A patient with a positive result on the old-school thumb–palm test is highly likely to have an ascending aortic aneurysm, US researchers have confirmed.

A team from Yale University, in Connecticut, has become the first to verify the utility of the test in a clinical setting.

For the past two decades, cardiothoracic surgeon Professor John Elefteriades and colleagues have used the test on their own patients and taught it to medical students.

A positive result — when the patient’s thumb extends beyond the width of their flat palm — supposedly suggests connective-tissue disease and a risk of aneurysm, but its accuracy has never been formally assessed.