Heart Transplant RejectionNCT06656065
IMR-Heart Trasplant Study
An observational study of Heart Transplant Rejection and Microvascular Resistance, run by Hospital Miguel Servet at 2 sites in Spain.
Trial summary
Acute allograft rejection (AAR) is an important cause of morbi-mortality in heart transplant (HT) patients, particularly during the first year. Endomyocardial biopsy (EMB) is the "gold standard" to guide post- heart transplantation treatment. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Heart Transplant Rejection, Microvascular Resistance
- How many people
- 100 participants
- Where
- 2 sitesSpain
- Study dates
- 23 May 2023to 14 Oct 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Heart trasplant patients that have signed informed consent and meet all inclusion and exclusion criteria for undergoing IMR assessment.
Who may be able to join
- Heart transplant patients >18 years.
- Patients who have received and signed informed consent.
Who cannot join
- Patients with hemodynamic instability after HT, including cardiogenic shock or severe coagulopathy.
- Patients with acute cellular rejection before intracoronary physiological assessment.
- Patients with bronchial asthma or bronchopathy with a positive bronchodilation test, which contraindicates the use of adenosine.
- Patients with epicardial coronary lesions with a resting physiological index ≤0.89 or ≤0.80 at hyperemia.
- Patients unlikely to cooperate or with inability or unwillingness to give informed consent.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Ainhoa Perez Guerrero, MD contact
Spain2 sites, 1 recruiting
- Active, not recruiting
Hospital Universitario de Bellvitge
L'Hospitalet de Llobregat, Barcelona, 08907
- Recruiting
Hospital Miguel Servet
Zaragoza, Zaragoza, 50009
Georgina Fuertes, MDPHD, 0034976765500 ext. 5160, georginaff@hotmail.com
Ainhoa Perez Guerrero, MD, 976765500 ext. 5160, ainhoaperezguerrero@gmail.com
About this study
Official title: Index Microvascular Resistance (IMR) in Heart Transplant Patients
Acute allograft rejection (AAR) is an important cause of morbi-mortality in heart transplant (HT) patients, particularly during the first year. Endomyocardial biopsy (EMB) is the "gold standard" to guide post- heart transplantation treatment. However, it is associated with complications that can be potentially serious. The index of microvascular resistance (IMR) is a specific physiological parameter used to assess microvascular function. Invasive coronary assessment has been shown to be both feasible and safe. Detection of coronary microvascular dysfunction (MCD) by IMR may help to identify high risk HT patients. In fact, an increased IMR measured early after HT has been associated with AAR, higher all-cause mortality and adverse cardiac events. A high IMR value early after HT may identify patients at higher risk who require increased surveillance or adjustments in immunosuppressive therapy. Conversely, a low IMR value may support reducing the number of EMBs. Our aim is to evaluate IMR in heart transplant patients within the first year. Changes in management after knowing IMR values and prognostic implications of IMR in a long term follow up will also be assessed.
Read the detailed description
The IMR-HT study is a multicenter, prospective observational study that will include post-HT stable patients undergoing coronary physiological assessment in the first three months and one year.
Assessment of IMR, coronary flow reserve (CFR) and fractional flow reserve (FFR) will be performed using the standard thermodilution technique. The left anterior descending coronary artery will be evaluated in all patients. Circumflex or right coronary artery could be additionally evaluated at operator's discretion. An intracoronary pressure and temperature sensor-tipped guidewire (Pressure Wire TM X guide- wire 0.014', Abbott, IL, USA) will be used to perform the measurements. The tip pressure sensor will be advanced into the mid-to-distal portion of the evaluated vessel. Baseline aortic pressure (Pa) and distal intracoronary pressure (Pd) will be obtained to calculate the resting index Pd/Pa. To measure the mean transit time (Tmn) under basal conditions, intracoronary administration of 3 mL of room-temperature saline will be manually injected three times in succession (3 mL/s). Then maximal hyperemia will be induced using adenosine iv (140 to 180 mg/kg/min) and three additional intracoronary room temperature saline boluses of 3 ml will be administered to determine the mean transit time at hyperemia (Tmnh). Finally, fractional flow reserve (FFR), coronary flow reserve (CFR) and IMR will be calculated using the software Coroventis Coroflow (Coroventis Abbott, Uppsala, Sweden).
Changes in HT patient management (number of EMBs, immunosuppressive therapy modifications) after knowing IMR values will also be assessed.
Based on previously published clinical data on IMR in heart transplant patients, a post-HT management algorithm is proposed:
- IMR < 15: The frequency of biopsies could be reduced or maintained as per protocol. No changes to immunosuppressive therapy would be required.
- IMR ≥ 15: Biopsies would be performed at the standard frequency according to protocol. Immunosuppressive therapy could be intensified or maintained the same.
Of note, given the observational characteristics of the study, clinical management decisions will be made at the discretion of the treating physician, taking into account the patient's clinical condition and other complementary tests.
Both groups (IMR<15 vs IMR≥15) will be compared in terms of cardiac events occurrence.
Clinical conditions, laboratory findings and clinical events will be assessed at one month and one year. Follow up will be extended for up to five years. Data will be included in an online database specifically designed for the study on platform REDCap (Research Electronic Data Capture).
A number will be assigned to each patient; their identity will not be disclosed in any case. All shared information will be anonymized. The principal investigator at each center will be responsible for keeping the data anonymized.Data will be processed in accordance with the protection legislation in force (Spanish Personal Data Protection and Guarantee of Digital Rights Act 3/2018, and Regulation (EU) 2016/679).
Our aim will be to assess IMR values in heart transplant patients within one year and evaluate changes in management after knowing of IMR values. We believe it is important to move forward in AAR surveillance and reduce the number of endomyocardial biopsies. In addition to assessing their diagnostic capabilities, IMR should also be assessed based on clinical outcomes. Therefore, we are convinced the results of this trial will be very important for our HT patient population.
- Keywords
- Heart Trasplant, Acute cellular rejection, IMR, Endomyocardial biopsy
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| IMR≥15 | Heart trasplant patient with an index of microvascular resistance ≥ 15 measured in the first three months in the physiological study. | |
| IMR<15 | Heart trasplant patient with an index of microvascular resistance<15 measured in the first three months in the physiological study. |
What is being measured
The primary outcome is the main question the study is designed to answer.
IMR values in the first three months and one year after heart transplant
IMR measured by the invasive thermodilution technique. IMR is defined as the distal coronary pressure divided by the inverse of the hyperemic mean transit time and is expressed in units of mmHg.s.
Measured: One year
Secondary outcomes (7)
IMR variation between first three months after HT and one year
Comparison between the values of index of microvascular resistance (IMR) measured by bolus thermodilution technique between the first and 3rd month after HT and one year in the invasive physiological study. IMR may be expressed as mmHg·s.
Measured: One year
Acute cellular rejection
A ≥2R degree according to the 2010 ISHLT system. Two or more focal infiltration points associated with myocyte injury in EMB. Diffuse infiltration with multi-focal myocyte injury with/without oedema, hemorrhage or vasculitis.
Measured: One year
Cardiac allograft vasculopathy
Accelerated fibroproliferative process characterized by diffuse, concentric and longitudinal thickening of the intima of the vascular tree of the graft, affecting everything from the major epicardial arteries to the coronary microvasculature.
Measured: Five years
Cardiovascular mortality
Caused by cardiovascular disease or unknown death
Measured: Five years
Heart failure
Diastolic or systolic heart failure after heart transplant
Measured: Five years
Inmunosupressive therapy
Changes in any of the inmunosuppresive agents pre-established in each center heart transplant protocol
Measured: Five years
EMB performed in each center within the first year
The number of biopsies performed by each center, after knowing IMR baseline values.
Measured: One year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Oct 2024
- Study start23 May 2023
- Primary completion23 May 2028 (estimated)
- Study completion14 Oct 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (9)Papers the sponsor has linked to this study.
- Other trials for Heart Transplant RejectionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Hospital Miguel Servet
- Sponsor type
- University, hospital or other
- Collaborators
- Central University Hospital of Asturias, Hospital Universitario La Fe, University Hospital Virgen de la Arrixaca, Murcia, Hospital Universitario 12 de Octubre, Hospital Universitario Reina Sofia de Cordoba, Hospital Universitari de Bellvitge, Hospitales Universitarios Virgen del Rocío
- Responsible party
- Principal investigator, Georgina Fuertes Ferre, Hospital Miguel Servet
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06656065
- Sponsor's protocol ID
- C.I. PI23/242
- Status last verified
- Nov 2025
- First submitted
- 15 Oct 2024
- Last updated
- 21 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- Yes: All collected IPD
Publications
Lee JM, Choi KH, Choi JO, Shin D, Park Y, Kim J, Lee SH, Kim D, Yang JH, Cho YH, Sung K, Choi JY, Park M, Kim JS, Park TK, Song YB, Hahn JY, Choi SH, Gwon HC, Oh JK, Jeon ES. Coronary Microcirculatory Dysfunction and Acute Cellular Rejection After Heart Transplantation. Circulation. 2021 Nov 2;144(18):1459-1472. doi: 10.1161/CIRCULATIONAHA.121.056158. Epub 2021 Sep 3.
PubMed 34474597Okada K, Honda Y, Luikart H, Yock PG, Fitzgerald PJ, Yeung AC, Valantine HA, Khush KK, Fearon WF. Early invasive assessment of the coronary microcirculation predicts subsequent acute rejection after heart transplantation. Int J Cardiol. 2019 Sep 1;290:27-32. doi: 10.1016/j.ijcard.2019.04.018. Epub 2019 Apr 8.
PubMed 30987835Ahn JM, Zimmermann FM, Gullestad L, Angeras O, Karason K, Russell K, Lunde K, Okada K, Luikart H, Khush KK, Honda Y, Pijls NHJ, Lee SE, Kim JJ, Park SJ, Solberg OG, Fearon WF. Microcirculatory Resistance Predicts Allograft Rejection and Cardiac Events After Heart Transplantation. J Am Coll Cardiol. 2021 Dec 14;78(24):2425-2435. doi: 10.1016/j.jacc.2021.10.009.
PubMed 34886963Hiemann NE, Wellnhofer E, Knosalla C, Lehmkuhl HB, Stein J, Hetzer R, Meyer R. Prognostic impact of microvasculopathy on survival after heart transplantation: evidence from 9713 endomyocardial biopsies. Circulation. 2007 Sep 11;116(11):1274-82. doi: 10.1161/CIRCULATIONAHA.106.647149. Epub 2007 Aug 20.
PubMed 17709643Saraiva F, Matos V, Goncalves L, Antunes M, Providencia LA. Complications of endomyocardial biopsy in heart transplant patients: a retrospective study of 2117 consecutive procedures. Transplant Proc. 2011 Jun;43(5):1908-12. doi: 10.1016/j.transproceed.2011.03.010.
PubMed 21693299Khush KK, Cherikh WS, Chambers DC, Harhay MO, Hayes D Jr, Hsich E, Meiser B, Potena L, Robinson A, Rossano JW, Sadavarte A, Singh TP, Zuckermann A, Stehlik J; International Society for Heart and Lung Transplantation. The International Thoracic Organ Transplant Registry of the International Society for Heart and Lung Transplantation: Thirty-sixth adult heart transplantation report - 2019; focus theme: Donor and recipient size match. J Heart Lung Transplant. 2019 Oct;38(10):1056-1066. doi: 10.1016/j.healun.2019.08.004. Epub 2019 Aug 10. No abstract available.
PubMed 31548031Costanzo MR, Dipchand A, Starling R, Anderson A, Chan M, Desai S, Fedson S, Fisher P, Gonzales-Stawinski G, Martinelli L, McGiffin D, Smith J, Taylor D, Meiser B, Webber S, Baran D, Carboni M, Dengler T, Feldman D, Frigerio M, Kfoury A, Kim D, Kobashigawa J, Shullo M, Stehlik J, Teuteberg J, Uber P, Zuckermann A, Hunt S, Burch M, Bhat G, Canter C, Chinnock R, Crespo-Leiro M, Delgado R, Dobbels F, Grady K, Kao W, Lamour J, Parry G, Patel J, Pini D, Towbin J, Wolfel G, Delgado D, Eisen H, Goldberg L, Hosenpud J, Johnson M, Keogh A, Lewis C, O'Connell J, Rogers J, Ross H, Russell S, Vanhaecke J; International Society of Heart and Lung Transplantation Guidelines. The International Society of Heart and Lung Transplantation Guidelines for the care of heart transplant recipients. J Heart Lung Transplant. 2010 Aug;29(8):914-56. doi: 10.1016/j.healun.2010.05.034. No abstract available.
PubMed 20643330Lund LH, Edwards LB, Kucheryavaya AY, Benden C, Dipchand AI, Goldfarb S, Levvey BJ, Meiser B, Rossano JW, Yusen RD, Stehlik J. The Registry of the International Society for Heart and Lung Transplantation: Thirty-second Official Adult Heart Transplantation Report--2015; Focus Theme: Early Graft Failure. J Heart Lung Transplant. 2015 Oct;34(10):1244-54. doi: 10.1016/j.healun.2015.08.003. Epub 2015 Aug 28. No abstract available.
PubMed 26454738Perez-Guerrero A, Vilchez-Tschischke JP, Bonet LA, Diez Gil JL, Peiro TB, Brugaletta S, Gomez-Lara J, Costello JG, Antuna P, Fernandez VA, Cebada FS, Garcia-Cosio MD, Lesmes FH, Granados AL, Lopez-Palop R, Garrido IP, Cardenal Piris RM, Sousa DR, Fuertes Ferre G. Index microvascular resistance (IMR) in heart transplant patients (IMR-HT study): Study protocol. PLoS One. 2025 May 16;20(5):e0315053. doi: 10.1371/journal.pone.0315053. eCollection 2025.
PubMed 40378366
Study at a glance
From the registry record, last updated by the sponsor on 21 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Index Microvascular Resistance (IMR) in Heart Transplant Patients
- ClinicalTrials.gov ID
- NCT06656065
- Acronym / sponsor ID
- C.I. PI23/242
- Keywords
- Heart Trasplant, Acute cellular rejection, IMR, Endomyocardial biopsy
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Hospital Miguel ServetUniversity, hospital or other
- Collaborators
- Central University Hospital of Asturias, Hospital Universitario La Fe, University Hospital Virgen de la Arrixaca, Murcia, Hospital Universitario 12 de Octubre, Hospital Universitario Reina Sofia de Cordoba, Hospital Universitari de Bellvitge, Hospitales Universitarios Virgen del Rocío
- Study start
- 23 May 2023 (actual)
- Primary completion
- 23 May 2028 (estimated)
- Study completion
- 14 Oct 2028 (estimated)
- First posted
- 24 Oct 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Acute allograft rejection (AAR) is an important cause of morbi-mortality in heart transplant (HT) patients, particularly during the first year. Endomyocardial biopsy (EMB) is the "gold standard" to guide post- heart transplantation treatment. However, it is associated with complications that can be potentially serious. The index of microvascular resistance (IMR) is a specific physiological parameter used to assess microvascular function. Invasive coronary assessment has been shown to be both feasible and safe. Detection of coronary microvascular dysfunction (MCD) by IMR may help to identify high risk HT patients. In fact, an increased IMR measured early after HT has been associated with AAR, higher all-cause mortality and adverse cardiac events. A high IMR value early after HT may identify patients at higher risk who require increased surveillance or adjustments in immunosuppressive therapy. Conversely, a low IMR value may support reducing the number of EMBs. Our aim is to evaluate IMR in heart transplant patients within the first year. Changes in management after knowing IMR values and prognostic implications of IMR in a long term follow up will also be assessed.
Detailed description
The IMR-HT study is a multicenter, prospective observational study that will include post-HT stable patients undergoing coronary physiological assessment in the first three months and one year.
Assessment of IMR, coronary flow reserve (CFR) and fractional flow reserve (FFR) will be performed using the standard thermodilution technique. The left anterior descending coronary artery will be evaluated in all patients. Circumflex or right coronary artery could be additionally evaluated at operator's discretion. An intracoronary pressure and temperature sensor-tipped guidewire (Pressure Wire TM X guide- wire 0.014', Abbott, IL, USA) will be used to perform the measurements. The tip pressure sensor will be advanced into the mid-to-distal portion of the evaluated vessel. Baseline aortic pressure (Pa) and distal intracoronary pressure (Pd) will be obtained to calculate the resting index Pd/Pa. To measure the mean transit time (Tmn) under basal conditions, intracoronary administration of 3 mL of room-temperature saline will be manually injected three times in succession (3 mL/s). Then maximal hyperemia will be induced using adenosine iv (140 to 180 mg/kg/min) and three additional intracoronary room temperature saline boluses of 3 ml will be administered to determine the mean transit time at hyperemia (Tmnh). Finally, fractional flow reserve (FFR), coronary flow reserve (CFR) and IMR will be calculated using the software Coroventis Coroflow (Coroventis Abbott, Uppsala, Sweden).
Changes in HT patient management (number of EMBs, immunosuppressive therapy modifications) after knowing IMR values will also be assessed.
Based on previously published clinical data on IMR in heart transplant patients, a post-HT management algorithm is proposed:
- IMR < 15: The frequency of biopsies could be reduced or maintained as per protocol. No changes to immunosuppressive therapy would be required.
- IMR ≥ 15: Biopsies would be performed at the standard frequency according to protocol. Immunosuppressive therapy could be intensified or maintained the same.
Of note, given the observational characteristics of the study, clinical management decisions will be made at the discretion of the treating physician, taking into account the patient's clinical condition and other complementary tests.
Both groups (IMR<15 vs IMR≥15) will be compared in terms of cardiac events occurrence.
Clinical conditions, laboratory findings and clinical events will be assessed at one month and one year. Follow up will be extended for up to five years. Data will be included in an online database specifically designed for the study on platform REDCap (Research Electronic Data Capture).
A number will be assigned to each patient; their identity will not be disclosed in any case. All shared information will be anonymized. The principal investigator at each center will be responsible for keeping the data anonymized.Data will be processed in accordance with the protection legislation in force (Spanish Personal Data Protection and Guarantee of Digital Rights Act 3/2018, and Regulation (EU) 2016/679).
Our aim will be to assess IMR values in heart transplant patients within one year and evaluate changes in management after knowing of IMR values. We believe it is important to move forward in AAR surveillance and reduce the number of endomyocardial biopsies. In addition to assessing their diagnostic capabilities, IMR should also be assessed based on clinical outcomes. Therefore, we are convinced the results of this trial will be very important for our HT patient population.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| IMR≥15 | – | –Heart trasplant patient with an index of microvascular resistance ≥ 15 measured in the first three months in the physiological study. |
| IMR<15 | – | –Heart trasplant patient with an index of microvascular resistance<15 measured in the first three months in the physiological study. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Heart trasplant patients that have signed informed consent and meet all inclusion and exclusion criteria for undergoing IMR assessment.
Key inclusion criteria (2 listed)
- Heart transplant patients >18 years.
- Patients who have received and signed informed consent.
Key exclusion criteria (5 listed)
- Patients with hemodynamic instability after HT, including cardiogenic shock or severe coagulopathy.
- Patients with acute cellular rejection before intracoronary physiological assessment.
- Patients with bronchial asthma or bronchopathy with a positive bronchodilation test, which contraindicates the use of adenosine.
- Patients with epicardial coronary lesions with a resting physiological index ≤0.89 or ≤0.80 at hyperemia.
- Patients unlikely to cooperate or with inability or unwillingness to give informed consent.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
IMR values in the first three months and one year after heart transplant
Time frame: One year
IMR measured by the invasive thermodilution technique. IMR is defined as the distal coronary pressure divided by the inverse of the hyperemic mean transit time and is expressed in units of mmHg.s.
7 secondary outcomes
IMR variation between first three months after HT and one year
Time frame: One year
Acute cellular rejection
Time frame: One year
Cardiac allograft vasculopathy
Time frame: Five years
Cardiovascular mortality
Time frame: Five years
Heart failure
Time frame: Five years
Inmunosupressive therapy
Time frame: Five years
EMB performed in each center within the first year
Time frame: One year
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Nov 2025.
- Background: PubMed 34474597Lee JM, Choi KH, Choi JO, Shin D, Park Y, Kim J, Lee SH, Kim D, Yang JH, Cho YH, Sung K, Choi JY, Park M, Kim JS, Park TK, Song YB, Hahn JY, Choi SH, Gwon HC, Oh JK, Jeon ES. Coronary Microcirculatory Dysfunction and Acute Cellular Rejection After Heart Transplantation. Circulation. 2021 Nov 2;144(18):1459-1472. doi: 10.1161/CIRCULATIONAHA.121.056158. Epub 2021 Sep 3.
- Background: PubMed 30987835Okada K, Honda Y, Luikart H, Yock PG, Fitzgerald PJ, Yeung AC, Valantine HA, Khush KK, Fearon WF. Early invasive assessment of the coronary microcirculation predicts subsequent acute rejection after heart transplantation. Int J Cardiol. 2019 Sep 1;290:27-32. doi: 10.1016/j.ijcard.2019.04.018. Epub 2019 Apr 8.
- Background: PubMed 34886963Ahn JM, Zimmermann FM, Gullestad L, Angeras O, Karason K, Russell K, Lunde K, Okada K, Luikart H, Khush KK, Honda Y, Pijls NHJ, Lee SE, Kim JJ, Park SJ, Solberg OG, Fearon WF. Microcirculatory Resistance Predicts Allograft Rejection and Cardiac Events After Heart Transplantation. J Am Coll Cardiol. 2021 Dec 14;78(24):2425-2435. doi: 10.1016/j.jacc.2021.10.009.
- Background: PubMed 17709643Hiemann NE, Wellnhofer E, Knosalla C, Lehmkuhl HB, Stein J, Hetzer R, Meyer R. Prognostic impact of microvasculopathy on survival after heart transplantation: evidence from 9713 endomyocardial biopsies. Circulation. 2007 Sep 11;116(11):1274-82. doi: 10.1161/CIRCULATIONAHA.106.647149. Epub 2007 Aug 20.
- Background: PubMed 21693299Saraiva F, Matos V, Goncalves L, Antunes M, Providencia LA. Complications of endomyocardial biopsy in heart transplant patients: a retrospective study of 2117 consecutive procedures. Transplant Proc. 2011 Jun;43(5):1908-12. doi: 10.1016/j.transproceed.2011.03.010.
- Background: PubMed 31548031Khush KK, Cherikh WS, Chambers DC, Harhay MO, Hayes D Jr, Hsich E, Meiser B, Potena L, Robinson A, Rossano JW, Sadavarte A, Singh TP, Zuckermann A, Stehlik J; International Society for Heart and Lung Transplantation. The International Thoracic Organ Transplant Registry of the International Society for Heart and Lung Transplantation: Thirty-sixth adult heart transplantation report - 2019; focus theme: Donor and recipient size match. J Heart Lung Transplant. 2019 Oct;38(10):1056-1066. doi: 10.1016/j.healun.2019.08.004. Epub 2019 Aug 10. No abstract available.
- Background: PubMed 20643330Costanzo MR, Dipchand A, Starling R, Anderson A, Chan M, Desai S, Fedson S, Fisher P, Gonzales-Stawinski G, Martinelli L, McGiffin D, Smith J, Taylor D, Meiser B, Webber S, Baran D, Carboni M, Dengler T, Feldman D, Frigerio M, Kfoury A, Kim D, Kobashigawa J, Shullo M, Stehlik J, Teuteberg J, Uber P, Zuckermann A, Hunt S, Burch M, Bhat G, Canter C, Chinnock R, Crespo-Leiro M, Delgado R, Dobbels F, Grady K, Kao W, Lamour J, Parry G, Patel J, Pini D, Towbin J, Wolfel G, Delgado D, Eisen H, Goldberg L, Hosenpud J, Johnson M, Keogh A, Lewis C, O'Connell J, Rogers J, Ross H, Russell S, Vanhaecke J; International Society of Heart and Lung Transplantation Guidelines. The International Society of Heart and Lung Transplantation Guidelines for the care of heart transplant recipients. J Heart Lung Transplant. 2010 Aug;29(8):914-56. doi: 10.1016/j.healun.2010.05.034. No abstract available.
- Background: PubMed 26454738Lund LH, Edwards LB, Kucheryavaya AY, Benden C, Dipchand AI, Goldfarb S, Levvey BJ, Meiser B, Rossano JW, Yusen RD, Stehlik J. The Registry of the International Society for Heart and Lung Transplantation: Thirty-second Official Adult Heart Transplantation Report--2015; Focus Theme: Early Graft Failure. J Heart Lung Transplant. 2015 Oct;34(10):1244-54. doi: 10.1016/j.healun.2015.08.003. Epub 2015 Aug 28. No abstract available.
- Derived from this study: PubMed 40378366Perez-Guerrero A, Vilchez-Tschischke JP, Bonet LA, Diez Gil JL, Peiro TB, Brugaletta S, Gomez-Lara J, Costello JG, Antuna P, Fernandez VA, Cebada FS, Garcia-Cosio MD, Lesmes FH, Granados AL, Lopez-Palop R, Garrido IP, Cardenal Piris RM, Sousa DR, Fuertes Ferre G. Index microvascular resistance (IMR) in heart transplant patients (IMR-HT study): Study protocol. PLoS One. 2025 May 16;20(5):e0315053. doi: 10.1371/journal.pone.0315053. eCollection 2025.
- Individual participant dataSharing planned: Yes. All collected IPD
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Ainhoa Perez Guerrero, MD contact
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Heart Transplant Rejection and Microvascular Resistance, run by Hospital Miguel Servet at 2 sites in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 21 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Georgina Fuertes, MD PHD (0034 976765500 ext. 5160, georginaff@hotmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
IMR values in the first three months and one year after heart transplant (time frame: One year). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06656065, which also lists 9 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Nov 2025.