ATTR Cardiomyopathy is Associated with Poor Functional Class and More Severe Clinical Course Compared with Heart Failure Patients Negative for ATTR by Tc-PYP Scan

Introduction: Cardiac transthyretin (ATTR) amyloidosis is an increasingly recognized cause of heart failure (HF) in majority cases presented as restrictive cardiomyopathy. As we described previously a sizably proportion of patients with ATTR in our series had reduced LVEF. There is paucity of data on clinical course of patients with cardiac ATTR.

Aim: To describe the clinical course of ATTR cardiomyopathy and evaluate association between presence of ATTR and functional status as well as incidence of HF exacerbation.

Methods: Patients referred to our Heart Failure clinic were included in this study. All patients underwent echocardiography and planar and SPECT Tc-PYP Scan. Positivity of Tc-PYP Scan was defined according to Perugini score (score 0 and 1 considered negative, score 2 and 3 considered positive). Data regarding functional status (NYHA class), comorbidities and need for IV therapy for HF exacerbation 3 years prior to diagnosis and 1 year following the recruitment were collected.

Results: From April 2017 to October 2018, 84 patients (male 61%, age 68.9±10.9) were included. Overall, 45 patients (53.6%) had positive Tc-PYP Scan and 39 (46.4%) patients had negative scan. Patients with ATTR were more symptomatic (NYHA FC 3-4) compared with those negative for ATTR (57.8% vs 23.1%, p=0.005). A significant larger proportion of patients with ATTR required IV treatment (HF exacerbation) compared to those without ATTR during 3 years prior to recruitment (20 (44.4%) vs 7 (17.9%), p=0.01). In addition, during 1 year follow-up a larger number of HF exacerbation events were observed among patients positive for ATTR (12 (26.7%) vs 2 (5.1%), p=0.008). This general trend was seen among both groups of patients, those with preserved and reduced LVEF.

Conclusion: Our study demonstrated that patients with HF and ATTR based on Tc-PYP Scan are more symptomatic and have more severe clinical course of HF represented by higher incidence of HF exacerbation prior to diagnosis and at 1 year follow-up.