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Pulmonary Vascular Resistance Is Higher in Patients with Repaired Congenital Diaphragmatic Hernia Compared to Age Matched Controls

M. Zussman

Michelle Cash

D. W. Benson

Russel Hirsch


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Conference: 2010 International PHA Conference and Scientific Sessions

Release Date: 06.24.2010

Presentation Type: Abstracts

Zussman M, Bagby M, Benson DW, Hirsch R.
The Heart Institute of Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA

BACKGROUNDPulmonary hypertension (PH) frequently complicates the course of infants born with congenital diaphragmatic hernia (CDH). Despite the apparent normalization of pulmonary artery (PA) pressures in survivors (as estimated by echocardiography), a number remain symptomatic with chronic respiratory infections and failure-to-thrive (FTT). In this report, we summarize our catheterization findings in this population, and compare them to age matched controls.

METHODSPatients aged 6-36 months with repaired CDH who underwent follow-up cardiac catheterization (CC) were identified from an institutional database. Indications for CC included a history of severe perioperative PH (n=8), recurrent respiratory infections (n=3) or FTT (n=4). Echo data was reviewed in the study population. Hemodynamic variables measured at catheterization (indexed pulmonary blood flow (Qp), mean PA pressure (mPAP), pulmonary capillary wedge pressure (PCWP), and indexed pulmonary vascular resistance (PVR)) were compared to those in age matched controls undergoing elective percutaneous closure of patent ductus arteriosus (PDA). The control cohort had no evidence of chronic lung disease. Controls were included only if PA oxygen saturations were sampled from each pulmonary artery, and were similar.

RESULTSEight patients were identified in the study group and 10 in the control group. There was no significant difference in age, weight or gender between the groups; (19.5 vs 17.4 mo; 16.9 vs 10.5 kg; 50% vs 40% males). Four of the 8 study patients had normal RV pressures as estimated by tricuspid regurgitation (TR) or PDA gradient; 2 had elevated pressures (< half systemic), and 2 had no reliable TR. Despite the lower Qp in study subjects (4.1 vs 6.6 ml/min/m2), the mPAP in the CDH patient group trended higher than in the controls (22.63 +/- 4.46 vs 17.78 +/- 4.13 mmHg; p>0.05). PCWP was similar between the 2 groups (7.8 vs 9.8 mmHg). The calculated PVR in the CDH group was significantly higher (3.8 +/- 0.8 vs 1.2 +/- 0.4 wU x m2; p<0.05).

Figure 1: Comparison of mean PAP (A) and PVR (B) in patients aged 6-36 months after CDH repair or during PDA closure (control).

Pulmonary Vascular Resistance Is Higher in Patients with Repaired Congenital Diaphragmatic Hernia Co

CONCLUSIONThis report indicates that despite apparent normalization of the PA pressures by non-invasive measures, patients with repaired CDH and a history of severe PH may continue to demonstrate persistently elevated PVR. Since earlier initiation of vasodilator therapy may help prevent progression of vascular occlusive disease in this population, a more aggressive invasive approach to assessing asymptomatic patients with repaired CDH may be indicated.