Pulmonary vein orientation is independently associated with outcomes following cryoballoon-based atrial fibrillation ablation

Evaluating the consistency in different methods for measuring left atrium diameters

BACKGROUND

The morphological information of the pulmonary vein (PV) and left atrium (LA) is of immense clinical importance for effective atrial fibrillation ablation. The aim of this study is to examine the consistency in different LA diameter measurement techniques.

METHODS

Retrospective imaging data from 87 patients diagnosed with PV computed tomography angiography were included. The patients consisted of 50 males and 37 females, with an average age of (60.74 ± 8.70) years. Two physicians independently measured the anteroposterior diameter, long diameter, and transverse diameter of the LA using six different methods. Additionally, we recorded the post-processing time of the images. Physician 1 conducted measurements twice with a one-month interval between the measurements to assess intra-rater reliability. Using the intraclass correlation coefficient (ICC), the consistency of each LA diameter measurement by the two physicians was evaluated. We compared the differences in the LA diameter and the time consumed for measurements using different methods. This was done by employing the rank sum test of a randomized block design (Friedman M test) and the q test for pairwise comparisons among multiple relevant samples.

RESULTS

(1) The consistency of the measured LA diameter by the two physicians was strong or very strong. (2) There were statistical differences in the anteroposterior diameter, long diameter, and transverse diameter of LA assessed using different methods (χ2 = 222.28, 32.74, 293.83, P < 0.001). (3) Different methods for measuring the diameters of LA required different amounts of time (χ2 = 333.10, P < 0.001).

CONCLUSION

The results of left atrium (LA) diameter measurements conducted by different physicians were found to be reliable. However, the LA diameters obtained through various techniques exhibited variations. It was observed that measuring LA long diameters using only the VR (volume rendering) picture was the most clinically applicable method.

Predictors of late pulmonary vein reconnection in patients with arrhythmia recurrence after cryoballoon ablation-per vein analysis including cardiac computed tomography-based anatomic factors

AIMS

To identify predictors of individual late pulmonary vein (PV) reconnection after second-generation cryoballoon (CB2) ablation. Anatomic indicators of late pulmonary vein reconnection (LPVR) post-CB2 ablation have not yet been studied on an individual PV level, nor weighed against clinical and procedural factors.

METHODS AND RESULTS

Clinical, procedural, and PV anatomic data from 125 patients with a repeat procedure for arrhythmia recurrence after index CB2 ablation were analyzed. Preprocedural computed tomography (CT) evaluated 486 PVs for measurement of size; shape (ovality index); carina width; and orientation angle in frontal (superior/inferior) and transversal (anterior/posterior) plane (with horizontal line 0° as reference and upper/lower half circle as positive/negative value, respectively). Durable isolation in all PVs was demonstrated in 50/125 (40%) patients. Late reconnection rates at the different PVs were as follows: 16% left superior (LS), 12% left inferior (LI), 17% right superior (RS), and 31% right inferior (RI) PV. Multivariable analysis performed per vein showed following independent determinants predicting LPVR: ovality index [odds ratio (OR) 1.61, 95% confidence interval (CI) 1.07-2.41, P = 0.022] and carina width (OR 0.75, CI 0.59-0.96, P = 0.024) for LSPV; carina width (OR 0.71, CI 0.53-0.95, P = 0.020) for LIPV; frontal angle (OR 0.91, CI 0.87-0.95, P < 0.001) for RIPV; and transversal angle (OR 1.15, CI 1.03-1.31, P = 0.032) for RSPV.

CONCLUSION

Cardiac CT-based evaluation of anatomic PV characteristics presented higher predictive value compared to clinical and procedural variables for individual LPVR after CB2 ablation. Pre-procedural identification of unfavourable PV anatomy might be important to tailor the ablation approach.

Atrial fibrillation ablation: the position of computed tomography in pre-procedural imaging

Atrial fibrillation (AF) is the most common supraventricular arrhythmia. Despite significant advances in its treatment, it still remains one of the leading causes of cardiovascular morbidity and mortality. In the last two decades, pulmonary vein isolation (PVI) was developed as the most effective treatment option. The reported effectiveness of a single ablation procedure ranges from 40% to 69% with single, and up to 88% with repeated procedures, with acceptable safety profile. The PubMed database was searched, using terms including ‘atrial fibrillation ablation’, ‘pulmonary vein isolation’, ‘computed tomography’, ‘pulmonary vein anatomy’ and ‘ovality index’. Papers were reviewed for relevance and scientific merit. Different imaging techniques are used for pre-procedural assessment of left atrial (LA) anatomy, of which computed tomography (CT) is the most common. It allows assessing pulmonary vein (PV) anatomy, the LA wall thickness in different regions and the left atrial appendage (LAA) anatomy, together with excluding the presence of intracardiac thrombi. Pre-procedural PVs imaging is important regardless of the selected ablation technique, however, cryoballoon (CB) ablation seems to be particularly anatomy-dependent. Additionally, CT also permits assessment of several PVs characteristics (geometry, dimensions, angulations, the ostium area, orientation and ovality index (OI), which are essential for the patients’ qualification and designing the strategy of AF ablation. In this paper, we have reviewed the role of CT imaging in patients undergoing ablation procedure due to recurrent/symptomatic atrial fibrillation. Moreover, we discussed the relevant literature.

Clinical applications of cardiac computed tomography: a consensus paper of the European Association of Cardiovascular Imaging-part II

Cardiac computed tomography (CT) was initially developed as a non-invasive diagnostic tool to detect and quantify coronary stenosis. Thanks to the rapid technological development, cardiac CT has become a comprehensive imaging modality which offers anatomical and functional information to guide patient management. This is the second of two complementary documents endorsed by the European Association of Cardiovascular Imaging aiming to give updated indications on the appropriate use of cardiac CT in different clinical scenarios. In this article, emerging CT technologies and biomarkers, such as CT-derived fractional flow reserve, perfusion imaging, and pericoronary adipose tissue attenuation, are described. In addition, the role of cardiac CT in the evaluation of atherosclerotic plaque, cardiomyopathies, structural heart disease, and congenital heart disease is revised.

Characteristics of anatomical difficulty for cryoballoon ablation: insights from CT

Background

The limited availability of balloon sizes for cryoballoon leads to anatomical limitations for pulmonary vein (PV) isolation. We conducted a comprehensive systematic analysis on procedural success rate, atrial fibrillation (AF) recurrence rate and complications of cryoballoon ablation in association with the anatomy of the left atrium and PV based on preprocedural CT to gain insights into proper treatments of patients with AF using cryoballoon.

Method

A systematic search of literature databases, including PubMed, Web of Science and Cochrane Library, from the inception of each database through February 2021 was conducted. Search keywords included ‘atrial fibrillation’, ‘cryoballoon ablation’ and ‘anatomy’.

Results

Overall, 243 articles were identified. After screening, 16 articles comprising 1396 patients were included (3, 5 and 8 for acute success, AF recurrence and complications, respectively). Regarding acute success and AF recurrences, thinner width of the left lateral ridge, higher PV ovality, PV ostium-bifurcation distance, shorter distance from the non-coronary cusp to inferior PVs, shallower angle of right PVs against the atrial septum and larger right superior PV (RSPV) were associated with poor outcomes. Regarding complications, shorter distance between the RSPV ostium and the right phrenic nerve, larger RSPV-left atrium angle, larger RSPV area and smaller right carina width were associated with incidences of phrenic nerve injury.

Conclusion

This study elucidated several key anatomical features of PVs possibly affecting acute success, AF recurrence and complications in patients with AF using cryoballoon ablation. CT analysis has helped to describe benefits and anatomical limitations for cryoballoon ablation.

Comparison of atrial fibrillation ablation using cryoballoon versus radiofrequency in patients with left common pulmonary veins: mid-term follow-up results

PURPOSE

Cryoballoon (CB) and radiofrequency (RF) ablation techniques have similar outcomes for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). However, there is limited data about the impact of different ablation strategies in patients with left common pulmonary vein (LCPV). Our aim was to compare the safety and efficacy of RF and CB ablation in AF patients with LCPV.

METHODS

One hundred and twenty-seven (n = 80 CB and n = 47 RF) AF patients with LCPV detected by preprocedural computerized tomography (CT) were included in the study. Ostial dimensions and trunk distance were measured in all patients. Atrial tachyarrhythmia (ATa) recurrence was defined as detection of AF, atrial flutter, or atrial tachycardia (≥ 30 s) after a 3-month blanking period.

RESULTS

There was no significant difference in acute procedural success rates for PVI (97.5% in CB and 97.9% in RF, respectively, P = 0.953) and complication rates were similar between the groups (6 (7.5%) in CB and 4 (8.5%) in RF, respectively, P = 1.000). During a median follow-up of 20.7 (4.8-50.2) months for CB and 20.5 (6.2-36.0) months for RF, ATa recurrence was 35.0% and 38.2%, respectively (P = 0.777). Multivariate analysis did not reveal any of the morphologic parameters of LCPV as a significant predictor of ATa recurrence.

CONCLUSIONS

Our findings demonstrated that both CB and RF ablation techniques have similar efficacy and safety in AF patients with LCPV during the mid-term follow-up.

Immediate and long-term outcomes of cryoballoon catheter ablation in patients with atrial fibrillation and left common pulmonary vein anatomy

PURPOSE

The efficacy of cryoballoon (CB) for atrial fibrillation (AF) ablation is still debatable in case of anatomical variations like left common pulmonary vein (LCPV). We aimed to assess the impact of LCPV trunk on the acute and long-term clinical outcomes in patients with CB based AF ablation.

METHODS

We compared a total of 82 AF patients (62.5% paroxysmal and 37.5% persistent) who underwent pulmonary vein isolation using CB (LCPV+ group) with a propensity score-matched cohort of 76 AF patients (LCPV- group) (61.8% paroxysmal and 38.2% persistent). Preprocedural computed tomography was performed in all patients and ostial dimensions and trunk distance were measured. Atrial tachyarrhythmia (ATa) recurrence was defined as detection of AF, atrial flutter, or atrial tachycardia (≥ 30 s) after a 3-month blanking period.

RESULTS

Acute procedural success was similar between the groups (100% and 98.7% for LCPV- and LCPV+, respectively, P = 0.991). Overall, 22/76 (28.9%) patients in LCPV- and 21/82 (25.6%) patients in LCPV+ had ATa recurrence at a mean follow-up of 31 ± 15 months (P = 0.770). A multivariate analysis identified only the left atrial (LA) diameter as a predictor of recurrent ATs (HR, 3.28; 95% CI, 1.67-6.41; P = 0.001). In the LCPV+ group, patients with single application had higher ATa recurrence (8/18 patients) compared with sequential freeze group (13/64 patients) (P = 0.042).

CONCLUSIONS

Our findings indicated that CB was an effective tool in patients with LCPV and freedom from ATa was similar between LCPV- and LCPV+ groups. Only LA diameter predicted the ATa recurrence during long-term follow-up.

Impact of anatomical features of the left atrial appendage on outcomes after cryoablation for atrial fibrillation

AIMS

Pulmonary vein isolation (PVI) using cryoballoon has been accepted as a safe and effective method for treatment of atrial fibrillation (AF). Despite advances in catheter-based technologies, some patients still experience AF recurrence. In this study, we aimed to compare left atrial appendage (LAA) morphology in AF patients and subjects with sinus rhythm and also investigate the association between LAA morphology and success of PVI using cryoballoon in subjects with AF.

METHODS

In this prospective study, 359 AF patients who underwent pre-ablation computed tomographic angiography (CTA) scan between January 2013-March 2016 were included as the patient group. 100 age and gender-matched subjects in sinus rhythm who had no AF episodes in 24-h Holter monitoring that underwent CTA were included as the control group.

RESULTS

Non-chicken wing LAA morphology was more common in AF patients (p < 0.001). LAA was significantly deeper (p < 0.001) and short-axis diameter of LAA orifice and LAA orifice area were significantly larger (p < 0.001) in AF patients. Low take-off type morphology of LAA was more common in controls compared to AF patients (p = 0.006). At a median follow-up of 37 months, only longitudinal-axis left atrial diameter on CT (p = 0.003) and cauliflower-type LAA morphology (p = 0.004) were independent predictors of AF recurrence.

CONCLUSION

This is the first study in the literature that investigates the relationship between anatomical variations of LAA and AF recurrence following cryoablation. Our findings demonstrate that cauliflower-type LAA morphology is associated with two-fold increased risk of AF recurrence.