The risks of inappropriateness in cardiac imaging

Abstract

The immense clinical and scientific benefits of cardiovascular imaging are well-established, but are also true that 30 to 50% of all examinations are partially or totally inappropriate. Marketing messages, high patient demand and defensive medicine, lead to the vicious circle of the so-called Ulysses syndrome. Mr. Ulysses, a typical middle-aged "worried-well" asymptomatic subject with an A-type coronary personality, a heavy (opium) smoker, leading a stressful life, would be advised to have a cardiological check-up after 10 years of war. After a long journey across imaging laboratories, he will have stress echo, myocardial perfusion scintigraphy, PET-CT, 64-slice CT, and adenosine-MRI performed, with a cumulative cost of >100 times a simple exercise-electrocardiography test and a cumulative radiation dose of >4,000 chest x-rays, with a cancer risk of 1 in 100. Ulysses is tired of useless examinations, exorbitant costs. unaffordable even by the richest society, and unacceptable risks.

Keywords: appropriateness; benefit; radiation; risk.

Figure 1.

The balance between risks (red triangle) and benefits (green circles) determining the appropriateness score of testing. The three corners of the red triangle represent acute, subacute, and long-term (radiation) risks. Acute risks occur within seconds and minutes (for instance, death or myocardial infarction during stress or cath); sub-acute risks within days or weeks (for instance, contrast-induced nephropathy); and long-term risks (due to cumulative exposure to ionizing radiation) after years or decades.

Figure 2.

Ulysses’ voyage as a metaphor for the diagnostic pathway of the patient with suspected coronary artery disease. At the end of the first round of this odyssey, the cumulative cost is more than 100 times a simple exercise-electrocardiography. The cumulative radiation dose is that of more than 4,000 chest x-rays. The cumulative damage (including acute, subacute, and long-term risks) will cause a serious health detriment (including infarction, renal insufficiency, or cancer) in about 5–10% of patients.

Figure 3.

On the x axis, the doses of 4 common imaging examination are shown: coronary angiography (250 chest x-rays); myocardial perfusion scintigraphy (500 chest x-rays); 64-slice CT (750 chest x-rays); whole body CT- PET scan (1,250 chest x-rays). On y-axis risk for children (male and female), adults (men and women) and the elderly. Redrawn and modified from ref. [35].

Figure 4.

Inappropriateness in stress echocardiography (left) and cardiac stress imaging (right). Data are derived from [5] (Pisa and Brisbane echo labs in Italy and Australia) and [6] (Mayo Clinic nuclear cardiology lab in the USA).

Figure 5.

Future trends in the use of cardiac imaging up to the year 2020. Redrawn from the original data of reference [35].