Abstract 18302: Longitudinal Evaluation of the Diastolic to Systolic Time-velocity Integral Ratio as a Doppler Derived Measure of Pulmonary Regurgitant Fraction in Patients With Surgically Repaired Tetralogy of Fallot
Background: [[Unable to Display Character: –]] Pulmonary regurgitation (PR) following surgical repair for tetralogy of Fallot (TOF) is a major determinant of outcome but can be difficult to quantify by echocardiogram. We previously demonstrated a moderate correlation between the pulmonary artery diastolic-systolic time-velocity integral ratio (DSTVI) measured by echocardiogram and regurgitant fraction (RF) measured on cardiac magnetic resonance (CMR). We sought to investigate the ability of the DSTVI to identify temporal changes in PR.
Methods and Results: We conducted a longitudinal study of patients with baseline and follow up echocardiogram and CMR. Baseline studies were performed within 3 months of each other as part of a cross sectional research protocol. Follow up studies were performed <=7 months apart in cases with no interim interventions for PR. The DSTVI was calculated using Doppler interrogation in the main pulmonary artery. Wilcoxon matched-pairs signed-rank test was used to test whether changes in baseline to follow up DSTVI corresponded to changes in baseline to follow up PR. Linear regression of RF was fit on DSTVI to identify corresponding values of DSTVI.
Thirty-five subjects were included, age 18.3±3.5 years at follow up, 88.9% males. The time from baseline to follow up CMR was 60 months (interquartile range 46-73). On follow up, the DSTVI was 0.80 (±0.46) and RF was 35.5% (±17.8) with a moderate correlation between DSTVI and PR measured as RF by CMR (R=0.62, p=0.0001). A CMR RF of 20% and 40% (cut offs for moderate and severe PR) corresponded with a DSTVI of 0.52 (95% CI: 0.39[[Unable to Display Character: –]]0.66) and 0.79 (95% CI: 0.69[[Unable to Display Character: –]]0.89), respectively. Using the median DSTVI of 0.68 as a cutoff, DSTVI of <= 0.68 corresponded to a RF of 28% (20-37), whereas DSTVI > 0.68 corresponded to a RF of 44% (38-49), p=0.0001
Compared to the baseline study, there was no overall change in either DSTVI (p=0.61) or PR (p=0.89) at follow up and similarly, there was no difference in individual changes of RF and DSTVI (p=0.75).
Conclusions: [[Unable to Display Character: –]] The DSTVI provides an alternative and consistent quantitative measure of PR to RF by CMR that could be incorporated into the routine assessment of PR by echocardiogram. In addition, this index may help identify patients with TOF in need of early screening by CMR.
Author Disclosures: M. Bhat: None. E. Goldmuntz: Research Grant; Significant; NIH/NHLBI. L. Mercer-Rosa: Research Grant; Significant; NIH/NHLBI.
- © 2014 by American Heart Association, Inc.