Percutaneous balloon pulmonary valvuloplasty in a pregnant woman with severe pulmonary valve restenosis

Abstract

A 34-year-old woman, a known case of valvular heart disease, post balloon pulmonary valvuloplasty done 8 years ago during her first pregnancy, presented with progressive exertional breathlessness with New York Heart Association class III symptoms in her third trimester of pregnancy. On examination, she had features of right heart failure. ECG showed right axis deviation, right ventricular hypertrophy with strain pattern. Transthoracic echocardiography showed severe pulmonary valve stenosis, right ventricular hypertrophy, right ventricular and atrial dilatation with reduced right ventricular function. As the patient was symptomatic, she underwent percutaneous balloon pulmonary valvuloplasty. The procedure was successful with a significant reduction in the pulmonary valve gradient and the patient was discharged in stable condition with reduced symptoms. The timely intervention of the valvular stenotic lesion in pregnancy reduces the mortality risk to both the mother and the fetus.

Background

During pregnancy, the cardio-circulatory changes may cause significant haemodynamic burden and can lead to morbidity and even mortality in women with cardiac disease. Stenotic valvular lesions that limit the ability to increase cardiac output may not be well tolerated during pregnancy and delivery. Regurgitant lesions are generally better tolerated, especially if the underlying cardiac function is normal.¹

Pulmonary valvular stenosis (PS) is usually an isolated lesion, estimated to occur in up to 7% of children born with congenital heart disease (CHD) and 10%–12% of CHD in adults.^{2 3} Patients with mild or moderate PS are mostly asymptomatic and are diagnosed incidentally. Severe PS typically presents with symptoms related to increased right ventricular (RV) pressure and right heart failure.

Since the first percutaneous balloon pulmonary valvuloplasty (BPV), reported by Kan et al, this procedure has become the main treatment for pulmonary stenosis.⁴ Generally, balloon valvuloplasty of PS is an effective treatment with a good long-term prognosis. Freedom of re-intervention is 95.1%, 87.5% and 84.4% after 5 years, 10 years and 20 years, respectively, post-procedure. The re-intervention rates were higher with dysplastic valves.⁵

Mild and moderate PS are regarded as low-risk lesions. In severely symptomatic PS during pregnancy, who do not respond to medical therapy and bed rest, percutaneous balloon valvuloplasty can be undertaken.⁶ Presently described is a case of a pregnant patient with severe pulmonary valve restenosis who successfully underwent balloon valvuloplasty in the third trimester of pregnancy.

Case presentation

A 34-year-old woman, a known case of valvular heart disease, BPV done 8 years ago during her first pregnancy, presented with progressive exertional breathlessness with New York Heart Association (NYHA) class III symptoms in her third trimester of pregnancy.

The patient had similar symptoms in her first pregnancy. Her past echocardiography showed a pulmonary valve peak gradient of 150 mm Hg for which she underwent BPV in the latter part of the second trimester of her pregnancy. Post BPV, her pulmonary valve gradient had decreased to 110 mm Hg and the delivery was uneventful. The patient failed to follow-up after her first BPV.

On examination, the patient had bilateral pitting pedal oedema, elevated jugular venous pressure with prominent ‘a’ wave (video 1), left parasternal heave and a systolic thrill in the pulmonary area. On auscultation, P2 was soft, ejection systolic murmur was of grade-4 intensity and an ejection click was heard in the pulmonary area.

Video 1.

bcr-2021-246368supp001.mp4 ^{(668.9KB, mp4)}

DOI: 10.1136/bcr-2021-246368.video01

ECG (figure 1) showed right axis deviation, RV hypertrophy with strain pattern.

Figure 1.

ECG showed right axis deviation, right ventricular hypertrophy with strain pattern.

Two-dimensional transthoracic echocardiography (figures 2 and 3a, video 2) showed doming of pulmonary valve due to severe pulmonary valve stenosis, peak gradient of 203 mm Hg, post-stenotic dilatation of the pulmonary artery was seen, pulmonary valve annular size of 19 mm, RV hypertrophy, right atrial and RV dilatation, and reduced RV function with normal left ventricular function.

Figure 2.

Two-dimensional transthoracic echocardiography showed classical doming of valve in severe pulmonary stenosis (marked as red arrow), post-stenotic dilatation of MPA. MPA, Main pulmonary artery; RVOT, right ventricular outflow tract.

Figure 3.

Two-dimensional transthoracic echocardiography showing (A) pre-procedure pulmonary valve gradient of 203 mm Hg and (B) post-procedure pulmonary valve gradient of 137 mm Hg.

Video 2.

bcr-2021-246368supp002.mp4 ^{(668.9KB, mp4)}

DOI: 10.1136/bcr-2021-246368.video02

A diagnosis of severe pulmonary valvular restenosis was made and in view of her symptoms; the patient was counselled regarding a redo balloon pulmonary valvuloplasty.

Investigations

The patient’s liver function test, renal function test, coagulation profile and other biochemical parameters were normal.

Third trimester scan with Doppler

Single live intrauterine fetus at gestational age of 28–29 weeks seen. Lower margin of placenta covering the internal os (grade III previa) noted. Retroplacental hypoechoic zone is not visualised in the lower aspect of the uterus at the level of the urinary bladder—highly suggestive of placenta accreta.

Treatment

The patient was put on oral diuretics for 2 weeks to reduce the symptoms of right heart failure. As the patient persisted to have symptoms, she was suggested an elective redo percutaneous BPV and she consented. A lead protection for the fetus was placed. Through the right femoral venous route, the right heart catheterisation showed an RV pressure of 220/10 mm Hg, basal pulmonary artery pressure of 28/10 mm Hg and pulmonary valvular gradient of ~190 mm Hg. An exchange length guidewire was advanced to the distal left pulmonary artery, 40×22 mm Tyshak II balloon (NuMED, Canada), was placed across the valve and was positioned with the valve at the mid-portion of the balloon. The balloon was then inflated until the indentation produced by the valve on the balloon completely disappeared (figure 4, video 3). Post-procedure, the gradient across the pulmonary valve was 120 mm Hg. The presence of residual gradient even after three balloon dilatations was attributed to subvalvular infundibular obstruction related to RV hypertrophy. RV angiogram was not done pre-procedure and post-procedure as the patient had features of right heart failure. Post-interventional echocardiography was performed and a decrease in the pulmonary valvular gradient was noted (peak gradient: 137 mm Hg; mean gradient: 71 mm Hg) (figure 3b).

Figure 4.

Percutaneous BPV showing Tyshak II balloon indentation due to severe PS. BPV, balloon pulmonary valvuloplasty; PS, pulmonary valvular stenosis.

Video 3.

bcr-2021-246368supp003.mp4 ^{(668.9KB, mp4)}

DOI: 10.1136/bcr-2021-246368.video03

Outcome and follow-up

Post-procedure, the patient had a brief episode of mild hypotension lasting for about 30 min, which was managed conservatively. She experienced uterine contractions during this period, which subsided spontaneously. Obstetric consultation opined that the contractions were due to Braxton-Hicks contractions (false labour contractions). In view of placenta accreta, a caesarean section was suggested. The patient was discharged in a stable condition 2 days after BPV and she was symptomatically better. Later, she delivered a healthy baby in the 36th week of her gestation by caesarean section. Although the patient had placenta accreta, hysterectomy was not required. The patient was advised that if her pulmonary valve residual gradient persists and if there is recurrence of symptoms, she would require a surgical correction.

Discussion

Management of valvular heart diseases in pregnancy is challenging. In contrast to the CHDs being the most frequent cardiovascular disease (CVD) during pregnancy in the western world (75%–82%), rheumatic valvular disease occurs as the most common CVD during pregnancy in the non-western world (56%–89%).^7–9 These cardiac diseases are important causes of maternal and fetal morbidity and mortality.

Stenotic valve diseases carry a higher pregnancy risk and are poorly tolerated than regurgitant lesions. Left-sided valve diseases have a higher complication rate than right-sided valve lesions. Patients with NYHA class III/IV or with severely reduced function of the systemic ventricle are at higher risk during pregnancy.⁶ Between the first and second trimester, in stenotic lesions, increased cardiac output causes an increase in the transvalvular gradient of ~50%, which translates to an increased risk of maternal and fetal complications.¹⁰

As per the 2018 ACC/AHA guidelines,¹¹ the severity of pulmonary valve stenosis (PS) is determined by the peak gradient across the pulmonic valve as estimated using transthoracic echocardiography. Mild PS is defined as a peak gradient of <36 mm Hg, moderate PS with a peak gradient of 36–64 mm Hg and severe PS is described as a peak gradient of >64 mm Hg. PS is generally well tolerated during pregnancy.¹² However, severe stenosis may result in complications, including RV failure and arrhythmias. Pre-pregnancy relief of stenosis (usually by balloon valvuloplasty) should be performed in severe stenosis (peak Doppler gradient >64 mm Hg). In mild and moderate PS, which are regarded as low-risk lesions, it is sufficient to follow-up once every trimester. In severely symptomatic PS during pregnancy, not responding to medical therapy and bed rest, percutaneous valvuloplasty can be undertaken.⁶

Drenthen et al reported 108 pregnancies in 51 patients with isolated PS, and observed higher serious pregnancy/obstetric complications, including hypertension-related disorders, miscarriages, thromboembolic complications and premature rupture of membranes. They also had increased offspring mortalities (4.8%).¹³

The occurrence of restenosis differs between children and adults. There is a substantial incidence of restenosis (19%¹⁴) in children, particularly in newborns, which results in a need to redilate the valve. In contrast, the residual gradient in adults, measured across the valve and infundibulum markedly reduces after valvuloplasty. Therefore, in adults as compared with children, the resection of the hypertrophic infundibulum is usually not necessary.¹⁵

In this present case, the pregnant woman was diagnosed to have severe pulmonary valvular restenosis with a high pulmonary valve gradient of 203 mm Hg in her third trimester of pregnancy. She was subjected to percutaneous pulmonary balloon valvuloplasty as she had symptomatic severe PS with features of right heart failure. A decrease in pulmonary valve gradient was achieved post valvuloplasty and the patient was symptomatically better at discharge. Such exceptionally high gradient of severe restenosis is rare. The presence of the residual gradient following the first BPV was probably due to infundibular hypertrophy caused by the long-standing stenosis of the pulmonic valve, which did not regress as satisfactorily after balloon valvuloplasty as it does in children. The resection of the infundibulum may be required if the residual stenosis does not regress during follow-up.

Patient’s perspective.

When I was in the latter part of the second trimester of my pregnancy, I started having breathing difficulty on minimal activities. On consultation with the doctor, I was started on medications for 2 weeks. Even with medications, my symptoms did not subside for which a cardiology consultation was sought. After doing my heart scan, the doctor said that the heart valve has become narrow again. My husband and myself were counselled by the doctor regarding the procedure to open the valve through a balloon since my symptoms were worsening. We consented for the procedure and they placed a shield-like material over my abdomen before the procedure and said that it is to protect the baby from harmful radiation. Following the procedure, I had mild dizziness for which they started me on fluids and in some time I felt better. After some time, I started having mild contractions in my abdomen for which my obstetrician examined and reassured me that the baby was fine. Slowly the contractions subsided and the next day I was shifted from the ICU to the ward. The doctors advised my husband and myself about the need for surgical correction of the valve on a later date, post-delivery. Now I feel much better and am able to do activities better than before.

Learning points.

• Balloon valvotomy is feasible, effective and safe during pregnancy and should be considered in symptomatic patients refractory to medical therapy.

• Pregnant women with symptomatic severe pulmonary valvular stenosis should be treated in order to reduce feto-maternal complications and improve the likelihood of an optimal pregnancy outcome.

• Post balloon pulmonary valvuloplasty, the residual gradient usually decreases in adults. The recurrence of pulmonary valvular restenosis is unusual in adults.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s).