Myocarditis as a precipitating factor for heart failure: evaluation and 1-year follow-up using cardiovascular magnetic resonance and endomyocardial biopsy.

AIMS: The aim of this study was to evaluate myocarditis as a precipitating factor for heart failure using cardiovascular magnetic resonance (CMR) and endomyocardial biopsy. METHODS AND RESULTS: Eighty-five patients with suspected myocarditis and 20 controls were evaluated. Seventy-one patients with positive CMR were referred for endomyocardial biopsy and re-evaluation after 1 year. Cardiovascular magnetic resonance was performed using STIR T2-weighted (T2W), early T1-weighted (EGE), and late gadolinium-enhanced (LGE) images. Immunohistological and polymerase chain reaction (PCR) analysis of myocardial specimens was employed. In patients with myocarditis, T2 and EGE were increased compared with controls (2.6 ± 0.9 vs. 1.57 ± 0.13, P < 0.001 and 7.9 ± 5.5 vs. 3.59 ± 0.08, P < 0.001, respectively). Late gadolinium enhancement was found in all myocarditis patients. Endomyocardial biopsy performed in 50 of 71 patients with positive CMR showed positive immunohistology in 48% and presence of infectious genomes in 80% (mainly Chlamydia, Herpes, and Parvovirus B19). Left ventricular ejection fraction (LVEF) was significantly decreased compared with controls (47.7 ± 19.2 vs. 64 ± 0.2, P < 0.001). After 1 year, CMR showed normalization of T2 and EGE, and decreased LGE. Left ventricular ejection fraction increased in 36.5% of patients, remained stable in 56.5% and decreased in 7% of patients, in whom biopsy showed persistence of the initial infective agents. A negative correlation was identified between EGE, LGE, and LVEF. Patients with positive biopsies had lower LVEFs. CONCLUSION: In a Greek population with myocarditis, Chlamydia with viruses was a common finding. Cardiovascular magnetic resonance and PCR proved useful for the detection of myocarditis; EGE and LGE had the best correlation for the development of heart failure. Persistence of the initially detected infective agents was identified in patients who deteriorated further.

Myocardial inflammation in autoimmune diseases: investigation by cardiovascular magnetic resonance and endomyocardial biopsy.

INTRODUCTION: Myocardial inflammation often coexists with different types of autoimmune diseases. Our aim was to investigate the presence of myocarditis in these patients by Cardiovascular Magnetic Resonance (CMR) and endomyocardial biopsy. PATIENTS-METHODS: Twenty patients, aged 20-55 yrs with autoimmune diseases and cardiac symptoms (3 with Takayasu's arteritis, 3 with systemic lupus erythematosus, 5 with rheumatoid arthritis, 7 with autoimmune thyroid disease and 2 with systemic sclerosis) and 20 patients with the same autoimmune diseases but without cardiac symptoms (controls) were studied. The presence of myocarditis and LV function were evaluated by CMR. Myocarditis was documented using T2-weighted (T2-W), T1-weighted (T1-W) before and after contrast media injection and late enhanced images. In 10 patients (positive for myocarditis by CMR with either low LVEF or recent increase in troponin), endomyocardial biopsy was also performed. Myocardial specimens were evaluated by histology and polymerase chain reaction techniques (PCR). RESULTS: Myocarditis was identified in 18/20 patients by CMR. In the T2-W images the signal ratio of myocardium to skeletal muscle was 1.89+/-0.25 (control values 1.57+/-0.13, p<0.05). From the T1-W images the relative myocardial enhancement was 11.31+/-11.18 (control values 3.09+/-0.05, p<0.05). Epicardial late gadolinium enhanced areas were identified in 18/20. In myocardial specimens, histology revealed inflammation in 5/10 (50%) and PCR documented viral or microbial genomes in 8/10 (80%). Positive histology and PCR were in agreement with 50% and 80% of positive CMR examinations, respectively. Herpes virus was identified in 3/10, Adeno in 1/10, Coxsackie B6 in 1/10, echo in 1/10, Parvo-B19 in 3/10, CMV in 1/10 and Chlamydia trachomatis in 8/10. CONCLUSIONS: Myocardial inflammation is a common finding in patients with autoimmune diseases and cardiac symptoms. The diagnosis can be confirmed by CMR, which is a noninvasive and reliable tool for the investigation of these patients.

Effect of deflazacort on cardiac and sternocleidomastoid muscles in Duchenne muscular dystrophy: a magnetic resonance imaging study.

OBJECTIVE: To evaluate the involvement of cardiac and sternocleidomastoid muscles by magnetic resonance imaging (MRI) measurement of T2 relaxation time and the left ventricular systolic function in patients with Duchenne muscular dystrophy (DMD) on treatment with deflazacort and compare them with DMD patients without treatment. SUBJECTS: Seventeen patients with DMD (aged 17-22 years) on treatment with deflazacort for at least 7 years and 17 boys with DMD of younger age (12-15 years) without steroid treatment. All patients were free of cardiac or respiratory symptoms and had normal ECG and Holter monitor examination. METHODS: T2 relaxation time of the myocardium (H), left (SCM-L) and right sternocleidomastoid (SCM-R) muscles and left ventricular systolic function were evaluated by magnetic resonance imaging (MRI) in two groups of DMD patients. Myocardial and sternocleidomastoid muscles T2 relaxation time was calculated using 16 TEs (10-85 msec) and TR at least 2000 ms and T2 maps were created. RESULTS: DMD on deflazacort had higher T2 relaxation time values of the heart and of both sternocleidomastoid muscles (T2H median (range): 47 (41-48) vs. 33 (31-37)ms, p<0.001, T2 SCM-L median (range): 35 (30-37) vs. 23 (20-26)ms, p<0.001, T2 SCM-R median (range): 35 (32-37) vs. 23 (20-27)ms, p<0.001) and left ventricular systolic function (LVEDV median (range): 95 (75-120) vs. 90 (80-105)ml, p=0.03, LVESV median (range): 45 (38-55) vs. 47 (41-51)ml, p=0.81(NS), LVEF median (range): 53% (51-57) vs. 48% (42-51), p<0.001) compared to DMD without treatment. CONCLUSIONS: DMD patients on deflazacort are characterized by better preservation of the T2 relaxation time of myocardium and sternocleidomastoid muscles and better LV systolic function. The duration of this beneficial effect needs to be studied prospectively.

Magnetic resonance angiography, function and viability evaluation in patients with Kawasaki disease.

OBJECTIVES: We evaluated the ability of magnetic resonance imaging to perform a noninvasive assessment of coronary arteries, function and viability in one examination in a population with Kawasaki disease. BACKGROUND: Magnetic resonance angiography (MRA) can identify coronary abnormalities in patients with Kawasaki disease (KD). Contrast enhanced cardiovascular magnetic resonance (CeCMR) is the current gold standard for scar detection. Steady-state, free precession (SSFP) cine is a reliable technique to evaluate myocardial function and wall motion. METHODS: Twenty patients with KD aged 7-12 yrs, were examined. Coronary MRA was performed using a 1.5 T system with two ECG-triggered pulse sequences. CeCMR images were acquired 15 minutes after the i.v. injection of 0.1 mmol/kg Gd-DTPA using an inversion recovery sequence. SSFP cines were acquired using 6-mm short-axis slices from the atrioventricular ring to the apex. RESULTS: Aneurysms of the coronary arteries were identified in 7 patients and coronary ectasia was present in the remaining 12 patients while 1 patient had both. Transmural anterior-apical scar was detected by ceCMR in two cases, while small inferior necrosis was identified in another 2 cases. Left ventricular function was deteriorated only in the two patients with antero-apical infarction. The presence of myocardial infarction was detected in the territory supplied by the involved coronary artery. CONCLUSION: In Kawasaki disease MRA, SSFP cine and ceCMR are able to perform noninvasive coronary artery evaluation, function and infarct detection in a single study.

Anomalous origin of right coronary artery: magnetic resonance angiography and viability study.

OBJECTIVE: To detect origin and course and to evaluate viability in patients with anomalous RCA. DESIGN: 3D coronary MR angiography and viability study using gadolinium-enhanced magnetic resonance imaging (Gd-MRI) was performed. SETTING: A tertiary hospital center. PATIENTS: Four patients, selected from the catheter lab, were studied. RESULTS: Anomalous RCA from the left sinus of Valsalva was identified in all patients. Inferior myocardial infarction was documented in three patients. CONCLUSIONS: Magnetic resonance imaging can non-invasively identify anomalous RCA and perform viability study in the same examination.

A comparison of magnetic resonance imaging and cardiac biopsy in the evaluation of heart iron overload in patients with beta-thalassemia major.

OBJECTIVES: To apply magnetic resonance imaging (MRI) for the assessment of myocardial iron deposition in patients with beta-thalassemia and compare the results with cardiac biopsy data. BACKGROUND: Myocardial iron accumulation is the main cause for cardiac complications in beta-thalassemia. METHODS: Twenty-five consecutive thalassemic patients were studied using a 0.5-T (Tesla) system, ECG-gated, with echo time (TE) = 17-68 ms. T2 relaxation time of the interventricular septum was calculated assuming simple monoexponential decay. A heart T2 relaxation time value of 32 ms was used for the discrimination between high and low iron deposition. Heart biopsy was performed within a week after the MRI study. Patients with stainable iron in more than 50% of the myofibrils were graded as having severe iron deposition. A serum ferritin level below 2000 ng/mL was considered as an indication of successful chelation. RESULTS: Seven of the 25 patients had heart biopsy indicative of low iron deposition (Group L) and the remaining 18 patients had heart biopsy indicative of high iron deposition (Group H). T2 relaxation time of the heart (T2H) was lower in Group H compared to Group L (31.5 +/- 3.9 (range: 28-40) ms vs. 35.7 +/- 3.7 (range: 29-40) ms, P = 0.026). The T2H was in agreement with heart biopsy in 86% of the patients in Group L and in 78% of the patients in Group H (overall agreement 80%). Similarly, serum ferritin levels were in agreement with heart biopsy in 28% and 88%, respectively (overall agreement 72%). In Group L, MRI was in better agreement with biopsy compared to serum ferritin (86% vs. 28%, P < 0.05). A receiver operating characteristic curve (ROC) analysis confirmed that a T2 relaxation time of 32 ms had the highest discriminating ability for the corresponding biopsy outcome. CONCLUSIONS: Heart T2 relaxation time appears in agreement with cardiac biopsy, both in high and low iron deposition, and may become a useful non-invasive index in beta-thalassemia.

Coronary flow evaluation by TIMI frame count and magnetic resonance flow velocity in patients with coronary artery ectasia.

PURPOSE: Coronary artery ectasia (CAE) is defined as a dilatation of an arterial segment to a diameter at least 1.5 times that of the adjacent artery. It is characterized by slow flow, predisposing to thrombosis. The TIMI frame count (TFC) technique has been successfully used for the assessment of coronary flow velocity using coronary angiograms (CA). Our aim was to compare TFC with magnetic resonance peak flow velocity (PFV) for the evaluation of the coronary flow in patients with CAE. METHODS: Fifteen male patients with CAE, aged 45-60 yrs, and 15 age-matched male controls were studied by both techniques. Only patients without coronary obstructive disease were included. Magnetic resonance coronary angiography (MRA) was performed with a 1.5T scanner. The most ectatic part of the proximal 1/3 of the vessel involved was examined. Velocity-encoded MR images were acquired in a double oblique imaging plane, which was perpendicular to the same ectatic segment. The findings were compared with TFC results. RESULTS: Ten patients had RCA ectasia and five LAD ectasia. In CAE patients, peak flow velocity was 10.7 +/- 1.4 cm/sec in RCA and 11.4 +/- 2.3 cm/sec in LAD. TFC was 42.9 +/- 7.4 in RCA and 52.0 +/- 20.1 in LAD. In controls, peak flow velocity was 18.1 +/- 1.9 in RCA and 21.0 +/- 1.7 cm/sec in LAD. TFC was 20.4 +/- 1.59 in RCA and 19.8 +/- 1.12 in LAD. Controls had significantly higher peak flow velocity (p < 0.001) and lower TFC (p < 0.001) in both RCA and LAD, compared to patients with CAE. In patients with CAE, there was a negative correlation between PFV and TFC measurements (r = -0.74, p < 0.001). CONCLUSION: Coronary flow in CAE patients can be assessed both by TFC and PFV. The noninvasive nature of PFV gives the opportunity for serial, easily repeatable, flow evaluation in these patients.

Cardiac and sternocleidomastoid muscle involvement in Duchenne muscular dystrophy: an MRI study.

OBJECTIVE: To examine the extent of cardiac muscle and sternocleidomastoid muscle (SCM) involvement detected by MRI measurement of T2 relaxation time in patients with Duchenne muscular dystrophy (DMD) and no cardiorespiratory symptoms. DESIGN: Prospective controlled study. SETTING: Teaching referral hospital and university hospital. SUBJECTS: Seventeen patients with DMD (age range, 7 to 25 years) and 17 age-matched control subjects. All patients were free of cardiac or respiratory complaints and had normal ECG, echocardiograph, and Holter monitor examination findings. METHODS: We assessed respiratory function by means of standard pulmonary function testing. MRI measurements included the T2 relaxation time of the myocardium and the SCM in patients and control subjects. RESULTS: The FVC and FEV1 values were lower in patients with DMD than in age-matched control subjects, whereas the FEV1/FVC ratio was normal in all subjects. Patients with DMD had lower T2 relaxation time of the heart (37.8 +/- 6.1 ms vs 58.1 +/- 7.1 ms, p < 0.001) and lower T2 relaxation time of the right SCM (24.5 +/- 2.6 ms vs 42.2 +/- 1.3 ms, p < 0.001) and left SCM (23.2 +/- 3.2 ms vs 42.2 +/- 1.6 ms, p < 0.001), compared to control subjects (+/- SD). In children (< 12 years of age), the T2 of the SCM was lower than that of the control subjects, but T2 of the heart did not differ between the two groups. In the patient group, T2 relaxation time of the heart decreased with age (r = - 0.80, p < 0.001). In patients with FVC < 80% of predicted, the T2 values of the heart were lower than the T2 values of patients with FVC > or = 80% of predicted (35.6 +/- 5.8 ms vs 41.8 +/- 4.6 ms, p < 0.05). CONCLUSIONS: MRI measurements of the T2 relaxation time in the myocardium and SCM of patients with DMD and no cardiorespiratory symptoms are abnormal, indicating altered tissue composition. These measurements may prove a clinically useful test for monitoring cardiac and respiratory muscle involvement in these patients.

Correlation between magnetic resonance angiography (MRA) and quantitative coronary angiography (QCA) in ectatic coronary vessels.

Coronary artery ectasia (CAE) is defined as a dilatation of an arterial segment to a diameter at least 1.5 times that of the adjacent normal artery. The correct follow-up of ectatic vessels is hampered by the need for repeat angiograms. In this work we compared quantitative coronary angiography (QCA) measurements of the diameter of the proximal most ectatic part of coronary vessels, with corresponding measurements obtained by magnetic resonance angiography (MRA) using both gradient echo and turbo spin echo imaging sequences. Fifteen patients (14 male), aged 45-65 years, with known CAE were prospectively studied. Two electrocardiogram (ECG)-triggered pulse sequences were implemented for coronary magnetic resonance angiography. The first was a three-dimensional (3D), segmented, k-space gradient-echo sequence, employing a T2-weighted preparation prepulse and a frequency-selective, fat-saturation prepulse to enhance "white blood" (WB) contrast of the coronary arteries. The second sequence was an M2D dual Inversion Recovery (IR) Turbo Spin-Echo with a linear k-space acquisition scheme, providing "black-blood" (BB) contrast of the coronaries. All scans were carried out with the patient free breathing using a 2D, real-time Navigator beam, for respiratory motion tracking and gating. All patients underwent QCA, and the diameter of the proximal most ectatic part of each vessel was measured and compared with "white-blood" and "black-blood" MRA measurements. The average length of continuously visualized LM, LAD, LCx, and RCA by MRA was 2.5 +/- 0.3, 5.8 +/- 0.8, 3.9 +/- 1.0, and 7.2 +/- 1.2 cm, respectively. There were no statistically significant differences between diameter measurements of the proximal most ectatic part of each vessel, obtained with WB and BB sequences. There was a close correlation between MRA and QCA measurements (r = 0.87, p < 0.001). Bland-Altman analysis showed no systematic differences between the examined methods, over the whole range of vessel diameters measured. Coronary MRA is in close correlation with QCA for CAE detection. Magnetic resonance angiography, being noninvasive, may prove of significant value for the efficient follow-up of these patients.

Magnetic resonance angiography is equivalent to X-ray coronary angiography for the evaluation of coronary arteries in Kawasaki disease.

OBJECTIVES: The purpose of this study was to compare the results of magnetic resonance angiography (MRA) with X-ray coronary angiography (XCA) in a pediatric population. BACKGROUND: Coronary artery abnormalities in Kawasaki disease (KD) develop in about 15% to 25% of young patients, mostly in the form of aneurysms. METHODS: Thirteen patients (12 male), age three to eight years, were studied. The maximal diameter and length of the aneurysm were recorded. Coronary MRA was performed using a 1.5 T Philips Intera CV magnetic resonance scanner with an electrocardiographically triggered pulse sequence. It was a three-dimensional segmented k-space gradient-echo sequence (TE = 2.1 ms, TR = 7.5 ms, flip angle = 30 degrees, slice thickness = 1.5 mm) employing a T2-weighted preparation pre-pulse and a frequency selective fat-saturation pre-pulse. Data acquisition was performed in mid-diastole. All scans were carried out with the patient free breathing using a two-dimensional real-time navigator beam. All patients underwent XCA within a week. RESULTS: In six patients, aneurysms of the coronary arteries were identified, while coronary ectasia alone was present in the remaining seven patients. Magnetic resonance angiography and XCA diagnosis of coronary artery aneurysm agreed completely. Maximal aneurysm diameter and length and ectasia diameter by MRA and XCA were similar. No stenotic lesion was identified by either technique. CONCLUSIONS: In conclusion, MRA is a reliable diagnostic tool, equivalent to XCA for coronary artery aneurysm identification in patients with KD. Magnetic resonance angiography may prove to be of great value for the serial non-invasive evaluation of these patients.