Acute massive pulmonary embolism without deep venous thrombosis | |
DOI: 10.5606/e-cvsi.2014.223 | |
Özge Korkmaz, 1 M. Birhan Yılmaz, 2 Sabahattin Göksel, 1 Müslim Gül, 3 Öcal Berkan1 | |
1Department of Cardiovascular Surgery, Medical Faculty of Cumhuriyet University, Sivas, Turkey 2Department of Cardiology, Medical Faculty of Cumhuriyet University, Sivas, Turkey 3Department of Cardiovascular Surgery, Sivas Numune Hospital, Sivas, Turkey |
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Keywords: Computed tomography; coronary artery bypass grafting; deep venous thrombosis; pulmonary embolism | |
Acute pulmonary embolism is rarely encountered following coronary artery bypass graft (CABG) surgery. Herein, we present a 75-yearold
woman who developed an acute massive pulmonary embolism without deep venous thrombosis 20 days after four-vessel CABG
surgery. She was diagnosed using a thoracic computed tomography scan, yielding subtotal occlusion of the right and left pulmonary
arteries. She was administered successful thrombolytic therapy and discharged uneventfully without problems during the follow-up
period. |
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Acute pulmonary embolism (PE) following cardiac
bypass surgery is an uncommon complication, yet
leads to potentially fatal complications. It is known
to increase morbidity and mortality. The estimated
incidence of acute PE ranges between 0.5% and 4%.[1]
The diagnosis is often challenging as symptoms
such as shortness of breath, chest pain, hypoxia, and
leg swelling are often attributed to pre-procedural
changes. Therefore, the diagnosis of PE or deep vein
thrombosis (DVT) may be challenging. Furthermore,
on occasion, DVT may not accompany acute PE after
coronary artery bypass graft (CABG). In the light
of the current literature data, we present a case who
developed acute PE after CABG in the absence of
detectable DVT along with successful recovery after
thrombolytic therapy. |
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CASE PRESANTATION
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A 75-year-old woman (body mass index <20) who
did not have accompanying diabetes mellitus or
hyperlipidemia, underwent coronary angiography
which showed serious lesions of the left anterior
descending artery, right coronary artery, and
circumflex coronary artery after presenting with
unstable angina pectoris. According her medical
story, she was on a beta blocker for hypertension.
She underwent a four-vessel CABG with the use
left internal mammarian artery for grafting the left
anterior descending artery, and saphenous vein graft
which was harvested using a classic method for
grafting first branch of obtuse marginal, first branch
of diagonal and right coronary artery. The surgical procedure was not complicated with a cross-clamp
time of 79 minutes and with a cardiopulmonary
bypass time of 116 minutes. During the first
operative night, all vital parameters were steady
and there were no complications. On the first
postoperative day, she was transferred to the ward.
She was administered a daily dose of 8000 IU low
molecular weight heparin in addition to 100 mg of
acetyl salicylic acid and 75 mg of clopidogrel. She
was discharged on the 10th postoperative day. Prior
to discharge, she was prescribed acetyl salicylic
acid, clopidogrel, metoprolol, atorvastatin and
ramipril. Twenty days postoperatively, the patient
was admitted to the emergency department with
shortness of breath and chest pain, which started
four hours earlier. On admission, vital parameters
were as follows: respiratory rate 35/minute, heart
rate 135/minute, and blood pressure 85/45 mmHg
with moderate oxygen desaturation (85%), and cold
sweats. Echocardiography showed sinus tachycardia
along with negative T waves on the anterior leads.
Transthoracic echocardiography was performed
immediately and revealed mild right ventricular
(RV) dilatation with hypocontractility in the
interventricular septum. A differential diagnosis of acute coronary syndrome (ACS) versus acute PE was
considered. Therefore, cardiac enzymes and D-dimer
were studied. Troponin level was 0.19 ng/mL and
D-dimer level was 17.48 ng/mL. In the light of
these findings, an emergent thoracic computed
tomography (CT) scan was sought and it confirmed
subtotal occlusion of the right and left pulmonary
arteries (Figure 1). In the meantime, she had
similar ECG and echocardiographic abnormalities
in the previous records, postoperatively; hence,
the diagnosis of ACS was eliminated. In addition,
her deep venous system was investigated using
Doppler ultrasonography which produced negative
results. Since her hemodynamic condition was not
improving, she was referred for thrombolytic therapy
of 0.6 mg/kg tissue plasminogen activator (tPA). No
complications were detected during this protocol.
During in-hospital follow-up, troponin levels
slightly increased, then decreased sharply within
24 hours, while the level of D-dimer declined slowly
within four days. She was hospitalized for 10 days
and no complication was seen. She was discharged
with warfarin, acetyl salicylic acid, metoprolol,
atorvastatin, and ramipril. She was scheduled for
visit two weeks later after discharge. |
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Previous retrospective studies reported that acute PE
was an uncommon complication with a maximum
incidence of 0.6%.[2] On the other hand, most of
recent studies introduced an incidence of acute
PE that is higher than the previous reports with
a range between 2.7% and 3.9%.[2] Acute PE is a life-threatening condition. Unfortunately, the
presentation after CABG may be deceptive. Most
patients, as in our case, suffer from ambiguous
symptoms which are not helpful in the tentative
diagnosis of acute PE after CABG. Moreover, these
findings do not help the differential diagnosis of acute
myocardial infarction or congestive heart failure.
Even measuring D-dimer level and the cardiac
enzyme profile may not be helpful for a definitive
diagnosis. In addition, echocardiography is not useful
in the differential diagnosis due to preexisting wall
motion abnormalities, either due to CABG itself
of due to previous infarctions, which may cause
some confusion, though, severe right ventricular
dilatation may help in case of hemodynamically
significant PE.[3] In this present case, the diagnosis
was confirmed with a CT scan due to the fact that
multi-slice CT, which was able to accurately make
the differential diagnosis, was not available in the
emergency department setting. Recent guidelines recommend thrombolytic therapy in patients having acute massive acute PE with a high risk for early death.[4] A number of controlled clinical trials confirm streptokinase, urokinase or alteplase therapy for patients suffering from significant acute PE. Currently, there is a consensus that patients with massive acute PE presenting with serious right ventricular failure with or without clinical instability and cardiogenic shock should be treated with thrombolytic agents expeditiously.[5] Hence, in our case, as soon as the definitive diagnosis was made, thrombolytic therapy of 0.6 mg/kg tPA was dispensed within one hour in the intensive care unit. After therapy, she was administered warfarin and low-molecular weight heparin. Symptoms and hemodynamic status recovered remarkably in 48 hours. In conclusion, although acute PE is an uncommon complication after cardiac surgery, the rate of incidence is higher than expected. Early diagnosis and rapidly tailored medical therapy is crucial. For the differential diagnosis of acute PE accurately, the gold standard remains to be thoracic CT scanning, particularly if a triple scan is available with multi-slice CT.
Declaration of conflicting interests
Funding |
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