Role of Cardiovascular Magnetic Resonance as a Gatekeeper to Invasive Coronary Angiography in Patients Presenting With Heart Failure of Unknown Etiology

Abstract

Background-In patients presenting with new-onset heart failure of uncertain etiology, the role of coronary angiography (CA) is unclear. Although conventionally performed to differentiate underlying coronary artery disease from dilated cardiomyopathy, CA is associated with a risk of complications and may not detect an ischemic cause resulting from arterial recanalization or an embolic episode. In this study, we assessed the diagnostic accuracy of a cardiovascular magnetic resonance (CMR) protocol incorporating late gadolinium enhancement (LGE) and magnetic resonance CA as a noninvasive gatekeeper to CA in determining the etiology of heart failure in this subset of patients. Methods and Results-One hundred twenty consecutive patients underwent CMR and CA. The etiology was ascribed by a consensus panel that used the results of the CMR scans. Similarly, a separate consensus group ascribed an underlying cause by using the results of CA. The diagnostic accuracy of both strategies was compared against a gold-standard panel that made a definitive judgment by reviewing all clinical data. The study was powered to show noninferiority between the 2 techniques. The sensitivity of 100%, specificity of 96%, and diagnostic accuracy of 97% for LGE-CMR were equivalent to CA (sensitivity, 93%; specificity, 96%; and diagnostic accuracy, 95%). As a gatekeeper to CA, LGE-CMR was also found to be a cheaper diagnostic strategy in a decision tree model when United Kingdom-based costs were assumed. The economic merits of this model would change, depending on the relative costs of LGE-CMR and CA in any specific healthcare system. Conclusion-This study showed that LGE-CMR is a safe, clinically effective, and potentially economical gatekeeper to CA in patients presenting with heart failure of uncertain etiology.

T1 Mapping in Characterizing Myocardial Disease

“…[1][2][3][4][5][6][7][8] However, there are multiple situations where LGE is not sufficiently sensitive to detect myocardial disease because it is not yet, or not at all, characterized by sufficient regional accumulation of reparative fibrosis. [9][10][11] In NICMs, where LGE is a recognized marker of irreversible damage and advanced disease, early stages are characterized by a multitude of diffuse interstitial disease processes, including low-grade interstitial inflammation, fibrosis, and infiltration, resulting in an expansion of extracellular space.…”

Reliable exclusion of prognostically significant coronary disease in left ventricular dysfunction by cardiac MRI

“…However, the argument to identify single vessel disease to inform changes to medical management by way of antiplatelet and lipid lowering therapy is contentious in a heart failure population (29,30). Those with 100% sensitivity have been in cohorts with confirmed myocardial infarctions (18) or have included CMR proximal coronary artery imaging in the protocol (17). This is the first study to assess the utility of LGE CMR without proximal coronary artery imaging to detect prognostically significant CAD.…”

“…This is predominantly because the evidence for the predictive value of LGE CMR to detect CAD in LVSD is inconsistent with variable sensitivities depending upon the definition of CAD, the patient population, and the use of proximal coronary artery imaging (MRCA). Whilst CMR using a combination of (LGE CMR) with proximal coronary artery imaging by MRCA has been shown to accurately categorise the aetiology of heart failure as ascribed by a consensus panel (17), MRCA is not routinely available in many centres, is time consuming to perform and image quality is unreliable. LGE CMR without MRCA is a sensitive and specific marker of single vessel CAD in heart failure for those with a previously diagnosed myocardial infarction (18), however, the sensitivity is lower for those without a history of myocardial infarction (80-95%) (19)(20)(21).…”

“How many times must a man look up before he can really see the sky?” Rheumatic cardiovascular disease in the era of multimodality imaging

“…Pre-contrast T1W and T2W dark blood imaging but also post-gadolinium T1W imaging can reveal presence of inflammation, even when the disease is clinically under remission [60] ; (2) Function, oedema, early, late gadolinium enhancement and stress CMR for RA, SLE, SSc and MTCD. Evidence of myocardial inflammation and/or fibrosis can be identified by STIR T2, early and late gadolinium enhancement, even if the rheumatic disease is under remission [61,62] ; (3) Additionally, it is the gatekeeper for differential diagnosis between various types of scar: scar due to CAD that should motivate coronary artery evaluation (subendocardial or transmural scar following the distribution of coronary arteries in CAD) and scar due to inflammation or vasculitis (subepicardial or intramural scar not following the distribution of coronary arteries in inflammation and diffuse subendocardial fibrosis in case of diffuse subendocardial vasculitis) [61][62][63] ; (4) Function, oedema, early and late gadolinium enhancement in inflammatory myopathies using SSFP, STIR T2, early and late gadolinium enhancement, even if the disease is under remission [64,65] ; (5) Carotid angiography and vessel wall imaging in RA and SLE [60] ; (6) Coronary angiography, oedema, early, late gadolinium enhancement, stress CMR and scar detection for Kawasaki disease [66] ; and (7) Assessment of PAH includes information about low risk for CAD in SLE patients using a technetium99m sestamibi [44] . Finally, in SLE patients with cardiac symptoms an abnormal glucose metabolism of the myocardium was detected, shown as a pathological 18FDG scan, whereas perfusion appeared normal (reversed mismatch) [45] .…”