Clinical Features of Acute Massive Pulmonary Embolism Complicated by Radiofrequency Ablation: An Observational Study

Right ventricular area predicts short-term mortality in acute pulmonary embolism based on CT pulmonary angiography: A retrospective study

We performed this cohort study to assess the prognostic value of right ventricular size, including diameter, area, and volume, in short-term mortality of acute pulmonary embolism (APE) based on 256-slice computed tomography compared with D-dimer, creatine kinase muscle and brain isoenzyme, and Wells scores. A total of 225 patients with APE, who were followed up for 30 days were enrolled in this cohort study. Clinical data, laboratory indices (creatine kinase, creatine kinase muscle and brain isoenzyme, and D-dimer), and Wells scores were collected. The 256-slice computed tomography was used to quantify cardiac parameters (RVV/LVV, RVD/LVD-ax, RVA/LVA-ax, RVD/LVD-4ch, RVA/LVA-4ch) and the diameter of the coronary sinus. Participants were divided into non-death and death groups. The values mentioned above were compared between the 2 groups. The RVD/LVD-ax, RVA/LVA-ax, RVA/LVA-4ch, RVV/LVV, D-dimer, and creatine kinase levels were significantly higher in the death group than in the non-death group (P < .05). The active period of the malignant tumor, heart rate ≥ 100 beats/minutes, and RVA/LVA-ax were positively correlated with early death from APE (P < .05). Active stage of malignant tumor (OR:9.247, 95%CI:2.682-31.888, P < .001) and RVA/LVA-ax (OR:3.073, 95%CI:1.447-6.528, P = .003) were independent predictors of early death due to APE. According to the receiver operating characteristic curve, the cutoff point of RVA/LVA-ax was 1.68 with a sensitivity of 46.7% and specificity of 84.8%. The measurement of ventricular size in the short-axis plane is more convenient and reliable than that in the 4-chamber cardiac plane. RVA/LVA-ax is an independent predictor of early death from APE, and when RVA/LVA-ax > 1.68, the risk of early death from APE increases.

Current Venous Thromboembolism Prevention Practices Following Endovascular Electrophysiological Procedures in the UK: A retrospective study

Objectives

This study aimed to evaluate the incidence of venous thromboembolism (VTE) cases at the Leeds General Infirmary, Leeds, UK, as well as to survey current VTE practices and preventative strategies at other UK-based electrophysiology (EP) centres.

Methods

This retrospective study involved all patients who underwent EP studies at Leeds General Infirmary from January 2014 to December 2016. In addition, a telephone survey was conducted of 35 other UK-based EP centres.

Results

Of 1,020 patients who underwent EP studies at Leeds General Infirmary, 0.3% developed a post-procedural VTE. In addition, 28 other EP centres were surveyed (response rate: 80%), of which 18% reported VTE cases in the last two years. There were wide variations in VTE prevention strategies and the use of post-procedural thromboprophylaxis.

Conclusion

Despite the low incidence of VTE cases, many UK centres continue to experience this complication with no consensus on optimal preventative strategies. As current VTE guidelines do not recommend antithrombotics after EP studies, further research is needed.

Acute Hemodynamic and Tissue Effects of Cryoballoon Ablation on Pulmonary Vessels: The IVUS-Cryo Study

Background

Cryoballoon‐based pulmonary vein isolation (CB‐PVI) has been widely used for the treatment of atrial fibrillation. Although generally safe and effective, the procedure may be associated with pulmonary vein (PV) stenosis and bronchial or esophageal injury. The mechanisms leading to these complications have not been studied in detail. Our aim was to examine acute effects of cryoballoon on the pulmonary vessel and right heart pressures as well as PV wall morphology.

Methods and Results

In 8 patients (5 men, mean age 55±14 years) undergoing CB‐PVI, pressure in each PV was measured by catheter located inside the PV directly before and after CB‐PVI. The right atrial, right ventricular, and pulmonary artery pressures as well as pulmonary arterial wedge capillary pressure in the pulmonary artery branch corresponding to target PV were also measured. Morphological changes in PVs were assessed using intravascular ultrasonography.

There were no significant differences in PV pressures before and after ablation. The pulmonary arterial wedge capillary pressure significantly increased during cryoapplication (left superior: 20±10 versus 29±8.5 mm Hg, P=0.004; left inferior: 24±10 versus 32±6 mm Hg, P=0.012; right superior: 25±9 versus 35±10 mm Hg, P=0.002; right inferior: 24±10 versus 37±12 mm Hg, P=0.0036). The right atrial and pulmonary artery pressures increased significantly after CB‐PVI (9±6 versus 13±8 mm Hg, P=0.004, and 20±9 versus 24±10 mm Hg, P=0.048, respectively). Intravascular ultrasonography showed acute edema and dissection‐like changes causing relative lumen narrowing in 90% of PVs.

Conclusions

CB‐PVI causes significant rise in pulmonary artery and right atrial pressures as well as PV wall damage. The clinical significance of these findings warrants further investigations.

Pulmonary Hypertension due to Radiofrequency Catheter Ablation (RFCA) for Atrial Fibrillation: The Lungs, the Atrium or the Ventricle?

Atrial fibrillation is the most common heart rhythm disorder in United States, characterised by rapid and irregular beating of both the atria resulting in the similar ventricular response. While rate and rhythm control using pharmacological regimens remain the primary management strategies in these patients, radiofrequency catheter ablation (RFCA) is rapidly rising as an alternative modality of treatment. Increase in the incidence of RFCA has shed light on complications associated with this procedure. Pulmonary hypertension (PH) is one of the long-term complications that has been observed postcatheter ablation. There have been multiple mechanisms which have been proposed to explain these elevated pulmonary pressures. These include the involvement of the lungs due to pulmonary vein stenosis, pulmonary vein occlusion and, rarely, pulmonary embolism. Radiofrequency catheter ablation can also lead to scarring of the atrium which can cause left atrial diastolic dysfunction leading to elevated pulmonary pressures. Recently, it was also proposed that elevated pulmonary pressure was related to the unmasking of left ventricular diastolic dysfunction occurring after this procedure. In this article, we review all the mechanisms that are associated with the development of pulmonary hypertension in patients undergoing RCFA for atrial fibrillation and the approach to diagnosis and management of such patients.

Prevention and Treatment of Lower Limb Deep Vein Thrombosis after Radiofrequency Catheter Ablation: Results of a Prospective active controlled Study

We conducted a prospective, single-center, active controlled study from July 2013 to January 2015, in Chinese patients with rapid ventricular arrhythmia who had received radiofrequency catheter ablation (RFCA) treatment to determine formation of lower extremity deep vein thrombosis (LDVT) post RFCA procedure, and evaluated the effect of rivaroxaban on LDVT. Patients with asymptomatic pulmonary thromboembolism who had not received any other anticoagulant and had received no more than 36 hours of treatment with unfractionated heparin were included. Post RFCA procedure, patients received either rivaroxaban (10 mg/d for 14 days beginning 2–3 hours post-operation; n = 86) or aspirin (100 mg/d for 3 months beginning 2–3 hours post-operation; n = 90). The primary outcome was a composite of LDVT occurrence, change in diameter of femoral veins, and safety outcomes that were analyzed based on major or minor bleeding events. In addition, blood flow velocity was determined. No complete occlusive thrombus or bleeding events were reported with either of the group. The lower incidence rate of non-occluded thrombus in rivaroxaban (5.8%) compared to the aspirin group (16.7%) indicates rivaroxaban may be administered post-RFCA to prevent and treat femoral venous thrombosis in a secure and effective way with a faster inset of action than standard aspirin therapy.