+ All Categories
Home > Documents > HEAT PPCI

HEAT PPCI

Date post: 24-Feb-2016
Category:
Upload: finley
View: 89 times
Download: 0 times
Share this document with a friend
Description:
HEAT PPCI. H ow E ffective are A ntithrombotic T herapies in PPCI. Heparin versus Bivalirudin in PPCI. Dr Adeel Shahzad Dr Rod Stables (PI) Liverpool Heart and Chest Hospital Liverpool, UK. Background. Anti-thrombotic therapy in PPCI - PowerPoint PPT Presentation
Popular Tags:
79
HEAT PPCI Dr Adeel Shahzad Dr Rod Stables (PI) Liverpool Heart and Chest Hospital Liverpool, UK Heparin versus Bivalirudin in PPCI H ow E ffective are A ntithrombotic T herapies in PPCI
Transcript
Page 1: HEAT PPCI

HEAT PPCI

Dr Adeel ShahzadDr Rod Stables (PI)

Liverpool Heart and Chest HospitalLiverpool, UK

Heparin versus Bivalirudin in PPCI

How Effective areAntithrombotic Therapies in PPCI

Page 2: HEAT PPCI

HEAT PPCI

• Anti-thrombotic therapy in PPCI• Selective (‘bailout’) use of GP IIb/IIIa antagonists (GPI)• Increasingly the norm in routine practice• Recommended by international guidelines• ESC ACCF / AHA

Background

Page 3: HEAT PPCI

HEAT PPCI

• Anti-thrombotic therapy in PPCI

• Selective (‘bailout’) use of GP IIb/IIIa antagonists (GPI)

• Increasingly the norm in routine practice

• Recommended by key guidelines (ESC, ACCF / AHA)

• Bivalirudin + selective (7% - 15%) use of GPI

• Established anti-thrombotic treatment option

Background

Page 4: HEAT PPCI

HEAT PPCI

• Bleeding is associated with less favourable outcomes

• Increased GPI use - results in increased bleeding

•Observed for both bivalirudin and heparin

• Relative performance of bivalirudin and heparin -

• Cannot be reliably assessed with differential GPI use

• HEAT PPCI

• Bivalirudin + selective GPI v Heparin + selective GPI

Background

Page 5: HEAT PPCI

HEAT PPCI

• Bleeding is associated with less favourable outcomes

• Increased GPI use - results in increased bleeding

•Observed for both bivalirudin and heparin

• Relative performance of bivalirudin and heparin -

• Cannot be assessed reliably with differential GPI use

• HEAT PPCI

• Bivalirudin + ‘bailout’ GPI v Heparin + ‘bailout’ GPI

Background

Page 6: HEAT PPCI

HEAT PPCI

• Single centre RCT

• Trial recruitment: Feb 2012 - Nov 2013 22 months

• Bivalirudin v Unfractionated Heparin

• STEMI patients

• Randomised at presentation

• Acute phase management with Primary PCI

Study Description

Page 7: HEAT PPCI

HEAT PPCI

• Single centre RCT

• Trial recruitment: Feb 2012 - Nov 2013 22 months

• Bivalirudin v Unfractionated Heparin

• STEMI patients

• Randomised at presentation

• Acute phase management with Primary PCI

Study Description

• Philosophy for clinical teams:

• Assess ‘Every Patient - Every Time’

Page 8: HEAT PPCI

HEAT PPCI

Inclusion Criterion

• All STEMI patients activating PPCI pathway

Study Population

Exclusion Criteria

• Active bleeding at presentation

• Factors precluding administration of oral A-P therapy

• Known intolerance / contraindication to trial medication

• Previous enrolment in this trial

Page 9: HEAT PPCI

HEAT PPCI

• Dual oral anti-platelet therapy pre-procedure

• Heparin: 70 units/kg body weight pre-procedure

• Bivalirudin: Bolus 0.75 mg/kg

Infusion 1.75 mg/kg/hr - procedure duration

Study Medication

Page 10: HEAT PPCI

HEAT PPCI

• Dual oral anti-platelet therapy pre-procedure

• Heparin: 70 units/kg body weight pre-procedure

• Bivalirudin: Bolus 0.75 mg/kg

Infusion 1.75 mg/kg/hr - procedure duration

Study Medication

• GPI - Abciximab

• Selective (‘bailout’) use in both groups

• ESC guideline indications

Page 11: HEAT PPCI

HEAT PPCI

At 28 days

Primary Efficacy Outcome Measure

• Major Adverse Cardiac Events (MACE) -

• All-cause mortality

• Cerebrovascular accident (CVA)

• Re-infarction

•Unplanned target lesion revascularisation (TLR)

Outcome Measures

Page 12: HEAT PPCI

HEAT PPCI

At 28 days

Primary Efficacy Outcome Measure

• Major Adverse Cardiac Events (MACE)

Outcome Measures

Primary Safety Outcome Measure

• Major bleeding -

• Type 3-5 bleeding as per BARC definitions

Page 13: HEAT PPCI

HEAT PPCI

• Data Monitoring and Safety Committee (DMSC)

• All key clinical events adjudicated

• Clinical Events Committee

• Blinded to the treatment allocation

• Use of a delayed consent strategy

Study Organisation

Page 14: HEAT PPCI

HEAT PPCI

• Full UK ethical approval

• Patients randomised and treated without discussion

• Subsequent informed consent in recovery phase

• Additional national approval -

•Use of data from patients who died before consent

Delayed Consent

Page 15: HEAT PPCI

HEAT PPCI

Results - Population1917 patients scheduled for emergency angiography

29 (1.5%) already randomised in the trial59 (3.0%) met one or more other exclusion criteria

1829 eligible for recruitment

Page 16: HEAT PPCI

HEAT PPCI

Results - Population1917 patients scheduled for emergency angiography

29 (1.5%) already randomised in the trial59 (3.0%) met one or more other exclusion criteria

1829 eligible for recruitment

1829 Randomised

Representative ‘Real-World’ Population

Page 17: HEAT PPCI

HEAT PPCI

Results - PopulationAssigned to Heparin 914 915 Assigned to Bivalirudin

Received allocated Rx 900 Received no study drug 14

Treatment cross-over 0LMWH pre-procedure 3

907 Received allocated Rx7 Received no study drug908 Treatment cross-over 4 LMWH pre-procedure

Page 18: HEAT PPCI

HEAT PPCI

Results - PopulationAssigned to Heparin 914

Included in analysis 907

915 Assigned to Bivalirudin

905 Included in analysis

Consent not available in surviving patients

Consent not available in surviving patients

7 10

Received allocated Rx 900 Received no study drug 14

Treatment cross-over 0LMWH pre-procedure 3

907 Received allocated Rx7 Received no study drug908 Treatment cross-over 4 LMWH pre-procedure

Page 19: HEAT PPCI

HEAT PPCI

Baseline Characteristics Characteristic Bivalirudin Heparin

Median age (years) 62.9 63.6

Female sex (%) 28.5 26.9

Caucasian race (%) 95.8 95.9

Diabetes mellitus (%) 12.6 15.1

Previous MI (%) 13.5 10.3

eGFR (ml/min/1.73m2) 80.0 80.0

Haemoglobin (g/dl) 13.6 13.7

Page 20: HEAT PPCI

HEAT PPCI

Procedural Information Characteristic Bivalirudin (%) Heparin (%)

P2Y12 use - Any 99.6 99.5

- Clopidogrel 11.8 10.0

- Prasugrel 27.3 27.6

- Ticagrelor 61.2 62.7

GPI use 13.5 15.5

Radial arterial access 80.3 82.0

PCI performed 83.0 81.6

Page 21: HEAT PPCI

HEAT PPCI

PCI Procedural Data Characteristic Bivalirudin (%) Heparin (%)

Thrombectomy 59.1 57.6

Single vessel Tx 93.2 90.3

Any stent implant 92.8 92.2

DES implantation 79.8 79.9

TIMI III flow - post PCI 93.3 92.7

Page 22: HEAT PPCI

HEAT PPCI

Primary Efficacy Outcome

Page 23: HEAT PPCI

HEAT PPCI

Primary Efficacy Outcome Bivalirudin Heparinn % % n

MACE 79 8.7 % v 5.7 % 52

Absolute risk increase = 3.0% (95% CI 0.6, 5.4)

Relative risk = 1.52 (95% CI 1.1 – 2.1) P=0.01

Page 24: HEAT PPCI

HEAT PPCI

Timing of First MACE Event

Event curve shows first event experienced

Page 25: HEAT PPCI

HEAT PPCI

MACE Outcome - All Events Bivalirudin Heparinn % % n

Death 46 5.1 % v 4.3 % 39

CVA 15 1.6% v 1.2% 11

Reinfarction 24 2.7% v 0.9% 8

TLR 24 2.7% v 0.7% 6

Any MACE 79 8.7 % v 5.7 % 52

Page 26: HEAT PPCI

HEAT PPCI

MACE Outcome - All Events Bivalirudin Heparinn % % n

Death 46 5.1 % v 4.3 % 39

CVA 15 1.6% v 1.2% 11

Reinfarction 24 2.7% v 0.9% 8

TLR 24 2.7% v 0.7% 6

Any MACE 79 8.7 % v 5.7 % 52

Page 27: HEAT PPCI

HEAT PPCI

MACE Outcome - HierarchicalBivalirudin Heparinn % % n

Death 46 5.1 % v 4.3 % 39

CVA 11 1.2% v 0.6% 6

Reinfarction 21 2.3% v 0.8% 7

TLR 1 0.1% v 0% 0

Any MACE 79 8.7 % v 5.7 % 52

Censored by the most significant event - in order displayed

Page 28: HEAT PPCI

HEAT PPCI

MACE Outcome - HierarchicalBivalirudin Heparinn % % n

Death 46 5.1 % v 4.3 % 39

CVA 11 1.2% v 0.6% 6

Reinfarction 21 2.3% v 0.8% 7

TLR 1 0.1% v 0% 0

Any MACE 79 8.7 % v 5.7 % 52

Censored by the most significant event - in order displayed

Page 29: HEAT PPCI

HEAT PPCI

Stent ThrombosisBivalirudin Heparinn % % n

All Events 24 3.4 % v 0.9 % 6

Relative risk = 3.91 (95% CI 1.6 - 9.5) P=0.001

ARC definite or probable stent thrombosis events

Page 30: HEAT PPCI

HEAT PPCI

Stent ThrombosisBivalirudin Heparinn % % n

Definite 23 3.3 % v 0.7 % 5

Probable 1 0.1 % v 0.1 % 1

Acute 20 2.9 % v 0.9 % 6

Subacute 4 0.6% v 0% 0

ARC definite or probable stent thrombosis events

Page 31: HEAT PPCI

HEAT PPCI

Primary Safety Outcomes Bivalirudin Heparinn % % n

Major Bleed 32 3.5 % v 3.1 % 28

Relative risk = 1.15 (95% CI 0.7 - 1.9) P=0.59

Major Bleed BARC grade 3-5

Page 32: HEAT PPCI

HEAT PPCI

Safety Outcomes Bivalirudin Heparinn % % n

Minor Bleed 83 9.2 % v 10.8 % 98

Major or Minor 113 12.5 % v 13.5 % 122

Minor Bleed P=0.25 Major or Minor P=0.54

Major Bleed BARC grade 3-5 Minor Bleed BARC grade 2

Page 33: HEAT PPCI

HEAT PPCI

• Single centre

• Potential impact minimised by:

•Meticulous trial conduct

•Unselected representative population

• Study treatments are iv drugs (no ‘skill’ component)

• Multiple operators

•Outcomes as expected by national norms

Study Limitations

Page 34: HEAT PPCI

HEAT PPCI

• Single centre

• Open label

• Potential impact minimised by:

• Complete follow-up - No ‘lost’ cases

•Outcome measures were overt clinical events

• Most MI events involved angiographic imaging

• Independent blinded adjudication

•Open label used in HORIZONS and EUROMAX

Study Limitations

Page 35: HEAT PPCI

HEAT PPCI

• A unique study with 100% recruitment of eligible patients

Conclusions

Page 36: HEAT PPCI

HEAT PPCI

• A unique study with 100% recruitment of eligible patients

Use of heparin rather than bivalirudin

• Reduced rate of major adverse events (NNT = 33)

• Fewer stent thromboses and reinfarction events

Conclusions

Page 37: HEAT PPCI

HEAT PPCI

• A unique study with 100% recruitment of eligible patients

Use of heparin rather than bivalirudin

• Reduced rate of major adverse events (NNT = 33)

• Fewer stent thromboses and reinfarction events

• Consistent effect across pre-specified subgroups

Conclusions

Page 38: HEAT PPCI

HEAT PPCI

• A unique study with 100% recruitment of eligible patients

Use of heparin rather than bivalirudin

• Reduced rate of major adverse events (NNT = 33)

• Fewer stent thromboses and reinfarction events

• Consistent effect across pre-specified subgroups

• No increase in bleeding complications

Conclusions

Page 39: HEAT PPCI

HEAT PPCI

• A unique study with 100% recruitment of eligible patients

Use of heparin rather than bivalirudin

• Reduced rate of major adverse events (NNT = 33)

• Fewer stent thromboses and reinfarction events

• Consistent effect across pre-specified subgroups

• No increase in bleeding complications

• Potential for substantial saving in drug costs

Conclusions

Page 40: HEAT PPCI

HEAT PPCI

Reserve Slides 0

Page 41: HEAT PPCI

HEAT PPCI

Subgroups – Primary OutcomeSubgroup Relative Risk (95% CI)

P Value for interaction

All patients 1.52 (1.09, 2.13)Arterial access site 0.87 Radial 1.58 (1.01, 2.48) Femoral 1.45 (0.70, 2.98)Diabetes 0.35 Yes 2.22 (1.04, 4.76) No 1.54 (1.04, 2.28)Age 0.11 ≥75 1.09 (0.68, 1.77) <75 1.97 (1.23, 3.16)

Favours Bivalirudin Favours Heparin

1

Page 42: HEAT PPCI

HEAT PPCI

Subgroups – Primary OutcomeSubgroup Relative Risk (95% CI)

P Value for interaction

P2Y12 agent used 0.78 Clopidogrel 1.34 (0.54, 3.31) Prasugrel 1.91 (0.87, 4.21) Ticagrelor 1.41 (0.93, 2.14)Left Ventricular Function Impaired 0.67 Yes 1.28 (0.84, 1.95) No 1.63 (0.64, 4.16)PCI attempted 0.88 Yes 1.55 (1.06, 2.28) No 1.45 (0.71, 2.96)

Favours Bivalirudin Favours Heparin

2

Page 43: HEAT PPCI

HEAT PPCI

Timing of First Major Bleed Event

Event curve shows first major bleed experienced

3

Page 44: HEAT PPCI

HEAT PPCI

Secondary Outcomes

Bivalirudin Heparin P value

Thrombocytopenia (%) new onset <150 8.3 7.3 0.49

CKMB post procedureMedian (ng/dl) 97 106 0.55

Door-first device time Median (mins) 29 29 0.33

4

Page 45: HEAT PPCI

HEAT PPCI

LV Function post Index MI Event

Bivalirudin Heparin P value

Normal (EF >54%) 45.4% 43.9% 0.53

Mild (EF 45-54%) 25.2% 26.2% 0.65

Moderate (EF 36-44%) 20.1% 19.8% 0.88

Severe (EF <36%) 9.3% 10.1% 0.60

5

Page 46: HEAT PPCI

HEAT PPCI

Common assumptions - based on historic connotations

• Smaller studies - often underpowered

• Potential subversion of randomisation

• Less robust trial procedures and documentation

• No adjudication of adverse events

Single-centre Trials ? 6

Page 47: HEAT PPCI

HEAT PPCI

Common assumptions - based on historic connotations

• Smaller studies - often underpowered

• Potential subversion of randomisation

• Less robust trial procedures and documentation

• No adjudication of adverse events

Single-centre Trials ?

No active problems for HEAT PPCI

7

Page 48: HEAT PPCI

HEAT PPCI

Issues related to the patient population

• Unselected: External referral to trial centre

• Near universal inclusion in trial

• Patients typical for UK population

• Predominantly Caucasian race

Single-centre Trials ? 8

Page 49: HEAT PPCI

HEAT PPCI

Issues related to the patient population

• Unselected: External referral to trial centre

• Near universal inclusion in trial

• Patients typical for UK population

• Predominantly Caucasian race

Single-centre Trials ?

May affect generalisation to other populations

8

Page 50: HEAT PPCI

HEAT PPCI

Issues related to clinical performance and outcomes

In HEAT PPCI -

• Randomised treatments are routine iv medications

• Established and standardised approach to

• Purchase and storage

• Administration and dosing

• Outcomes are not affected by practice pattern or ‘skill’

Single-centre Trials ? 9

Page 51: HEAT PPCI

HEAT PPCI

Issues related to clinical performance and outcomes

In HEAT PPCI -

• Randomised treatments are routine iv medications

• Established and standardised approach to

• Purchase and storage

• Administration and dosing

• Outcomes are not affected by practice pattern or ‘skill’

Single-centre Trials ?

Minimal threat in HEAT PPCI

10

Page 52: HEAT PPCI

HEAT PPCI

Issues related to clinical performance and outcomes

• Treatments administered in setting of a PPCI procedure

• Procedures performed by 14 different cardiologists

• Operator and institution outcomes as expected

•Match national and international norms for PPCI

Single-centre Trials ? 11

Page 53: HEAT PPCI

HEAT PPCI

Issues related to clinical performance and outcomes

• Treatments administered in setting of a PPCI procedure

• Procedures performed by 14 different cardiologists

• Operator and institution outcomes as expected

•Match national and international norms for PPCI

Single-centre Trials ?

Minimal threat in HEAT PPCI

12

Page 54: HEAT PPCI

HEAT PPCI

Mortality Outcomes in PPCIRegistry and TrialPPCI Outcomes Mortality (%)

HORIZONS (30d) 2.6 %

EUROMAX (30d) 3.0 %

US CathPCI 2011 (In-Hosp) 5.7 %

UK BCIS 2012 (30d) 6.4 %

HEAT PPCI (28d) 4.7 %

13

Page 55: HEAT PPCI

HEAT PPCI

• Comprehensive follow-up

•No ‘lost’ cases

Open Label Design ? 14

Page 56: HEAT PPCI

HEAT PPCI

• Comprehensive follow-up

• All primary efficacy and safety outcome measures -

•Overt clinical events with robust documentation

•MI events substantiated by imaging in almost all cases

Open Label Design ? 15

Page 57: HEAT PPCI

HEAT PPCI

• Comprehensive follow-up

• All primary efficacy and safety outcome measures

•Overt clinical events with robust documentation

•MI events substantiated by imaging in almost all cases

• Independent adjudication of events

• Blinded to patient identity and treatment allocation

Open Label Design ? 16

Page 58: HEAT PPCI

HEAT PPCI

• Comprehensive follow-up

• All primary efficacy and safety outcome measures

•Overt clinical events with robust documentation

•MI events substantiated by imaging in almost all cases

• Independent adjudication of events

• Open label norm - used in HORIZONS EUROMAX

Open Label Design ? 17

Page 59: HEAT PPCI

HEAT PPCI

• Estimated MACE rate = 7.5%

• Sample size 1800 patients

• Two-sided testing

• Allows superiority testing in favour of either agent

• Pre-specified boundaries for

•Non-Inferiority Equivalence

• Calculations based on absolute event rate difference

Power Calculation 18

Page 60: HEAT PPCI

HEAT PPCI

• Assuming no observed treatment difference

‘Treatment A’ 7.5% = 7.5% ‘Treatment B’

• Event rate difference = 0%

• Calculate 95% CI for the rate difference

Power Calculation

0%+2.4

%-2.4%

19

Page 61: HEAT PPCI

HEAT PPCI

• Assuming an observed treatment difference

‘Treatment A’ 5.5% = 8.0% ‘Treatment B’

• Event rate difference = 2.5%

• Calculate 95% CI for the rate difference

Power Calculation

2.5%

+2.3%

-2.3%

20

Page 62: HEAT PPCI

HEAT PPCI

Conventional Superiority - Tx A

0%

1%

2%

3%

4%

4%

3%

2%

1%

Event Rate Difference

Favours Treatment A Favours Treatment B

2.5%

+2.3%

-2.3%

21

Page 63: HEAT PPCI

HEAT PPCI

Conventional Superiority - Tx B

0%

1%

2%

3%

4%

4%

3%

2%

1%

Event Rate Difference

Favours Treatment A Favours Treatment B

2.5%

+2.3%

-2.3%

22

Page 64: HEAT PPCI

HEAT PPCI

Pre-specified Equivalence Zone

0%

1%

2%

3%

4%

4%

3%

2%

1%

Event Rate Difference

Favours Treatment A Favours Treatment B

Point estimate lies in zone ± 0.5% from zero difference

25

Page 65: HEAT PPCI

HEAT PPCI

Equivalence - Examples

0%

1%

2%

3%

4%

4%

3%

2%

1%

Event Rate Difference

Favours Treatment A Favours Treatment B

0.4%

+2.4%

-2.4%

0.4%

+2.4%

-2.4%

26

Page 66: HEAT PPCI

HEAT PPCI

Non-Inferiority - Example for Tx A

0%

1%

2%

3%

4%

4%

3%

2%

1%

Event Rate Difference

Favours Treatment A Favours Treatment B

Point estimate better than (-0.5%)

23

Page 67: HEAT PPCI

HEAT PPCI

Non-Inferiority - Example for Tx A

0%

1%

2%

3%

4%

4%

3%

2%

1%

Event Rate Difference

Favours Treatment A Favours Treatment B

Point estimate better than (-0.5%)

1%+2.4

%-2.4%

24

Page 68: HEAT PPCI

HEAT PPCI

• Anti-thrombotic therapy in PPCI for STEMI

• Selective (‘bailout’) use of GP IIb/IIIa antagonists (GPI)

• Increasingly the norm in routine practice

• Recommended by key guidelines (ESC, ACCF / AHA)

• Bivalirudin + selective (7% - 15%) use of GPI

• Established anti-thrombotic treatment option

Background

Page 69: HEAT PPCI

HEAT PPCI

• Bivalirudin and heparin -

• Appear to have similar anti-ischaemic efficacy

• Similar impact on MACE events

Background

Page 70: HEAT PPCI

HEAT PPCI

Bivalirudin v Heparin

HAS REPLACE REPLACE 2

ISAR REACT 4 ACUITY ISAR REACT 3

HORIZONS ISAR REACT 3A EUROMAX

No difference in ischaemic outcomes

Page 71: HEAT PPCI

HEAT PPCI

• Bivalirudin and heparin - similar impact on MACE events

• Use of GPI agents causes increased bleeding

•When used with heparin

Background

Page 72: HEAT PPCI

HEAT PPCI

Heparin - Differential GPI useHeparin Heparin

EPIC Placebo GPI Universal

RESTORE Placebo GPI Universal

PRISM Plus Placebo GPI Universal

CAPTURE Placebo GPI Universal

↑ bleeding with ↑ GPI use

Page 73: HEAT PPCI

HEAT PPCI

• Bivalirudin and heparin - similar impact on MACE events

• Use of GPI agents causes increased bleeding

•When used with heparin

•When used with bivalirudin

Background

Page 74: HEAT PPCI

HEAT PPCI

Bivalirudin - Differential GPI useBivalirudin Bivalirudin

GPI Bailout GPI Universal

ACUITY 9 % 97 %

↑ bleeding with ↑ GPI use

Page 75: HEAT PPCI

HEAT PPCI

• Bivalirudin and heparin - similar impact on MACE events

• Use of GPI agents causes increased bleeding

• With similar GPI use -

• Bivalirudin and heparin have similar bleeding rates

Background

Page 76: HEAT PPCI

HEAT PPCI

Both Drugs with Similar GPI useBivalirudin Heparin

GPI Universal GPI Universal

ACUITY 97 % 97 %

REPLACE 72 % 71 %

No differences in bleeding

Page 77: HEAT PPCI

HEAT PPCI

• Bivalirudin and heparin - similar impact on MACE events

• Use of GPI agents causes increased bleeding

• With similar GPI use -

• Bivalirudin and heparin have similar bleeding rates

• With differential GPI use -

• Bivalirudin and heparin have different bleeding rates

Background

Page 78: HEAT PPCI

HEAT PPCI

Both Drugs with Differential GPI use

Bivalirudin Heparin

GPI Bailout GPI Universal

ACUITY 9 % 97 %

ISAR REACT 4 0 % 100 %

HORIZONS 7 % 98 %

EUROMAX 9 % 70 %

↑ bleeding with ↑ GPI use

Page 79: HEAT PPCI

HEAT PPCI

• Bleeding is associated with less favourable outcomes

• Increased GPI use - results in increased bleeding

•Observed for both bivalirudin and heparin

• Relative performance of bivalirudin and heparin -

• Cannot be assessed reliably with differential GPI use

• HEAT PPCI

• Bivalirudin + selective GPI v Heparin + selective GPI

Background


Recommended