Anatomic predictors of recurrence after cryoablation for atrial fibrillation: a computed tomography based composite score

BACKGROUND

Effective pulmonary vein isolation (PVI) with cryoablation depends on adequate occlusion of pulmonary veins (PV) by the cryoballoon and is therefore likely to be affected by PV and left atrial (LA) anatomical characteristics and variants. Thus, the objective of this study was to investigate the effect of LA and PV anatomy, evaluated by computed tomography (CT), on acute and long-term outcomes of cryoablation for atrial fibrillation (AF).

METHODS

Fifty-eight patients (64.72 + 9.44 years, 60.3% male) undergoing cryoablation for paroxysmal or early persistent AF were included. Pre-procedural CT images were analyzed to evaluate LA dimensions and PV anatomical characteristics. Predictors of recurrence were identified using regression analysis.

RESULTS

60.3% of patients had two PVs on each side with separate ostia, whereas 29.3% and 10.3% had right middle and left common PVs, respectively. The following anatomic characteristics were found to be independent predictors of recurrence: right superior PV ostial max:min diameter ratio > 1.32, left superior PV ostial max:min diameter ratio > 1.2, right superior PV antral circumference > 69.1 mm, right inferior PV antral circumference > 61.38 mm, right superior PV angle > 22.7°. Using these factors, LA diameter and right middle PV, a scoring model was created for prediction of "unfavorable" LA-PV anatomy (AUC = 0.867, p = 0.000009, score range = 0-7). Score of ≥ 4 predicted need for longer cryoenergy ablation (p = 0.039) and more frequent switch to radiofrequency energy (p = 0.066) to achieve PVI, and had a sensitivity of 83.3% and specificity of 82.5% to predict clinical recurrence.

CONCLUSION

CT-based scoring system is useful to identify "unfavorable" anatomy prior to cryo-PVI, which can result in procedural difficulty and poor outcomes.

Evaluation of acute chest pain: Evolving paradigm of coronary risk scores and imaging

There is a broad differential diagnosis for patients presenting with acute chest pain. History, physical examination, electrocardiogram, and serial troponin assays are pivotal in assessing patients with suspected acute coronary syndrome. However, if the initial workup is equivocal, physicians are faced with a challenge to find the optimal strategy for further triage. Risk stratification scores have been validated for patients with known acute coronary syndrome, such as the TIMI and GRACE scores, but there may be limitations in undifferentiated chest pain patients. Advancements in imaging modalities such as coronary computed tomography angiography and the addition CT derived fractional flow reserve, have demonstrated utility in evaluating patients presenting with acute chest pain. With this article, we aim to provide a comprehensive review of the non-invasive modalities that are available to evaluate acute chest pain patients suspected of cardiac etiology in the emergency room. We also added a focus on new imaging modalities that have shown to have prognostic implications in stable ischemic heart disease.

A standardized protocol to reliably visualize the left atrial appendage with intracardiac echocardiography: Importance of multiple imaging sites

BACKGROUND

Currently, there is no accepted protocol for left atrial appendage (LAA) imaging with intracardiac echocardiography (ICE).

OBJECTIVE

This study aimed to assess the utility of ICE to reliably visualize the entire cavity of the LAA and propose a specific procedural protocol to achieve the above objective.

METHODS

We created a three-dimensional reconstruction of the LAA, using two-dimensional ICE sections obtained from three different location (the right atrium [RA], right ventricle inflow [RVI], and right ventricular outflow [RVOT]). We then compared the three-dimensional LAA reconstruction by ICE with one obtained by cardiac computed tomography angiography (CCTA) for morphological and volume differences.

RESULTS

Three-dimensional reconstruction with ICE could reliably reproduce the LAA as visualized with CCTA but only when ICE sampling was performed from at least two catheter positions. There was no statistically significant difference between LAA volumes obtained with ICE and CCTA (P = 0.33). The contribution of each anatomical location to the total volume was 17% ± 16.6%, 74% ± 13.3%, and 33% ± 26% for RA, RVI, and RVOT, respectively.

CONCLUSION

In comparison with CCTA, the LAA can be reliably visualized in its entity by ICE, but only if multiple imaging positions (RA, RV inflow, and RVOT) are used.

The neglected lead on electrocardiogram: T wave inversion in lead aVL, nonspecific finding or a sign for left anterior descending artery lesion?

BACKGROUND

The electrocardiogram (ECG) is the most important diagnostic tool for acute myocardial infarction (AMI). T wave inversion (TWI) in lead aVL has not been emphasized or well recognized.

OBJECTIVE

This study examined the relationship between the presence of TWI before the event and mid-segment left anterior descending (MLAD) artery lesion in patients with AMI.

METHODS

Retrospective charts of patients with acute coronary syndrome between the months of January 2009 and December 2011 were reviewed. All patients with MLAD lesion were identified and their ECG reviewed for TWI in lead aVL.

RESULTS

Coronary angiography was done on 431 patients. Of these, 125 (29%) had an MLAD lesion. One hundred and six patients (84.8%) had a lesion > 50% and 19 patients (15.2%) had a lesion < 50%. Of the 106 patients who had a MLAD lesion > 50%, 90 patients (84.9%) had TWI in lead aVL and one additional lead. Of the 19 patients who had an MLAD lesion < 50%, 8 patients (42.1%) had TWI in lead aVL and one additional lead. Isolated TWI in lead aVL had an overall sensitivity of 76.7% (95% confidence interval [CI] 0.65-0.86), a specificity of 71.4% (95% CI 0.45-0.88), a positive predictive value of 92%, a negative predictive value of 41.7%, a positive likelihood ratio of 2.7 (95% CI 1.16-6.22), and negative likelihood ratio of 0.32 (95% CI 0.19-0.58) for predicting a MLAD lesion of > 50% (p = 0.0011).

CONCLUSIONS

TWI in lead aVL might signify a mid-segment LAD lesion. Recognition of this finding and early appropriate referral to a cardiologist might be beneficial. Additional studies are needed to validate this finding.

Abstract 51: Can Wellens’ Sign be used to Predict Significant Proximal Left Anterior Descending Artery Lesion?

Background: Wellens’ sign (WS) has been reported as a sign of critical proximal left anterior descending (PLAD) artery lesion with lumen narrowing greater than 90%. Wellens’ ECG signs for critical PLAD lesion are characterized by two different electrocardiogram (ECG) patterns: 1) Deep T wave inversion in leads V2, V3 (approximately 76% of cases); and 2) Biphasic T wave in leads V2, V3 (approximately 24% of cases). The prevalence of the ECG feature of WS ranges from 14-18%. The prognostic significance of WS in detecting significant coronary artery lesion defined as a luminal narrowing of the coronary vessel by more than 70% has not been well studied. Our study’s goal was to evaluate if WS is present in all patients with critical and significant PLAD lesions and is a sensitive or specific sign for critical and significant (>70% stenosis) PLAD lesions.

Methods: All patients that underwent percutaneous coronary intervention (PCI) at an urban community hospital between January 2009 and December 2011 were included in the study. Log books from the cardiac catheterization laboratory were reviewed for all lesion types and corresponding demographics. The ECGs of patients with PLAD lesion were reviewed for T wave changes in precordial leads. Additionally, demographics such as age, gender and cardiovascular risk factors were recorded and analyzed. Descriptive statistics were used to analyze the data.

Results: A total of 431 patients underwent PCI [emergent PCI 152 (35.3%), elective PCI 279 (64.7%)]. A total of 78 patients (18.1%) from both groups were found to have PLAD lesion. Fifty eight patients were male and 20 patients were female. The average age was 63.7 years.

Critical PLAD lesion was present in 26 patients (33.3%) and 52 patients (66.7%) had PLAD lesion less than 90%. Of the 26 patients, 17 (65.4%) had WS. Wellens’ sign for predicting a critical PLAD had a sensitivity of 65.4%, a specificity of 69.2%, a positive predictive value (PPV) of 51.5% and a negative predictive value (NPV) of 80% (p = 0.0069, two-tailed Fisher’s exact test).

Of the 42 patients who had PLAD lesion greater than 70%, 21 patients (50%) had WS. Of the 36 patients who had PLAD lesion less than 70%, 11 patients (30.6%) had WS. Wellens’ sign for predicting significant PLAD lesion in this cohort has a sensitivity of 50%, a specificity of 69.4%, a PPV of 65.6% and a NPV of 54.3% ( p = 0.1074).

Conclusion: Our results corroborated prior studies showing that WS predicts the presence of critical (90%) PLAD lesion. Unfortunately, the value of WS for detecting/predicting significant CAD in PLAD was weak. Our results indicated that we were not able to predict the presence of significant (70%) PLAD lesion using WS. However, in appropriate clinical settings such as Non-ST elevation MI (NSTEMI) or unstable angina, Wellens’ sign may indicate the need for a more aggressive treatment strategy with patients proceeding to the cardiac catheterization suite sooner than later.