Can cardiovascular MRI be used to more definitively characterize cardiac masses initially identified using echocardiography?

In diagnosing cardiac and paracardiac masses, cardiac MRI (CMR) has gained acceptance as the gold standard. CMR has been observed to be superior to echocardiography in characterizing soft-tissue structures and, specifically, in classifying cardiac masses. The aim of our study was to evaluate the association between mortality and cardiac or paracardiac masses initially identified by echocardiography (ECHO) and confirmed by CMR. Between January 2002 and August 2007, a total of 158 patients underwent both ECHO and CMR for the evaluation of cardiac masses that were equivocal or undefined by ECHO. The primary study endpoints were 5-year all-cause mortality and 5-year cardiac mortality. Causes of death as of April 1, 2015 were obtained from medical records or the National Death Index. Patients were analyzed according to mass type determined by CMR using the Kruskal-Wallis test, Kaplan-Meier curves, and the log-rank test. Over a mean duration of follow-up of 10.4 ± 2.9 years (range: 0.01-12 years) post-CMR, the overall all-cause mortality rate was 25.9% (41/158). Median age at death was 76 years and there were 21 females (51.2%). Mortality rates in the different classifications of cardiac masses by CMR were as follows: 20% (1/5) in patients with a Nondiagnostic CMR; 20% (1/5) in Other Diagnoses; 17.9% (7/39) in No Masses (includes Normal Anatomical Variants); 16.7% (3/18) in Benign Masses; 23.8% (15/63) in Fat; 50% (5/10) in Thrombus; and 61.5% (8/13) in Malignant Mass. The mean survival time in patients with No Mass (n = 39) was not significantly longer than patients with any type of cardiac mass (n = 114) (P = .16). No significant difference was found in age at death between patients when grouped by CMR classification (P = .40). However, among CMR-confirmed masses, there were some significant differences by mass classification type (P = .006). During the follow-up period, 26% (41/158) of patients died and 22% (9/41) of the deaths were cardiovascular related; there was no significant difference in mean survival times with respect to cause of mortality (P = .23). In patients with cardiac masses, dually confirmed by ECHO and CMR, significant differences in survival time were observed based upon CMR classified type of mass while CMR was instrumental in obviating invasive biopsy.

Mid wall fibrosis on CMR with late gadolinium enhancement may predict prognosis for LVAD and transplantation risk in patients with newly diagnosed dilated cardiomyopathy-preliminary observations from a high-volume transplant centre.

BACKGROUND: Patients with newly diagnosed dilated cardiomyopathy (DCM) and advanced heart failure have a very high morbidity and mortality with an unpredictable clinical course. We investigated the role of cardiovascular magnetic resonance (CMR) imaging using late gadolinium enhancement (LGE) in this cohort of high-risk patients. We hypothesized that LGE has high prognostic value in primary DCM patients referred for possible transplantation/left ventricular assist device (LVAD) consideration. METHODS: Over 49 consecutive months, 61 consecutives DCM patients were referred for standard CMR(1.5T, GE) to interrogate the LV pattern, distribution, and extent of LGE (MultiHance, Princeton, NJ). Inclusion criteria for a primary non-ischaemic DCM and EF <45% were met in 31 patients. DCM patients were categorized into: (i) presence of midwall LV stripe (+Stripe) and (ii) absence of midwall stripe (-Stripe) groups. Primary outcome was defined by the composite of death, need for LV assist device (LVAD), and urgent orthotopic cardiac transplantation (Tx) during a 12-month follow-up period. Kaplan-Meier survival analysis was conducted grouping patients by +Stripe and -Stripe. RESULTS: There were no differences between groups for demographics, blood pressure, labs, baseline LVEF, NYHA class, or invasive haemodynamics. There were 18 patients (58%) with +Stripe. Nine events occurred: seven patients required urgent Tx and/or LVAD implantation and two patients died. The +Stripe categorization strongly predicted the need for LVAD, urgent Tx surgery, and death (log-rank = 9, P = 0.002). All the events occurred in the +Stripe patients with no MACE experienced in the -Stripe group. The -Stripe group experienced marked signs of improvement in LVEF (P = 0.01) at follow-up. LVEDD was predictive of need for LVAD/Tx and death by univariate analysis. Otherwise, no common clinical metric such as LVEF, LVEDV, RVEF, RVEDV, or any invasive haemodynamic parameter predicted MACE. CONCLUSIONS: The presence of +Stripe on CMR is strongly predictive of LVAD, transplant need, and death during a 12-month follow-up period in DCM patients in this proof of concept study. All -Stripe patients survived without experiencing any events. Incorporating CMR imaging into routine clinical practice may have prognostic value in DCM patients; indicating conservative management in low-risk patients while expectantly managing high-risk patients.

Contrast-enhanced CMR is equally effective as TEE in the evaluation of left atrial appendage thrombus in patients with atrial fibrillation undergoing pulmonary vein isolation procedure.

BACKGROUND: Patients with atrial fibrillation (AF) routinely undergo transesophageal echocardiography (TEE) for the evaluation of the left atrial appendage (LAA) to rule out thrombus prior to undergoing pulmonary vein isolation (PVI). Cardiac magnetic resonance (CMR) is now increasingly used for the evaluation of patients with AF to define pulmonary vein (PV) anatomy prior to PVI. OBJECTIVE: To hypothesize that a retrospective comparison of 2-dimensional/3-dimensional (2D/3D) contrast-enhanced CMR sequences with TEE for the evaluation of LAA thrombus in patients with AF selected for PVI will demonstrate equivalence. METHODS: Ninety-seven (N = 97) consecutive patients with AF underwent near-simultaneous TEE and noncontrast and contrast CMR prior to undergoing an initial PVI procedure. The CMR images were analyzed in 2 categories: (1) the 2D noncontrast cine images and early gadolinium enhancement images showing LAA and (2) 3D contrast source images acquired during PV magnetic resonance angiography. CMR variables evaluated were the presence or absence of LAA thrombus and the quality of images, and they were compared with the results of TEE in a blinded fashion. RESULTS: All subjects were analyzed for the presence or absence of LAA thrombus. Thrombus was absent in 98% of the patients on both TEE and CMR and present in 2% on both studies (100% correlation). In 6 subjects, 2D cine CMR images were indeterminate whereas all 2D early gadolinium enhancement images and 3D contrast images were successful in excluding LAA thrombus. There was 100% concordance between CMR and TEE for the final diagnosis of LAA thrombus. CONCLUSIONS: In one single examination, CMR offers a comparable alternative to TEE for the complete noninvasive evaluation of LAA thrombus and PV anatomy in patients with AF referred for PVI without obligate need for TEE.

Mitral valve regurgitation: paradoxical behavior of dobutamine stress cardiac magnetic resonance imaging.

A 62-year-old woman with mitral regurgitation (MR) underwent cardiac magnetic resonance (CMR) and dobutamine stress CMR imaging, a widely used method to analyze left ventricular function and MR volumes. During dobutamine provocation at escalating doses, the left ventricular end-diastolic diameter (LVEDD) decreased, with a corresponding decrease in MR. At peak dobutamine dose, the LVEDD further decreased, with near complete relief of MR. Upon cessation of dobutamine provocation, the MR returned to predobutamine level. This case thereby demonstrates that MR may be reversible under certain conditions.

Cardiac sarcoidosis or giant cell myocarditis? On treatment improvement of fulminant myocarditis as demonstrated by cardiovascular magnetic resonance imaging.

Giant cell myocarditis, but not cardiac sarcoidosis, is known to cause fulminant myocarditis resulting in severe heart failure. However, giant cell myocarditis and cardiac sarcoidosis are pathologically similar, and attempts at pathological differentiation between the two remain difficult. We are presenting a case of fulminant myocarditis that has pathological features suggestive of cardiac sarcoidosis, but clinically mimicking giant cell myocarditis. This patient was treated with cyclosporine and prednisone and recovered well. This case we believe challenges our current understanding of these intertwined conditions. By obtaining a sense of severity of cardiac involvement via delayed hyperenhancement of cardiac magnetic resonance imaging, we were more inclined to treat this patient as giant cell myocarditis with cyclosporine. This resulted in excellent improvement of patient's cardiac function as shown by delayed hyperenhancement images, early perfusion images, and SSFP videos.

LV reverse remodeling imparted by aortic valve replacement for severe aortic stenosis; is it durable? A cardiovascular MRI study sponsored by the American Heart Association.

BACKGROUND: In patients with severe aortic stenosis (AS), long-term data tracking surgically induced effects of afterload reduction on reverse LV remodeling are not available. Echocardiographic data is available short term, but in limited fashion beyond one year. Cardiovascular MRI (CMR) offers the ability to serially track changes in LV metrics with small numbers due to its inherent high spatial resolution and low variability. HYPOTHESIS: We hypothesize that changes in LV structure and function following aortic valve replacement (AVR) are detectable by CMR and once triggered by AVR, continue for an extended period. METHODS: Twenty-four patients of which ten (67 ± 12 years, 6 female) with severe, but compensated AS underwent CMR pre-AVR, 6 months, 1 year and up to 4 years post-AVR. 3D LV mass index, volumetrics, LV geometry, and EF were measured. RESULTS: All patients survived AVR and underwent CMR 4 serial CMR's. LVMI markedly decreased by 6 months (157 ± 42 to 134 ± 32 g/m2, p < 0.005) and continued trending downwards through 4 years (127 ± 32 g/m2). Similarly, EF increased pre to post-AVR (55 ± 22 to 65 ± 11%,(p < 0.05)) and continued trending upwards, remaining stable through years 1-4 (66 ± 11 vs. 65 ± 9%). LVEDVI, initially high pre-AVR, decreased post-AVR (83 ± 30 to 68 ± 11 ml/m2, p < 0.05) trending even lower by year 4 (66 ± 10 ml/m2). LV stroke volume increased rapidly from pre to post-AVR (40 ± 11 to 44 ± 7 ml, p < 0.05) continuing to increase non-significantly through 4 years (49 ± 14 ml) with these LV metrics paralleling improvements in NYHA. However, LVmass/volume, a 3D measure of LV geometry, remained unchanged over 4 years. CONCLUSION: After initial beneficial effects imparted by AVR in severe AS patients, there are, as expected, marked improvements in LV reverse remodeling. Via CMR, surgically induced benefits to LV structure and function are durable and, unexpectedly express continued, albeit markedly incomplete improvement through 4 years post-AVR concordant with sustained improved clinical status. This supports down-regulation of both mRNA and MMP activity acutely with robust suppression long term.

Expanding role of cardiovascular magnetic resonance in left and right ventricular diastolic function.

This article focuses on the role of cardiovascular magnetic resonance (CMR) in understanding the physiology of diastolic function and on the future applications of CMR as they relate to diastolic function evaluation. CMR has a demonstrated potential to define diastolic function and quantify its properties, in terms of active and passive stages, and its relaxation and compliance characteristics. CMR is also useful for assessing inflow and myocardial velocities, and untwisting properties of the chamber and myocardium, thus providing insights not fully available in other invasive and noninvasive strategies. CMR, which offers the necessary capabilities to evaluate the complex structure of the right ventricle, can serve in the future as the standard for evaluating diastolic function as it currently does for systolic function.

Cardiovascular magnetic resonance of the charcoal heart.

We report a case of malignant melanoma metastasis to the heart presenting as complete heart block. The highlight of the case is to demonstrate that silent cardiac metastasis is not uncommon and CMR has the potential to characterize these cardiac metastases and should be used routinely as a screening tool for those cancers with a high chance of cardiac involvement.

Routine evaluation of left ventricular diastolic function by cardiovascular magnetic resonance: a practical approach.

BACKGROUND: Cardiovascular magnetic resonance (CMR) has excellent capabilities to assess ventricular systolic function. Current clinical scenarios warrant routine evaluation of ventricular diastolic function for complete evaluation, especially in congestive heart failure patients. To our knowledge, no systematic assessment of diastolic function over a range of lusitropy has been performed using CMR. METHODS AND RESULTS: Left ventricular diastolic function was assessed in 31 subjects (10 controls) who underwent CMR and compared with Transthoracic echocardiogram (TTE) evaluation of mitral valve (MV) and pulmonary vein (PV) blood flow. Blood flow in the MV and PV were successfully imaged by CMR for all cases (31/31,100%) while TTE evaluated flow in all MV (31/31,100%) but only 21/31 PV (68%) cases. Velocities of MV flow (E and A) measured by CMR correlated well with TTE (r = 0.81, p < 0.001), but demonstrated a systematic underestimation by CMR compared to TTE (slope = 0.77). Bland-Altman analysis of the E:A ratio and deceleration time (DT) calculated from each modality showed excellent agreement (bias -0.29, and -10.3 ms for E:A and DT, respectively). When assessing morphology using TTE, CMR correctly identified patients as having normal or abnormal inflow conditions. CONCLUSION: We have shown that there is homology between CMR and TTE for the assessment of diastolic inflow over a wide range of conditions, including normal, impaired relaxation and restrictive. There is excellent agreement of quantitative velocity measurements between CMR and TTE. Diastolic blood flow assessment by CMR can be performed in a single scan, with times ranging from 20 sec to 3 min, and we show that there is good indication for applying CMR to assess diastolic conditions, either as an adjunctive test when evaluating systolic function, or even as a primary test when TTE data cannot be obtained.

Correction of temporal misregistration artifacts in jet flow by conventional phase-contrast MRI.

PURPOSE: To show that accuracy of jet flow representation by magnetic resonance (MR) phase-contrast (PC) velocity-encoded (VE) cine imaging is dominated by error terms resulting from the temporal distribution of data, and to present a generally applicable data interpolation-based approach to correct for this phenomenon. MATERIALS AND METHODS: Phase-contrast data were acquired in a stenotic orifice flow phantom using a physiologic pulsatile flow waveform. A temporally registered scan, acquired without data segmentation or interleaving was obtained (17 minutes) and taken as the reference (REF). Conventional PC data sets were acquired using segmentation and data interleaving. An enhanced temporal registration (ETR) algorithm was applied to the acquired data to temporally interpolate component sets and output data at matching time points, thereby reducing temporal dispersion. RESULTS: Compared to the REF data, conventionally processed PC data consistently overestimated peak velocities in laminar jet flow regions (127% +/- 28%) and exhibited relatively weak correlations (r = 0.67 +/- 0.23). The ETR-processed data better represented peak velocities (101% +/- 13%, P < 0.001) and correlated more closely with the REF data (r = 0.94 +/- 0.05, P < 0.001). CONCLUSION: The temporal distribution of PC data impacts the accuracy of velocity representation in pulsatile jet flow. A temporal registration postprocessing algorithm can minimize loss of accuracy.

Coronary artery fistula; non-invasive diagnosis by cardiovascular magnetic resonance imaging.

Coronary arteriovenous fistulas are among rare anomalies of coronary arteries. Role of X-ray angiography is well established in identification and characterization of these anomalies, however there accurate course and termination is often not defined. We demonstrate role of routine cardiovascular MRI in non-invasively diagnosing and characterizing the course and termination of these anomalous coronary branches.

Physiologic compensation is supranormal in compensated aortic stenosis: does it return to normal after aortic valve replacement or is it blunted by coexistent coronary artery disease? An intramyocardial magnetic resonance imaging study.

BACKGROUND: In compensated aortic stenosis (AS), cardiac performance measured at the ventricular chamber is typically supranormal, whereas measurements at the myocardium are often impaired. We investigated intramyocardial mechanics after aortic valve replacement (AVR) and the effects relative to the presence or absence of coronary artery disease (CAD+ or CAD-), respectively. METHODS AND RESULTS: Twenty-nine patients (46 to 91 years, 10 female) with late but not decompensated AS underwent cardiovascular MRI before AVR (PRE), with follow-up at 6+/-1 (EARLY) and 13+/-2 months (LATE) to determine radiofrequency tissue-tagged left ventricle (LV) transmural circumferential strain, torsion, structure, and function. At the myocardial level, concentric LV hypertrophy regressed 18% LATE (93+/-22 versus 77+/-17 g/m2; P<0.0001), whereas at the LV chamber level, ejection fraction was supranormal PRE, 67+/-6% (ranging as high as 83%) decreasing to 59+/-6% LATE (P<0.05), representing not dysfunction but a return to more normal LV physiology. Between the CAD+ and CAD- groups, intramyocardial strain was similar PRE (19+/-10 versus 20+/-10) but different LATE, with dichotomization specifically related to the CAD state. In the CAD- patients, strain increased to 23+/-10% (+20%), whereas in CAD+ patients it fell to 16+/-11% (-26%), representing a nearly 50% decline after AVR (P<0.05). This was particularly evident at the apex, where CAD- strain LATE improved 17%, whereas for CAD+ it decreased 2.5-fold. Transmural strain and myocardial torsion followed a similar pattern, critically dependent on CAD. AVR impacted LV geometry and mitral apparatus, resulting in decreased mitral regurgitation, negating the double valve consideration. CONCLUSIONS: In AS patients after AVR, reverse remodeling of the supranormal systolic function parallels improvement in cardiovascular MRI-derived regression of LV hypertrophy and LV intramyocardial strain. However, discordant effects are evident after AVR, driven by CAD status, suggesting that the typical AVR benefits are experienced disproportionately by those without CAD and not by those obliged to undergo concomitant coronary artery bypass grafting/AVR.

Imaging of ventricular function by cardiovascular magnetic resonance.

Over the past 15 years, cardiac magnetic resonance imaging (CMR) has vaulted to the forefront as the ideal diagnostic modality for the evaluation of both left and right ventricular function. The accumulated literature supports this contention for the left ventricle. However, for the right ventricle, typically poorly visualized accurately by traditional imaging techniques, CMR has emerged as the test of choice. Although earlier CMR sequences have become even more robust, resulting in further improvements in spatial and temporal resolution, CMR has avidly remained the gold standard. Yet, these attributes that have so benefited investigations of the systole need not be so constrained. In this review, we discuss recent applications of CMR to the study of lusitropy, demonstrating the potential for further advances in our understanding of diastole.