The Challenge of Making Cardiac Resonance a Global Reality

Diagnostic Imaging/trends; Magnetic Resonance Spectroscopy; Cardiovascular Diseases/mortality; Death,Sudden; Cardiomyopathes; Endomyocardial Fibrosis; Myocardial Ischemia; Stroke Volume

Despite substantially reducing age-adjusted cardiovascular mortality rates in recent decades, cardiovascular disease remains the most common cause of death.¹ Studies estimate that sudden cardiac death is responsible for approximately 50% of all deaths from cardiovascular causes, with ventricular tachycardia with degeneration to ventricular fibrillation and asystole being the most common fatal sequence of pathophysiological events.²

The hard work done by authors of the article³ published in the Arquivos Brasileiros de Cardiologia illustrates the role of cardiac magnetic resonance (CMR) in the etiological elucidation of sudden death events encountered in clinical practice. In addition to the already expected Chagas and ischemic diseases, a wide variety of other diagnoses have been recognized: myocarditis, hypertrophic cardiomyopathy, dilated cardiomyopathy, arrhythmogenic heart disease, muscular dystrophy, hypertensive cardiomyopathy, metastases, non-compacted myocardium, and adrenergic cardiomyopathy (Takotsubo syndrome). The CMR was conclusive in more than 90% of cases and is a key tool for excluding structural heart disease and attributing the fatal event to extracardiac causes.

On the other hand, the study showed how far we are from good criteria for the prevention of sudden cardiac death by left ventricular ejection fraction (LVEF): only one-third of the patients had an LVEF ≤ 35%, and almost 40% of the individuals had an LVEF > 50%. It is not new that studies indicate that LVEF alone is not a sufficient criterion for the proper identification of patients whom most benefit from ICD.⁴ Therefore, in recent years, efforts have been made to identify new markers capable of refining the prognostic stratification of sudden death. Genetic analysis and magnetic resonance imaging are extremely useful tools for improving this process.⁵

The Brazilian Society of Cardiology recently updated its guidelines on implantable electronic cardiac devices.⁶Although it maintained LVEF ≤ 35% as the main parameter for indicating an implantable cardioverter-defibrillator (ICD) in the primary prevention of sudden death, new tools were incorporated into this process, especially for non-ischemic heart diseases, such as the detection of fibrosis by CMR or high-risk genetic alterations by molecular tests.

Myocardial fibrosis detected by CMR with the delayed gadolinium enhancement technique was present in approximately 70% of the cases of sudden death in the present study³ and is a strong predictor of ventricular arrhythmia and sudden death, both in ischemic and non-ischemic heart disease.⁷-¹¹ Especially in non-ischemic dilated heart disease, a delayed enhancement in patients with LVEF > 35% offered a higher arrhythmic risk than in those patients with LVEF 21-35% but without delayed enhancement, thus re-stratifying the risk in one-third of cases.¹¹

Cardiac resonance is a multipurpose cardiac imaging modality with a wide variety of information used to assess morphology, function, tissue characterization, perfusion, flows, and scars/fibrosis. Myocardial ischemia research by CMR has become an important part of the cardiac imaging arsenal, as it is more accurate than SPECT and offers excellent prognostic information.¹³,¹⁴ In evaluating cardiomyopathies, it can be an important technique to exclude coronary artery disease as the underlying cause. However, recent studies suggest that delayed gadolinium enhancement may be sufficient to establish the etiology of heart failure in most cases.¹⁵

In recent years, we have witnessed an avalanche of scientific articles on cardiac resonance imaging on the usefulness of parametric maps, either in the early cardiac involvement of different pathologies or in the specific etiological diagnosis, especially the T1 Map in the differential diagnosis of hypertrophic phenotypes such as Cardiac Amyloidosis or by Anderson Fabry.¹⁶,¹⁸ However, these techniques require advanced software and significant time to acquire pre- and post-contrast data, and using this technology in developing countries is expensive and time-consuming acquisition and post-processing.

Even with so much possibility of information, however, CMR is still little used, mainly due to its lack of availability, as it is a technique considered complicated, slow, expensive, and, in some cases where the understanding of the technique is limited, may not add to the diagnostic arsenal. Because of this situation, the INCA¹⁹ study carried out in Lima, Peru, and later replicated in other developing countries,²⁰ demonstrated that it is possible to perform the test in less than 30 minutes, reducing costs by 30-60%, but without losing its high impact in the management of heart disease.

In this sense, the effort to implement and disseminate faster cardiac resonance protocols would increase access to the method, offering accurate information for interventions capable of reducing cardiovascular morbidity and mortality. Cardiac MRI must be faster, easier, and more cost-effective for global and sustainable delivery.

Referências

• ¹
  Malta DC, Teixeira R, Oliveira GMM, Ribeiro ALP. Cardiovascular Disease Mortality According to the Brazilian Information System on Mortality and the Global Burden of Disease Study Estimates in Brazil, 2000-2017. Arq Bras Cardiol. 2020 Aug 28;115(2):152-60. doi: 10.36660/abc.20190867.
  » https://doi.org/10.36660/abc.20190867
• ²
  Huikuri HV, Castellanos A, Myerburg RJ. Sudden Death Due to Cardiac Arrhythmias. N Engl J Med. 2001;345(20):1473-82. doi:10.1056/nejmra000650
  » https://doi.org/10.1056/nejmra000650
• ³
  Marçal PC, Braggion-Santos MF, Wada DT, Santos MK, Moreira HT, Volpe GJ, et al. Cardiac Magnetic Resonance as an Etiological Diagnosis Tool in Recovered Sudden Cardiac Death or Unstable Ventricular Arrhythmia Patients. Arq Bras Cardiol. 2023; 120(4):e20220411
• ⁴
  Buxton AE, Lee KL, Hafley GE, Pires LA, Fisher JD, Gold MR, et al., MUSTT Investigators. Limitations of ejection fraction for prediction of sudden death risk in patients with coronary artery disease: lessons from the MUSTT Study. J Am Coll Cardiol. 2007 Sep 18;50(12):1150-7. doi: 10.1016/j.jacc.2007.04.095.
• ⁵
  Rizzello V. Selection of patients eligible for implantable cardioverter defibrillator: beyond left ventricular ejection fraction. Eur Heart J.2022;24 (Suppl 1);1139-42. doi: 10.1093/eurheartjsupp/suac087.
• ⁶
  Teixeira RA, Fagundes AA, Baggio Junior JM, Oliveira JC, Medeiros PTJ, Valdigem BP, et al, Brazilian Guidelines for Cardiac Implantable Electronic Devices - 2023. Arq Bras Cardiol. 2023 Jan 23;120(1):e20220892. doi: 10.36660/abc.20220892..
• ⁷
  Ganesan AN, Gunton J, Nucifora G, McGavigan AD, Selvanayagam JB. Impact of Late Gadolinium Enhancement on mortality, sudden death and major adverse cardiovascular events in ischemic and nonischemic cardiomyopathy: A systematic review and meta-analysis. Int J Cardiol. 2018 Mar 1;254:230-7. doi: 10.1016/j.ijcard.2017.10.094.
• ⁸
  Volpe GJ, Moreira HT, Trad HS, Wu KC, Braggion-Santos MF, Santos MK, et al. Left Ventricular Scar and Prognosis in Chronic Chagas Cardiomyopathy. J Am Coll Cardiol.2018;72:2567-76. Doi:10.1016/j.jacc.2018.09035
  » https://doi.org/10.1016/j.jacc.2018.09035
• ⁹
  Senra T, Ianni BM, Costa ACP, Mady C, Martinelli-Filho M, Kalil-Filho R, Rochitte CE. Long-Term Prognostic Value of Myocardial Fibrosis in Patients With Chagas Cardiomyopathy. J Am Coll Cardiol. 2018;72:2577-87. Doi:10.1016/j.jacc.2018.08.2195
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  Greenwood JP, Herzog BA, Brown JM, Everett CC, Nixon J, Bijsterveld P, et al. Prognostic Value of Cardiovascular Magnetic Resonance and Single-Photon Emission Computed Tomography in Suspected Coronary Heart Disease: Long-Term Follow-up of a Prospective, Diagnostic Accuracy Cohort Study. Ann Intern Med. 2016 Jul 5;165(1):1-9. doi: 10.7326/M15-1801.
• ¹¹
  Gentile P, Merlo M, Peretto G, Ammirati E, Sala S, Della Bella P, et al. Post-discharge arrhythmic risk stratification of patients with acute myocarditis and life-threatening ventricular tachyarrhythmias. Eur J Heart Fail.2021;23(12):2045-54. Doi:10.002/ejhf.2288
  » https://doi.org/10.002/ejhf.2288
• ¹²
  Di Marco A, Brown PF, Bradley J, Nucifora G, Claver E, de Frutos F, et al. Improved Risk Stratification for Ventricular Arrhythmias and Sudden Death in Patients With Nonischemic Dilated Cardiomyopathy. J Am Coll Cardiol. 2021 Jun 15;77(23):2890-905. doi: 10.1016/j.jacc.2021.04.030. PMID: 34112317.
• ¹³
  Greenwood JP, Maredia N, Younger JF, Brown JM, Nixon J, Everett CC, et al. Cardiovascular magnetic resonance and single-photon emission computed tomography for diagnosis of coronary heart disease (CE-MARC): a prospective trial. Lancet. 2012 Feb 4;379(9814):453-60. doi: 10.1016/S0140-6736(11)61335-4.
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  Lipinski MJ, McVey CM, Berger JS, Kramer CM, Salerno M. Prognostic value of stress cardiac magnetic resonance imaging in patients with known or suspected coronary artery disease: a systematic review and meta-analysis. J Am Coll Cardiol. 2013 Aug 27;62(9):826-38. doi: 10.1016/j.jacc.2013.03.080.
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  Gulsin GS, Shetye A, Khoo J, Swarbrick DJ, Levelt E, Lai FY, et al. Does stress perfusion imaging improve the diagnostic accuracy of late gadolinium enhanced cardiac magnetic resonance for establishing the etiology of heart failure? BMC Cardiovasc Disord. 2017 Apr 8;17(1):98. doi: 10.1186/s12872-017-0529-y.
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  Haaf P, Garg P, Messroghli DR, Broadbent DA, Greenwood JP, Plein S. Cardiac T1 Mapping and Extracellular Volume (ECV) in clinical practice: a comprehensive review. J Cardiovasc Magn Reson. 2016 Nov 30;18(1):89. doi: 10.1186/s12968-016-0308-4.
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  Ferreira VM, Piechnik SK, Robson MD, Neubauer S, Karamitsos TD. Myocardial tissue characterization by magnetic resonance imaging: novel applications of T1 and T2 mapping. J Thorac Imaging. 2014 May;29(3):147-54. doi: 10.1097/RTI.0000000000000077.
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  Andrade Gomes HJ, de Padua Vieira AV, Nacif MS. The Value of T1 Mapping Techniques in the Assessment of Myocardial Interstitial Fibrosis. Magn Reson Imaging Clin N Am. 2019 Aug;27(3):563-74. doi: 10.1016/j.mric.2019.04.007.
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  Menacho K, Ramirez S, Segura P, Nordin S, Abdel-Gadir A, Illatopa V, et al. INCA (Peru) Study: Impact of Non-Invasive Cardiac Magnetic Resonance Assessment in the Developing World. J Am Heart Assoc. 2018 Sep 4;7(17):e008981. doi: 10.1161/JAHA.118.008981.
• ²⁰
  Menacho KD, Ramirez S, Perez A, Dragonetti L, Perez de Arenaza D, Katekaru D, et al. Improving cardiovascular magnetic resonance access in low- and middle-income countries for cardiomyopathy assessment: rapid cardiovascular magnetic resonance. Eur Heart J. 2022 Jul 7;43(26):2496-507. doi: 10.1093/eurheartj/ehac035.

• Short Editorial related to the article: Cardiac Magnetic Resonance as an Etiological Diagnosis Tool in Recovered Sudden Cardiac Death or Unstable Ventricular Arrhythmia Patients

Publication Dates

• Publication in this collection
  21 Apr 2023
• Date of issue
  2023