Clinical and economic consequences of non-cardiac incidental findings detected on cardiovascular computed tomography performed prior to transcatheter aortic valve implantation (TAVI).

Transcatheter aortic valve implantation (TAVI) is an effective treatment option for patients with severe degenerative aortic valve stenosis who are high risk for conventional surgery. Computed tomography (CT) performed prior to TAVI can detect pathologies that could influence outcomes following the procedure, however the incidence, cost, and clinical impact of incidental findings has not previously been investigated. 279 patients underwent CT; 188 subsequently had TAVI and 91 were declined. Incidental findings were classified as clinically significant (requiring treatment), indeterminate (requiring further assessment), or clinically insignificant. The primary outcome measure was all-cause mortality up to 3 years. Costs incurred by additional investigations resultant to incidental findings were estimated using the UK Department of Health Payment Tariff. Incidental findings were common in both the TAVI and medical therapy cohorts (54.8 vs. 70.3%; P = 0.014). Subsequently, 45 extra investigations were recommended for the TAVI cohort, at an overall average cost of £32.69 per TAVI patient. In a univariate model, survival was significantly associated with the presence of a clinically significant or indeterminate finding (HR 1.61; P = 0.021). However, on multivariate analysis outcomes after TAVI were not influenced by any category of incidental finding. Incidental findings are common on CT scans performed prior to TAVI. However, the total cost involved in investigating these findings is low, and incidental findings do not independently identify patients with poorer outcomes after TAVI. The discovery of an incidental finding on CT should not necessarily influence or delay the decision to perform TAVI.

Clinical utility and prognostic value of left atrial volume assessment by cardiovascular magnetic resonance in non-ischaemic dilated cardiomyopathy.

AIMS: Echocardiographic studies have shown that left atrial volume (LAV) predicts adverse outcome in small heart failure (HF) cohorts of mixed aetiology. However, the prognostic value of LAV in non-ischaemic dilated cardiomyopathy (DCM) is unknown. Cardiovascular magnetic resonance (CMR) allows accurate and reproducible measurement of LAV. We sought to determine the long-term prognostic significance of LAV assessed by CMR in DCM. METHODS AND RESULTS: We measured LAV indexed to body surface area (LAVi) in 483 consecutive DCM patients referred for CMR. Patients were prospectively followed up for a primary endpoint of all-cause mortality or cardiac transplantation. During a median follow-up of 5.3 years, 75 patients died and 9 underwent cardiac transplantation. After adjustment for established risk factors, LAVi was an independent predictor of the primary endpoint [hazard ratio (HR) per 10 mL/m(2) 1.08; 95% confidence interval (CI) 1.01-1.15; P = 0.022]. LAVi was also independently associated with the secondary composite endpoints of cardiovascular mortality or cardiac transplantation (HR per 10 mL/m(2) 1.11; 95% CI 1.04-1.19; P = 0.003), and HF death, HF hospitalization, or cardiac transplantation (HR per 10 mL/m(2) 1.11; 95% CI 1.04-1.18; P = 0.001). The optimal LAVi cut-off value for predicting the primary endpoint was 72 mL/m(2). Patients with LAVi >72 mL/m(2) had a three-fold elevated risk of death or transplantation (HR 3.00; 95% CI 1.92-4.70; P < 0.001). LAVi provided incremental prognostic value for the prediction of transplant-free survival (net reclassification improvement 0.17; 95% CI 0.05-0.29; P = 0.002). CONCLUSIONS: LAVi is a powerful independent predictor of transplant-free survival and HF outcomes in DCM. Assessment of LAV improves risk stratification in DCM and should be incorporated into routine CMR examination.

International reproducibility of single breathhold T2* MR for cardiac and liver iron assessment among five thalassemia centers.

PURPOSE: To examine the reproducibility of the single breathhold T2* technique from different scanners, after installation of standard methodology in five international centers. MATERIALS AND METHODS: Up to 10 patients from each center were scanned twice locally for local interstudy reproducibility of heart and liver T2*, and then flown to a central MR facility to be rescanned on a reference scanner for intercenter reproducibility. Interobserver reproducibility for all scans was also assessed. RESULTS: Of the 49 patients scanned, the intercenter reproducibility for T2* was 5.9% for the heart and 5.8% for the liver. Local interstudy reproducibility for T2* was 7.4% for the heart and 4.6% for the liver. Interobserver reproducibility for T2* was 5.4% for the heart and 4.4% for the liver. CONCLUSION: These data indicate that T2* MR may be developed into a widespread test for tissue siderosis providing that well-defined and approved imaging and analysis techniques are used.

Clinical management and short-term cost - 64-slice MDCT vs. myocardial perfusion scintigraphy.

There are currently no published studies of the impact of CT coronary angiography (CTA) on patient management or cost when compared with other established imaging techniques. We assessed the short term investigation and treatment costs of CTA compared with myocardial perfusion scintigraphy (MPS) using real clinical scenarios. Clinical information with either their CTA or MPS results were presented to 20 cardiologists in a random order. They decided further investigations and treatment required based on these data. Short term cost was calculated for each imaging strategy. Whilst the total number of further investigations requested did not differ between groups patients undergoing CTA were more likely to be referred for invasive coronary angiography, receive aspirin, statins, ACE inhibitors, ß-blockers or clopidogrel. Overall cost and investigation costs were similar between CTA and MPS; however treatment costs were higher with CTA. There are significant differences in further clinical management when using CTA compared with MPS, in particular with greater use of secondary preventative medication.

Integrated cardiac and vascular assessment in Takayasu arteritis by cardiovascular magnetic resonance.

OBJECTIVE: This study was undertaken to evaluate the value of cardiovascular magnetic resonance (CMR) in the assessment of patients with Takayasu arteritis (TA). METHODS: Sixteen patients with TA and 2 populations comprising 110 normal volunteers were prospectively recruited. All patients with TA underwent a CMR protocol including measurement of carotid artery wall volume, assessment of left ventricular (LV) volumes and function, and late gadolinium enhancement for the detection of myocardial scarring. RESULTS: Carotid artery wall volume, total vessel volume, and the wall:outer wall ratio were elevated in TA patients compared with controls (wall volume 1,045 mm(3) in TA patients versus 640 mm(3) in controls, P < 0.001; total vessel volume 2,268 mm(3) in TA patients versus 2,037 mm(3) in controls, P < 0.05; wall:outer wall ratio 48% in TA patients versus 32% in controls, P < 0.001). The lumen volume was reduced in TA (1,224 mm(3) versus 1,398 mm(3) in controls, P < 0.05). In TA, LV function was more dynamic, with reduced end-systolic volume (mean +/- 95% confidence interval ejection fraction 74 +/- 3% versus 67 +/- 1% in controls, P < 0.001; LV end-systolic volume 19 +/- 4 ml/m(2) versus 25 +/- 1 ml/m(2) in controls, P < 0.001). Myocardial late gadolinium enhancement was present in 4 (27%) of 15 patients, indicating previously unrecognized myocardial damage. CONCLUSION: Our findings indicate that an integrated method of cardiovascular assessment by CMR in TA not only provides good delineation of vessel wall thickening, but has also demonstrated dynamic ventricular function, myocardial scarring, and silent myocardial infarction. CMR has benefits compared with other approaches for the assessment and followup of patients with TA, and has potential to identify patients most at risk of complications, allowing early preventative therapy.

Comparison of 64-slice cardiac computed tomography with myocardial perfusion scintigraphy for assessment of global and regional myocardial function and infarction in patients with low to intermediate likelihood of coronary artery disease.

BACKGROUND: Cardiac computed tomography (CCT) has the potential to assess both coronary anatomy and ventricular function in a single study. We examined the agreement between CCT and myocardial perfusion scintigraphy (MPS) for the assessment of global and regional ventricular function. METHODS AND RESULTS: Research CCT was performed in 52 patients with a low to intermediate likelihood of coronary artery disease referred for MPS. Left ventricular end-diastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction (LVEF), and myocardial wall motion and thickening were compared between techniques. In addition, myocardial contrast attenuation on CCT was compared with radiotracer uptake on MPS. LVEF values agreed well (mean difference, 4.1%; SD, 15.13%), but CCT left ventricular end-diastolic volume was greater compared with MPS (mean difference, 46.0 mL; SD, 33.34 mL) (P < .001). There was moderate agreement for segmental myocardial motion and thickening, with kappa values of 0.57 (95% confidence interval, 0.51-0.63) and 0.47 (95% confidence interval, 0.41-0.53), respectively. Seventeen patients had hypoattenuation in at least 1 myocardial segment on CCT. Three of four patients with concomitant abnormalities of wall motion and thickening on CCT had infarction in the same territory on MPS. CONCLUSIONS: There was good agreement for LVEF between CCT and MPS but myocardial volumes differed, and these modalities cannot be used interchangeably. Mild abnormalities of regional function are detected more commonly by CCT than by MPS. Myocardial hypoattenuation on CCT is highly specific for myocardial infarction when associated with reduction of systolic wall thickening and regional wall motion abnormality.