A study has found that in a cohort of pregnant women implanted with bioprosthetic valves (BPV), structural valve dysfunction (SVD) of left-sided BPVs was linked to higher rates of adverse pregnancy outcomes compared to right-sided BPVs. The findings, published Monday online ahead of the Nov 22 issue of the Journal of the American College of Cardiology, also found SVD present in 27% of women at the first antenatal visit. “The risk for adverse maternal cardiac events (CEs) and fetal and neonatal events (FEs) was substantially increased in women with SVD of any left-sided BPV,” the study stated. “This association was not seen in women with right-sided SVD.” “This new information needs to be incorporated into decision making and highlights that the correct prosthesis choice for young women with significant left-sided valvular lesions remains difficult.” Study details Authors led by Barbara Wichert-Schmitt, MD, from the University of Toronto, Mount Sinai and Toronto General Hospitals, Toronto, and Kepler University Hospital, Linz, Austria, reported that women with preexisting heart disease were enrolled in a subset of the Canadian Cardiac Disease in Pregnancy (CARPREG) study between 1994 and 2019. These women had undergone implantation of BPVs prior to pregnancy. Clinical baseline data were recorded at the first antenatal visit, including maternal age, gestational age, parity status, valve lesion, and prior valve interventions. BPVs were defined according to their position (aortic, mitral, pulmonary, or tricuspid). Aortic BPVs were subclassified according to aortic prosthesis type: pulmonary autograft (after Ross operation) or bioprosthesis (pericardial and porcine xenografts and homografts). The time (years) between the most recent valve replacement surgery and the index pregnancy was also recorded. Adverse maternal CEs, FEs and obstetrical events were recorded from the first antenatal visit up to 6 months after delivery. Main findings In total, 125 pregnancies occurred in 101 women with one or more BPVs. Of these women, 27% had left-sided BPV and 73% had right-sided BPV. SVD was present in 27% of the pregnancies (44% with left-sided BPVs vs 21% with right-sided BPVs; P = 0.009). CEs occurred in 13% of pregnancies and were more frequent in women with SVD compared with those with normally functioning BPVs (26% vs 8%: P = 0.005). Further findings revealed that CEs were more common in women with left-sided BPVs with SVD compared with normally functioning BPVs (47% vs 5%: P = 0.01). However, CEs were similar in women with right-sided BPVs with or without SVD (11% in those with SVD vs 8% in those without SVD; P = 0.67). Left-sided SVD (P = 0.007), maternal age >35 years (P = 0.001), and a composite variable of “high-risk” features (P = 0.006) were predictors of CEs, the researchers said, adding that fetal events occurred in 28% of pregnancies. “We found that SVD was common in young pregnant women with left-sided BPVs, even early after valve replacement and was associated with an increased risk for CEs and FEs,” the team said. “The durability of BPVs is reduced in young patients, in whom SVD may be accelerated because of higher functional demand and a more active immune system.” Differences in SVD rates between women with left- and right-sided BPVs at the time of pregnancy were also highlighted, with 44% with left-sided BPVs having SVD on average 7±3 years after surgery, and 21% with right-sided BPVs had SVD on average 11 ±7 years after surgery. The team suggested this reflected earlier degeneration of left-sided BPVs due to higher functional demand in a high-pressure vs a low-pressure circulation. Editorial thoughts In an accompanying editorial, Deirdre J. Mattina, MD, from the Cleveland Clinic, and colleagues, described the study as “meriting praise.” “In the CARPREG study, right-sided BPVs were more common than left, although left-sided lesions had worse outcomes. “We know that congenital heart disease makes up a larger percentage of antenatal heart disease in high-income countries resulting in more right-sided BPVs,” they added. “Rheumatic heart disease (RHD) with more commonly left-sided valve disease accounts for most antenatal heart disease in low- and middle-income countries. “Therefore, the burden of BPV SVD in countries with a high prevalence of RHD and access to surgical valve replacement is likely to be higher.” In commenting on the impact of SVD on CEs, the editorialists believed it raised important hemodynamic considerations when counseling women on the choice of a BPV or a mechanical valve. “Increases in cardiac output, stroke volume, heart rate, and physiologic anemia in pregnancy place women with fixed stenotic lesions at risk for hemodynamic compromise. “This study adds to our knowledge of CEs and FEs in women with BPVs. It will enrich informed, individualized, shared decision-making when choosing the type of prosthetic valve as well as expectant pregnancy management for those patients with BPVs placed before pregnancy.” Sources: Wichert-Schmitt B, Grewal J, Malinowski AK, et al. Outcomes of Pregnancy in Women With Bioprosthetic Heart Valves With or Without Valve Dysfunction. J Am Coll Cardiol 2022;80:2014–2024. Mattina DJ, French K, Poppas A. Impact of Bioprosthetic Valve Dysfunction on Pregnancy Outcomes: Left Side, Right Side, and Beyond. J Am Coll Cardiol 2022;80:2025–2027. Image Credit: auremar – stock.adobe.com