The Relative Apical Sparing Strain Pattern in Severe Aortic Valve Stenosis: A Marker of Adverse Cardiac Remodeling

BACKGROUND

The presence of a relative apical sparing (RAS) echocardiographic strain pattern raises a suspicion of underlying cardiac amyloidosis (CA). However, it is also increasingly observed in patients with aortic stenosis (AS). We aimed to evaluate the prevalence, dynamics, and clinical characteristics of the RAS strain pattern in severe AS patients who had been referred for surgical aortic valve replacement (SAVR).

METHODS

A total of 77 patients with severe AS and without CA were included with a mean age of 70 (62-73) years, 58% female, a mean aortic valve area index of 0.45 ± 0.1 cm2/m2, and a mean gradient of 54.9 (45-70) mmHg.

RESULTS

An RAS strain pattern was detected in 14 (18%) patients. RAS-positive patients had a significantly higher LV mass index (125 ± 28 g/m2 vs. 91 ± 32, p = 0.001), a lower LV ejection fraction (62 ± 12 vs. 68 ± 13, p = 0.040), and lower global longitudinal strain (-14.9 ± 3 vs. -18.7 ± 5%, p = 0.002). RAS strain pattern-positive patients also had higher B-type natriuretic peptide (409 (161-961) vs. 119 (66-245) pg/L, p = 0.032) and high-sensitivity troponin I (15 (13-29) vs. 9 (5-18) pg/L, p = 0.026) levels. Detection of an RAS strain pattern was strongly associated with increased LV mass index (OR 1.03, 95% CI 1.01-1.06, p < 0.001). The RAS strain pattern had resolved in all patients by 3 months after SAVR.

CONCLUSIONS

Our findings suggest that the RAS strain pattern can be present in patients with severe AS without evidence of CA. The presence of an RAS strain pattern is associated with adverse LV remodeling, and it resolves after SAVR.

Cardiac amyloidosis and aortic stenosis: a state-of-the-art review

Cardiac amyloidosis is caused by the extracellular deposition of amyloid fibrils in the heart, involving not only the myocardium but also any cardiovascular structure. Indeed, this progressive infiltrative disease also involves the cardiac valves and, specifically, shows a high prevalence with aortic stenosis. Misfolded protein infiltration in the aortic valve leads to tissue damage resulting in the onset or worsening of valve stenosis. Transthyretin cardiac amyloidosis and aortic stenosis coexist in patients > 65 years in about 4-16% of cases, especially in those undergoing transcatheter aortic valve replacement. Diagnostic workup for cardiac amyloidosis in patients with aortic stenosis is based on a multi-parametric approach considering clinical assessment, electrocardiogram, haematologic tests, basic and advanced echocardiography, cardiac magnetic resonance, and technetium labelled cardiac scintigraphy like technetium-99 m (99mTc)-pyrophosphate, 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid, and 99mTc-hydroxymethylene diphosphonate. However, a biopsy is the traditional gold standard for diagnosis. The prognosis of patients with coexisting cardiac amyloidosis and aortic stenosis is still under evaluation. The combination of these two pathologies worsens the prognosis. Regarding treatment, mortality is reduced in patients with cardiac amyloidosis and severe aortic stenosis after undergoing transcatheter aortic valve replacement. Further studies are needed to confirm these findings and to understand whether the diagnosis of cardiac amyloidosis could affect therapeutic strategies. The aim of this review is to critically expose the current state-of-art regarding the association of cardiac amyloidosis with aortic stenosis, from pathophysiology to treatment.

Echocardiographic predictors of presence of cardiac amyloidosis in aortic stenosis

AIMS

Aortic stenosis (AS) and cardiac amyloidosis (CA) frequently coexist but the diagnosis of CA in AS patients remains a diagnostic challenge. We aim to evaluate the echocardiographic parameters that may aid in the detection of the presence of CA in AS patients.

METHOD AND RESULTS

We performed a systematic literature search of electronic databases for peer-reviewed articles from inception until 10 January 2022. Of the 1449 patients included, 160 patients had both AS-CA whereas the remaining 1289 patients had AS-only. The result of our meta-analyses showed that interventricular septal thickness [standardized mean difference (SMD): 0.74, 95% CI: 0.36-1.12, P = 0.0001), relative wall thickness (SMD: 0.74, 95% CI: 0.17-1.30, P < 0.0001), posterior wall thickness (SMD: 0.74, 95% CI 0.51 to 0.97, P = 0.0011), LV mass index (SMD: 1.62, 95% CI: 0.63-2.62, P = 0.0014), E/A ratio (SMD: 4.18, 95% CI: 1.91-6.46, P = 0.0003), and LA dimension (SMD: 0.73, 95% CI: 0.43-1.02, P < 0.0001)] were found to be significantly higher in patients with AS-CA as compared with AS-only patients. In contrast, myocardial contraction fraction (SMD: -2.88, 95% CI: -5.70 to -0.06, P = 0.045), average mitral annular S' (SMD: -1.14, 95% CI: -1.86 to -0.43, P = 0.0017), tricuspid annular plane systolic excursion (SMD: -0.36, 95% CI: -0.62 to -0.09, P = 0.0081), and tricuspid annular S' (SMD: -0.77, 95% CI: -1.13 to -0.42, P < 0.0001) were found to be significantly lower in AS-CA patients.

CONCLUSION

Parameters based on echocardiography showed great promise in detecting CA in patients with AS. Further studies should explore the optimal cut-offs for these echocardiographic variables for better diagnostic accuracy.