Current Perspective No-Reflow Phenomenon

1
Current PerspectiveNo-Reflow Phenomenon

• By
• Rezkalla and Kloner
• Circulation 2002 February 5th

2
Overview

• Introduction
• Historical Perspective
• Pathophysiology
• Diagnosis
• Clinical Presentation
• Management
• Advantages
• Measures
• Treatments
• Conclusion

3
Introduction

• Epicardial verses microvasculature
• No-Reflow
• Low-Reflow

4
Historical Perspective

• Initially found in brain
• Occurs in heart, skin, skeletal muscle and kidney
• In hearts, mainly subendocardial myocardium
• EM shows swollen endothelium, intra luminal
  endothelial protrusions occasional platelets,
  fibrin, and oedema
• PTCA and emergency CABG

5
Pathophysiology 1

• Prolonged cessation of epicardial blood flow
  results in damage to microcirculation, which
  prevents restoration of normal flow
• Inadequate cardiac scar
• Process NOT an immediate event on reperfusion
• NO-Reflow area increases with time

6
Pathophysiology 2

• Endothelial swelling and intra luminal
  protrusions occlude microvasulature
• ? Why dexamethasone and Mannitol help
• Intravasular plugging fibrin and platelets
• Ibuprofen, PG E1, heparinised saline, platelet
  depletion

7
Pathophysiology 3

• Leukocytes
• ? Neutropenia, CD18 Ab, Free radiacl scavenging
• Microemboli
• Atherosclerotic debris in thrombolysis,
  angioplasty, rotablation and stenting more
  common in vein graft interventions

8
Reperfusion
Ischaemia
No Reflow
Atheroembolism
9
Coronary occlusion Reperfusion Atheroemb
olism
Endothelial damage Tissue oedema Platelet/fibrin
Oxygen/free radicals Leukocytes Tissue
contracture
No reflow
10
Diagnosis 1

• Angiography
• TIMI flow (thrombolysis in myocardial infarction)
• Grade 0 no flow
• Garde 1 fails to opacify whole artery
• Grade 2 opacification of coronaries but slow
• Grade 3 normal
• Quantify further using TIMI frame count

11
Diagnosis 2

• Coronary doppler
• Serial ECGs
• PET
• MRI
• Myocardial contrast echocardiography

12
Clinical Presentation

• Cath Lab post angioplasty
• CCU after thrombolysis
• Preinfact angina reduces chance of no-reflow
• No-Reflow linked to
• Ventricular arrhythmias
• Early CCF
• Cardiac rupture
• Death
• Post CABG
• Decreased EF despite completely successful
  revasculisation

13
Management advantages

• May not decrease infarct size
• Speed healing of necrotic area
• Reduce infarct expansion and aneurysm formation
• Help collateral circulation

14
Management measures

• Retrieval of debris in vein grafts and after
  atherectomy
• IABP
• GP IIb/IIIa clinical and lab evidence
• Anti-leukocyte Abs and complement inhibitors

15
Management treatments

• Calcium channel blockers eg Verapamil
• Adenosine
• ATP K channel opener eg Nicorandil
• Papaverine
• Urokinase no good
• Cardioplegia and transplant

16
Conclusion

• Previous 2 decades concentrated on epicardial
  arteries, next decade will concentrate on
  microvascular perfusion