Only one of the four studies entered into the meta-analysis involved prospective data collection, but three of the four found a significant advantage for preprocedural CTA when compared with no CTA for procedural success, meaning restoration of blood flow in the target CTO. The fourth study also associated preprocedural CTA with improved procedural success, but the advantage did not reach statistical significance.
When the data were combined for a meta-analysis, the odds ratio for procedural success for conducting a preprocedural CTA relative to no preprocedural CTA was 1.89 with a significant 95% confidence interval (1.18-3.04; P less than .05).
The four studies were published during 2012-2015. Two of them used CTA with only a 64-slice capacity, raising the possibility that an even greater improvement in results would have been achieved with CTA using the greater resolutions now available.
There were several important limitations of the study, particularly the potential for selection bias from the nonrandomized designs in the studies evaluated, Dr. Abuzeid acknowledged. However, the most likely selection bias would be funneling of more challenging cases to preprocedural CTA, a potential disadvantage for CTA if this resulted in a patient population likely to have a poor outcome.
Currently, few centers employ preprocedural CTA in routine management of CTO, according to Dr. Abuzeid.