Coming of age: coronary computed tomography angiography

Cost-effectiveness of computed tomography coronary angiography versus conventional invasive coronary angiography

OBJECTIVES

To determine the costs and cost-effectiveness of a diagnostic strategy including computed tomography coronary angiography (CTCA) in comparison with invasive conventional coronary angiography (CA) for the detection of significant coronary artery disease from the point of view of the healthcare provider.

METHODS

The average cost per CTCA was determined via a micro-costing method in four French hospitals, and the cost of CA was taken from the 2011 French National Cost Study that collects data at the patient level from a sample of 51 public or not-for-profit hospitals.

RESULTS

The average cost of CTCA was estimated to be 180<euro> (95 % CI 162-206<euro>) based on the use of a 64-slice CT scanner active for 10 h per day. The average cost of CA was estimated to be 1,378<euro> (95 % CI 1,126-1,670<euro>). The incremental cost-effectiveness ratio of CA for all patients over a strategy including CTCA triage in the intermediate risk group, no imaging test in the low risk group, and CA in the high risk group, was estimated to be 6,380<euro> (95 % CI 4,714-8,965<euro>) for each additional correctly classified patient. This strategy correctly classifies 95.3 % (95 % CI 94.4-96.2) of all patients in the population studied.

CONCLUSIONS

A strategy of CTCA triage in the intermediate-risk group, no imaging test in the low-risk group, and CA in the high-risk group, has good diagnostic accuracy and could significantly cut costs. Medium-term and long-term outcomes need to be evaluated in patients with coronary stenosis potentially misclassified by CTCA due to false negative examinations.

Indications, imaging technique, and reading of cardiac computed tomography: survey of clinical practice

OBJECTIVES

To obtain an overview of the current clinical practice of cardiac computed tomography (CT).

METHODS

A 32-item questionnaire was mailed to a total of 750 providers of cardiac CT in 57 countries.

RESULTS

A total of 169 questionnaires from 38 countries were available for analysis (23%). Most CT systems used (94%, 207/221) were of the latest generation (64-row or dual-source CT). The most common indications for cardiac CT was exclusion of coronary artery disease (97%, 164/169). Most centres used beta blockade (91%, 151/166) and sublingual nitroglycerine (80%, 134/168). A median slice thickness of 0.625 mm with a 0.5-mm increment and an 18-cm reconstruction field of view was used. Interpretation was most often done using source images in orthogonal planes (92%, 155/169). Ninety percent of sites routinely evaluate extracardiac structures on a large (70%) or cardiac field of view (20%). Radiology sites were significantly more interested in jointly performing cardiac CT together with cardiology than cardiologists. The mean examination time was 18.6 ± 8.4 min, and reading took on average 28.7 ± 17.8 min.

CONCLUSIONS

Cardiac CT has rapidly become established in clinical practice, and there is emerging consensus regarding indications, conduct of the acquisition, and reading.