Successful patent ductus arteriosus device closure in a patient with massive pulmonary embolism

Abstract

Patent ductus arteriosus, an essential vasculature structure during fetal life that becomes abnormal after 3 months of age, may be silent. However, the incidence of silent patent ductus arteriosus is as high as 1 in 500 patients. Existence of patent ductus arteriosus leads to left-to-right shunt. The development of pulmonary embolism in left-to-right shunt is rare. We present a case of a 33-year-old male patient who was incidentally diagnosed to have large patent ductus arteriosus along with the left-to-right shunt while being treated for pulmonary embolism. The patient was treated electively with device closure of patent ductus arteriosus.

<Learning objective: Pulmonary embolism in left-to-right shunt (although there is a large patent ductus arteriosus) cannot be overlooked. Device closure of large patent ductus arteriosus is possible in patients with massive pulmonary embolism.>

Introduction

Ductus arteriosus is considered as an essential vasculature structure during fetal life but becomes abnormal after 3 months of age [1]. Patent ductus arteriosus (PDA) is one of the common congenital heart problems. In many patients, it may remain silent (asymptomatic) throughout life or it may be diagnosed accidentally or when it becomes symptomatic. The incidence of silent PDA is as high as 1 in 500 patients [2]. The incidence of pulmonary embolism (PE), one of the fatal conditions with mortality rate >15% in the first 3 months after diagnosis, is low in the presence of PDA [3]. The development of PE is of particular significance in a patient with left-to-right shunt. It can compromise pulmonary vascular function and can lead to increase in pulmonary vascular resistance and thereby worsening of pulmonary hypertension. We present a case of a 33-year-old male diagnosed with large PDA with left-to-right shunt which was asymptomatic but became symptomatic when treated for PE.

Case report

A 33-year-old male presented to the clinic with chief complaints of sudden onset of progressively worsening breathlessness over the previous 2 days. At the age of 20 years, he experienced mild exertional dyspnea and palpitation. However, he had not been diagnosed with coronary heart disease (CHD). The risk factors for CHD (i.e. diabetes, hypertension, and smoking) were also absent. He did not have prior history of trauma, surgery, or varicose veins.

On admission, the patient's blood pressure and oxygen saturation were 90/70 mmHg and 88%, respectively. Echocardiogram evaluation of the patient revealed right ventricular systolic pressure of about 88 mmHg and tricuspid annular peak systolic excursion (TAPSE) around 14 mm suggesting significant right ventricular (RV) dysfunction. Laboratory investigation showed positive D-dimer test as well as elevated cardiac enzymes (troponin-T 0.4 ng/ml). Electrocardiogram (ECG) showed sinus tachycardia (non-specific T wave changes) with prominent right atrial (RA) and RV enlargement with northwest axis. ECG at the time of admission was suggestive of pulmonary embolism (Fig. 1). We suspected diagnosis of pulmonary hypertension.

Fig. 1.

Electrocardiogram of the patient at the time of admission.

Venous Doppler of the lower limbs was normal. All blood investigations including work-up for thrombophilia, i.e. protein C, protein S, and antithrombin-III, were normal. Serial blood culture was done to rule out infective endarteritis and was found negative.

Computed tomography (CT) pulmonary angiogram also revealed a large saddle thrombus at the bifurcation of the left main pulmonary artery (Fig. 2). We confirmed the diagnosis of pulmonary hypertension. In view of hypotension, the patient was treated with thrombolytic agent tenecteplase followed by oral anticoagulant warfarin to achieve target international normalized ratio (INR) 2–3. An oral phosphodiesterase-5 inhibitor (tadalafil 10 mg) was prescribed for the treatment of pulmonary hypertension.

Fig. 2.

Computed tomography pulmonary angiogram showing a large thrombus at the origin of the left pulmonary artery (LPA).

Post-thrombolysis, systolic heart murmur was noticed in the left infra-clavicular region. Follow-up echocardiography showed significant improvement in RV function (TAPSE >18 mm). Repeat angiogram, performed after thrombolysis, revealed a large non-restrictive PDA (Fig. 3) with left-to-right shunt. Follow-up ECG after the acute event also suggested left atrial (LA) and left ventricular (LV) volume overload which correlated well with a large left-to-right shunting PDA.

Fig. 3.

Descending aortic angiogram showing large patent ductus arteriosus (PDA) with left-to-right shunt. Ao, aorta; PA, pulmonary artery.

The patient was reassessed after 6 months. An ECG displayed evidence of biventricular enlargement and a normal QRS axis. Chest X-ray indicated cardiomegaly with increased pulmonary blood flow. Cardiac catheterization showed that the mean pulmonary artery pressure was 46 mmHg (which was less than 50% of systemic pressure) with Qp:Qs more than 3.4. The angiogram also showed large PDA (20 mm) with left-to-right shunt. A test occlusion was done with a favorable response and it was decided to close the defect with a PDA device (24 mm × 26 mm) (CERA™) PDA occluder (Lifetech Scientific Co Ltd., Shenzhen, China) as shown in Fig. 4. ECG (Fig. 5) after PDA device closure showed LA and LV enlargement.

Fig. 4.

Descending aortic angiogram (after device closure) showing patent ductus arteriosus with device in situ.

Fig. 5.

Electrocardiogram of the patient after patent ductus arteriosus device closure.

The patient tolerated the procedure well and had an uneventful recovery. Oral anticoagulation was continued for 6 months. On the 6-month follow-up, the patient was symptomatically better with improved exercise tolerance and mild residual LV systolic dysfunction due to long-standing LV dilation and increase in LV afterload following PDA device closure. Angiotensin-converting enzyme inhibitor was prescribed on follow-up.

Discussion

The presence of PE in a patient having large PDA with left-to-right shunt is rare in the absence of any other risk factors for thromboembolism. Most of the cases reported have been secondary to infective endocarditis and due to the development of vegetation 4, 5. This patient had no feature of infective endocarditis and did not have any of the traditional risk factors for pulmonary thromboembolism, i.e. surgery, trauma, immobilization, deep-vein thrombosis, cancer, smoking, hypertension, CHD, or pneumonia. We had also carried out clinical investigations to determine the presence of secondary causes of massive PE related to hypercoagulability [6]. However, we got negative results for antithrombin-III, protein C, and protein S deficiency indicating the absence of thrombophilia in our patient. The mechanism or reason for PE in our patient is not clear.

PDA is usually diagnosed easily by its characteristic murmur. However, when there is pulmonary hypertension or increased pulmonary vascular resistance due to embolism, it may cause a significant reduction in the shunt and may even lead to reversal of shunt causing the murmur to disappear. In our case also, RV systolic pressure (80 mmHg) was equal to the systolic blood pressure (80 mmHg) at the time of admission. This may explain why the heart murmur was not present even though large PDA (∼20 mm) was present and the patient remained undiagnosed initially. However, upon successful treatment of PE, the murmur – an indication of PDA with left-to-right shunt – reappeared.

Moller et al. [7] reported a similar case where a patient experienced near fatal recurrent PE which originated from PDA. However, PDA was diagnosed intraoperatively during endarterectomy and was not suspected earlier. Yeh et al. [8] reported a case in which a 25-year-old woman presented signs and symptoms of PE on her post-partum day 7 and she was treated for PE aggressively. However, upon three-dimensional CT, giant PDA was diagnosed. Another case study was reported by Khush et al. [9], in which a 40-year-old male patient, diagnosed with uncorrected PDA, experienced pulmonary infarction as a result of pulmonary artery thrombosis.

Pressure and oximetry studies suggested that PDA was operable and hence closure of PDA was contemplated. During PDA device closure, the appropriately sized device was tugged close to PDA without delivery to watch for the raise in LV end-diastolic pressure (LVEDP) and the development of pulmonary edema as well as residual shunt across the PDA by an angiogram in descending aorta. There was no residual shunt and the LVEDP did not rise significantly (rise from 10 mm to 12 mm) so as to produce pulmonary edema. We considered it as a favorable response to occlusion test, and then the device was delivered safely.

Due to early recognition of the presence of PDA, the patient was successfully managed with PDA device closure after treating PE and pulmonary arterial hypertension with anti-coagulant and phosphodiesterase-5 inhibitors, respectively. There was no evidence of clinically significant embolism during hospitalization as well as during the 6-month follow-up.

We suggest that in selected patients at least reassessment after initial treatment of acute PE will help to uncover the diagnosis of PDA, because PDA may often be the source of the thrombus 10, 11. There is a possibility of treating large PDA by PDA device closure even in patients who have suffered massive PE.

Conflict of interest

The authors declare no conflict of interest.