Impact of a Checklist-Based Strategy for Cardiac Amyloidosis Screening on Diagnosis Rates in Heart Failure Patients (CHECKAMIC Study).

Background: Transthyretin-associated cardiac amyloidosis (ATTR-CM) is an underdiagnosed cause of heart failure (HF), particularly in elderly patients. Delayed diagnosis limits access to emerging disease-modifying therapies. We aimed to evaluate the impact of implementing a checklist-based screening strategy for ATTR-CM in specialized HF units.

Methods: We conducted a prospective, multicenter, observational study in three Spanish tertiary hospitals, enrolling patients ≥65 years old with HF and a positive checklist based on ESC red-flag criteria. All underwent a structured diagnostic workup for ATTR-CM. A retrospective control cohort from the same centers was used for comparison. The primary outcome was ATTR-CM diagnosis rate. Secondary analyses included identification of independent predictors of ATTR-CM and clinical outcomes at 6 months.

Results: Of 102 patients in the prospective cohort, 22 (21.6 %) were diagnosed with ATTR-CM, compared to only 2 of 110 patients (1.8 %) in the retrospective cohort (p < 0.001). The strongest independent predictor of ATTR-CM was a low QRS-to-mass ratio (OR 41.02; 95 % CI: 1.92-875.25; p = 0.017), followed by increased septal thickness, older age, higher left ventricular mass index, and lower body mass index. At 6-month follow-up, clinical outcomes were similar between patients with and without ATTR-CM.

Conclusions: In this prospective multicenter study of elderly HF patients, implementing a diagnostic checklist increased ATTR-CM detection tenfold compared to historical controls. A low QRS-to-mass ratio emerged as the strongest independent predictor. Checklist-based screening is a feasible strategy to improve early diagnosis of this underrecognized condition.