Why doesn’t CMR perfusion reach higher ground?

I always wonder why CMR perfusion is not embraced more quickly by the cardiologists. CCT is newer but has taken the cardiology field so rapidly, providing sometimes much less significant information than CMR. On the many discussions on the topic, I can only think the main reason is simplicity. CCT (as well as SPECT) is so obvious and the pictures presented so clearly, despite the fact that they may not correlate to physiological findings as well as CMR. Why don’t the vendors and software providers develop new tools so we can present our data better? Try to explain a subtle perfusion defect in cine mode to a clinician and you will understand what I mean. Bring on the colorful donuts to CMR!!!

Continua la RMC aportando grandes datos del proceso de cicatrización después de IAM con elevación del segmento ST y las implicaciones que esos cambios tienen a nivel de los parametros ventriculares, mostrandose claramente como este método puede ayudar al seguimiento de la evolución temporal de los procesos isquémicos agudos.

Cardiac Magnetic Resonance Evaluation of
Edema After ST-Elevation Acute Myocardial
Infarction

José V. Monmeneua, Vicente Bodíb, Juan Sanchisb, María P. López-Lereua, Luis Mainarb, Julio Núñezb,Fabián Chaustreb, Eva Rumizb, Francisco J. Chorrob y Ángel Llácerb
Unidad de Imagen Cardiaca. Hospital Clínico Universitario de Valencia. Valencia. España.
Servicio de Cardiología. Hospital Clínico Universitario de Valencia. Valencia. España

Introduction and objectives. The aims of the study were to characterize myocardial edema after ST-elevation acute myocardial infarction using cardiac magnetic resonance imaging and to investigate its impact onventricular function and its subsequent evolution.

Methods. In total, 134 patients admitted to hospital for a first ST-elevation myocardial infarction who had a patent infarct-related artery underwent cardiac magnetic resonance imaging. Cine images (at rest and with low-dose dobutamine) and edema, perfusion and viability images were acquired. Imaging was repeated after 6 months.

Results. In the first week after infarction, edema was detected in at least one segment in 96.6% of patients (4±2.1 segments per patient). Extensive edema (≥4 segments) was associated with large ventricular enddiastolic and end-systolic volumes (P<.0001), a small left ventricular ejection fraction at rest (P=.001) and with lowdose dobutamine (P=.006), a large number of segments showing hypoperfusion (P=.001) or microvascular obstruction (P=.009), a more extensive infarct (P=.017) and greater transmural extent of the infarct (P=.003). The association between the presence and extent of edema during the first week and functional, perfusion and viability variables was still observable after 6 months. No patient exhibited edema at 6 months.

Conclusions. Cardiac magnetic resonance imaging was useful for characterizing the myocardial edema that occurred after ST-elevation acute myocardial infarction. Extensive edema was with poor left ventricular characteristics. Edema was a transitory phenomenon that vanished within 6 months.

Rev Esp Cardiol. 2009;62(8):858-66

Prognostic Value of a Comprehensive Cardiac Magnetic Resonance Assessment Soon After a First ST-Segment Elevation Myocardial Infarction

Realmente un gran logro de la RMC para el seguimiento de los pacientes pos-IAM con elevación del segmento ST tratados bien sea con trombolítico o angioplastia primaria. La importancia de poder estratificar nuestros pacientes posterior a un evento cardíaco es uno de los mayores aportes que este método ha brindado a todos los cardiólogos clínicos, no solo para predecir eventos , si no también para optimizar cada día mejor el tratamiento medicamentoso con el fin de mejorar la calidad de vida de estos pacientes.

Vicente Bodi, MD*,*, Juan Sanchis, MD*, Julio Nunez, MD*, Luis Mainar, MD*, Maria P. Lopez-Lereu, MD , Jose V. Monmeneu, MD , Eva Rumiz, MD*, Fabian Chaustre*, Isabel Trapero*, Oliver Husser, MD*, Maria J. Forteza*, Francisco J. Chorro, MD*, Angel Llacer, MD*

Cardiology Department, Hospital Clinico Universitario, Universidad de Valencia, Valencia, Spain

Objectives: To evaluate the prognostic value of a comprehensive cardiac magnetic resonance (CMR) assessment soon after a first ST-segment elevation myocardial infarction (STEMI).

Background: CMR allows for a simultaneous assessment of wall motion abnormalities (WMA), WMA with low-dose dobutamine (WMA-dobutamine), microvascular obstruction, and transmural necrosis. This approach has been proven to be useful to predict late systolic recovery soon after STEMI. Its prognostic value and the relative prognostic weight of these indexes are not well-defined.

Methods: We studied 214 consecutive patients with a first STEMI treated with thrombolytic therapy or primary angioplasty discharged from hospital. In the first week (7 ± 1 day after infarction), with CMR we determined the extent (number of segments) of WMA, WMA-dobutamine, microvascular obstruction, and transmural necrosis.

Results: During a median follow-up of 553 days, 21 major adverse cardiac events (MACE) including 4 cardiac deaths, 6 nonfatal myocardial infarctions, and 11 readmissions for heart failure were documented. The MACE was associated with a larger extent of WMA (8 ± 4 segments vs. 5 ± 3 segments, p < 0.001), WMA-dobutamine (6 ± 4 segments vs. 4 ± 3 segments, p = 0.004), microvascular obstruction (3 ± 3 segments vs. 1 ± 2 segments p <0.001), and transmural necrosis (7 ± 3 segments vs. 3 ± 3 segments, p < 0.001). In a complete multivariate analysis that included baseline characteristics, electrocardiogram, biomarkers, angiography, ejection fraction, left ventricular volumes, and all CMR indexes, WMA/segment (hazard ratio: 1.29 [95% confidence interval: 1.11 to 1.49], p = 0.001) and the extent of transmural necrosis/segment (hazard ratio: 1.30 [95% confidence interval: 1.12 to 1.51], p < 0.001) were the only independent prognostic variables.

Conclusions: A comprehensive CMR assessment is useful for stratifying risk soon after STEMI, but only the extent of systolic dysfunction and of transmural necrosis provide independent prognostic information.
Key Words: cardiac magnetic resonance • myocardial infarction • prognosis.

Am Coll Cardiol Img, 2009; 2:835-842.

Resincronizacón Ventricular: RMC mejor que la Cámara Gamma (SPECT)

"Un interesante estudio donde se observa el valor de la resonancia cardiovascular para predecir que pacientes serán respondedores a la terapia de resincronización ventricular. En este trabajo se compara el realce tardío con gadolínio con las imágenes de perfusión miocárdica (SPECT). Los resultados arrojan una clara ventaja de la RMC sobre una técnica ampliamente utilizada en la actualidad como es la cámara gamma."

Magnetic Resonance Imaging is Superior to Cardiac Scintigraphy to Identify Nonresponders to Cardiac Resynchronization Therapy
MIKI YOKOKAWA
Background: Left ventricular (LV) postero-lateral scar and total scar burden are factors responsible for a poor response to cardiac resynchronization therapy (CRT). Contrast-enhanced magnetic resonance imaging (CMR) and 99mTc-2-methoxy isobutyl isonitrile single photon emission computed tomography(SPECT) perfusion imaging are widely used to detect myocardial scar tissue; however, their ability to detect regional scars and predict a positive response to CRT has not been fully evaluated.
Methods: CMR and SPECT were performed in 17 patients with dilated cardiomyopathy (DCM) and seven patients with ischemic cardiomyopathy (ICM) before CRT. All images were scored, using a 17-segment model. To analyze the LV scar regions by CMR, we assessed the transmural delayed enhancement extent as the transmural score in each segment (0 = no scar, 4 = transmural scar). Similarly, a perfusion defect score was assigned to each segment by SPECT (0 = normal uptake, 4 = defect).
Results: By both SPECT and CMR imaging, the total scar score was significantly higher in the ICM than in the DCM group. An LV postero-lateral wall scar region was detected using both imaging modes. By SPECT imaging, the percentage of regional scar score in the LV inferior wall was significantly higher in the DCM than in the ICM group.
Conclusions: By SPECT imaging in the DCM group, severe perfusion defects, due to attenuation artifacts, were frequently observed in the LV inferior wall, resulting in the overestimation of scar tissue. CMR identified nonresponders to CRT more reliably than SPECT in patients with DCM. (PACE 2009;32:S57–S62)

New SCMR-LAC Newsletter Posted

A new issue of the SCMR-LAC Newsletter has been posted.

Download the PDF in in this link (it's a Sendspace link absolutely safe).


Juliano

How to use CMR in electrophysiology studies?

This review provides a very thorough guide on the topic. If only our elecrophysiologists could read more about it...

Download the full article here.

Juliano

CMR: the safest choice

Every week we see new talks of how radiation is affecting the way physicians order exams. Whether all true or not, CMR has an strategic position to provide high definition functional imaging without the risk of radiation. The combination of CCT + CMR is a definite plus but we seem not to remember that to our referrals. If only our coronaries could advance a little more...

CMR on CABG

Highlight this week


JACC Cardiovasc Imaging. 2009 Apr;2(4):437-45.


Magnetic resonance adenosine perfusion imaging in patients after coronary artery bypass graft surgery.
Klein C, Nagel E, Gebker R, Kelle S, Schnackenburg B, Graf K, Dreysse S, Fleck E.

German Heart Institute, Berlin, Germany. klein@dhzb.de

OBJECTIVES: The aim of the study was to evaluate the feasibility and diagnostic performance of the combination of adenosine stress perfusion and late gadolinium enhancement (LGE) in patients after coronary artery bypass graft surgery (CABG). BACKGROUND: Cardiac magnetic resonance (CMR) imaging allows the detection of significant coronary artery disease by adenosine stress perfusion and infarct imaging. Myocardial contrast kinetics may be altered in patients after CABG owing to more complex myocardial perfusion and different distances of the contrast bolus through different bypasses and native coronary vessels. Additionally, all studies have excluded patients after CABG. METHODS: In all, 78 patients (age 66 +/- 8 years; 71 men) underwent CMR imaging including left ventricular function, first-pass adenosine stress perfusion (adenosine 140 microg/min/kg) using 0.05 mmol/kg body weight gadolinium-diethylenetriaminepenta-acetic acid and an additional 0.15 mmol/kg for LGE 1 day before invasive coronary angiography. Images were analyzed visually using the speed of contrast wash-in and maximal signal intensity. Transmural LGE defects of the size of a vessel or graft territory defined by angiography were considered true negatives, even when supplied by a stenosed/occluded vessel/graft. Stenoses >50% in grafts and grafted or ungrafted native vessels (diameter > or =2 mm) in invasive angiography were considered significant. RESULTS: The prevalence of patients with significant stenosis was 63% (69% functionally 1-vessel, 28% 2-vessel, and 3% 3-vessel disease). Sensitivity and specificity were 77% and 90%, respectively, on a patient basis, and 71% and 89% on a vessel territory basis. Sensitivity, if only areas supplied by grafts (n = 196) were evaluated, was 78% and specificity was 94%, compared with territories supplied by ungrafted native vessels (n = 51) with sensitivity and specificity of 63% and 91%, respectively. Sensitivity and specificity for the 53 areas with prior infarction were 88% and 79%, respectively. CONCLUSIONS: For patients after surgical revascularization, the combination of stress perfusion and LGE yields good diagnostic accuracy for the detection and localization of significant stenoses. However, sensitivity is reduced compared with published data in patients without CABG. Prior myocardial infarction can be examined without loss of accuracy.

HYPERTROPHIC CARDIOMYOPATHY - Fundamental roles of CMR

A special JACC issue covers various aspects of hypertrophic cardiomyopathy with 3 very interesting articles regarding the use of CMR:

5. Hypertrophic Cardiomyopathy Phenotype Revisited After 50 Years With Cardiovascular Magnetic Resonance
Pages 220-228
Martin S. Maron, Barry J. Maron, Caitlin Harrigan, Jacki Buros, C. Michael Gibson, Iacopo Olivotto, Leah Biller, John R. Lesser, James E. Udelson, Warren J. Manning, Evan Appelbaum

6. Outcome of Patients With Hypertrophic Cardiomyopathy and a Normal Electrocardiogram
Pages 229-233
Christopher J. McLeod, Michael J. Ackerman, Rick A. Nishimura, A. Jamil Tajik, Bernard J. Gersh, Steve R. Ommen

7. Outcome of Mildly Symptomatic or Asymptomatic Obstructive Hypertrophic Cardiomyopathy: A Long-Term Follow-Up Study
Pages 234-241
Paul Sorajja, Rick A. Nishimura, Bernard J. Gersh, Joseph A. Dearani, David O. Hodge, Heather J. Wiste, Steve R. Ommen

8. Cardiac Magnetic Resonance Detection of Myocardial Scarring in Hypertrophic Cardiomyopathy: Correlation With Histopathology and Prevalence of Ventricular Tachycardia
Pages 242-249
Deborah H. Kwon, Nicholas G. Smedira, E. Rene Rodriguez, Carmela Tan, Randolph Setser, Maran Thamilarasan, Bruce W. Lytle, Harry M. Lever, Milind Y. Desai

9. Risk Factors and Mode of Death in Isolated Hypertrophic Cardiomyopathy in Children
Pages 250-254
Jamie A. Decker, Joseph W. Rossano, E. O'Brian Smith, Bryan Cannon, Sarah K. Clunie, Corey Gates, John L. Jefferies, Jeffrey J. Kim, Jack F. Price, William J. Dreyer, Jeffrey A. Towbin, Susan W. Denfield

10. Aortic Stiffness Is Increased in Hypertrophic Cardiomyopathy With Myocardial Fibrosis: Novel Insights in Vascular Function From Magnetic Resonance Imaging
Pages 255-262
Thananya Boonyasirinant, Prabhakar Rajiah, Randolph M. Setser, Michael L. Lieber, Harry M. Lever, Milind Y. Desai, Scott D. Flamm

The access to the manuscript abstracts can be found in

http://www.sciencedirect.com/science/issue/4884-2009-999459996-1288053

Hemorragia intramiocárdica en el infarto

Impact of myocardial haemorrhage on left ventricular function and remodelling in patients with reperfused acute myocardial infarction. Javier Ganame. European Heart Journal 2009; 30, 1440–1449

"En este interesante trabajo se constata el valor de la "hemorragia intramiocardica" diagnosticada por RMC como predictor independiente de evolución en los pacientes con infarto de miocardio reperfundido. Con estos datos, se avala el la utilización de la RMC en la práctica clínica post infarto de miocardio. Posterior al procedimiento de reperfusión (trombolíticos o angioplastia) , estas imágenes en T2W o con realce tardío de Gadolinio, son fáciles de interpretar, aportando mayor utlilidad que las clásicos cambios observados en el electrocardiograma o en las enzimas cardíacas".

Introduction: Myocardial haemorrhage is a common complication following reperfusion of ST-segment-elevation acute myocardial infarction (MI). Although its presence is clearly related to infarct size, at present it is unknown whether post-reperfusion haemorrhage affects left ventricular (LV) remodelling. Magnetic resonance imaging (MRI) can be used to identify MI, myocardial haemorrhage, and microvascular obstruction (MVO), as well as measure LV volumes, function, and mass.
Methods and results: Ninety-eight patients (14 females, 84 males, mean age: 57.7 years) with MI reperfused with percutaneous coronary intervention (PCI) were studied within the first week (1W) and at 4 months (4M) after the event. T2-weighted MRI was used to differentiate between haemorrhagic (i.e. hypointense core) and non-haemorrhagic infarcts (i.e. hyperintense core). Microvascular obstruction and infarct size were determined on contrast-enhanced MRI, whereas cine MRI was used to quantify LV volumes, mass, and function. Twenty-four patients (25%) presented with a haemorrhagic MI. In the acute phase, the presence of myocardial haemorrhage was related to larger infarct size and infarct transmurality, lower LV ejection fraction, and lower systolic wall thickening in the infarcted myocardium (all P-values ,0.001). At 4M, a significant improvement in LV ejection fraction in patients with non-haemorrhagic MI was seen (baseline: 49.3+7.9% vs. 4M: 52.9+8.1%; P , 0.01). Left ventricular ejection fraction did, however, not improve in patients with haemorrhagic MI (baseline: 42.8+6.5% vs. 4M: 41.9+8.5%; P ¼ 0.68). Multivariate analysis showed myocardial haemorrhage to be an independent predictor of adverse LV remodelling at 4M (defined as an increase in LV end-systolic volume). This pattern was independent of the initial infarct size.
Conclusion: Myocardial haemorrhage, the presence of which can easily be detected with T2-weighted MRI, is a frequent complication after successful myocardial reperfusion and an independent predictor of adverse LV remodelling regardless of the initial infarct size