Usefulness of late gadolinium enhancement MRI combined with stress imaging in predictive significant coronary stenosis in new-diagnosed left ventricular dysfunction

Diagnostic accuracy of late gadolinium enhancement cardiac MRI for coronary artery disease in patients with reduced left ventricular ejection fraction

BACKGROUND

Identifying significant coronary artery disease (CAD) in patients with reduced left ventricular ejection fraction (rLVEF) is essential for guiding therapeutic decisions, including medical management, device implantation and potential revascularisation. Prior studies suggested that rest cardiac MRI (CMR) with late gadolinium enhancement (LGE) could reliably detect significant CAD. We aimed to evaluate the diagnostic accuracy of rest LGE-CMR for predicting significant CAD in rLVEF patients.

METHODS

In this prospective, multicentre cohort study across 10 centres, adults with new-onset rLVEF≤45% without obvious cause were included. All patients underwent rest CMR and coronary angiography. Independent, blinded committees reviewed images. Significant CAD was defined as ≥70% stenosis in major coronary arteries. Ischaemic scars were identified on CMR as subendocardial LGE. The primary outcome was the sensitivity of CMR in detecting significant CAD.

RESULTS

Among 380 patients (median age 63 years, 68% male), significant CAD was present in 49 (13%). CMR identified ischaemic scars in 106 (28%). The sensitivity of CMR for detecting significant CAD was 57% (95% CI: 43% to 71%), specificity 76% (95% CI: 72% to 81%), positive predictive value 26% (95% CI: 18% to 35%) and negative predictive value 92% (95% CI: 89% to 95%). A CMR-first strategy would have missed 43% of significant CAD cases, many requiring revascularisation (86% of missed cases).

CONCLUSIONS

In this large, prospective multicentre study with independent image review, rest LGE-CMR demonstrated limited sensitivity for detecting significant CAD in patients with rLVEF. Relying solely on CMR could lead to missed diagnoses and undertreatment. CMR should be integrated with other diagnostic tools to optimise care in this population.

TRIAL REGISTRATION NUMBER

NCT03231189.

Charting the Unseen: How Non-Invasive Imaging Could Redefine Cardiovascular Prevention

Cardiovascular diseases (CVDs) remain a major global health challenge, leading to significant morbidity and mortality while straining healthcare systems. Despite progress in medical treatments for CVDs, their increasing prevalence calls for a shift towards more effective prevention strategies. Traditional preventive approaches have centered around lifestyle changes, risk factors management, and medication. However, the integration of imaging methods offers a novel dimension in early disease detection, risk assessment, and ongoing monitoring of at-risk individuals. Imaging techniques such as supra-aortic trunks ultrasound, echocardiography, cardiac magnetic resonance, and coronary computed tomography angiography have broadened our understanding of the anatomical and functional aspects of cardiovascular health. These techniques enable personalized prevention strategies by providing detailed insights into the cardiac and vascular states, significantly enhancing our ability to combat the progression of CVDs. This review focuses on amalgamating current findings, technological innovations, and the impact of integrating advanced imaging modalities into cardiovascular risk prevention, aiming to offer a comprehensive perspective on their potential to transform preventive cardiology.

Nonischemic or Dual Cardiomyopathy in Patients With Coronary Artery Disease

BACKGROUND

Randomized trials in obstructive coronary artery disease (CAD) have largely shown no prognostic benefit from coronary revascularization. Although there are several potential reasons for the lack of benefit, an underexplored possible reason is the presence of coincidental nonischemic cardiomyopathy (NICM). We investigated the prevalence and prognostic significance of NICM in patients with CAD (CAD-NICM).

METHODS

We conducted a registry study of consecutive patients with obstructive CAD on coronary angiography who underwent contrast-enhanced cardiovascular magnetic resonance imaging for the assessment of ventricular function and scar at 4 hospitals from 2004 to 2020. We identified the presence and cause of cardiomyopathy using cardiovascular magnetic resonance imaging and coronary angiography data, blinded to clinical outcomes. The primary outcome was a composite of all-cause death or heart failure hospitalization, and secondary outcomes were all-cause death, heart failure hospitalization, and cardiovascular death.

RESULTS

Among 3023 patients (median age, 66 years; 76% men), 18.2% had no cardiomyopathy, 64.8% had ischemic cardiomyopathy (CAD+ICM), 9.3% had CAD+NICM, and 7.7% had dual cardiomyopathy (CAD+dualCM), defined as both ICM and NICM. Thus, 16.9% had CAD+NICM or dualCM. During a median follow-up of 4.8 years (interquartile range, 2.9, 7.6), 1116 patients experienced the primary outcome. In Cox multivariable analysis, CAD+NICM or dualCM was independently associated with a higher risk of the primary outcome compared with CAD+ICM (adjusted hazard ratio, 1.23 [95% CI, 1.06-1.43]; P=0.007) after adjustment for potential confounders. The risks of the secondary outcomes of all-cause death and heart failure hospitalization were also higher with CAD+NICM or dualCM (hazard ratio, 1.21 [95% CI, 1.02-1.43]; P=0.032; and hazard ratio, 1.37 [95% CI, 1.11-1.69]; P=0.003, respectively), whereas the risk of cardiovascular death did not differ from that of CAD+ICM (hazard ratio, 1.15 [95% CI, 0.89-1.48]; P=0.28).

CONCLUSIONS

In patients with CAD referred for clinical cardiovascular magnetic resonance imaging, NICM or dualCM was identified in 1 of every 6 patients and was associated with worse long-term outcomes compared with ICM. In patients with obstructive CAD, coincidental NICM or dualCM may contribute to the lack of prognostic benefit from coronary revascularization.

Hybrid PET/MR in Cardiac Imaging

In the last few years, technological advances in MR imaging, PET detectors, and attenuation correction algorithms have allowed the creation of truly integrated PET/MR imaging systems, for both clinical and research applications. These machines allow a comprehensive investigation of cardiovascular diseases, by offering a wide variety of detailed anatomical and functional data in combination. Despite significant pathophysiologic mechanisms being clarified by this new data, its clinical relevance and prognostic significance have not been demonstrated yet.

Cardiac Magnetic Resonance in Fabry Disease: Morphological, Functional, and Tissue Features

Fabry disease (FD) is an X-linked inheritable storage disease caused by a deficiency of alpha-galactosidase causing lysosomal overload of sphingolipids. FD cardiomyopathy is characterized by left ventricular (LV) hypertrophy and should be considered in differential diagnosis with all the other causes of LV hypertrophy. An early diagnosis of FD is very important because the enzyme replacement therapy (ERT) may change the fate of patients by blocking both cardiac and systemic involvement and improving prognosis. Diagnosis may be relatively easy in young patients with the typical signs and symptoms of FD, but in male patients with late onset of disease and in females, diagnosis may be very challenging. Morphological and functional aspects are not specific to FD, which cannot be diagnosed or excluded by echocardiography. Cardiac magnetic resonance (CMR) with tissue characterization capability is an accurate technique for the differential diagnosis of LV hypertrophy. The finding of decreased myocardial T1 value in LV hypertrophy is specific to FD. Late gadolinium enhancement (LGE) is found in the late stage of the disease, but it is useful to predict the cardiac response to ERT and to stratify the prognosis.

Accuracy of cardiac magnetic resonance imaging to rule out significant coronary artery disease in patients with systolic heart failure of unknown aetiology: Single-centre experience and comprehensive meta-analysis

BACKGROUND

Coronary artery disease (CAD) is the leading cause of systolic heart failure (HF). Cardiac magnetic resonance imaging (CMR) is a non-invasive technique that detects a myocardial infarction scar as subendocardial or transmural late gadolinium enhancement (st-LGE).

AIM

We sought to evaluate whether a lack of st-LGE could rule out CAD in new-onset systolic HF of unknown aetiology.

METHODS

We included 232 consecutive patients with new-onset HF and left ventricular ejection fraction ≤35% who underwent both coronary angiography and CMR to assess HF aetiology. CAD was defined as the presence of coronary artery stenosis≥50% on a coronary angiogram. We assessed sensitivity, specificity, and positive and negative likelihood ratios (PLR and NLR) of the presence of st-LGE to detect underlying CAD. A complementary meta-analysis of 11 studies (including ours) was also performed.

RESULTS

In our study, 49 (21.1%) patients had CAD. The sensitivity and specificity of the presence of st-LGE to detect CAD were 69 and 92%, respectively. PLR and NLR were 8.47 and 0.33, respectively. In the meta-analysis, 1227 patients were included, and the prevalence of CAD ranged from 19.2 to 68.3%. Sensitivity, specificity, PLR and NLR were 87% (95% confidence interval [CI] 0.80-0.92), 93% (95% CI 0.89-0.96), 12.91 (95% CI 7.70-21.64) and 0.14 (95% CI 0.09-0.22), respectively. Altogether, 55 patients presented CAD with no st-LGE; inversely, 75 patients presented st-LGE with no CAD.

CONCLUSION

With a CMR specificity of 93%, the absence of st-LGE rules out significant underlying CAD in patients with systolic HF of unknown aetiology in most cases.

Advanced Non-invasive Imaging Techniques in Chronic Heart Failure and Cardiomyopathies : Focus on Cardiac Magnetic Resonance Imaging and Computed Tomographic

Cardiomyopathies (Cs) are a heterogeneous group of myocardial diseases with structural and/or functional abnormalities.The aetiology is due to genetic-family substrate in most cases, however, the correct and detailed analysis of morphofunctional abnormalities (severity and distribution of hypertrophy, ventricular dilatation, ventricular dysfunction) and tissue characteristics (myocardial fibrosis, myocardial infiltration) are a crucial element for a definite diagnosis.Among the different diagnostic imaging modalities applied in clinical practice (echocardiography, nuclear medicine), cardiac magnetic resonance (CMR) has emerged as a non-invasive diagnostic tool having high ability to quantify systolic function and tissue abnormalities that represent the substrates of many Cs.The main added value of CMR is the ability to identify cardiomyopathies with respect to ischemic heart disease and, above all, to discriminate the major types of cardiomyopathies based on morpho-functional presentation patterns and the presence and location of myocardial fibrosis.Many CMR elements allow increasing diagnostic accuracy but CMR data should be integrated with an appropriate clinical and instrumental context.Computed Tomographic (CT) scan technology has showed a complementary role in patients having Cs and HF.In this chapter, the diagnostic, pathophysiologic and prognostic value of CMR and CT in heart failure due to the most common cardiomyopathies will be discussed.