May 17, 2011
By Todd Neale, Staff Writer
AMSTERDAM — Using CT coronary angiography early in the diagnostic process for patients with stable chest pain can reduce costs, without adversely affecting clinical outcomes, a randomized trial showed.
Considering the costs of all of the diagnostic tests used in the study, the total cost per patient was lower in the CT angiography arm than in the arm that used standard diagnostic testing ($729 versus $904, P<0.001), according to Ajay Yerramasu, MBBS, of Wellington Hospital in London.
Although follow-up was ongoing and final calculations were not yet available, initial data show that rates of revascularization and major adverse cardiovascular events are similar in the two groups, he reported at the International Conference on Non-Invasive Cardiovascular Imaging here.
Yerramasu told MedPage Today that he thinks this study will be one of many exploring the cost-effectiveness of CT coronary angiography in patients with stable angina.
“Hopefully it will convince the physician community as well as the insurers to incorporate CT in the diagnosis of these patients,” he said. “It will help to simplify the diagnostic process. Also, it will reduce the total number of costs because CT yields a definitive diagnosis more often than other tests, and I’m sure that’s in the interest of patients as well as the insurers.”
The trial, dubbed RADICAL, is being conducted in London at four hospitals that have Rapid Access Chest Pain Clinics, which are designed to get all patients with stable chest pain evaluated within two weeks.
In these clinics, initial assessment usually consists of a clinical history, a physical examination, an electrocardiogram, and an exercise treadmill test for those who can perform it.
Patients who required further testing after this initial work-up were eligible for the trial, which recruited 597 patients — 302 in the study arm and 295 in the control arm.
In the control group, patients underwent further testing according to existing hospital protocols, which included stress echocardiography, myocardial perfusion imaging by SPECT, or conventional coronary angiography.
Patients in the study arm first underwent a coronary calcium scan. Those with a score of 1,000 Agatston units or higher went immediately to conventional coronary angiography. Those with a lower score underwent CT coronary angiography, the results of which guided future treatment.
If patients had less than 50% stenosis on the scan, they were discharged. Those with 50% to 70% stenosis underwent functional imaging. Abnormal results on functional imaging resulted in conventional coronary angiography, and normal results led to discharge. Patients with more severe stenosis went right to conventional angiography.
The patients were generally well-matched in the two groups, with a mean age of 61 and a median pretest probability of coronary artery disease of 51%. Dyslipidemia was more common in the study arm (72% versus 62%, P=0.014).
There were 15 patients in the study arm who were sent to conventional coronary angiography following the calcium scan and did not undergo CT angiography.
In the rest of the patients, CT angiography revealed that 38% had no stenosis, 30% had nonobstructive coronary artery disease, and 32% had obstructive disease. Patients in the first two groups were discharged.
Aside from CT angiography, functional testing and conventional coronary angiography were performed in a greater number of patients in the control arm — there were 118 coronary angiograms in the controls versus 71 in the CT patients.
Considering the costs of all testing, the total cost was lower in the CT angiography arm ($220,000 versus $252,000).
The radiation burden was comparable in the two study arms, at 7.1 mSv in the study arm (6.2 from CT and 0.9 from the calcium scan) and 6.8 in the control arm.
Primary source: International Conference on Non-Invasive Cardiovascular Imaging
Yerramasu A, Patel D “Randomized controlled trial to evaluate the cost and clinical effectiveness of CT coronary angiography in patients with stable angina pectoris (RADICAL trial)” ICNC 2011; Abstract 198.