Diagnostic role of aortic valve calcium scoring in various etiologies of aortic stenosis

Prognostic and therapeutic implications of a low aortic valve calcium score in patients with low-gradient aortic stenosis

AIMS

Low-gradient (LG) aortic stenosis (AS) poses a diagnostic challenge. Aortic valve calcium score (AVCS) assessment has emerged as a complementary diagnostic method when echocardiography provides discordant results. However, the diagnostic and prognostic values of AVCS in LGAS have not been thoroughly studied. Our aims in this study were to investigate the prognostic importance of AVCS in LGAS and to assess whether symptomatic patients with LGAS and low AVCS may benefit from aortic valve intervention (AVI).

METHODS AND RESULTS

A total of 327 symptomatic patients (78.5 ± 7.3 years, 51% women) with severe AS defined by the aortic valve area who underwent computed tomography for transcatheter aortic valve intervention (TAVI) planning were enrolled. AVCS was measured. AVCS < 2000AU in men and < 1200 AU in women was considered a low AVCS. A total of 243 patients had high gradient (HG) and 84 had LGAS. A low AVCS was present in 25 (10%) patients with HG and 34 (40%) with LGAS. Over a median follow-up period of 4.9 years, 194 deaths occurred. In multivariate analysis, AVCS was a significant independent predictor of all-cause mortality among patients with HGAS [adjusted hazard ratio (aHR): 2.317; CI: 1.104-4.861; P = 0.026] but not among those with LGAS (aHR: 0.848; CI: 0.434-1.658; P = 0.630). After propensity score matching between patients who underwent AVI and those who were medically treated, AVI (94% TAVI) was a significant and independent predictor of survival among LGAS patients with a low AVCS even after adjustment for clinical variables (aHR: 0.102, CI: 0.028-0.369; P < 0.001).

CONCLUSION

The prevalence of a low AVCS is much higher in patients with LGAS than in those with HGAS. In patients with symptomatic severe LGAS, a low AVCS does not entail a better prognosis. AVI is equally beneficial in LGAS patients with a high or low AVCS, similarly to those with HGAS.

Aortic Valve Calcium Score: Applications in Clinical Practice and Scientific Research-A Narrative Review

In this narrative review, we investigate the essential role played by the computed tomography Aortic Valve Calcium Score (AVCS) in the cardiovascular diagnostic landscape, with a special focus on its implications for clinical practice and scientific research. Calcific aortic valve stenosis is the most prevalent type of aortic stenosis (AS) in industrialized countries, and due to the aging population, its prevalence is increasing. While transthoracic echocardiography (TTE) remains the gold standard, AVCS stands out as an essential complementary tool in evaluating patients with AS. The advantage of AVCS is its independence from flow; this allows for a more precise evaluation of patients with discordant findings in TTE. Further clinical applications of AVCS include in the assessment of patients before transcatheter aortic valve replacement (TAVR), as it helps in predicting outcomes and provides prognostic information post-TAVR. Additionally, we describe different AVCS thresholds regarding gender and the anatomical variations of the aortic valve. Finally, we discuss various scientific studies where AVCS was applied. As AVCS has some limitations, due to the pathophysiologies of AS extending beyond calcification and gender differences, scientists strive to validate contrast-enhanced AVCS. Furthermore, research on developing radiation-free methods of measuring calcium content is ongoing.

Aortic Valve Calcium Score by Computed Tomography as an Adjunct to Echocardiographic Assessment-A Review of Clinical Utility and Applications

Aortic valve stenosis (AS) is increasing in prevalence due to the aging population, and severe AS is associated with significant morbidity and mortality. Echocardiography remains the mainstay for the initial detection and diagnosis of AS, as well as for grading of severity. However, there are important subgroups of patients, for example, patients with low-flow low-gradient or paradoxical low-gradient AS, where quantification of severity of AS is challenging by echocardiography and underestimation of severity may delay appropriate management and impart a worse prognosis. Aortic valve calcium score by computed tomography has emerged as a useful clinical diagnostic test that is complimentary to echocardiography, particularly in cases where there may be conflicting data or clinical uncertainty about the degree of AS. In these situations, aortic valve calcium scoring may help re-stratify grading of severity and, therefore, further direct clinical management. This review presents the evolution of aortic valve calcium score by computed tomography, its diagnostic and prognostic value, as well as its utility in clinical care.

Calcium Scoring to Classify Aortic Valve Stenosis Severity: What Is the Current Data?

PURPOSE OF REVIEW

This review explores current clinical value of aortic valve calcification (AVC) in classifying aortic valve stenosis (AS) severity, refining patient's follow-up, as well as novel and potential applications of this highly accurate marker in improving outcomes for AS patients. AVC limitations and important particularities regarding sex, valve phenotype, and ethnicity will also be addressed.

RECENT FINDINGS

Sex-specific AVC cut-offs have been included in current guidelines to identify severe AS when echocardiography is inconclusive. AVC is also associated with AS progression and could help refine the timing for patient's follow-up. In patients with AS, Doppler echocardiography is the gold standard for the assessment of AS severity. However, in more than one-third of patients, echocardiographic parameters are discordant, casting shadow on the true severity of the disease. Considering active leaflet calcification is the driving mechanism of AS, quantification of AVC has been shown to be of great interest for distinguishing true-severe from pseudo-severe AS. Moreover, AVC is closely associated with AS progression and outcomes.