Procedural, pregnancy, and short-term outcomes after fetal aortic valvuloplasty


Procedural, pregnancy, and short-term outcomes after fetal aortic valvuloplasty

Patel ND, Nageotte S, Ing FF, Armstrong AK, Chmait R, Detterich JA, Galindo A, Gardiner H, Grinenco S, Herberg U, Jaeggi E, Morris SA, Oepkes D, Simpson JM, Moon-Grady A, Pruetz JD.

Catheter Cardiovasc Interv. 2020 Mar 26. doi: 10.1002/ccd.28846. [Epub ahead of print]

PMID: 32216096

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Take Home Points:

  • Fetal aortic valvuloplasty offers promise in patients with congenital aortic stenosis to prevent progression to hypoplastic left heart syndrome
  • It is a high risk intervention and center experience is crucial to maximizing success
  • Further investigation of outcomes in patients who undergo fetal aortic valvuloplasty but still require single ventricle palliation is warranted

Dr. Ryan Romans (Kansas City, MO)
Commentary from Dr. Ryan Romans (Kansas City, MO), section editor of Congenital Heart Disease Interventions Journal Watch: Fetal aortic valvuloplasty (FAV) was first reported in 1991 as an option to treat congenital aortic stenosis in mid-gestation fetuses with the goal to prevent progression to hypoplastic left heart syndrome (HLHS). The process involves using ultrasound guidance to puncture through the maternal abdomen and uterus, then into the fetal thigh to deliver analgesia and a muscle relaxant. A different needle is then passed through the fetal chest and into the left ventricle. A wire is advanced through the needle across the aortic valve. A balloon is advanced over the wire and inflated across the aortic valve. Most centers performing fetal aortic valvuloplasty perform a small number of cases. Boston Children’s Hospital has performed the largest number of these cases and have previously reported their procedural outcomes (Freud LR, McElhinney DB, Marshall AC, et al. Fetal aortic valvuloplasty for evolving hypoplastic left heart syndrome: postnatal outcomes of the first 100 patients. Circulation. 2014;130(8):638-645 and Friedman KG, Sleeper LA, Freud LR, et al. Improved technical success, postnatal outcome, and refined predictors of outcome for fetal aortic valvuloplasty. Ultrasound Obstet Gynecol. 2018;52(2):212-220), as have several other smaller single center studies. Procedure related fetal mortality rates are variable across centers (6.5-32.1%). The International Fetal Cardiac Interventions Registry (IFCIR) was created in 2010 to collect data on fetal interventions from multiple centers (19 centers actively entering data) and improve outcomes. The goal of this study was to look at several technical and procedural aspects of FAV (cannula size, balloon size, number of cardiac punctures) to determine if they were related to procedural and pregnancy outcomes.
Patel et al. report on their analysis of patients from 15 centers in the IFCIR who were candidates for fetal cardiac intervention from 2002-2018. The median center volume was 5 (range 1-21). Patients from Boston Children’s Hospital were excluded as data on those patients had already been presented in the previously mentioned studies. A total of 128 fetuses with a mean gestational age (GA) of 26.1 ± 3.4 weeks were deemed candidates. 108 of these fetuses underwent cardiac puncture and had adequate data in the database to be included for analysis. The indication for FAV was evolving HLHS in 103 fetuses (95.4%). The needle used to puncture the LV was 17 gauge in 15.7%, 18 gauge in 63.9%, and 19 gauge in 29.6%. A single puncture was needed in 77.1%, two punctures in 19.4%, and three punctures in 5.6%. 100 fetuses had an aortic balloon valvuloplasty performed, 90 (83.3%) of which were technically successful (defined as increased forward flow across aortic valve or new aortic regurgitation). The mean aortic valve Z-score was -2.5 ± 1.1 for all fetuses and the median balloon: aortic valve ratio was 1.1. 52 fetuses (48.1%) had at least one intraprocedural complication including bradycardia requiring treatment (37, 34.3%), pericardial effusion requiring treatment (24, 22.2%), pleural effusion (3, 2.8%), balloon rupture (6, 5.6%), and intraprocedural death (9, 8.3%). The overall procedural related mortality was 16.7% (9 intraprocedure deaths, 9 additional deaths within 48 hours). More than one puncture was associated with higher rates of procedural complications (specifically bradycardia, pleural effusion, and intraprocedural death). On multivariate analysis, later GA at intervention and technical success of the procedure were independently associated with live birth.
The outcomes of the pregnancies and infants born is shown below. The 81 fetuses born alive had a median GA of 38.1 weeks, with 26 of them being born prematurely (<37 weeks GA).

This study shows that fetal intervention is often technically successful and offers promise for a biventricular circulation. However, it has significant associated risk with a complication rate of nearly 50% and procedure related mortality of 16.7% (Boston Children’s Hospital’s most recent report had a mortality rate of 6.5%). The higher mortality in this series is multifactorial and likely involves the known learning curve that has been seen in performing this procedure. The authors highlight the importance of center experience and appropriate fetal positioning to minimize the number of punctures. Also, the authors discuss that later GA at the time of the procedure decreased risk likely due to larger fetus size. However, fetuses that were candidates later in gestation may also have less severe disease and waiting for many fetuses could lead to missing the window for prevention of HLHS. Interestingly, of the 81 patients born alive, 22 (27.1%) died prior to hospital discharge. Data from the Single Ventricle Reconstruction trial showed hospital mortality or need for transplantation at 18% (Pasquali SK, Ohye RG, Lu M, Kaltman J, Caldarone CA, Pizarro C, Dunbar-Masterson C, Gaynor JW, Jacobs JP, Kaza AK, Newburger J, Rhodes JF, Scheurer M, Silver E, Sleeper LA, Tabbutt S, Tweddell J, Uzark K, Wells W, Mahle WT, Pearson GD; Pediatric Heart Network Investigators. Variation in perioperative care across centers for infants undergoing the Norwood procedure. J Thorac Cardiovasc Surg. 2012; 144:915–921. doi: 10.1016/j.jtcvs.2012.05.021). While it is unknown if this difference is statistically significant and how many of those patients who died underwent attempted single ventricle palliation, the outcomes of patients that have had a fetal intervention and still require single ventricle palliation versus those that have not warrants further future investigation.