Cardiovascular Magnetic Resonance for Risk Stratification in Patients With ST-Segment–Elevation Myocardial Infarction

HomeCirculation: Cardiovascular ImagingVol. 10, No. 11Cardiovascular Magnetic Resonance for Risk Stratification in Patients With ST-Segment–Elevation Myocardial Infarction Free AccessEditorialPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessEditorialPDF/EPUBCardiovascular Magnetic Resonance for Risk Stratification in Patients With ST-Segment–Elevation Myocardial InfarctionA Novel Tool to Tailor Therapy or Emperor's New Clothes? Jacob Lønborg, MD, PhD, DMSci and Thomas Engstrøm, MD, PhD, DMSci Jacob LønborgJacob Lønborg From the Department of Cardiology, Rigshospitalet, University of Copenhagen, Denmark. and Thomas EngstrømThomas Engstrøm From the Department of Cardiology, Rigshospitalet, University of Copenhagen, Denmark. Originally published16 Nov 2017https://doi.org/10.1161/CIRCIMAGING.117.007108Circulation: Cardiovascular Imaging. 2017;10:e007108During the past decades, there has been a dramatic change in the management and treatment of patients presenting with ST-segment–elevation myocardial infarction (STEMI), which has resulted in a reduction in mortality.1 One great advance has been the introduction of reperfusion therapy first by fibrinolysis2 and subsequently by primary percutaneous coronary intervention.3,4See Article by Pontone et alEarly reperfusion restores coronary blood flow and increases myocardial salvage, thereby reducing myocardial infarct size and preserving left ventricular (LV) function.5However, despite great improvements in the treatment of patients with STEMI, the 1-year mortality rate after a STEMI is still ≈10%,1,6 and around 10% develop clinical heart failure.7 The 30-day mortality is around 7% but declines thereafter.6 Early risk stratification is, therefore, pivotal to identify patients at high risk for short- and long-term complications. However, besides treatment of individual risk factors (eg, diabetes mellitus, smoking, hypercholesterolemia, and hypertension) and complete revascularization for patients with multivessel disease, risk-based directed therapy relies almost exclusively on assessment of LV ejection fraction (LVEF) by echocardiography. In patients with reduced LVEF after acute myocardial infarction, treatment with an implanted cardioverter-defibrillator and intensive medication is recommended.8 Importantly, however, LVEF is hampered by postinfarction stunning and compensatory hyperkinesia of the remote myocardium. Thus, there is still a need for further improvement in risk assessment of patients with STEMI and a more detailed evaluation of the extent of myocardial damage beyond LVEF.The magnitude of myocardial damage after STEMI is easily assessed by cardiac biomarkers.However, the measured troponin T value depends on the coronary blood flow and duration of ischemia before reperfusion9 leading to great variability and imprecision, and using the value of cardiac biomarkers for risk assessment on a patient-based level is uncertain. On the other hand, noninvasive imaging provides direct visualization of the myocardial damage after a STEMI also known as the infarct size. Late gadolinium enhancement cardiovascular magnetic resonance (CMR) imaging is the gold standard modality for assessing infarct size and myocardial scarring.10 Gadolinium is a contrast agent that is distributed in the extracellular space, which is increased in the infarcted myocardial region.11 In addition, CMR protocols provide further characterization of the infarcted myocardium, and specifically, the use of late gadolinium enhancement and T2* allows for visualization of microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH), within the infarcted myocardium. There are also sequences (T1 mapping, T2-weighted imaging, and contrast-enhanced steady-state free precession) to visualize myocardial edema, which in patients with STEMI represent the extent of myocardium or area at risk. Measuring area at risk and infarct size makes it possible to calculate myocardial salvage (myocardial salvage index). Today, several observational studies have demonstrated that infarct size, MVO, and IMH measured by CMR after a STEMI are strong predictors for subsequent major adverse cardiac events, including mortality and heart failure.12–18 However, most studies are observational, and the different parameters are often expressed as continuous values without strict cutoff value, postprocession algorithms have not been standardized, and there is no evidence on how to use this information to direct therapy.In the current issue of Circulation: Cardiovascular Imaging, Pontone et al19 prospectively performed CMR in 209 patients with STEMI 3 days after treatment with primary percutaneous coronary intervention and explored associations between the CMR findings and subsequent major adverse cardiac events (death and congestive heart failure). As expected, the article confirms previous observations that infarct size, MVO, IMH, LVEF, and myocardial salvage index associate with major adverse cardiac events and provide independent prognostic information beyond the well-established Global Registry of Acute Coronary Events risk score. Moreover, using receiver operating characteristics statistics, the authors also identified optimal cutoff values for predicting major adverse cardiac events for each CMR parameter. Interestingly, the cutoff value for MVO was 2.6% of LV and 37.5% for LVEF, which were similar to the values identified in another recent study (2.6% and 43% of LV, respectively).16 Using optimized cutoff values for IMH, MVO, LVEF, and myocardial salvage index, the authors constructed a 17-point CMR-based risk score that provides strong prognostic value compared with the standard Global Registry of Acute Coronary Events score and LVEF by echocardiography. In multivariable Cox regression modeling, the χ2 value from each step was used to create a weighted risk score as follows: 12.5 points for the presence of IMH, 2.5 points for MVO >2.6% of LV, 2.5 points for LVEF <37.5%, and 0.3 points for myocardial salvage index <0.40.Creating a CMR-based risk score that integrates different parameters is intriguing, and the authors should be congratulated for undertaking this effort. However, given the observational nature of the study, the results should be interpreted with caution. A limitation of the study is that it does not provide evidence as to whether and how the CMR risk score will impact patient management. In addition, using the risk score routinely after STEMI is complicated by the fact that only few institutions have this capacity. Area at risk and IMH are both pivotal factors in the risk score, and in the study by Pontone et al, these are assessed using T2-weighted images. However, the T2-weighted images are prone to artefacts and poor image quality that affects diagnostic quality.20 Therefore, IMH and area at risk may be better assessed using T2*, T1 mapping, T2 mapping, or contrast-enhanced steady-state free precession. Finally, omitting infarct size from the CMR risk score is questionable because infarct size in multiple previous studies has been demonstrated to be a strong prognostic predictor.Thus, to conclude, there is no doubt that CMR in patients with STEMI provides incremental prognostic value to established clinical risk factors, and a CMR-based risk score is intriguing.However, prospective studies using CMR to tailor treatment and patient management are warranted to move this field forward. Until then, the risk score could be useful to stratify patients when assessing effects of new treatment modalities in the context of clinical research studies.DisclosuresNone.FootnotesThe opinions expressed in this article are not necessarily those of the editors or of the American Heart Association.Correspondence to Jacob Lønborg, MD, PhD, DMSci, Department of Cardiology, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen, Denmark. E-mail [email protected]References1. Fokkema ML, James SK, Albertsson P, Akerblom A, Calais F, Eriksson P, Jensen J, Nilsson T, de Smet BJ, Sjögren I, Thorvinger B, Lagerqvist B. Population trends in percutaneous coronary intervention: 20-year results from the SCAAR (Swedish Coronary Angiography and Angioplasty Registry).J Am Coll Cardiol. 2013; 61:1222–1230. doi: 10.1016/j.jacc.2013.01.007.CrossrefMedlineGoogle Scholar2. Indications for fibrinolytic therapy in suspected acute myocardial infarction: collaborative overview of early mortality and major morbidity results from all randomised trials of more than 1000 patients. Fibrinolytic Therapy Trialists' (FTT) Collaborative Group.Lancet. 1994; 343:311–322. MedlineGoogle Scholar3. Keeley EC, Boura JA, Grines CL. Primary angioplasty versus intravenous thrombolytic therapy for acute myocardial infarction: a quantitative review of 23 randomised trials.Lancet. 2003; 361:13–20. doi: 10.1016/S0140-6736(03)12113-7.CrossrefMedlineGoogle Scholar4. Boersma E; Primary Coronary Angioplasty vs. Thrombolysis Group. Does time matter? A pooled analysis of randomized clinical trials comparing primary percutaneous coronary intervention and in-hospital fibrinolysis in acute myocardial infarction patients.Eur Heart J. 2006; 27:779–788. doi: 10.1093/eurheartj/ehi810.CrossrefMedlineGoogle Scholar5. Gersh BJ, Stone GW, White HD, Holmes DR. Pharmacological facilitation of primary percutaneous coronary intervention for acute myocardial infarction: is the slope of the curve the shape of the future?JAMA. 2005; 293:979–986. doi: 10.1001/jama.293.8.979.CrossrefMedlineGoogle Scholar6. Pedersen F, Butrymovich V, Kelbæk H, Wachtell K, Helqvist S, Kastrup J, Holmvang L, Clemmensen P, Engstrøm T, Grande P, Saunamäki K, Jørgensen E. Short- and long-term cause of death in patients treated with primary PCI for STEMI.J Am Coll Cardiol. 2014; 64:2101–2108. doi: 10.1016/j.jacc.2014.08.037.CrossrefMedlineGoogle Scholar7. Terkelsen CJ, Jensen LO, Tilsted HH, Trautner S, Johnsen SP, Vach W, Bøtker HE, Thuesen L, Lassen JF. Health care system delay and heart failure in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention: follow-up of population-based medical registry data.Ann Intern Med. 2011; 155:361–367. doi: 10.7326/0003-4819-155-6-201109200-00004.CrossrefMedlineGoogle Scholar8. Moss AJ, Zareba W, Hall WJ, Klein H, Wilber DJ, Cannom DS, Daubert JP, Higgins SL, Brown MW, Andrews ML; Multicenter Automatic Defibrillator Implantation Trial II Investigators. Prophylactic implantation of a defibrillator in patients with myocardial infarction and reduced ejection fraction.N Engl J Med. 2002; 346:877–883. doi: 10.1056/NEJMoa013474.CrossrefMedlineGoogle Scholar9. Zabel M, Hohnloser SH, Köster W, Prinz M, Kasper W, Just H. Analysis of creatine kinase, CK-MB, myoglobin, and troponin T time-activity curves for early assessment of coronary artery reperfusion after intravenous thrombolysis.Circulation. 1993; 87:1542–1550.LinkGoogle Scholar10. Kim RJ, Fieno DS, Parrish TB, Harris K, Chen EL, Simonetti O, Bundy J, Finn JP, Klocke FJ, Judd RM. Relationship of MRI delayed contrast enhancement to irreversible injury, infarct age, and contractile function.Circulation. 1999; 100:1992–2002.LinkGoogle Scholar11. Lima JA, Judd RM, Bazille A, Schulman SP, Atalar E, Zerhouni EA. Regional heterogeneity of human myocardial infarcts demonstrated by contrast-enhanced MRI. Potential mechanisms.Circulation. 1995; 92:1117–1125.LinkGoogle Scholar12. Lønborg J, Vejlstrup N, Kelbæk H, Holmvang L, Jørgensen E, Helqvist S, Saunamäki K, Ahtarovski KA, Bøtker HE, Kim WY, Clemmensen P, Engstrøm T. Final infarct size measured by cardiovascular magnetic resonance in patients with ST elevation myocardial infarction predicts long-term clinical outcome: an observational study.Eur Heart J Cardiovasc Imaging. 2013; 14:387–395. doi: 10.1093/ehjci/jes271.CrossrefMedlineGoogle Scholar13. Larose E, Rodés-Cabau J, Pibarot P, Rinfret S, Proulx G, Nguyen CM, Déry JP, Gleeton O, Roy L, Noël B, Barbeau G, Rouleau J, Boudreault JR, Amyot M, De Larochellière R, Bertrand OF. Predicting late myocardial recovery and outcomes in the early hours of ST-segment elevation myocardial infarction traditional measures compared with microvascular obstruction, salvaged myocardium, and necrosis characteristics by cardiovascular magnetic resonance.J Am Coll Cardiol. 2010; 55:2459–2469. doi: 10.1016/j.jacc.2010.02.033.MedlineGoogle Scholar14. Eitel I, Desch S, Fuernau G, Hildebrand L, Gutberlet M, Schuler G, Thiele H. Prognostic significance and determinants of myocardial salvage assessed by cardiovascular magnetic resonance in acute reperfused myocardial infarction.J Am Coll Cardiol. 2010; 55:2470–2479. doi: 10.1016/j.jacc.2010.01.049.CrossrefMedlineGoogle Scholar15. Eitel I, de Waha S, Wöhrle J, Fuernau G, Lurz P, Pauschinger M, Desch S, Schuler G, Thiele H. Comprehensive prognosis assessment by CMR imaging after ST-segment elevation myocardial infarction.J Am Coll Cardiol. 2014; 64:1217–1226. doi: 10.1016/j.jacc.2014.06.1194.CrossrefMedlineGoogle Scholar16. Symons R, Pontone G, Schwitter J, Francone M, Iglesias JF, Barison A, Zalewski J, de Luca L, Degrauwe S, Claus P, Guglielmo M, Nessler J, Carbone I, Ferro G, Durak M, Magistrelli P, Presti Lo A, Aquaro GD, Eeckhout E, Roguelov C, Andreini D, Vogt P, Guaricci AI, Mushtaq S, Lorenzoni V, Muller O, Desmet W, Agati L, Janssens S, Bogaert J, Masci PG. Long-term incremental prognostic value of cardiovascular magnetic resonance after ST-segment elevation myocardial infarction: a study of the collaborative registry on CMR in STEMI [published online ahead of print August 11, 2017].JACC Cardiovasc Imaging. doi: 10.1016/j.jcmg.2017.05.023. https://www.ncbi.nlm.nih.gov/pubmed/28823746. Accessed November 7, 2017.Google Scholar17. Stone GW, Selker HP, Thiele H, Patel MR, Udelson JE, Ohman EM, Maehara A, Eitel I, Granger CB, Jenkins PL, Nichols M, Ben-Yehuda O. Relationship between infarct size and outcomes following primary PCI: patient-level analysis from 10 randomized trials.J Am Coll Cardiol. 2016; 67:1674–1683. doi: 10.1016/j.jacc.2016.01.069.CrossrefMedlineGoogle Scholar18. Carrick D, Haig C, Ahmed N, Eteiba H, McEntegart M, Watkins S, Lindsay M, Radjenovic A, Oldroyd KG, Berry C. 8 Myocardial haemorrhage after acute reperfused st-elevation myocardial infarction: temporal evolution, relation to microvascular obstruction and prognostic significance.Heart. 2015; 101:A4.3–A5.CrossrefGoogle Scholar19. Pontone G, Guaricci AI, Andreini D, Ferro G, Guglielmo M, Baggiano A, Fusini L, Muscogiuri G, Lorenzoni V, Mushtaq S, Conte E, Annoni A, Formenti A, Mancini ME, Carità P, Verdecchia M, Pica S, Fazzari F, Cosentino N, Marenzi G, Rabbat MG, Agostoni P, Bartorelli AL, Pepi M, Masci PG. Prognostic stratification of patients with ST-segment–elevation myocardial infarction: a cardiac magnetic resonance study.Circ Cardiovasc Imaging. 2017; 10:e006428. doi: 10.1161/CIRCIMAGING.117.006428.LinkGoogle Scholar20. Nordlund D, Klug G, Heiberg E, Koul S, Larsen TH, Hoffmann P, Metzler B, Erlinge D, Atar D, Aletras AH, Carlsson M, Engblom H, Arheden H. Multi-vendor, multicentre comparison of contrast-enhanced SSFP and T2-STIR CMR for determining myocardium at risk in ST-elevation myocardial infarction.Eur Heart J Cardiovasc Imaging. 2016; 17:744–753. doi: 10.1093/ehjci/jew027.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Holzknecht M, Reindl M, Tiller C, Reinstadler S, Lechner I, Pamminger M, Schwaiger J, Klug G, Bauer A, Metzler B and Mayr A (2021) Global longitudinal strain improves risk assessment after ST-segment elevation myocardial infarction: a comparative prognostic evaluation of left ventricular functional parameters, Clinical Research in Cardiology, 10.1007/s00392-021-01855-6, 110:10, (1599-1611), Online publication date: 1-Oct-2021. Albani S, Fabris E, Stolfo D, Falco L, Barbati G, Aquaro G, Vitrella G, Rakar S, Korcova R, Lardieri G, Giannini F, Perkan A and Sinagra G (2019) Prognostic relevance of pericardial effusion in STEMI patients treated by primary percutaneous coronary intervention: a 10-year single-centre experience, European Heart Journal. Acute Cardiovascular Care, 10.1177/2048872619884858, 10:1, (71-80), Online publication date: 5-Mar-2021. Su S, Wang J, Wang J, Yu R, Sun L, Zhang Y, Song L, Pu W, Tang Y, Yu Y and Zhou K (2022) Cardioprotective effects of gypenoside XVII against ischemia/reperfusion injury: Role of endoplasmic reticulum stress, autophagy, and mitochondrial fusion fission balance, Phytotherapy Research, 10.1002/ptr.7493 November 2017Vol 10, Issue 11 Advertisement Article InformationMetrics © 2017 American Heart Association, Inc.https://doi.org/10.1161/CIRCIMAGING.117.007108PMID: 29146588 Originally publishedNovember 16, 2017 Keywordsrisk assessmentEditorialshumansST elevation myocardial infarctionpercutaneous coronary interventionPDF download Advertisement SubjectsMagnetic Resonance Imaging (MRI)