Utilization rates and determinants of PYP and CMR among patients with unexplained left ventricular hypertrophy on echocardiography.

Background: Cardiac amyloidosis (CA) is an underdiagnosed cause of heart failure with a poor prognosis if left untreated. Echocardiography provides an excellent screening tool, but it is unknown how frequently patients with features consistent with CA undergo further testing.

Methods: The study aims to investigate the rates of cardiac MRI (CMR) and PYP scan utilization and identify the clinical and echocardiographic factors associated with their use. We performed a retrospective cohort study from December 2018 to September 2020. Patients age ≥ 18 years with echocardiographic features consistent with CA were included (moderate or greater concentric left ventricular hypertrophy plus moderate or severe diastolic dysfunction). We estimated multiple logistic regression models to identify factors associated with subsequent testing with CMR or PYP.

Results: Of 1015 patients, 83 patients (8.2 %) underwent further testing. On multivariable analysis, factors associated with further testing include age 65+ years (aOR: 2.27; 95 % CI: 1.31-3.96; p = 0.004), Black race (aOR: 1.76; 95 % CI: 1.04-2.99; p = 0.036), diagnosis of HFrEF (aOR: 2.08; 95 % CI: 1.04-4.17; p = 0.040), severe diastolic dysfunction (aOR: 2.14; 95 % CI: 1.24-3.67; p = 0.006), severe wall thickness (aOR: 2.66; 95 % CI: 1.52-4.66; p = 0.001), and echocardiogram ordered by a cardiologist (aOR: 1.95; 95 % CI: 1.19-3.20; p = 0.009).

Conclusion: Among patients with echocardiographic features consistent with CA, follow-up testing remains low. Features consistent with advanced disease were associated with follow-up testing for CA, suggesting the need to implement strategies to better identify patients earlier in the disease process.