The detection of pulmonary embolisms after a coronary artery bypass graft surgery by the use of 64-slice multidetector CT

Risk factors for acute pulmonary embolism in patients with off-pump coronary artery bypass grafting: implications for nursing

Objective

Acute pulmonary embolism (APE) is a serious complication after off-pump coronary artery bypass grafting (OPCABG). We aimed to analyze the risk factors for APE in patients with OPCABG.

Methods

In this retrospective, observational study, patients with OPCABG who were treated in our hospital from 1 January 2018 to 31 March 2020 were included. The basic characteristics of patients and results of preoperative laboratory examinations were collected and analyzed.

Results

A total of 707 patients with OPCABG were included and the incidence of APE was 3.21%. Left ventricular ejection fraction (LVEF), a history of smoking, number of bypass grafting, duration of surgery, and age were significant risk factors for APE in patients with OPCABG. The areas under the curves of LVEF, number of bypass grafting, duration of surgery, and age were 0.773, 0.759, 0.738, and 0.723, respectively. The cutoff values of LVEF, number of bypass grafting, duration of surgery, and age were 59.84, 3.18, 237.42, and 73.28, respectively.

Conclusions

LVEF, a history of smoking, number of bypass grafting, duration of surgery, and age may be risk factors for APE in patients with OPCABG. Early measures should be taken to target these risks to prevent APE.

Bleeding complications after cardiac surgery, before anticoagulation start and then with argatroban or heparin in the early postoperative setting

OBJECTIVES

After elective cardiac surgery a postoperative anticoagulation is obligatory. With critically ill patients the conventional anticoagulation standard heparin is sometimes impossible, e.g. based on HIT II. Then, argatroban is currently a possible alternative, however, due to its impaired metabolism in critically ill patients, anticoagulation effect is harder to anticipate, thus resulting in higher bleeding risk. Furthermore, to date no antidote is available. Hence, severe postoperative bleeding incidents under anticoagulation are commonly mono-causal attributed to the anticoagulation itself. This study concentrates on the number of well-defined postoperative bleeding incidents before any anticoagulation started, then actually under argatroban as well as compared to those under heparin (or switched from heparin to argatroban).

MATERIAL AND METHODS

Retrospective study including 215 patients undergoing elective cardiac surgery with a postoperative stay in ICU ≥48 h. Postoperative bleeding complications before and after start of anticoagulation were evaluated. Definition of bleeding complications were: decrease of hemoglobin by more than 2 g/dl without dilution (mean value of volume balance plus one standard deviation) and/or increased need of red blood cell transfusion/day (average transfusion rate + 2 standard deviations).

RESULTS

Within the study group of 215 patients, 143 were treated with heparin, 43 with argatroban, 29 switched from heparin to argatroban. Overall, 26.5% (57/215) postoperative bleeding complications occurred. In 54.4% (31/57) bleeding complications occurred before start of anticoagulation; in 43.6% (26/57) after. Of these, 14 bleeding incidents occurred under heparin 9.8% (14/143), 6 under argatroban 14% (6/43) and 6 switched 20.7% (6/29). Higher bleeding complications before start of anticoagulation was related to concomitant factors influencing the overall bleeding risk; e.g. score of severity of illness. These observations further correlate with postoperative, but not anticoagulation induced mortality rate of 2.8% of then given heparin, 20.9% then argatroban, 20.7% then switched.

CONCLUSIONS

Postoperative bleeding complications cannot simply be attributed to anticoagulation since occurring often before anticoagulation was started. The risk for bleeding complications after start of anticoagulation was quite comparable for argatroban and heparin. Accordingly, the influence of argatroban on bleeding complications in the postoperative period may be less significant than previously thought.

Frequency of Deep Vein Thrombosis and/or Pulmonary Embolism After Coronary Artery Bypass Grafting Investigation Regardless of Clinical Suspicion

Venous thromboembolism (VTE) includes deep vein thrombosis (DVT) and/or pulmonary embolism (PE). Many surgeons and clinicians believe that VTE after coronary artery bypass grafting (CABG) has little clinical significance because it is seldom diagnosed. This study aimed to identify VTE after CABG, independent of clinical suspicion. In this prospective, observational, single-center study, 100 patients underwent computed tomographic pulmonary angiography (multidetector-64) and lower extremity venous compressive ultrasound after elective CABG. Patients with high risk for VTE were excluded. Aspirin was maintained throughout the preoperative and postoperative periods, and early ambulation was encouraged. Postoperatively, no mechanical or heparin prophylaxis was used in any patients. At the discretion of the surgeons, 83 surgeries were on-pump, and 17 were off-pump. On average, tomography and ultrasound were performed 7 ± 3 days after CABG. Isolated PE was observed in 13 of 100 patients (13%), simultaneous PE and DVT in 8 of 100 (8%), and isolated DVT in 4 of 100 (4%), thus totaling 25/100 VTEs (25%). Of the 21 PEs, 3 of 21 (14%) involved subsegmental, 15 of 21 (71%) segmental, 1 of 21 (5%) lobar, and 2 of 21 (10%) central pulmonary arteries. Of the 12 DVTs, all were distal (below the popliteal vein), and 2 of 12 (17%) were also proximal; 5 of 12 (42%) were unilateral, of which 3 of 5 (60%) on the contralateral saphenous vein-harvested leg. No VTE caused hemodynamic instability, and none was clinically suspected. In conclusion, VTEs were frequent, some extensive proximal VTEs occurred, but most were distally localized. Many patients in this series would have been discharged without diagnosis of and treatment for PE and/or DVT.

Prevalence and significance of clinically unsuspected pulmonary embolism: detection using coronary computed tomography angiography

BACKGROUND AND AIM

Clinically unsuspected pulmonary embolism can be detected using coronary computed tomography (CT), but the clinical significance of unsuspected pulmonary embolism remains unclear.

METHODS

Pulmonary embolism was assessed using consecutive coronary CT from March 2003 to June 2007 to assess 1077 patients. Coronary CT was performed using a 16-row multidetector CT (MDCT) scanner with ECG-gating. A radiologist and a cardiologist retrospectively assessed the images of pulmonary arteries to arrive at a consensus diagnosis.

RESULTS

Unsuspected pulmonary embolism was detected in 32/1,077 (3.0%) patients. No significant difference was observed with regard to death and acute pulmonary embolism between patients with and without unsuspected pulmonary embolism at five years (6.7% vs. 4.1%, p = 0.61). Prior cardiac surgery within three months of diagnosis of pulmonary embolism was an independent risk factor for unsuspected pulmonary embolism, which was detected in 10/89 (11%) of such patients. The absence of anticoagulant therapy was a risk factor (p = 0.015) for unsuspected pulmonary embolism post-cardiac surgery. Although only one out of 10 patients received anticoagulant therapy, none of the 10 experienced critical events. Five of the 10 patients underwent repeated coronary CT, and the embolus disappeared regardless of its size and location in four of the five patients who did not receive anticoagulant therapy.

CONCLUSIONS

The prevalence of unsuspected pulmonary embolism detected using coronary CT was 3.0%. Prior cardiac surgery within three months of diagnosing pulmonary embolism was an independent risk factor for unsuspected pulmonary embolism. The long-term clinical outcomes of patients with unsuspected pulmonary embolism were favorable.