ATTR Cardiomyopathy: ‘Red Flags’ for Screening

Certain “red flags” should prompt screening for transthyretin amyloid cardiomyopathy (ATTR-CM), according to consensus recommendations.

Increased wall thickness with either heart failure or “red flag” signs and symptoms in men over age 65 years and women over 70 warrant screening, Pablo Garcia-Pavia, MD, PhD, of the Hospital Universitario Puerta de Hierro in Madrid, and colleagues wrote in JACC: Heart Failure.

Those red flags that should further heighten suspicion were:

• Reduced longitudinal strain with apical sparing

• Left ventricular hypertrophy on imaging but normal, low-normal, or low voltages on electrocardiography

• Atrioventricular block when there’s increased left ventricular wall thickness

• Infiltrative features on ECG, such as thicker atrioventricular valves, interatrial septum, and right ventricular free wall

• On cardiac MRI, marked extracellular volume expansion, abnormal nulling time, or diffuse late gadolinium enhancement

• Polyneuropathy, dysautonomia (orthostatic hypotension, diarrhea/constipation, and erectile dysfunction), or both

• Persistent mildly elevated troponin levels

“Early accurate diagnosis is … key to improving patient outcomes, particularly in the context of the positive phase 3 trial of tafamidis for the treatment of ATTR-CM and other promising therapies under development,” Garcia-Pavia’s group noted.

“With the availability of scintigraphy as an inexpensive, non-invasive diagnostic tool, the rationale to screen for ATTR-CM in high risk populations of patients is increasingly warranted,” the team added.

FDA approved tafamidis meglumine (Vyndaqel) and tafamidis (Vyndamax) in May for the treatment of wild-type or hereditary ATTR cardiomyopathy, the first agents to get the greenlight for this rare disease.

The number of patients identified with the condition “will undoubtedly rise” now that there is “a convenient and relatively inexpensive imaging modality, bone scintigraphy, having strong evidence as an accurate, non-invasive approach to diagnosing ATTR-CM,” the group wrote.

Sorting out diagnosis is important, because treating for conditions it is frequently misdiagnosed as, such as congestive heart failure, with beta-blockers, ACE inhibitors, or angiotensin II receptor antagonists is not only ineffective but often leads to clinical worsening.