1 / 33

No conflicts of interest

The index of microvascular resistance measured acutely predicts infarct severity and left ventricular function at 3 months in patients with ST segment elevation myocardial infarction .

tosca
Download Presentation

No conflicts of interest

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The index of microvascular resistance measured acutely predicts infarct severity and left ventricular function at 3 months in patients with ST segment elevation myocardial infarction McGeoch RJ12, Watkins S1, Berry C1,2, Davie A1, Byrne J1, Hillis WS1, Lindsay MM1, Robb SD1, Dargie HJ1, Oldroyd KG11Department of Cardiology, Golden Jubilee National Hospital2BHF Glasgow Cardiovascular Research Centre, Faculty of Medicine, University of Glasgow

  2. No conflicts of interest

  3. Background • Immediate aim of reperfusion therapy in STEMI is to achieve patency of infarct related artery • TIMI grade 3 flow achieved 90% of patients1 • Despite this a significant proportion of patients do not achieve complete myocardial perfusion • Keeley EC, et al Lancet 2003

  4. Microvascular obstruction in STEMI • Can effect up to 50 % of patients who undergo successful reperfusion • Studies have shown MVO is associated with higher adverse clinical events including heart failure and death.1,2 • No currently agreed gold standard for assessment of MVO in the cath lab • Hombach et al Eur Heart J 2005 • Wu et al Circulation 1998

  5. Index of microcirculatory resistance (IMR) using the RADITM pressure and temperature wire • Performed at the time of PCI. • Numerical value for myocardial resistance. • In vivo and in vitro validation1,2 • Independent of variations in haemodynamic states.3 • IMR = Pd x Tmn1 • Aarnoudse W et al Catheter Cardiovasc Interv 2004 • Fearon W et al Circulation 2004 • Ng MKC, Yeung AC, Fearon WF Circulation 2006

  6. Thermodilution derived mean transit times at rest and hyperaemia

  7. Assessment of MVO and LV function by cardiac MRI • CMR allows accurate assessment of LV volumes, ejection fraction and visualisation of MVO and infarct size1 • Cannot be performed at the time of emergency PCI when potential interventions would be of maximal benefit • Task force of the ESC Eur Heart J. 1998

  8. Anterior STEMI

  9. Anterior MI – Late gadolinium contrast MVO absent MVO present

  10. Hypothesis • Microvascular function measured invasively at the time of reperfusion will predict the severity of myocardial injury subsequently revealed by MRI. • Specifically, we aimed to determine whether IMR calculated immediately after successful epicardial reperfusion in patients presenting with STEMI could be used as a predictor of MVO and myocardial damage using ceCMR as the gold standard comparison.

  11. Flow Diagram of the Study 57 patients with STEMI treated by emergency PCI Initial consent PCI with pressure wire assessment Re-consent ceCMR at 24-48 hours ceCMR at 3 months

  12. Methods: physiological assessment • PCI performed in line with current international guidelines. • Pressure wire (Radi Medical Systems, Uppsala, Sweden) was used as the primary guide-wire. • IMR calculated post procedure during maximal hyperaemia (adenosine 140 mcg/kg/min) • Mean aortic and distal coronary pressures were recorded during maximal hyperemia.

  13. Methods: ceCMR • 1.5 T Siemens Avanto • ceCMR at 24-48h • ceCMR at 3 months • Contrast agent: gadolinium-DTPA

  14. Demographics Mean age (range) : 58 (32-83)

  15. Results: ceCMR • Successful physiological measurements where achieved in all patients • 53/57 had complete baseline ceCMR • 47/57 had complete follow up scans

  16. Results: MVO

  17. Results: MVO

  18. Predictors of LVEF at baseline

  19. Predictors of LVEF at 3 months

  20. Predictors of Infarct Volumes at Baseline

  21. Predictors of Infarct Volumes at 3 months

  22. Conclusions • IMR is significantly higher in those with MVO as assessed by ceCMR • IMR measured acutely at the end of emergency PCI independently predicts infarct size and LV function in the longer term • Potentially this relatively simple wire based technique could be used at the time of PCI as a marker of MVO and myocardial damage

  23. Chief Scientist Office Scotland Robertson Centre for Biostatistics, University of Glasgow Acknowledgements

  24. Correlation between both methods of IMR calculation

  25. IMR vs. LVEF at baseline

  26. IMR vs. Peak troponin I

  27. Results: MVO

  28. Predictors of LVEF at baseline

  29. Predictors of LVEF at 3 months

  30. Predictors of Infarct Volumes at Baseline

  31. Predictors of Infarct Volumes at 3 months

  32. Patients aged > 18 ECG and symptomatic evidence of acute STEMI and who undergo emergency PCI. Informed written consent. Standard contraindications to MRI. Contraindications to Gadolinium. Contraindications to adenosine. Cardiogenic shock. Previous myocardial infarction in the same territory as the index event Pregnant Inclusion/exclusion criteria

More Related