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CompletedNCT02325973AMICROUpdated Aug 8, 2025Results posted

Assessing Microvascular Resistance Via IMR To Predict Cumulative Outcome in STEMI Patients Undergoing Primary PCI

An interventional study of PressureWire Certus guidewire in Multi Vessel Coronary Artery Disease and STEMI, sponsored by Abbott Medical Devices. Completed at 14 sites in Italy. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-08-08.

Sponsored by Abbott Medical Devices · Not applicable, Interventional, and Diagnostic

Phase
Not applicable
Study type
Interventional
Enrollment
242
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

The purpose of this study is to assess whether the Index of Microcirculatory Resistance (IMR) can be considered a prognostic predictor for the occurrence of events at one year of follow up after primary Percutaneous Coronary Intervention (PCI) in ST-Elevation Myocardial Infarction (STEMI) patients.

Any correlation between IMR and the short and medium term outcomes, defined as cardiovascular death, re-Myocardial Infarct (MI), re-hospitalization for Heart Failure (HF), resuscitation or Implantable Cardioverter Defibrillator (ICD) appropriate shock, will be assessed in the study.

Read the detailed description

Prospective, multicentre study designed to evaluate IMR ability to predict events occurrence, defined as Cardiovascular death, re-MI, re-hospitalization for HF, resuscitation or ICD appropriate shock, during a 1 year follow-up period.

All participants will have the culprit lesion treated following clinical practice and guidelines; Fractional Flow Reserve (FFR) and IMR will be measured after the primary PCI procedure to evaluate treatment success and myocardial viability. Non-culprit lesions will be functionally evaluated through FFR index and will be treated if FFR will show functional stenosis. FFR and IMR will be measured to evaluate treatment success and myocardial viability. Patients will be followed-up at 1m, 6m and 1y periods.

02

Conditions studied

  • Multi Vessel Coronary Artery Disease
  • STEMI

Keywords

  • STEMI
  • IMR
  • FFR
  • microcirculatory
03

In context

ST Elevation Myocardial Infarction

666 studies on the registry are indexed under ST Elevation Myocardial Infarction; 179 are open to participants now.

This study's enrollment of 242 is above the median of 194 across 427 interventional studies indexed under ST Elevation Myocardial Infarction.

Browse ST Elevation Myocardial Infarction studies →

Lead sponsor

Abbott Medical Devices is the lead sponsor of 525 studies on the registry; 35 are open to participants now.

Of its 52 completed or terminated interventional studies of FDA-regulated products, 43 (83%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  1. Patient of legal age in hosting country able and willing to provide informed consent form
  2. Hospital admission either within 12 h of symptom onset or between 12 and 24 h after onset with evidence of continuing ischemia
  3. Electrocardiographic ST-segment elevation ≥1 mm in two or more contiguous ECG leads, or with a left bundle-branch block (LBBB)
  4. Multivessel diseased patients with lesions in the proximal 2/3 part of the vessels
  5. Culprit Lesion EyeBall (EB) identified during evaluation of basal angiography
  6. Presence of at least one non-culprit lesion >50% EB detected in the basal angiography and eligible for PCI for which the operators decision is to perform a staged pre-discharge angioplasty procedure

Exclusion criteria

Exclusion Criteria:

  1. Patients who cannot give informed consent
  2. A life expectancy of less than 1 year
  3. Patients who are pregnant or nursing
  4. Contra-indication to angiography
  5. Allergy/intolerance to Adenosine
  6. Contra-indication/Allergy/Intolerance to contrast media or to medical therapy foreseen for PCI
  7. Documented allergy to Adenosine diphosphate (ADP) inhibitors (aspirin and clopidogrel)
  8. New infarct on the same area of a previous infarct
  9. Critical non treatable Lesion EB>70% downstream of the culprit lesion
  10. Absence of non-culprit lesion/s
  11. Patient with hemodynamic instability not controllable with medical therapy and/or need intra aortic balloon pump implantation (IABP)
  12. Prior Coronary Artery Bypass Graft (CABG) or indication for CABG
  13. Patients with Left Main (LM) coronary artery disease requiring revascularization
05

Study design

Phase
Not applicable
Primary purpose
Diagnostic
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
242 participants (actual)

Study arms

  • Other
    IMR evaluation

    Assessment of IMR index in coronaries through PressureWire Certus guidewire

    Device: PressureWire Certus guidewire

Interventions

  • DevicePressureWire Certus guidewire

    Assessment of IMR index in coronaries through PressureWire Certus guidewire

06

What researchers measure

Primary outcomes

  1. Composite of: Cardiovascular Death*, Re-myocardial Infarct, Re-hospitalization for Heart Failure (HF) and Congestive Heart Failure (CHF), Resuscitation or ICD Appropriate Shock.

    Composite of: cardiovascular death\*, re-myocardial infarct, re-hospitalization for heart failure (HF) and Congestive Heart Failure (CHF), resuscitation or ICD appropriate shocK, at 1 year. \* = timing of mortality evaluation: once culprit lesion has been evaluated through IMR Composite endpoint was evaluated as time to first event, whichever individual component occurred first.

    Time frame: 1 year

Secondary outcomes

  1. New Congestive Heart Failure (CHF) During Index Hospitalization

    Count of participants with a new CHF during index hospitalization. Hospital stay expected average = 5-10 days

    Time frame: At the end of hospital stay

  2. Left Ventricular (LV) Remodeling

    Left Ventricular (LV) remodeling at 1 year; improvement of Ejection Fraction %(EF) assessed by TTE. A TTE evaluation has been done both at discharge and at 1-year fup.

    Time frame: 1 year

  3. Left Ventricular (LV) Remodeling

    Left Ventricular (LV) remodeling at 1 year; improvement of Left Ventricular End Systole Volume (LVESV) and Left Ventricular End Diastole Volume (LVEDV) assessed by TTE. A TTE evaluation has been done both at discharge and at 1-year fup.

    Time frame: 1 year

  4. Left Ventricular (LV) Remodeling

    Left Ventricular (LV) remodeling at 1 year; improvement of Left Ventricular End Diastole Diameter (LVEDD) and Left Ventricular End Systole Diameter (LVESD) assessed by TTE. A TTE evaluation has been done both at discharge and at 1-year fup.

    Time frame: 1 year

  5. Left Ventricular (LV) Remodeling

    Left Ventricular (LV) remodeling at 1 year; improvement of 16 segments Wall Motion Score Index (WMSI) assessed by TTE. A TTE evaluation has been done both at discharge and at 1-year fup. 16WMSI = 1 is considered normokinetic; 16WMSI = 1,5 is considered mild hypokinesia; 16WMSI = 2 is considered hypokinesia; 16WMSI = 2,5 is considered severe hypokinesia; 16WMSI = 3 is considered akinetic. Scale range: from 1 to 3

    Time frame: 1 year

  6. Left Ventricular (LV) Remodeling - Mitral Insufficiency

    Left Ventricular (LV) remodeling at 1 year; improvement of mitral insufficiency (MI) values assessed by TTE. A TTE evalutation has been done both at discharge and at 1-year fup. Each row reports the number of participants that have that specific grade of mitral insufficiency. Grade = 0 indicates no MI; grade = 1 indicates mild MI; grade = 2 indicates moderate MI; grade = 3 indicates severe MI

    Time frame: 1 year

  7. Need for New Revascularization

    Incidence of new revascularizations at 1 year

    Time frame: 1 year

  8. Stent Thrombosis

    Incidence of stent thrombosis at 1 year

    Time frame: 1 year

  9. Evaluation of a Better Cut-off of IMR Index Based on Primary Endpoints Events

    Evaluation of a better cut-off of IMR index based on primary endpoints events. Table below reports the values of ROC curve.

    Time frame: 1 year

  10. Evaluation of Possible Events Predictors

    Results of logistic regression model; differences were considered statistically significant when p\<0,05.

    Time frame: 1 year

07

Results

Posted Aug 8, 2025

Participant flow

Participant flow — Overall Study
MilestoneSTEMI Patient
Started242
Completed221
Not completed21
Withdrew: Death5
Withdrew: Withdrawal by subject or investigator16

Outcome measures

PrimaryComposite of: Cardiovascular Death*, Re-myocardial Infarct, Re-hospitalization for Heart Failure (HF) and Congestive Heart Failure (CHF), Resuscitation or ICD Appropriate Shock.

Composite of: cardiovascular death\*, re-myocardial infarct, re-hospitalization for heart failure (HF) and Congestive Heart Failure (CHF), resuscitation or ICD appropriate shocK, at 1 year. \* = timing of mortality evaluation: once culprit lesion has been evaluated through IMR Composite endpoint was evaluated as time to first event, whichever individual component occurred first.

Time frame:
1 year
Reported as:
Count of participants · Participants
Composite of: Cardiovascular Death*, Re-myocardial Infarct, Re-hospitalization for Heart Failure (HF) and Congestive Heart Failure (CHF), Resuscitation or ICD Appropriate Shock.
ParticipantsSTEMI Patient
Composite of: Cardiovascular Death*, Re-myocardial Infarct, Re-hospitalization for Heart Failure (HF) and Congestive Heart Failure (CHF), Resuscitation or ICD Appropriate Shock.8
SecondaryNew Congestive Heart Failure (CHF) During Index Hospitalization

Count of participants with a new CHF during index hospitalization. Hospital stay expected average = 5-10 days

Time frame:
At the end of hospital stay
Reported as:
Count of participants · Participants
New Congestive Heart Failure (CHF) During Index Hospitalization
ParticipantsSTEMI Patient
New Congestive Heart Failure (CHF) During Index Hospitalization8
SecondaryLeft Ventricular (LV) Remodeling

Left Ventricular (LV) remodeling at 1 year; improvement of Ejection Fraction %(EF) assessed by TTE. A TTE evaluation has been done both at discharge and at 1-year fup.

Time frame:
1 year
Reported as:
Mean · % of ejection fraction
Left Ventricular (LV) Remodeling
% of ejection fractionSTEMI Pat. at DischargeSTEMI Pat. at 1 Y Fup
Left Ventricular (LV) Remodeling53.3 ± 8.656.2 ± 7.9
SecondaryLeft Ventricular (LV) Remodeling

Left Ventricular (LV) remodeling at 1 year; improvement of Left Ventricular End Systole Volume (LVESV) and Left Ventricular End Diastole Volume (LVEDV) assessed by TTE. A TTE evaluation has been done both at discharge and at 1-year fup.

Time frame:
1 year
Reported as:
Mean · ml
Left Ventricular (LV) Remodeling
mlSTEMI Pat. at DischargeSTEMI Pat. at 1 Y Fup
LVESV (ml)50.6 ± 21.847.4 ± 20.3
LVEDV (ml)101.7 ± 28.5102.3 ± 32.4
SecondaryLeft Ventricular (LV) Remodeling

Left Ventricular (LV) remodeling at 1 year; improvement of Left Ventricular End Diastole Diameter (LVEDD) and Left Ventricular End Systole Diameter (LVESD) assessed by TTE. A TTE evaluation has been done both at discharge and at 1-year fup.

Time frame:
1 year
Reported as:
Mean · mm
Left Ventricular (LV) Remodeling
mmSTEMI Pat. at DischargeSTEMI Pat. at 1 Y Fup
LVESD (mm)35.5 ± 8.533.9 ± 6.6
LVEDD (mm)51.4 ± 29.750.2 ± 7.5
SecondaryLeft Ventricular (LV) Remodeling

Left Ventricular (LV) remodeling at 1 year; improvement of 16 segments Wall Motion Score Index (WMSI) assessed by TTE. A TTE evaluation has been done both at discharge and at 1-year fup. 16WMSI = 1 is considered normokinetic; 16WMSI = 1,5 is considered mild hypokinesia; 16WMSI = 2 is considered hypokinesia; 16WMSI = 2,5 is considered severe hypokinesia; 16WMSI = 3 is considered akinetic. Scale range: from 1 to 3

Time frame:
1 year
Reported as:
Mean · index
Left Ventricular (LV) Remodeling
indexSTEMI Pat. at DischargeSTEMI Pat. at 1 Y Fup
Left Ventricular (LV) Remodeling1.8 ± 2.91.9 ± 3.9
SecondaryLeft Ventricular (LV) Remodeling - Mitral Insufficiency

Left Ventricular (LV) remodeling at 1 year; improvement of mitral insufficiency (MI) values assessed by TTE. A TTE evalutation has been done both at discharge and at 1-year fup. Each row reports the number of participants that have that specific grade of mitral insufficiency. Grade = 0 indicates no MI; grade = 1 indicates mild MI; grade = 2 indicates moderate MI; grade = 3 indicates severe MI

Time frame:
1 year
Reported as:
Count of participants · Participants
Left Ventricular (LV) Remodeling - Mitral Insufficiency
ParticipantsSTEMI Pat. at DischargeSTEMI Pat. at 1 Y Fup
Grade 03533
Grade 1130139
Grade 22926
Grade 351
SecondaryNeed for New Revascularization

Incidence of new revascularizations at 1 year

Time frame:
1 year
Reported as:
Count of participants · Participants
Need for New Revascularization
ParticipantsSTEMI Patient
Need for New Revascularization12
SecondaryStent Thrombosis

Incidence of stent thrombosis at 1 year

Time frame:
1 year
Reported as:
Count of participants · Participants
Stent Thrombosis
ParticipantsSTEMI Patient
Stent Thrombosis1
SecondaryEvaluation of a Better Cut-off of IMR Index Based on Primary Endpoints Events

Evaluation of a better cut-off of IMR index based on primary endpoints events. Table below reports the values of ROC curve.

Time frame:
1 year
Reported as:
Number · probability
Evaluation of a Better Cut-off of IMR Index Based on Primary Endpoints Events
probabilityTrue Positive RateFalse Positive RateArea Under the Curve
IMR cut-off value = 950.1250.1140.505
IMR cut-off value = 650.3750.2110.582
IMR cut-off value = 550.50.2810.610
IMR cut-off value = 480.6250.3250.650
IMR cut-off value = 34.50.750.4910.629
IMR cut-off value = 320.8750.5310.672
IMR cut-off value = 300.8750.570.652
IMR cut-off value = 200.8750.7680.554
SecondaryEvaluation of Possible Events Predictors

Results of logistic regression model; differences were considered statistically significant when p\<0,05.

Time frame:
1 year
Reported as:
Number · correlation coefficient
Evaluation of Possible Events Predictors
correlation coefficientSTEMI Patient
Age0,3139
Male0,8407
Number of PCIs (PCIs done both during Primary and Staged procedures)0,0415
Hypertension0,3039
Lipids0,1948
Smoking0,5603
LVEF (at discharge)0,0320
WMSI (at discharge)0,2320

Adverse events

Collected over Adverse event data have been collected over 1 year period of time from primary procedure. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
STEMI Patient5/242 (2.1%)58/242 (24%)16/242 (6.6%)
Most frequent serious events
Showing 10 of 38
Most frequent serious events
EventSTEMI Patient
Heart failureCardiac disorders5/242
Coronary revascularizationCardiac disorders5/242
Angina or atypical chest painCardiac disorders3/242
Atrial FibrillationCardiac disorders3/242
Intra-stent thrombosisVascular disorders3/242
Coronary artery dissectionVascular disorders3/242
Effort anginaCardiac disorders2/242
Ventricular fibrillationCardiac disorders2/242
Stable anginaCardiac disorders2/242
Urinary SepsiRenal and urinary disorders2/242
Most frequent other events
Showing 10 of 12
Most frequent other events
EventSTEMI Patient
Atrial fibrillationCardiac disorders3/242
Heart failureCardiac disorders2/242
Chest pain not coronary relatedRespiratory, thoracic and mediastinal disorders2/242
Chest painCardiac disorders1/242
DiarrheaGastrointestinal disorders1/242
Probably neuralgic painNervous system disorders1/242
LypothymiaNervous system disorders1/242
CoughtRespiratory, thoracic and mediastinal disorders1/242
Asymptomatic culprit vessel occlusion founded during staged procedureVascular disorders1/242
Acute thrombosis stentVascular disorders1/242

Baseline characteristics

Age, Continuous
Age, Continuous(years)IMR Evaluation
Mean63.5 ± 9.9
Sex: Female, Male
Sex: Female, Male(Participants)IMR Evaluation
Female35
Male207
Race and Ethnicity Not Collected
Race and Ethnicity Not Collected(Participants)IMR Evaluation
Height
Height(cm)IMR Evaluation
Mean169.6 ± 6.9
Weight
Weight(kg)IMR Evaluation
Mean77 ± 11.8
Systolic Blood Pressure
Systolic Blood Pressure(mmHg)IMR Evaluation
Mean133.5 ± 24.8
Diastolic Blood Pressure
Diastolic Blood Pressure(mmHg)IMR Evaluation
Mean78.6 ± 13.8
Heart Rate
Heart Rate(bpm (Beats Per Minute))IMR Evaluation
Mean74.5 ± 15.8

15 further baseline measures are reported on the registry.

08

Study locations

14 sites
  • Ospedale Giovanni Paolo II
    Sciacca, Agrigento 92019, Italy
  • Ospedale Generale Regionale "F. Miulli"
    Acquaviva delle Fonti, BA 70021, Italy
  • Azienda Ospedaliera Universitaria Careggi
    Florence, FI 50134, Italy
  • Azienda Ospedaliera Villa Scassi
    Genova, GE 16149, Italy
  • Fondazione Toscana G.Monasterio - Ospedale del Cuore
    Massa, MS 54100, Italy
  • Azienda Ospedaliera di Padova
    Padova, PD 35128, Italy
  • Azienda Ospedaliera Ospedali Riuniti Marche Nord
    Pesaro, PU 61121, Italy
  • Fondazione IRCCS Policlinico S.Matteo
    Pavia, PV 27100, Italy
  • Arcispedale Santa Maria Nuova
    Reggio Emilia, RE 43123, Italy
  • Ospedale di Castelfranco Veneto
    Castelfranco Veneto, Treviso 31033, Italy
  • Presidio Ospedaliero di Conegliano
    Conegliano, Treviso 31015, Italy
  • Ospedale di Circolo Fondazione Macchi
    Varese, VA 21100, Italy
  • Ospedale Sant'Andrea
    La Spezia, 19100, Italy
  • Policlinico Le Scotte
    Siena, 53100, Italy
09

References and documents

Publications

  • Fineschi M, Verna E, Barioli A, Mezzapelle G, Bartolini D, Turiano G, Guiducci V, Manari A, Lucarelli K, Uguccioni L, Repetto A, Tarantini G. One-year results from the Assessing MICRO-vascular resistances via IMR to predict outcome in ST-elevation myocardial infarction patients with multivessel disease undergoing primary PCI (AMICRO) trial. Front Cardiovasc Med. 2022 Dec 2;9:1051174. doi: 10.3389/fcvm.2022.1051174. eCollection 2022. PubMed 36531736 ↗

Study documents

  • Protocol and statistical analysis plan · Oct 22, 2014

Documents are hosted by the registry — open the source record to download them.

10

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Aug 8, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
11

Registry details

Key details

Study ID
NCT02325973
Lead sponsor
Abbott Medical Devices
Responsible party
Sponsor
First posted
Dec 25, 2014
Start date
Jun 2013
Primary completion
Feb 2018
Completion
Feb 2018
Results posted
Aug 8, 2025
Last update
Aug 8, 2025

Study contacts

Massimo Fineschi, MD
study chair · Policlinico Le Scotte, Siena
Marco Valgimigli, MD
study chair

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

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