Letter by Poullis Regarding Article, “Associations Between Adding a Radial Artery Graft to Single and Bilateral Internal Thoracic Artery Grafts and Outcomes: Insights From the Arterial Revascularization Trial”

Taggart et al 1 need to be congratulated on their post hoc analysis of their ART (Arterial Revascularization Trial) data.However, their work raises a number of questions.This study involved the nonrandomized use of the radial artery and, unsurprisingly, has demonstrated its superiority, in common with other nonrandomized publications. 2Nonrandomized trials usually involve patient selection as a major source of bias, hence the need for randomized trials.However, the largest randomized studies with regard to radial artery outcomes, performed by Hayward et al, 3 failed to identify any significant difference.ART was initially powered to investigate whether a survival difference between single and bilateral mammary artery use existed at 10 years, 4 drawing the power of the present analysis by Taggart et al into question.Of note, no power calculation was included in the article.The use of composite end points has been criticized widely from statistical, patient, and researcher points of view. 5The finding of no significant difference between myocardial infarction, cardiovascular death, and repeat revascularization when analyzed separately needs to be noted.By way of example, reanalysis of the data provided in Table 3 after matching with regard to death (1.4% versus 0.8%), return to operating room (4.3% versus 3%), renal replacement therapy (7.1% versus 5.7%), and sternal wounds (4% versus 3%) indicates that radial artery use is associated with a significantly worse outcome compared with saphenous vein graft only (16.8% versus 12.5%; P=0.03).Multiple imputation was used to address missing data.However, no mention was made of how much data were missing for this technique being used, potentially introducing a source of error.Taggart et al have to be congratulated in performing the ART trial; however, post hoc underpowered interpretation needs to be cautioned against.