Evaluation of echocardiographic features and cardiac biomarkers in patients with AA amyloidosis: a retrospective comparative study with patients with al amyloidosis and hypertrophic cardiomyopathy.

Interventricular septum diameter (IVSd) differed significantly across all three groups, with AA amyloidosis patients having the least wall thickening.

• Mean IVSd was 11.8 ± 2.3 mm in AA-A, 14.6 ± 3.7 mm in AL-A, and 17.4 ± 4.3 mm in HCM
• p < 0.001 for each pairwise comparison
• Study included 139 AA-A patients, 89 AL-A patients, and 54 HCM patients
• All groups were predominantly male (56%, 52%, and 57.4% respectively)

Posterior wall diameter (PWd) was significantly different between AA-A and the other two groups, but not between AL-A and HCM.

• Mean PWd was 10.5 ± 1.7 mm in AA-A, 12.9 ± 2.8 mm in AL-A, and 12 ± 1.6 mm in HCM
• p < 0.001 for AA-A vs. AL-A and AA-A vs. HCM comparisons
• p = 0.056 for the AL-A vs. HCM comparison, which was not statistically significant

Fulfillment of the Gertz et al. cardiac amyloidosis criteria was substantially lower in AA amyloidosis than in AL amyloidosis, and absent in HCM.

• 34.5% of AA-A patients fulfilled the Gertz et al. criteria for suspected cardiac amyloidosis
• 68.5% of AL-A patients fulfilled the Gertz et al. criteria
• 0% of HCM patients fulfilled the Gertz et al. criteria
• p < 0.001 for each pairwise comparison

A combined criterion of PWd > 12.5 mm plus troponin > 13.15 pg/mL plus serum creatinine > 1.085 mg/dL was met by a small proportion of AA-A patients but more commonly in AL-A patients.

• 4.3% of AA-A patients met this combined criterion
• 27.3% of AL-A patients met this combined criterion
• 2% of HCM patients met this combined criterion
• This criterion incorporated both echocardiographic and biomarker thresholds alongside a renal function marker

In multivariate analysis, posterior wall diameter and left ventricular diastolic dysfunction were independently associated with suspected cardiac amyloidosis according to the Gertz et al. criteria in AA amyloidosis patients.

• Analysis was performed within the AA-A patient group (n = 139)
• PWd and LV diastolic dysfunction were the key echocardiographic predictors identified
• The analysis was multivariate, controlling for other potential confounders

Higher posterior wall diameter and reduced ejection fraction were independently associated with increased mortality in AA amyloidosis patients on Cox regression analysis.

• Cox regression analysis was performed within the AA-A group
• Both PWd and reduced EF emerged as significant predictors of mortality
• These findings suggest echocardiographic parameters have prognostic value in AA-A

Survival was lower in AA amyloidosis patients who met various cardiac involvement criteria or had specific echocardiographic abnormalities.

• Lower survival was observed in patients meeting the Gertz et al. criteria
• Lower survival was also seen in those meeting Gertz et al. plus granular echogenicity criteria
• Lower survival was found in those meeting the PWd > 12.5 mm plus troponin > 13.15 pg/mL plus Screa > 1.085 mg/dL criterion
• Patients with increased PWd, reduced ejection fraction, advanced diastolic dysfunction, and granular echogenicity also showed lower survival

Troponin and pro-BNP cut-off values were identified by ROC analysis as predictors of higher mortality in AA amyloidosis patients.

• Troponin > 24.5 pg/mL had 100% sensitivity and 66.1% specificity for predicting higher mortality
• Pro-BNP > 636.5 pg/mL had 94.4% sensitivity and 53.7% specificity for predicting higher mortality
• Both biomarker thresholds were derived from ROC analysis within the AA-A patient cohort

The study was a retrospective observational study conducted at a single referral center for amyloidosis in Istanbul, Türkiye, without histopathological or MRI confirmation of cardiac amyloidosis.

• Retrospective design limits causal inference
• No cardiac biopsy or cardiac MRI was used to confirm cardiac amyloidosis in the AA-A group
• Authors call for prospective studies with histopathological and/or MRI confirmation to better define cardiac involvement in AA-A
• The study population consisted of patients from a referral center, which may affect generalizability