Agreement of duplex ultrasonography vs. computed tomography angiography for evaluation of native and in-stent SFA re-stenosis--findings from a randomized controlled trial

Background

Multidetector CT angiography (CTA) is a non-invasive imaging technique for evaluation of peripheral vascular disease. CTA might be particularly useful for assessment of intermediate- and long-term morphological outcome after endovascular treatment. Validation of CTA vs. the current imaging standard, colour Doppler ultrasonography (CDUS), for quantification of native and in-stent re-stenosis in the superficial femoral artery (SFA) is required.

Methods

Seventy randomized patients who underwent stent implantation (n = 47) or balloon angioplasty (n = 23) underwent 6-month follow-up with CDUS and CTA. CTA was compared with CDUS in both sub-groups of patients in terms of binary re-stenosis (>50% lumen narrowing) and re-occlusion. Agreement between CTA and CDUS was assessed using Kappa (κ) statistics with 95% confidence intervals, and correlation coefficients.

Results

Binary re-stenosis was detected in 16/70 (22.9%) patients by CTA and 17/70 (24.3%) patients by CDUS (κ = 0.88, 95% CI: 0.80–0.96). Re-stenosis rates after balloon angioplasty were 39.1% (9/23) on CTA and CDUS (κ = 0.82, 95% CI: 0.66–0.98), and after stent implantation 14.9% (7/47) on CTA and 17.0% (8/47) on CDUS (κ = 0.92, 95% CI: 0.84–1.00). Re-occlusions were detected in 3/70 (4.3%) patients by both CTA and CDUS (κ = 0.65; 95% CI 0.54–0.76). Significant correlations (r = 0.85, p < 0.001) were noted between degree of re-stenosis on CTA and peak velocity ratio on CDUS. The correlation coefficient was higher in patients after balloon angioplasty (r = 0.94, p < 0.001) than in patients after stent implantation (r = 0.71, p < 0.001).

Conclusion

CTA and CDUS show excellent agreement for evaluation of native and in-stent re-stenosis after endovascular treatment of SFA obstructions. CTA is an appropriate non-invasive imaging modality for follow-up after endovascular therapy.     

Long-Term Outcomes of Pre-emptive Valganciclovir Compared with Valacyclovir Prophylaxis for Prevention of Cytomegalovirus in Renal Transplantation

Prevention of cytomegalovirus (CMV) is essential in organ transplantation. The two main strategies are pre-emptive therapy, in which one screens for and treats asymptomatic CMV viremia, and universal antiviral prophylaxis. We compared these strategies and examined long-term outcomes in a randomized, open-label, single-center trial. We randomly assigned 70 renal transplant recipients (CMV-seropositive recipient or donor) to 3-month prophylaxis with valacyclovir (n=34) or pre-emptive valganciclovir for significant CMV viremia detected at predefined assessments through month 12 (n=36). Among the 55 patients who had a protocol biopsy specimen available at 3 years to allow assessment of the primary outcome, 9 (38%) of 24 patients in the prophylaxis group and 6 (19%) of 31 patients in the pre-emptive therapy group had moderate to severe interstitial fibrosis and tubular atrophy (odds ratio, 2.50; 95% confidence interval, 0.74-8.43; P=0.22). The prophylaxis group had significantly higher intrarenal mRNA expression of genes involved in fibrogenesis. The occurrence of CMV disease was similar in both groups, but pre-emptive therapy improved 4-year graft survival (92% versus 74%; P=0.049) as a result of worse outcomes in patients with late-onset CMV viremia. In conclusion, compared with valacyclovir prophylaxis, pre-emptive valganciclovir therapy may lead to less severe interstitial fibrosis and tubular atrophy and to significantly better graft survival.