This is an interesting systematic review of coronary computer tomography angiography that, I think, shows mostly that the endpoints for cardiology studies need to be re-evaluated. The conclusion that circulates in the new has been that positive CCTA was highly predictive of coronary events – patients with >1 segment of >50% stenosis on CCTA had an 11.9% annualized rate of coronary “events” when compared to the 1.1% annualized rate of patients without any >50% stenosis. This generates the 10.74 hazard ratio that has been circulating through the press releases trumpeting the predictive value of CCTA.
Unfortunately, this predictive value is a self-fulfilling prophecy because 62% of their “events” were revascularizations. If you subtract out the portion that went for revascularization, the remaining all-cause mortality, cardiovascular death, nonfatal MI, UA requiring hospitalization, that’s 5% annualized rate. Still higher than folks without any coronary stenoses at all, but you have to wonder – could we have predicted the population with a 5% cardiovascular morbidity risk without a CCTA? Does the management decision to perform revascularization confer upon this population a cardiovascular morbidity/mortality benefit? We are seeing a lot more in the literature showing that medical management is as advantageous as stenting, so, again, I’m not sure what the role of CCTA is – particularly from the Emergency Department.
“Meta-analysis and systematic review of the long-term predictive value of assessment of coronary atherosclerosis by contrast-enhanced coronary computed tomography angiography.”
http://www.ncbi.nlm.nih.gov/pubmed/21658564