Andrew Kelion

Randomized Trial of Complete Versus Lesion-Only Revascularization in Patients Undergoing Primary Percutaneous Coronary Intervention for STEMI and Multivessel Disease: The CvLPRIT Trial

Background The optimal management of patients found to have multivessel disease while undergoing primary percutaneous coronary intervention (P-PCI) for ST-segment elevation myocardial infarction is uncertain. Objectives CvLPRIT (Complete versus Lesion-only Primary PCI trial) is a U.K. open-label randomized study comparing complete revascularization at index admission with treatment of the infarct-related artery (IRA) only. Methods After they provided verbal assent and underwent coronary angiography, 296 patients in 7 U.K. centers were randomized through an interactive voice-response program to either in-hospital complete revascularization (n = 150) or IRA-only revascularization (n = 146). Complete revascularization was performed either at the time of P-PCI or before hospital discharge. Randomization was stratified by infarct location (anterior/nonanterior) and symptom onset (≤3 h or >3 h). The primary endpoint was a composite of all-cause death, recurrent myocardial infarction (MI), heart failure, and ischemia-driven revascularization within 12 months. Results Patient groups were well matched for baseline clinical characteristics. The primary endpoint occurred in 10.0% of the complete revascularization group versus 21.2% in the IRA-only revascularization group (hazard ratio: 0.45; 95% confidence interval: 0.24 to 0.84; p = 0.009). A trend toward benefit was seen early after complete revascularization (p = 0.055 at 30 days). Although there was no significant reduction in death or MI, a nonsignificant reduction in all primary endpoint components was seen. There was no reduction in ischemic burden on myocardial perfusion scintigraphy or in the safety endpoints of major bleeding, contrast-induced nephropathy, or stroke between the groups. Conclusions In patients presenting for P-PCI with multivessel disease, index admission complete revascularization significantly lowered the rate of the composite primary endpoint at 12 months compared with treating only the IRA. In such patients, inpatient total revascularization may be considered, but larger clinical trials are required to confirm this result and specifically address whether this strategy is associated with improved survival. (Complete Versus Lesion-only Primary PCI Pilot Study [CvLPRIT]; ISRCTN70913605)

Transthoracic echocardiography using second harmonic imaging with Valsalva manoeuvre for the detection of right to left shunts

AIMS To assess transthoracic echocardiography (TTE) using second harmonic imaging with Valsalva manoeuvre compared to transesophageal echocardiography (TEE) for the diagnosis of right to left cardiac and pulmonary shunts. METHODS AND RESULTS One hundred and ten patients referred for TEE underwent TTE with bubble contrast. Bubbles in the left atrium within three cardiac cycles were considered diagnostic for a patent foramen ovale (PFO) and later as a pulmonary shunt. Greater than 20 bubbles in the left atrium was considered a large shunt and less than 20 a small shunt. TEE was performed immediately afterwards and read blinded to the TTE results. Pick-up rates were similar with 19 TEE positive (13 PFO) and 18 TTE positive (14 PFO) patients. There were five TEE positive/TTE negative cases who had significantly poorer TTE image quality score (2.7 +/- 0.8 vs 1.9 +/- 0.6, p < 0.05). There were six TEE negative/TTE positive cases, two cases requiring Valsalva manoeuvre to become positive. The Valsalva manoeuvre significantly increased the number of bubbles shunting (10 +/- 11 vs 20 +/- 19, p < 0.005). CONCLUSION TTE with Valsalva manoeuvre is as good as TEE in diagnosing shunts. Valsalva manoeuvre increases the size of shunt. Both techniques produce false negative results.

Procedure Guidelines for Radionuclide Myocardial Perfusion Imaging

Radionuclide myocardial perfusion imaging (MPI) is an established and non-invasive imaging technique with diagnostic and prognostic efficacy in the investigation of coronary artery disease. It is the only widely available test for assessing myocardial perfusion directly but there are variations in the way it is performed in different centres. Harmonization of practice, at least at a national level, is therefore essential, and clinical governance now makes it mandatory for practice to be based upon evidence whenever possible [ 1]. This is best achieved by expert analysis of the evidence and to this end the British Nuclear Cardiology Society (BNCS) in association with the British Cardiac Society (BCS) and the British Nuclear Medicine Society (BNMS) have developed procedure guidelines for tomographic myocardial perfusion imaging. A systematic literature search was performed and every effort was made to conform with the AGREE recommendations [ 2]. All recommendations are therefore based on either evidence from clinical studies, previous published guidelines or expert consensus of the writing and advisory groups. The guidelines cover the clinical indications of MPI, the methods used for stress testing, the radiopharmaceuticals and the injected activities and also issues related to acquisition, processing and interpretation of images. They do not cover the benefits or drawbacks of the technique in specific circumstances; neither do they address its cost effectiveness in clinical diagnosis and management nor its potential impact on clinical outcomes. The guidelines aim to assist medical practitioners and other health care professionals in recommending, performing, interpreting and reporting single photon emission computed tomography (SPECT) of myocardial perfusion.

Role of non-invasive imaging in the management of coronary artery disease: an assessment of likely change over the next 10 years. A report from the British Cardiovascular Society Working Group

Coronary angiography has been the gold standard for determining the severity, extent and prognosis of coronary atheromatous disease for the past 15–20 years. However, established non-invasive testing (such as myocardial perfusion scintigraphy and stress echocardiography) and newer imaging modalities (multi-detector x ray computed tomography and cardiovascular magnetic resonance) now need to be considered increasingly as a challenge to coronary angiography in contemporary practice. An important consideration is the degree to which appropriate use of such techniques impacts on the need for coronary angiography over the next 10–15 years. This review aims to determine the role of the various investigation techniques in the management of coronary artery disease and their resource implications, and should help determine future service provision, accepting that we are in a period of significant technological change.

Cardiac iodine-123 metaiodobenzylguanidine imaging predicts ventricular arrhythmia in heart failure patients receiving an implantable cardioverter-defibrillator for primary prevention

Objective To assess the prognostic value of cardiac iodine-123 metaiodobenzylguanidine (123I-MIBG) scintigraphy to predict ventricular arrhythmias in patients with heart failure (HF) listed for implantable cardioverter-defibrillator (ICD) devices as primary prevention. Design, setting and patients A prospective cohort study in 27 patients with HF referred for ICD implantation (alone or in combination with cardiac resynchronisation therapy) at a tertiary cardiac centre. Methods Cardiac 123I-MIBG scintigraphy was performed with calculation of early and late heart-to-mediastinum (H:M) ratios, washout rate, and summed defect score from single photon emission computed tomography (SPECT) acquisition. Resting myocardial perfusion SPECT using 99mTc-tetrofosmin was also performed and a summed score calculated. Innervation-perfusion mismatch was evaluated by comparing SPECT scores. Main outcome measure Ventricular arrhythmia requiring ICD therapy. Results At 16 months median follow-up, 10 (37%) patients experienced a significant arrhythmic event. Compared with patients who suffered no event, these individuals had lower early and late H:M ratio and higher 123I-MIBG SPECT defect scores: 1.83±0.43 versus 2.34±0.33 (p<0.001); 1.54±0.38 versus 1.96±0.38 (p=0.005); 37.0±9.4 versus 25.5±7.7 (p=0.001). Mismatch scores were also higher: 18.5±8.5 versus 8.4±5.0 (p<0.01). Optimal thresholds for predicting arrhythmia were <1.94 for early H:M ratio (sensitivity 70%, specificity 88%); <1.54 for late H:M ratio (sensitivity 60%, specificity 88%); 123I-MIBG SPECT defect score ≥31 (sensitivity 78%, specificity 77%). Conclusions In HF patients without prior ventricular arrhythmia, 123I-MIBG imaging strongly predicts future arrhythmic risk. This may inform the process of case selection for ICD therapy on an individual basis, although no single measurement provides sufficient reassurance to obviate device implantation if otherwise clinically indicated.

The effect of long‐term left ventricular assist device support on myocardial sympathetic activity in patients with non‐ischaemic dilated cardiomyopathy

Dilated cardiomyopathy (DCM) patients have abundant levels of norepinephrine secondary to failure of the norepinephrine transporter uptake mechanism. Little is known about the effects of an LV assist device (LVAD) on cardiac sympathetic innervations and norepinephrine transporter dysfunction. This study examines the effects of continuous‐flow HeartMate II LVAD on cardiac sympathetic innervations using [123I]metaiodobenzylguanidine ([123I]MIBG) nuclear imaging.

Myocardial perfusion scintigraphy in the UK: insights from the British Nuclear Cardiology Society Survey 2000.

Background: The National Institute for Health and Clinical Excellence (NICE) has recently published a very positive technology appraisal of myocardial perfusion scintigraphy (MPS). This has important implications for service provision within the National Health Service, and an accurate knowledge of the current level of MPS activity is necessary. Methods: A postal questionnaire was sent to 207 nuclear medicine departments in the UK, requesting information about nuclear cardiology facilities, activity, and practice. Non-responding departments were sent a second questionnaire, followed where necessary by a telephone call. Results: A response rate of 61% was achieved; 52% of departments performed MPS, and these tended to have more gamma cameras than those which did not (median (25th–75th centile) 2.0, 1.5–2.5 v 1.0, 0.5–1.5; p  =  0.02). The median number of studies performed was 256 (144–460). The estimated rate of MPS in the UK for the year 2000 was 1200 per million population. The median (25th–75th centile) waiting time for MPS was 16 (9–24) weeks. Pharmacological stress was used in 77% of studies, and a technetium-99m based radiopharmaceutical in 60% (two day protocol in 75%). Tomographic rather than planar imaging was performed in 88% of studies, of which 22% were ECG gated. A cardiologist was involved in reporting in 35% of studies. Conclusions: MPS activity in the UK remains low, and it tends to be provided as a low volume service with unacceptably long waiting times and a lack of involvement by cardiologists. The recent NICE appraisal may provide an impetus for further resourcing and development.

Does a selective adenosine A(1) receptor agonist protect against exercise induced ischaemia in patients with coronary artery disease

Background: The “warm up” effect in angina may represent ischaemic preconditioning, which is mediated by adenosine A1 receptors in most models. Objective: To investigate the effect of a selective A1 agonist, GR79236 (GlaxoSmithKline), on exercise induced angina and ischaemic left ventricular dysfunction in patients with coronary artery disease. Design: A double blind crossover study. Patients: 25 patients with multivessel coronary artery disease. Interventions: On mornings one week apart, patients received intravenous GR79236 10 μg/kg or placebo, and then carried out two supine bicycle exercise tests separated by 30 minutes. Equilibrium radionuclide angiography was done before and during exercise. Results: The onset of chest pain or 1 mm ST depression was delayed and occurred at a higher rate–pressure product during the second exercise test following either placebo or GR79236. Compared with placebo, GR79236 did not affect these indices during equivalent tests. GR79236 reduced resting global ejection fraction from (mean (SD)) 63 (7)% to 61 (5)% (p < 0.05) by a selective reduction in the regional ejection fraction of “ischaemic” left ventricular sectors (those where the ejection fraction fell during the first exercise test following placebo). Ischaemic sectors showed increased function during the second test following placebo (72 (21)% v 66 (20)%; p = 0.0001), or during the first test following GR79236 (69 (21)% v 66 (20)%; p = 0.0001). Sequential exercise further increased the function of ischaemic sectors even after drug administration. Conclusions: GR79236 failed to mimic the warm up effect, and warm up occurred even in the presence of this agent. This suggests that ischaemic preconditioning is not an important component of this type of protection. The complex actions of the drug on regional left ventricular function at rest and during exercise suggest several competing A1 mediated actions.

Setting up a myocardial perfusion scintigraphy service: clinical and business aspects.

Writing groupAndrew Kelion, Consultant Cardiologist, Harefield HospitalConstantinos Anagnostopoulos, Consultant Nuclear Physician, Royal Brompton HospitalGlyn Davies, Head of Medical Physics, Hull and East Yorkshire HospitalsJane Flint, Consultant Cardiologist, Dudley Group of HospitalsMark Harbinson, Consultant Cardiologist, Queens University BelfastAndrew Hilson, Consultant Nuclear Physician, Royal Free HospitalAvijit Lahiri, Consultant Cardiologist, Wellington HospitalEric Lim, Research Fellow, Wellington HospitalLiz Prvulovich, Consultant Nuclear Physician, Middlesex HospitalNikant Sabharwal, Specialist Registrar in Cardiology, Oxford DeaneryAnn Tweddel, Consultant Cardiologist, Hull Royal InfirmaryRichard Underwood, Professor of Cardiac Imaging, Imperial CollegeSimon Woldman, Consultant Cardiologist, Ayr HospitalAdvisory groupRoger Boyle, National Director for Heart Disease, Department of HealthIan Jones, Nuclear Medicine Technologist, South Derbyshire Acute HospitalsKate Latus, Nurse Practitioner, Royal Brompton HospitalCharlie McKenna, Consultant Cardiologist, Royal Berkshire and Battle HospitalsVicky Parkin, Nuclear Medicine Technologist, Bristol Royal InfirmarySarah Powell, Southampton City Primary Care Trust

Does exercise radionuclide angiography still have a role in clinical cardiac assessment

ConclusionsThe technology and computer processing required to perform exercise RNA have been available for more than 20 years, and much information is available concerning its value in different clinical situations. There is little doubt that, compared with alternative imaging approaches, exercise RNA performs poorly in the simple diagnosis or exclusion of coronary artery disease. However, it provides robust prognostic information in a wide variety of populations with known or possible coronary artery disease. Exercise RNA should be reserved for patients with minimal symptoms for whom purely prognostic data are required, when the mere presence or absence of coronary artery disease does not carry management implications (Table II). In the setting of severe aortic regurgitation, exercise RNA should be considered at baseline assessment and when there is any doubt concerning the onset of symptoms or resting LV dysfunction. With these indications in mind, exercise RNA provides unique and valuable information about the response of global LV function to exercise and continues to have an important if circumscribed role in noninvasive cardiac assessment.