Role of Cardiovascular Magnetic Resonance in Native Valvular Regurgitation: A Comprehensive Review of Protocols, Grading of Severity, and Prediction of Valve Surgery

Abstract

Valvular regurgitation is common in developed countries with an increasing prevalence due to the aging of the population and more accurate diagnostic imaging methods. Echocardiography is the gold standard method for the assessment of the severity of valvular heart regurgitation. Nonetheless, cardiovascular magnetic resonance (CMR) has emerged as an additional tool for assessing mainly the severity of aortic and mitral valve regurgitation in the setting of indeterminate findings by echocardiography. Moreover, CMR is a valuable imaging modality to assess ventricular volume and flow, which are useful in the calculation of regurgitant volume and regurgitant fraction of mitral valve regurgitation, aortic valve regurgitation, tricuspid valve regurgitation, and pulmonary valve regurgitation. Notwithstanding this, reference values and optimal thresholds to determine the severity and prognosis of valvular heart regurgitation have been studied lesser by CMR than by echocardiography. Hence, further larger studies are warranted to validate the potential prognostic relevance of the severity of valvular heart regurgitation determined by CMR. The present review describes, analyzes, and discusses the use of CMR to determine the severity of valvular heart regurgitation in clinical practice.

Quantification of primary mitral regurgitation by echocardiography: A practical appraisal

“…Maréchaux et al reported that a cut-off of 3D-RegFrac ≥ 40% accurately discriminates patients with 3+ or 4+ MR, with a grey zone of overlap between 1+ or 2+ vs. 3+ or 4+ patients reduced by 3D-TTE compared to 2D-TTE (130). Consistently, CMR studies emphasized the discriminative value of a CMR-RegFrac ≥ 40%, that is below the 50% threshold still retained in guidelines, and with prognostic implications (181). Independently from the imaging modality used (2D-TTE, 3D-TTE, or CMR), further multicenter prospective studies should be conducted to standardize the severity thresholds of RegFrac based on outcome predictions in patients with primary MR.…”

The right ventricle systolic force ratio could predict the severity of the tricuspid regurgitation‐RIVIERA ratio

“…Over the past 20–25 years, cardiovascular magnetic resonance (CMR) has established itself as the gold standard for assessing left and right ventricular mass, volume, and function. Additionally, it has developed into a trustworthy and precise tool for calculating the volumetric quantification of the heart valves utilizing a number of methods that are independent of jet morphology 19–21 . When evaluating TR using an integrated strategy that considers both qualitative and quantitative parameters, echocardiography is the recommended and advised initial imaging technique.…”

“…The most recent recommendations suggest applying the same severity criteria in regurgitant fraction for TR as have been applied for mitral regurgitation (i.e., a regurgitant fraction of less than 15% for mild TR, more than 15% for severe TR, and between 16% and 25% for moderately severe TR) 19,21,22 . The ferromagnetic effects of metallic implants, claustrophobia, respiratory artifacts, arhythmia artifacts, claustrophobia, the lack of technology in all centers, and a shortage of imaging professionals to interpret images are some of the drawbacks of CMR 19–22 . Regurgitant fraction predictors, a crucial factor in TR grading in CMR, must be found using echocardiographically similar methods.…”

“…These well‐known and commonly used criteria do, however, have a number of drawbacks that should be taken into account 14–19 . For quantitative valve assessment, cardiac magnetic resonance imaging (CMR) frequently serves as gold standard 19–22 . The ferromagnetic effects of metallic implants, claustrophobia, respiratory artifacts, arhythmia artifacts, claustrophobia, lack of technology in all centers, and a shortage of imaging professionals to interpret images are some of the drawbacks of CMR 19–22 .…”

“…[14][15][16][17][18][19] For quantitative valve assessment, cardiac magnetic resonance imaging (CMR) frequently serves as gold standard. [19][20][21][22] The ferromagnetic effects of metallic implants, claustrophobia, respiratory artifacts, arhythmia artifacts, claustrophobia, lack of technology in all centers, and a shortage of imaging professionals to interpret images are some of the drawbacks of CMR. [19][20][21][22] Considering the unique disadvantages of the parameters mentioned earlier and the undeniable effect of severe TR on mortality, it can be speculated that the parameters obtained by using these parameters together can better define the severity of TR.…”