| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4221482 | Clinical Imaging | 2015 | 5 Pages |
IntroductionTranscatheter aortic valve replacement (TAVR) typically requires computed tomographic angiography (CTA) for aortoiliofemoral assessment to determine feasibility of a transfemoral approach, although many candidates being considered for TAVR are at increased risk of contrast-induced nephropathy (CIN).ObjectiveTo determine the feasibility and safety of a load contrast load CTA protocol in octogenarians and nonagenarians at risk of CIN.ApproachWe evaluated 54 consecutive octogenarians and nonagenarians considered for TAVR who underwent CTA using a standard contrast protocol (n= 21) versus a protocol incorporating low-dose contrast in patients at risk of CIN (n= 33). We compared clinical characteristics, CTA image quality (score 1–4) and interpretability, and clinical outcomes, including CIN and vascular complications.ResultsThe mean age was 88.5±4.0 years, 37% were male, and chronic renal insufficiency was common in both the standard and low-dose contrast cohorts (57% vs. 70%, P= .39). The low-dose contrast protocol was associated with a significantly less contrast volume compared to standard contrast protocol (127±18 ml vs 76±55 ml, P< .001). Individuals imaged using low-dose (n= 16) versus standard (n= 17) contrast protocols received 80% less contrast volume (23±10 vs. 125±23 ml, P< .001). There was similar graded image quality (3.8±0.4 vs. 3.9±0.3, P= .76) and interpretability (100% for each, P= 1.0) between standard and low-dose contrast protocol groups. There was no significant difference in rates of CIN after CTA between standard and low-dose contrast protocol groups (10% vs. 3%, P= .55), with no CIN events in those imaged by low-dose CTA. There were no major vascular injuries associated with TAVR or pigtail insertion, no major bleeding for CTA, and no noninterpretable studies in all patients.ConclusionIn this proof-of-principle study, a low-dose contrast protocol appears feasible and safe in octogenarians and nonagenarians undergoing screening for TAVR, and results in significant reduction in contrast load as compared to a standard contrast protocol without observed differences in image quality or safety.
