

Month

17

Day

URL releasing protocol

Publication of results

Unpublished

URL related to results and publications

Number of participants that the trial has enrolled

Results

Results date posted

Results Delayed

Results Delay Reason

Date of the first journal publication of results

Baseline Characteristics

Participant flow

Adverse events

Outcome measures

Plan to share IPD

IPD sharing Plan description

Recruitment status

Preinitiation

Date of protocol fixation

2026

Year

08

Month

01

Day

Date of IRB

Anticipated trial start date

2026

Year

08

Month

01

Day

Last follow-up date

2028

Year

03

Month

31

Day

Date of closure to data entry

Date trial data considered complete

Date analysis concluded

Other related information

Millimeter-wave radar (MWR) will be installed in the patient's room or examination room to continuously monitor respiratory activity without attaching any sensors to the patient.

MWR measurements will be performed in parallel with routine clinical care. No additional treatment or modification of clinical management will be performed for research purposes.

Respiratory rate, sleep apnea and hypopnea events, and periodic breathing measured by MWR will be compared with conventional assessment methods used in routine clinical practice, including bedside monitors, pulse oximetry, and sleep studies.

Patients undergoing elective PCI or catheter ablation will be evaluated before and after treatment. Patients with acute heart failure or acute coronary syndrome will be followed from the acute phase to the recovery phase. Patients newly initiating CPAP therapy will undergo longitudinal assessment during the early treatment period.

Exploratory analyses will be performed to evaluate the associations between respiratory patterns and clinical findings, laboratory data, imaging results, and CPAP usage parameters.

Registered date

2026

Year

07

Month

14

Day

Last modified on

2026

Year

07

Month

15

Day

Link to view the page

Value
https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000071188