Vaginal delivery in a patient with severe aortic stenosis under epidural analgesia, a case report

Background

The management of pregnant patients with a history ofcardiac disease is challenging even for expert anesthesiologists. Although the prevalence of clinically relevant heartdisease is relatively low, occurring in approximately 1% ofpregnancies, major cardiac events occur in up to 13% ofpregnant patients with history of previous cardiac disease[1]. Valvular heart disease accounts for approximately 40%of these cases. The presence of a bicuspid aortic valvewith/without stenosis or insufficiency is the most prevalent defect, and represents the most common indicationfor cardiac surgery in women of a fertile age [2].

Briefly from a physiological stand point, hormonal shiftsduring pregnancy (specifically, the rise in progesteroneand prostacyclin) bring about significant hemodynamicchanges: systemic vascular resistance and blood pressuredecrease, whereas heart rate and stroke volume increase,determining a rise in cardiac output [3].

The risk of cardiac complications is greatest duringthe peripartum period, when factors such as uterinecontractions, pain, fatigue, bleeding, uterine involutionand anesthesia/analgesia may cause significant shifts inhemodynamics, leading to acute heart failure [4]. Thereis no consensus on the absolute contraindications tovaginal delivery in valvular heart disease, but central regional anesthesia is traditionally considered contraindicated in patients with severe aortic stenosis [5].

Here we report on the management of a pregnant womanwith severe aortic stenosis who underwent labor with epidural analgesia and close hemodynamic monitoring.

Case presentation

A 29-year-old primigravid woman with severe aortic stenosis was admitted to the obstetrics department for programmed labor induction. She weighed 54 Kilograms (Kg),was 160 cm (cm) high, and had no allergies. The patient hadundergone valvuloplasty at the age of 2 years for the correction of congenital aortic stenosis, followed by total valve replacement (with a biological prosthesis) at the age of 21.Over the last 2 years (prior to and during her pregnancy),the patient had presented episodes of supraventriculartachycardia/atrial fibrillation, treated successfully with flecainide. At the last echocardiography performed at 36 weeksand 4 days gestation, she presented a left ventricle with normal dimensions, thickness and systolic function, a biologicalprosthesis on site with a thick and less mobile right coronary cusp, and normal motility of the left coronary and noncoronary cusps (Videos 1 and 2) with a maximum pressuregradient of 52 mmHg and an average of 31 mmHg (Fig.1).

The aortic valve area (AVA) was 0.9–1.0 cm2. She presented mild mitral insufficiency, an estimated pulmonarysystolic pressure of 27 mmHg and a normal left atrium(Fig.2). Electrocardiography revealed a normal sinusrhythm (Fig.3). The patient was medicated with enoxaparin, 4000 international units (IU), twice daily.

The patient was followed by the‘high-risk pregnancy service’provided by our institution. Gestational age was calculated at the first trimester ultrasound scan. Her risk forchromosomal anomalies was low, and early and late fetalanomaly scans described normal fetal anatomy. An ultrasound scan performed at 35 weeks and 5 days gestation revealed normal fetal parameters and growth and anestimated fetal weight of 2888 g (65th percentile). A multidisciplinary team followed the patient, providing tailoredtherapy (anticoagulation), and following evaluation (a detailed obstetric visit and fetal weight estimation) the date ofdelivery was set to 38 weeks and 4 days of gestation. Considering the clinical history of the patient and her own preferences, and in accordance with the obstetricians, we optedfor epidural labor analgesia. On the morning of the programmed labor induction, the patient’s vital parameterswere monitored: electrocardiography (ECG), oxygen saturation (SpO2), non-invasive blood pressure (NIBP), andcardiotocography. A defibrillator was ready and nearby.We placed two large-bore intravenous catheters andstarted infusion with Ringer’s acetate solution. We thenadded a non-invasive hemodynamic monitoring system,using the ClearSight™and EV1000 Platform (EdwardsLifesciences, Irvine, California, USA).

A trans-abdominal ultrasound scan with a convex probe3.5 MHz (Voluson E, GE Healthcare, Chicago, Illinois,USA) showed a cephalic presentation, a maximal verticalpocket (DVP) of 80 mm, and an umbilical artery pulsatilityindex (UA PI) of 0.80 (Figs.4and5). Vaginal examinationrevealed the cervix to be 2 cm dilated, 50% effaced, and tohave a Bishop Score of 6. The patient’s baseline vitalparameters were: heart rate (HR), 82 beats per minute(bpm); median blood pressure (mAP), 85 mmHg; SpO2,100%; fetal heart rate (FHR), 159 bpm; cardiac index (CI), 4L/min/m2; stroke volume index (SVI), 56 ml/m2.

Her laboratory exams reported: 11.1 g/dL hemoglobin;220.000 platelets; international normalized ratio (INR),0.91; activated partial thromboplastin time ratio (aPTTr),0.89; fibrinogen, 551 mg/dL. Enoxaparin therapy wassuspended 24 h before induction.

Using an 18-gauge (G) Tuohy needle, an epidural 20 Gcatheter (B. Braun, Melsungen, Germany) was placed into

lumbar (L) vertebral space 2–3 and tested with ropivacaine 0.2%, 5 mL, fractionated into small boluses. All vitalparameters were constantly monitored and inductionstarted with a low dose oxytocin infusion (Table1).

Five hours later, good progression of the first stage oflabor was evident, with 5 cm cervical dilation and goodeffacement. An amniotomy was performed at this point.The patient gave a pain rating of 5 out of 10 (using thenumeric pain rating scale, NPRS) and her hemodynamicparameters were stable. We started with an epidural infusion of ropivacaine 0.1%, 5 mL, and sufentanil, 3.75mcg. After 30 min, the patient had a dermatomal levelaround thoracic (T) spinal nerve T10 (Table2).

During the following hours, we maintained an acceptable level of analgesia, a constant dermatomal level, andstable hemodynamic parameters with small boluses ofropivacaine 0.1% and sufentanil, ranging from 5 to 10 mL.During this period, the dose of oxytocin was increased bythe obstetrician, and cervical dilation proceeded untilcomplete dilation. At this point, in order to guarantee accurate hemodynamic monitoring, an artery line was put inplace and connected to the FloTrac™system (EdwardsLifesciences, Irvine, California, USA).

Three hours later, following episiotomy, the fetus was extracted using a vacuum (Kiwi Omni-C Cup, Ri.mos., Italy)to avoid excessive exertion by the mother and in responseto initial alterations in the fetal cardiotocograph. Pain wascontrolled with alkalinized lidocaine 2%, 4 mL, given beforeextraction, and all vital and hemodynamic parametersremained stable (Table1). A male baby weighing 3270 g was

delivered with Apgar scores of 8 and 8 at minute 1 and 5,respectively. Blood loss did not exceed 100 mL. All the patient’s vital parameters were monitored for the next 10 h; wethen removed the epidural catheter and all other monitoringdevices and the patient was dismissed to the obstetrics wardwith stable parameters. Pain was treated with 1000 mg paracetamol and 600 mg ibuprofen every 8 h, with an NRS < 3.

The post-partum period was characterized by episodes offever and a suspected phlebitis of the hand. Considering thehigh cardiovascular risk of the patient, the infectologist suggested antibiotic therapy with daptomycin and piperacillin/tazobactam, then de-escalated to amoxicillin-clavulanic acidfor a total of 20 days. One week after labor, echocardiography was repeated and shown to be equivalent to the oneperformed pre-partum. The patient was discharged fromthe hospital 11 days post-partum.

Discussion

A history of previous cardiac disease increases the maternalmortality risk by as much as 100% [6]. The most commonetiologies include congenital heart disease (~ 60%), valvularheart disease (~ 30%), and cardiomyopathies (~ 6%), whereas

ischemic heart disease, aortopathies, and pulmonary hypertension account for a minority of cases (~ 4–5%) [7].Peripartum cardiomyopathy is an idiopathic and rare heartdisease that manifests itself in the late phases of pregnancyor early post-partum [8], with an incidence of one in 968live births in American women [9]. It can clinically presentwith congestion symptoms, such as dyspnea on exertion,paroxysmal nocturnal dyspnea, orthopnea, and edema ofthe lower extremities [10]. Cardiogenic shock occurs in asmall percentage of cases and less frequently unstable arrhythmias and arterial thromboembolism [8,11,12]. Leftand right-sided congestion are the typical clinical signs [8]and echocardiography is the best diagnostic tool [13].

All women of a fertile age with a history of heartdisease should undergo pre-conception risk-assessmentand counseling in centers with high expertise for cardiacdiseases in pregnancy. Risk assessment should includehistory and physical examination, 12-lead ECG, andechocardiography. A cardiac CT scan or MRI and exercise testing may be required in specific cases [14].

The most widely used risk assessment score is the modified version of the WHO classification, which takes into account the specific cardiac lesion and divides patients intofour classes of risk. Class I patients have no/mild risk, class IIand III patients have intermediate/high risk, and class IV patients are at very high risk (pregnancy contraindicated) [4].

Severe asymptomatic aortic stenosis, as present in thepatient of this case, is classified as WHO class III, with a19–27% risk of maternal cardiac events. Expert counseling, monthly follow-ups during pregnancy, and deliveryin a specialized center are advised [4]. Figure6describesthe management of pregnancy and delivery in womenwith heart disease.

Pregnancy is generally well tolerated in patients with moderate or severe asymptomatic aortic stenosis, whereas symptomatic severe stenosis patients are more likely to requirehospitalization. The most common complications are: heartfailure, pulmonary edema, and arrhythmias [15,16]. Despitethe severity of our patient’s stenosis, she was asymptomaticbefore conception and maintained a good functional statusthroughout the pregnancy. Valvular gradients, as measuredby echocardiography, can increase during pregnancy due tothe physiological hemodynamic changes that occur.

Patients with a history of valve replacement carry a specific risk of prosthetic thrombosis (higher for mechanicalvalves) and valve deterioration (in the case of biologica valves). Bioprosthetic valves, like the one carried by ourpatient, are usually advised in women of childbearing agebecause of the lower requirement for anticoagulation therapy [17,18].

Although no RCTs have assessed the safety of epidural analgesia in patients with aortic stenosis (vasoplegia is of particular concern in patients highly dependent on pre-load),some case reports exist describing the feasibility of epiduralanalgesia to facilitate labor and minimize the pain-responsein obstetric patients with severe aortic stenosis [19,20].

The management of induction and labor in a pregnantwoman with aortic stenosis depends on the grade of thevalvular stenosis (moderate or severe) and the presence ofsymptoms. In asymptomatic patients with severe aorticstenosis, it is important to consider an individual approach[4]. The woman’s cardiac status, the fetus’s well-being,and the cervix characteristics should all influence thechoice and timing of delivery. Although the rate of caesarean section in patients with aortic stenosis is high, at 75%,evidence exists suggesting that vaginal labor should bepreferred unless the obstetrician specifically advisesagainst it [15,21]. Studies comparing methods of deliveryin patients with different heart diseases report caesareansection rates to range from 21 to 55% [22,23]. Moreover,caesarean section is associated with a higher risk of adverse outcomes in the mother [15], earlier delivery, alower birth weight, major blood loss, higher infection risk,venous thrombosis, and thrombo-embolism [23].

Our case shows that labor induction combined with epidural analgesia in a patient with a severe aortic stenosis ispossible. The patient was followed by adequate andcontinuous hemodynamic and obstetric monitoring; sheshowed no signs of heart failure, ventricular dysfunction,pulmonary hypertension, or aortic dilation, and demonstrated strong will throughout labor and childbirth.

Because of a favorable initial Bishop score, inductionwas accomplished by starting with low doses of oxytocinfollowed by artificial rupture of the membranes at a laterstage, showing that these methods of induction can besafe in women with heart disease [4].

We chose to use the ClearSight™hemodynamic monitoring system during the first phase of labor to satisfy our requirement for a fast and precise hemodynamic monitoringdevice that was also non-invasive. For the second stageof labor, we supplemented our system with arterial cannulation and the minimally-invasive FloTrac™systemfor beat-by-beat blood pressure and hemodynamicmonitoring. This permitted us to allow labor to progressnaturally, and uterine contractions alone facilitated thedescent of the fetus to the pelvic floor. However, whencontinuous cardiotocography showed initial alterations,vacuum extraction was performed. Our aim was tominimize the maternal expulsive efforts, which could haveworsened her hemodynamic status, and reduced thesecond stage of labor. We propose a clinical managementalgorithm, as shown in Fig.7[24,25].

Conclusion

The case study herein reported demonstrates thatepidural analgesia and oxytocin induction are possiblefor the labor management of parturients with severe aortic stenosis given that continuous non-invasive followedby invasive hemodynamic monitoring can be providedand given the absence of any obstetric or cardiologiccontraindications and the strong will of the patient. Aprotocol for prompt intervention must always be inplace to provide for the management of any potentialcomplications. A proactive approach is perhaps the mostappropriate for this kind of patient.

Supplementary Information

Supplementary informationaccompanies this paper at https://doi.org/10.1186/s12947-020-00226-x.

Additional file 1.

Additional file 2.

Acknowledgements

None.

Authors’contributions

LV, FM, SD and AS conceived, designed and drafted the manuscript. LD, TD, ASand TB critical revised the manuscript for important intellectual content. DP, AL and FB edited the ultrasound images and critical reviewed the manuscript. Allauthors read and approved the final manuscript.

Funding

No funds were received for the manuscript’s preparation.

Availability of data and materials

Original data files are available upon request.

Ethics approval and consent to participate

No ethical approval was needed for this case report.

Consent for publication

Informed consent for publication of completely anonymous data wasobtained from the patient.

Competing interests

Luigi Vetrugno received travel support for Congress Lecture by CookMedical. The other authors declare no conflict of interest.

Author details

1Department of Medicine, Gynecology and Obstetrics Clinic, University ofUdine, Via Colugna n° 50, 33100 Udine, Italy.2Department of Maternal andChild Health, University-Hospital of Udine, P.le S. Maria della Misericordia n°15, 33100 Udine, Italy.3Department of Medicine, Anesthesia and IntensiveCare Clinic, University of Udine, Via Colugna n° 50, 33100 Udine, Italy.4Department of Anesthesia and Intensive Care, University-Hospital of Udine,P.le S. Maria della Misericordia n° 15, 33100 Udine, Italy.5Department ofCardiothoracic Sciences, University-Hospital of Udine, P.le S. Maria dellaMisericordia n° 15, 33100 Udine, Italy.

Received: 22 May 2020 Accepted: 20 October 2020

Published online:02November 2020