Multicentre medicoeconomic evaluation of cardiac magnetic resonance imaging for predicting coronary artery disease in left ventricular dysfunction: The CAMAREC study design.

BACKGROUND: Cardiac magnetic resonance imaging may provide a non-invasive alternative to coronary angiography for differentiating between ischaemic and non-ischaemic cardiomyopathy in cases of unexplained reduced left ventricular ejection fraction. AIM: The CAMAREC study aims to evaluate the diagnostic accuracy of cardiac magnetic resonance imaging in predicting significant coronary artery disease in patients with reduced left ventricular ejection fraction, using coronary angiography as the gold standard for comparison. METHODS: CAMAREC is a prospective cohort study of 406 patients in 10 centres with newly diagnosed, unexplained left ventricular ejection fraction ≤ 45%. Cardiac magnetic resonance imaging and coronary angiography will be conducted within a 2-week interval, starting with cardiac magnetic resonance imaging; independent committees will review the results blindly. Primary outcome is sensitivity of detecting ischaemic scar on cardiac magnetic resonance imaging for predicting significant coronary artery disease on coronary angiography according to Felker's criteria. Secondary outcomes include specificity and positive and negative predictive values (with 95% confidence intervals) of cardiac magnetic resonance imaging for predicting significant coronary artery disease in patients with reduced left ventricular ejection fraction, kappa concordance coefficient between cardiac magnetic resonance imaging and coronary angiography for diagnosing the affected myocardial territory, and the impact of cardiac magnetic resonance imaging on revascularization decisions. Two ancillary studies will evaluate the incremental cost-effectiveness of using cardiac magnetic resonance imaging first versus coronary angiography first, and the sensitivity of pre- and postcontrast T1-mapping for predicting significant coronary artery disease in patients with reduced left ventricular ejection fraction. CONCLUSION: Our study protocol is designed to rigorously evaluate cardiac magnetic resonance imaging as a non-invasive alternative to coronary angiography in patients with unexplained reduced left ventricular ejection fraction. The results will have significant implications for patient management, and may support growing evidence for the clinical utility of cardiac magnetic resonance imaging.

Cardiovascular Magnetic Resonance May Avoid Unnecessary Coronary Angiography in Patients With Unexplained Left Ventricular Systolic Dysfunction: A Retrospective Diagnostic Pilot Study.

BACKGROUND: Coronary angiography (CA) is usually performed in patients with reduced left ventricular ejection fraction (LVEF) to search ischemic cardiomyopathy. Our aim was to examine the agreement between CA and cardiovascular magnetic resonance (CMR) imaging among a cohort of patients with unexplained reduced LVEF, and estimate what would have been the consequences of using CMR imaging as the first-line examination. METHODS: Three hundred five patients with unexplained reduced LVEF of ≤45% who underwent both CA and CMR imaging were retrospectively registered. Patients were classified as CMR+ or CMR- according to presence or absence of myocardial ischemic scar, and classified CA+ or CA- according to presence or absence of significant coronary artery disease. RESULTS: CMR+ (n = 89) included all 54 CA+ patients, except 2 with distal coronary artery disease in whom no revascularization was proposed. Among the 247 CA- patients, 15% were CMR+. CMR imaging had 96% sensitivity, 85% specificity, 99% negative predictive value, and 58% positive predictive value for detecting CA+ patients. Revascularization was performed in 6.5% of the patients (all CMR+). Performing CA only for CMR+ patients would have decreased the number of CAs by 71%. CONCLUSIONS: In reduced LVEF, performing CA only in CMR+ patients may significantly decrease the number of unnecessary CAs performed, without missing any patients requiring revascularization.

Incidence, diagnostic methods, and evolution of left ventricular thrombus in patients with anterior myocardial infarction and low left ventricular ejection fraction: a prospective multicenter study.

BACKGROUND AND OBJECTIVES: We aimed to assess the incidence and evolution of left ventricular (LV) thrombi in a high-risk population of patients with LV systolic dysfunction after anterior myocardial infarction (ant-MI). We also compared the accuracy of transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging with contrast-delayed enhancement (CMR-DE) in detecting LV thrombi. METHODS: We prospectively included 100 consecutive patients with LV ejection fraction (LVEF) <45% at the first TTE performed <7 days after ant-MI. A second evaluation with TTE and CMR-DE (by blinded examiners) was performed at 30 days. A third TTE and assessment of clinical status were performed between 6 and 12 months after ant-MI. RESULTS: Patients (males 71%; mean age 59.1 ± 12.1 years; mean LVEF 33.5% ± 6.0%) were included at a median of 5.5 days (interquartile range 25th-75th percentile 4.25-6.0 days) after ant-MI. Thrombi were detected among 26 (26%) patients at a median of 12.0 days after ant-MI (7 patients at 1-7 days after MI; 15 at 8-30 days; and 4 after day 30). Sensitivity and specificity for LV thrombi detection were 94.7% and 98.5%, respectively, for TTE as compared with CMR-DE. Most thrombi (n = 24; 92.3%) disappeared after triple antithrombotic therapy (vitamin K antagonist in addition to dual antiplatelet therapy). CONCLUSION: Left ventricular thrombus is a frequent complication after ant-MI with systolic dysfunction. When a search for thrombus is prespecified, the accuracy of TTE is high as compared with CMR-DE. The best antithrombotic strategy is not known.