Incremental Value of Aortomitral Continuity Calcification for Risk Assessment after Transcatheter Aortic Valve Replacement

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.

CTA pulmonary artery enlargement in patients with severe aortic stenosis: Prognostic impact after TAVR

BACKGROUND

Identifying high-risk patients who will not derive substantial survival benefit from TAVR remains challenging. Pulmonary hypertension is a known predictor of poor outcome in patients undergoing TAVR and correlates strongly with pulmonary artery (PA) enlargement on CTA. We sought to evaluate whether PA enlargement, measured on pre-procedural computed tomography angiography (CTA), is associated with 1-year mortality in patients undergoing TAVR.

METHODS

We retrospectively included 402 patients undergoing TAVR between July 2012 and March 2016. Clinical parameters, including Society of Thoracic Surgeons (STS) score and right ventricular systolic pressure (RVSP) estimated by transthoracic echocardiography were reviewed. PA dimensions were measured on pre-procedural CTAs. Association between PA enlargement and 1-year mortality was analyzed. Kaplan-Meier and Cox proportional hazards regression analyses were performed.

RESULTS

The median follow-up time was 433 (interquartiles 339-797) days. A total of 56/402 (14%) patients died within 1 year after TAVR. Main PA area (area-MPA) was independently associated with 1-year mortality (hazard ratio per standard deviation equal to 2.04 [95%-confidence interval (CI) 1.48-2.76], p ​< ​0.001). Area under the curve (95%-CI) of the clinical multivariable model including STS-score and RVSP increased slightly from 0.67 (0.59-0.75) to 0.72 (0.72-0.89), p ​= ​0.346 by adding area-MPA. Although the AUC increased, differences were not significant (p ​= ​0.346). Kaplan-Meier analysis showed that mortality was significantly higher in patients with a pre-procedural non-indexed area-MPA of ≥7.40 ​cm² compared to patients with a smaller area-MPA (mortality 23% vs. 9%; p ​< ​0.001).

CONCLUSIONS

Enlargement of MPA on pre-procedural CTA is independently associated with 1-year mortality after TAVR.

Incremental Prognostic Value of Coronary Artery Calcium Score for Predicting All-Cause Mortality after Transcatheter Aortic Valve Replacement

Background Current risk models show limited performances for predicting all-cause mortality after transcatheter aortic valve replacement (TAVR). Purpose To determine the prognostic value of coronary artery calcium (CAC) scoring for predicting 30-day and 1-year mortality in patients undergoing TAVR. Materials and Methods In this single-center institutional review board-approved secondary analysis of prospectively collected data (SwissTAVI Registry), the authors evaluated participants who, before TAVR, underwent CT that included a nonenhanced electrocardiography-gated cardiac scan between May 2008 and September 2019 and who had not undergone previous coronary revascularization. Clinical data, including the European System for Cardiac Operative Risk Evaluation (EuroSCORE II), were recorded. The CAC score was determined, and 30-day and 1-year all-cause mortality were assessed by using Cox regression analyses. Results In total, 309 participants (mean age ± standard deviation, 81 years ± 7; 175 women) were included, with a median CAC score of 334 (interquartile range, 104-987). Seventy-seven of the 309 participants (25%) had a CAC score greater than or equal to 1000. A CAC score of 1000 or greater served as an independent predictor of 30-day (hazard ratio [HR], 4.5 [95% CI: 1.5, 13.6] compared with a CAC score <1000; P = .007) and 1-year (HR, 4.3 [95% CI: 1.5, 12.7] compared with a CAC score of 0-99; P = .008) mortality after TAVR. Similar trends were observed for each point increase of the EuroSCORE II as an independent predictor of 30-day (HR, 1.22 [95% CI: 1.10, 1.36]; P < .001) and 1-year (HR, 1.16 [95% CI: 1.08, 1.25]; P < .001) mortality. Adding the CAC score to the EuroSCORE II provided incremental prognostic value for 1-year mortality after TAVR over the EuroSCORE II alone (concordance index, 0.76 vs 0.69; P = .04). Conclusion In participants without prior coronary revascularization, the coronary artery calcium score represented an independent predictor of 30-day and 1-year mortality after transcatheter aortic valve replacement. ClinicalTrials.gov identifier, NCT01368250 © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Almeida in this issue.