CTCA before ICA reduces procedure time and contrast-induced nephropathy risk among patients with previous CABG

In a game-changing study, researchers have discovered a more effective approach for patients with previous coronary artery bypass grafting (CABG). Traditional invasive coronary angiography (ICA) for these patients often poses challenges and risks. However, a pioneering trial, the first of its kind, introduced computed tomography cardiac angiography (CTCA) as an adjunct before ICA as it minimizes procedural time and contrast-induced nephropathy. 

The study results were published in the journal Circulation. 

Individuals with prior coronary artery bypass grafting often need invasive coronary angiography (ICA). Yet, this procedure poses increased technical challenges and higher complication risks for them. Observational research indicates that computed tomography cardiac angiography (CTCA) might aid ICA in this population. However, no randomized controlled trial has validated this approach. Hence researchers conducted a randomized controlled trial called The BYPASS-CTCA Trial to assess the benefit of adjunctive CTCA in patients with previous coronary artery bypass grafting referred for ICA. 

In this single-center, open-label randomized controlled trial, patients were evenly divided into two groups: one undergoing CTCA before ICA, and the other undergoing ICA alone. Primary outcomes encompass ICA procedural duration, patient satisfaction measured through a validated questionnaire, and the occurrence of contrast-induced nephropathy. Statistical analyses employed linear regression for procedural duration and patient satisfaction, while logistic regression was used for contrast-induced nephropathy. Significance was determined with P<0.017 and 98.33% confidence intervals. Secondary endpoints included procedural complications and major adverse cardiac events over one year. 

Key findings: 

• Over a three-year period, 688 patients were randomly assigned, with a median follow-up of 1.0 years.
• The average age was 69.8±10.4 years; 108 (15.7%) were female, and 402 (58.4%) were White.
• The group had a high prevalence of comorbidities, with 85.3% having hypertension and 53.8% having diabetes.
• The median duration from coronary artery bypass grafting to angiography was 12.0 years, and participants had a median of 3 grafts each.
• In the CTCA+ICA group, the ICA procedure was significantly shorter taking 18.6±9.5 minutes, ICA alone took 39.5±16.9 minutes. 
• Shorter duration led to improved ICA satisfaction scores, and reduced incidence of contrast-induced nephropathy (3.4% vs. 27.9%).
• The CTCA+ICA group also experienced fewer procedural complications (2.3% vs. 10.8%) and lower rates of major adverse cardiac events at one year (16.0% vs. 29.4%). 

Thus, this groundbreaking research signifies a paradigm shift, offering a safer, more efficient path for patients with previous CABG. Considering these compelling outcomes, integrating CTCA before ICA emerges as a promising standard of care for this patient group, revolutionizing heart health management. 

Further reading: Jones DA, Beirne AM, Kelham M, et al. Computed Tomography Cardiac Angiography Before Invasive Coronary Angiography in Patients With Previous Bypass Surgery: The BYPASS-CTCA Trial. Circulation.  doi:10.1161/CIRCULATIONAHA.123.064465