Ceri Davies

Establishment and Performance of a Magnetic Resonance Cardiac Function Clinic

Our objective was to establish a cardiovascular magnetic resonance (CMR) cardiac function clinic to provide an assessment of cardiac volume, mass, and function in patients with heart failure on the same day as their cardiology outpatient clinic appointment. Sixty-four patients attended the CMR function clinic. The reproducibility, patient acceptability, and time efficiency of the CMR clinic were assessed and compared with radionuclide ventriculography (RNV) and echocardiography (echo). Reports were available in the cardiology outpatient clinic within 2 hr of the CMR appointment time. The reproducibility of volumes, ejection fraction, and mass in this heart failure population was good and comparable with CMR studies in the normal population. CMR was more acceptable to the patients than both RNV and echo (p < 0.05). The total time for CMR was less than that of RNV (42 +/- 4 and 61 +/- 4 min, respectively; p < 0.001) but more than that of echo (echo, 23 +/- 2 min; p < 0.001). Comparison of ejection fractions revealed a correlation between CMR and RNV of 0.7, but Bland-Altman limits of agreement were wide (-10.5% to 18.9%). For CMR versus echo, the correlation was 0.6, and the limits of agreement were wider (-29.9% to 23.3%). The correlation between RNV and echo was 0.2 with wider limits of agreement (-29.8% to 24. 9%). In conclusion, CMR can provide a rapid, reproducible, and patient acceptable assessment of cardiac function in heart failure patients, whereas other methods appear to have a wider variance. The high reproducibility of CMR lends itself to the follow-up of clinical progression and the effect of treatment in patients with heart failure.

Left ventricular function and mass after orthotopic heart transplantation: a comparison of cardiovascular magnetic resonance with echocardiography

OBJECTIVE We compared the assessment of left ventricular function and mass by M-mode echocardiography (echo) with fast breath-hold cardiovascular magnetic resonance (CMR) in patients who received orthotopic heart transplantation. We also sought to establish the reproducibility of breath-hold CMR in this patient population. METHODS We prospectively acquired 51 sets of echo and CMR data in 21 patients who had undergone orthotopic heart transplantation. We examined the intraobserver and interobserver reproducibility of breath-hold CMR in this group and compared it with published data. We compared the left ventricular ejection fraction (EF) and mass determined by echo with the CMR data. RESULTS The average time between CMR and echo was 0 +/- 7 days (mean +/- SD), the time between each set of CMR-echo data acquisition was 5.1 +/- 4.1 months. Cardiovascular magnetic resonance showed good reproducibility in this population, with intraobserver percentage variability of 2.2% +/- 2.4% for EF and 3. 2% +/- 2.7% for mass, and interobserver percentage variability of 2. 4% +/- 1.9% for EF and 2.2% +/- 1.9% for mass. The Bland-Altman limits of agreement between echo and CMR were wide for both EF (-9. 6% to 15%) and mass, irrespective of the formula used (-61.3 to 198 g for the Bennett and Evans formula, -65.4 to 196.8 g for the American Society of Echocardiography (ASE) formula, -65.3 to 181 g for the Devereux formula, and -95.2 to 64.6 g for the Teichholz formula). CONCLUSION Fast-acquisition CMR is reproducible in recipients of transplanted hearts. We found poor agreement with the results of echo. The choice of technique will depend on local resources as well as the clinical importance of the result. Echo remains readily available and gives rapid assessment of volumes, EF, and mass. However, the good reproducibility of CMR may make it a more suitable technique for long-term follow-up of an individual or of a study population.

Acute myocarditis presenting as acute coronary syndrome: role of early cardiac magnetic resonance in its diagnosis

Background In patients presenting with acute cardiac symptoms, abnormal ECG and raised troponin, myocarditis may be suspected after normal angiography. Aims To analyse cardiac magnetic resonance (CMR) findings in patients with a provisional diagnosis of acute coronary syndrome (ACS) in whom acute myocarditis was subsequently considered more likely. Methods and results 79 patients referred for CMR following an admission with presumed ACS and raised serum troponin in whom no culprit lesion was detected were studied. 13% had unrecognised myocardial infarction and 6% takotsubo cardiomyopathy. The remainder (81%) were diagnosed with myocarditis. Mean age was 45±15 years and 70% were male. Left ventricular ejection fraction (EF) was 58±10%; myocardial oedema was detected in 58%. A myocarditic pattern of late gadolinium enhancement (LGE) was detected in 92%. Abnormalities were detected more frequently in scans performed within 2 weeks of symptom onset: oedema in 81% vs 11% (p<0.0005), and LGE in 100% vs 76% (p<0.005). In 20 patients with both an acute (<2 weeks) and convalescent scan (>3 weeks), oedema decreased from 84% to 39% (p<0.01) and LGE from 5.6 to 3.0 segments (p=0.005). Three patients presented with sustained ventricular tachycardia, another died suddenly 4 days after admission and one resuscitated 7 weeks following presentation. All 5 patients had preserved EF. Conclusions Our study emphasises the importance of access to CMR for heart attack centres. If myocarditis is suspected, CMR scanning should be performed within 14 days. Myocarditis should not be regarded as benign, even when EF is preserved.

Randomized trial of combination cytokine and adult autologous bone marrow progenitor cell administration in patients with non-ischaemic dilated cardiomyopathy: the REGENERATE-DCM clinical trial

Aims The REGENERATE-DCM trial is the first phase II randomized, placebo-controlled trial aiming to assess if granulocyte colony-stimulating factor (G-CSF) administration with or without adjunctive intracoronary (IC) delivery of autologous bone marrow-derived cells (BMCs) improves global left ventricular (LV) function in patients with dilated cardiomyopathy (DCM) and significant cardiac dysfunction. Methods and results Sixty patients with DCM and left ventricular ejection fraction (LVEF) at referral of ≤45%, New York Heart Association (NYHA) classification ≥2 and no secondary cause for the cardiomyopathy were randomized equally into four groups: peripheral placebo (saline), peripheral G-CSF, peripheral G-CSF and IC serum, and peripheral G-CSF and IC BMC. All patients, except the peripheral placebo group, received 5 days of G-CSF. In the IC groups, this was followed by bone marrow harvest and IC infusion of cells or serum on Day 6. The primary endpoint was LVEF change from baseline to 3 months, determined by advanced cardiac imaging. At 3 months, peripheral G-CSF combined with IC BMC therapy was associated with a 5.37% point increase in LVEF (38.30% ± 12.97 from 32.93% ± 16.46 P = 0.0138), which was maintained to 1 year. This was associated with a decrease in NYHA classification, reduced NT-pro BNP, and improved exercise capacity and quality of life. No significant change in LVEF was seen in the remaining treatment groups. Conclusion This is the first randomized, placebo-controlled trial with a novel combination of G-CSF and IC cell therapy that demonstrates an improvement in cardiac function, symptoms, and biochemical parameters in patients with DCM.

Assessment of chemoreflex sensitivity in free breathing young subjects by correction for respiratory influence

BACKGROUND The assessment of autonomic function is an important tool for risk stratification in critically ill patients. Peripheral cardiac chemoreflex sensitivity has been considered a marker for increased risk of sudden cardiac death. In normals, the evaluation of peripheral cardiac chemoreflex sensitivity is performed under controlled breathing conditions during inhalation of hypoxic gas. Since this is poorly tolerated by patients, they are commonly studied under hyperoxic conditions, which are not physiological. METHODS We studied 20 healthy volunteers who underwent free and controlled breathing of a hypoxic gas mixture (10% O2 in N2) over 5 min. Values of peripheral cardiac chemoreflex sensitivity, corrected for respiratory influence, were compared with the results obtained experimentally under controlled breathing conditions in the same subjects. RESULTS We found a substantial difference between values obtained during free and controlled breathing (3.64 +/- 0.81 vs. 1.53 +/- 0.32 ms/mmHg, respectively; P < 0.05). After application of a respiratory correction, described and validated in this article, no significant difference was seen for these values (0.89 +/-0.91 vs. 1.53 +/- 0.32 ms/mmHg, P = 0.46). CONCLUSIONS This approach allows the evaluation of peripheral cardiac chemoreflex sensitivity in free breathing subjects. This correction could improve the assessment of cardiac chemoreflex sensitivity in patients with cardiorespiratory disorders, who find it difficult to control their breathing according to an experimental protocol.

An exploratory randomized control study of combination cytokine and adult autologous bone marrow progenitor cell administration in patients with ischaemic cardiomyopathy: the REGENERATE‐IHD clinical trial

The effect of combined cytokine and cell therapy in ischaemic cardiomyopathy is unknown. Meta‐analyses suggest improved cardiac function with cell therapy. The optimal cell delivery route remains unclear. We investigated whether granulocyte colony‐stimulating factor (G‐CSF) alone or in combination with intracoronary (i.c.) or intramyocardial (i.m.) injection of autologous bone marrow‐derived cells (BMCs) improves cardiac function.

Pulmonary vein measurements on pre-procedural CT/MR imaging can predict difficult pulmonary vein isolation and phrenic nerve injury during cryoballoon ablation for paroxysmal atrial fibrillation

OBJECTIVE We tested the hypothesis that pulmonary vein (PV) measurements on pre-procedural CT/MR imaging can predict difficulty in isolation and phrenic nerve (PN) injury during cryoballoon ablation for paroxysmal atrial fibrillation (AF). METHODS Consecutive patients with paroxysmal AF who had pre-procedural CT/MRI and underwent cryoballoon ablation as part of a randomized trial were studied. Imaging was anonymized for blinded analysis of: (1) maximum ostial diameter, (2) minimum ostial diameter, (3) ostial area and (4) ratio of maximum over minimum ostial diameter (eccentricity index). Veins that required more than 2 freezes of at least 200 s duration to isolate or not isolated were defined as difficult to isolate. Loss of PN pacing during right-sided ablation was defined as PN injury. Logistic regression was used to analyze the predictive effect of the measurements on the 2 outcomes. RESULTS 148 PVs in 38 patients (aged 60 ± 11 years, 76% male) were analyzed. Left inferior PV (LIPV) was most difficult to isolate with 23 out of 37 PVs (62%), and PN injury occurred in 3 of 38 (8%) right superior PV (RSPV). Greater eccentricity index predicted difficulty in isolating LIPV, OR 40.33 (95% CI 1.40 to 1160, p = 0.03) and smaller eccentricity index predicted PN injury in RSPV, OR 0.01 (95% CI 0.01-0.16, p = 0.001). CONCLUSIONS Eccentricity index measured from pre-procedural CT/MR imaging can predict difficulty of PV isolation and PN injury during cryoballoon ablation for paroxysmal AF.

A large ventricular septal defect complicating resuscitation after blunt trauma

A young adult pedestrian was admitted to hospital after being hit by a car. On arrival to the Accident and Emergency Department, the patient was tachycardic, hypotensive, hypoxic, and acidotic with a Glasgow Coma Scale of 3. Despite initial interventions, the patient remained persistently hypotensive. An echocardiogram demonstrated a traumatic ventricular septal defect (VSD) with right ventricular strain and increased pulmonary artery pressure. Following a period of stabilization, open cardiothoracic surgery was performed and revealed an aneurysmal septum with a single large defect. This was repaired with a bovine patch, resulting in normalization of right ventricular function. This case provides a vivid depiction of a large VSD in a patient following blunt chest trauma with hemodynamic compromise. In all thoracic trauma patients, and particularly those poorly responsive to resuscitation, VSDs should be considered. Relevant investigations and management strategies are discussed.

Cardiovascular changes in patients with acromegaly assessed by CMR

Summary The study describes cardiovascular changes in patients with acromegaly before and one year after treatment. Background Acromegaly causes a distinct cardiomyopathy, which remains poorly understood, because cardiac changes typically appear before the development of hypertension or diabetes. The aim of the study was to describe cardiovascular changes in patients with acromegaly before and one year after treatment. Methods Thirteen patients with acromegaly and age- and sexmatched controls (n=13) underwent CMR. Patients underwent scans before disease treatment and at twelve months after treatment. Cardiac parameters were calculated and indexed to body surface area (BSA). The comparison between groups was done using Mann-UWhitney test and within the group using Wilcoxon test. Results In patients with acromegaly left ventricular (LV) mass index (LVMi) was increased (65.7 vs. 45.8 g/m2, p=0.0021) and was observed in both females (58.8 v. 40.9 g/m2, p=0.0028) and males (71.1 vs. 56.7 g/m2, p=0.0286) compared to matched controls. The LVMi did not correlate with the serum insulin growth factor (IGF) activity (r=0.099, p=0.745) or age (r=-0.08, p=0.175). Patients with acromegaly had significantly higher cardiac index (CI; 3.7 vs. 3.0 l/min/m2, p=0.021) However, there were no differences between end diastolic volume index (EDVi; 86.9 vs. 75.4 ml/m2, p=0.0649), end systolic volume index (ESVi; 35.1 vs. 29.3 ml/m2, p=0.1662) and ejection fraction (EF; 60 vs. 59 %, p=0.327) in acromegaly group and controls. There were no differences between right ventricular (RV) RVEDVi (81.3 vs. 72.5 ml/m2, p=0.2382), RVESVi (32.7 vs. 29.1, p=0.6816) and RVEF (61 vs. 59 %, p=0.4407) in the acromegaly group and controls. At one year, patients with acromegaly demonstrated a significant fall in IGF with treatment (with somatostatin analogues or transphenoidal surgery) from baseline median IGF-I SDS +10.58 (range 1.19 to 6.52) to +0.40 (range -1.93 to 3.02) at one year (p=0.0042). CMR parameters of the LV did not change after 1 year of therapy: LVMi 65.7 vs. 61.0 g/m2, p=0.0547; EDVi 89.5 vs. 85.8 ml/m2, p=0.1641; ESVi 33.7 vs. 30.1 ml/m2, p=0.6523; EF 60 vs. 66 %, p=0.7792; CI 3.7 vs. 3.4 l/min/m2, p=0.4961.

Cardiac magnetic resonance myocardial feature tracking: feasibility for use in left ventricular non-compaction

Background Cardiac magnetic resonance (CMR) myocardial feature tracking (FT) is emerging as a sensitive and reproducible method for measuring myocardial strain parameters without the need to acquire additional images. Up until now adult CMRFT studies have primarily focussed on the reproducibility of the software,with very few studies addressing disease states beyond ischaemic cardiomyopathy. The aim of this pilot study was to assess the feasibility of cine-images derived quantitative CMR FT strain parameters to differentiate between normal individuals and patients with Left ventricular non-compaction (LVNC). Methods Patients were identified retrospectively from an established clinical CMR database. 8 LVNC patients with negative invasive angiography or stress CMR myocardial perfusion imaging were compared to 21 normal controls. LVNC was defined according to the Petersen criteria,with an end-diastolic ratio of non-compacted to compacted layer (NC/C) >2.3. LV morphological and functional parameters were performed off-line on a dedicated workstation. CMR 4chamber(4CH) and mid-ventricular short axis(SAX) cineimages were analysed in systole(S) and diastole(D) using dedicated FT software(Diogenes MRI,TomTec Imaging Systems,Munich Germany).