Benefits Assessed of CT Scan Before Invasive Coronary Angiography in Patients with Previous CABG

September 19, 2022—Results from the BYPASS CTCA trial showed that CT cardiac angiography (CTCA) before invasive coronary angiography (ICA) in patients who have previously undergone coronary artery bypass grafting (CABG) can reduce procedural duration and postprocedural kidney injury, as well as improve patient satisfaction.

BYPASS CTCA is a prospective, single-center, randomized controlled trial that enrolled 688 patients with previous CABG requiring ICA for standard indications. The study patients were randomized to receive CTCA before ICA or ICA alone at St Bartholomew’s Hospital in London, United Kingdom.

The findings were presented at TCT 2022, the 34th annual Transcatheter Cardiovascular Therapeutics scientific symposium of the Cardiovascular Research Foundation held September 16-19 in Boston, Massachusetts.

As noted in the TCT press release, studies have shown that one in five patients with ischemic heart disease who have undergone CABG will need coronary evaluation by means of ICA within 3 years.

Although ICA is effective, there are several risks associated with the procedure, and the risk of complications is increased in patients with previous CABG. Catheter manipulation to engage the grafts is associated with an increased risk of embolic stroke or dissection, as graft engagement is technically more difficult than native vessels since the location of the bypass ostia are often variable.

The study’s primary endpoints were ICA procedural duration, incidence of contrast-induced nephropathy (CIN), and patient satisfaction scores post-ICA.

The TCT press release reported that all three of the primary endpoints saw improvement with the use of CTCA:

• Procedural duration was 17.38 minutes for CTCA versus 39.50 without CTCA, a 66% relative reduction (P < .001).
• The amount of acute CIN caused by the ICA procedure was 3.4% with CTCA versus 27.9% without CTCA, a 92% relative risk reduction (P < .0001).
• Patient satisfaction scores on a scale from 1(very good) to 5 (very poor) after ICA were 1.49 with CTCA versus 2.54 without CTCA, a 40% relative improvement (P < .001)

The secondary endpoints included procedure metrics, procedural complications, and major adverse cardiovascular events (all-cause mortality, myocardial infarction, unscheduled revascularization) over 12 months. CTCA use resulted in reduced rates of procedural complication rates (2.33% vs 10.82%; P < .001) and reduced rates of MACE at 12 months (16.28% vs 29.36%; hazard ratio, 0.46; 95% CI, 0.32-0.66; P < .002).

“Our study found that the use of CTCA prior to ICA in patients with previous CABG can shorten procedure duration, reduce rates of kidney injury, and improve patient satisfaction,” stated lead investigator Daniel A. Jones, MRCP, PhD, in the TCT press release. Dr. Jones, who is Clinical Senior Lecturer at Queen Mary University of London and an interventional cardiologist with Barts Heart Center in London, concluded, “When possible, CTCA should be considered for any stable postbypass patient undergoing ICA.”