Open Access

ARTICLE

Diastolic velocity half time is associated with aortic coarctation gradient at catheterization independent of echocardiographic and clinical blood pressure gradients

Adam B. Christopher¹, Abraham Apfel², Tao Sun², Jackie Kreutzer¹, David S. Ezon³

1 Division of Pediatric Cardiology, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania
2 Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania
3 Department of Pediatric Cardiology, Mount Sinai Hospital, New York, New York

* Corresponding Author: Adam Christopher, Children’s Hospital of Pittsburgh of UPMC, One Children’s Hospital Drive, 4401 Penn Avenue, 5th Floor Faculty Pavilion, Pittsburgh, PA 15224. Email:

Congenital Heart Disease 2018, 13(5), 713-720. https://doi.org/10.1111/chd.12637

Abstract

Objective: The most accurate noninvasive parameter to predict whether a patient with aortic coarctation will meet interventional criteria at catheterization remains elusive. We aim to determine the best independent echocardiographic predictors of a coarctation peak‐to‐peak pressure gradient ≥20 mm Hg at catheterization, the ac‐ cepted threshold for intervention.
Design: Retrospective query of our catheterization database from 1/2007 to 7/2016 for the diagnostic code of aortic coarctation was performed. Multiple echocardio‐ graphic measurements and blood pressure gradients prior to cardiac catheterization were collected. Univariate correlation of variables with the continuous catheteriza‐ tion peak were calculated using Spearman’s rho. Univariate association with peak‐to‐ peak gradient at catheterization ≥20 mm Hg was tested using Mann‐Whitney U test and the Pearson chi‐square test or Fisher’s exact test. Multivariable logistic regres‐ sion assessed the independent association of the clinically relevant metrics with gra‐ dient at catheterization ≥20 mm Hg.
Results: Sixty‐eight patients met study criteria (median age 9.25 years), of whom 84% underwent intervention at catheterization. Echocardiographic peak and mean coarctation velocity, indexed systolic and diastolic velocity half times (SVHTi, DVHTi), and blood pressure gradient all had moderate correlation (Spearman’s rho = 0.529‐0.617, P < .001) with the continuous catheterization gradient and were significantly associated with the binary outcome of catheterization peak ≥20 mm Hg (P < .001). Logistic regression found echocardiographic mean systolic gradient (OR 1.213 [95% CI 1.041‐1.414]) and DVHTi (OR 1.039 [95% CI 1.004‐1.074]) indepen‐ dently associate with catheterization peak ≥20 mm Hg after controlling for blood pressure gradient (OR 1.066 [0.987‐1.150]).
Conclusions: Most echocardiographic estimates show moderate correlation with arch gradient at catheterization. Noninvasive four extremity blood pressure gradient is significantly associated with peak‐to‐peak gradient ≥20 mm Hg. DVHTi may pro‐ vide a unique independently associated echocardiographic estimate of coarctation severity. Further study of these variables with larger cohorts may allow for develop‐ ment of predictive models to direct catheterization.

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