Fluoroless Catheter Ablation of Cardiac Arrhythmias: A 5-Year Experience.

BACKGROUND: Catheter ablations have been traditionally performed with the use of fluoroscopic guidance, which exposes the patient and staff to the inherent risks of radiation. We have developed techniques to eliminate the use of fluoroscopy during cardiac ablations and have been performing completely fluoroless catheter ablations on our patients for over 5 years. METHODS: We present a retrospective analysis of the safety, efficacy, and feasibility data from 500 consecutive patients who underwent nonfluoroscopic catheter ablation, targeting a total of 639 arrhythmias, including atrioventricular reciprocating tachycardia (AVRT), atrioventricular nodal reentrant tachycardia (AVNRT), atrial tachycardia (AT), atrial fibrillation (AF), premature ventricular contractions (PVCs), and ventricular tachycardia (VT). We perform fluoroless ablations using intracardiac electrograms, electroanatomic mapping, and for most cases intracardiac echocardiography. Our experience includes exclusively endocardial cardiac ablations. RESULTS: The mean follow-up was 20.5 months. Recurrence rate for AVRT was 6.5%, for AVNRT 2.5%, for macro-reentrant AT 6.4%, for focal AT 5.4%, for AF 22.6%, for PVC 6.7%, and for VT 21.4%. Major complications occurred in five patients (1.0%); minor complications occurred in three patients (0.6%). No deaths occurred. Fluoroscopy was used in one instance, for 0.3 minutes, to confirm venous access. CONCLUSIONS: Completely fluoroless catheter ablations may be routinely performed for all endocardial ablations without compromising safety, efficacy, or procedural duration.

Derivation and validation of E/e' ratio as a parameter in the evaluation of left atrial appendage thrombus formation in patients with nonvalvular atrial fibrillation.

We sought to determine and prospectively validate, with concomitantly performed transthoracic (TTE) and transesophageal echocardiograms (TEE), a TTE-assessed E/e' threshold that can be useful in predicting left atrial appendage (LAA) thrombus in patients with nonvalvular atrial fibrillation (NVAF). The retrospective derivation cohort was comprised of 297 patients with NVAF with TTE performed within 1 year of TEE. The validation cohort was comprised of 266 prospectively enrolled patients with TTE performed immediately prior to TEE. LAA thrombus was detected by TEE in 6.4 % of patients in both cohorts. Receiver operating characteristic (ROC) analyses demonstrated a good discriminatory capacity of lateral E/e' in predicting LAA thrombus in the derivation cohort (AUC 0.72; CI 0.63-0.82; P = 0.001) which was confirmed in the validation cohort (AUC 0.83; CI 0.75-0.91; P < 0.001). In the derivation cohort, ROC curve point-coordinates identified E/e' thresholds of both 9.0 and 8.0 to be associated with 100 % sensitivity, with specificities of 36 and 30 %, respectively. An E/e' threshold of ≥8 was selected a priori for prospective validation, and was associated with 100 % sensitivity and 41 % specificity for LAA thrombus, with positive and negative predictive values of 10 and 100 %, respectively, and positive and negative likelihood ratios of 1.69 and 0, respectively. We determined and validated an E/e' threshold of 8 as a highly sensitive and useful parameter that can aid in identifying patients at very low risk for LAA thrombus and potentially obviate the need for a TEE prior to electrophysiology procedures and restoration of sinus rhythm.

Time-limited cryomapping during tachycardia: improved long-term outcomes for cryoablation of AVNRT.

PURPOSE: Cryothermal ablation (CTA) for atrioventricular nodal reentrant tachycardia (AVNRT) is considered safer than radiofrequency ablation (RFA) since it eliminates the risk of inadvertent AV block. However, it has not been widely adopted due to high late recurrence rate (LRR). In an effort to improve LRR, we evaluated a new approach to cryothermal mapping (CTM): "time to tachycardia termination" (TTT). METHODS: This single-center study had 88 consecutive patients who underwent CTA using TTT for AVNRT. The CTA catheter was positioned in sinus rhythm at the posteroseptal tricuspid annulus, and then AVNRT was induced. The CTA target site was identified by prompt tachycardia termination in ≤20 s during CTM. Procedural success was defined as no inducible AVNRT and ≤1 single AV nodal echoes. RESULTS: Acute procedural success was achieved in 87 of 88 patients (98.9 %) and was similar to prior studies for both CTA and RFA. No permanent AV block was observed. LRR was 3.7 % at a mean follow-up of 19.7 months. LRR was equivalent to that commonly reported for RFA and improved when compared to conventional CTA. CONCLUSION: TTT for CTA of AVNRT provides enhanced safety and similar long-term efficacy when compared to RFA. Based upon this experience, TTT provides an enhancement to conventional CTA that appears to result in improved long-term outcomes. In light of these findings, it seems reasonable to undertake additional randomized trials to determine whether RFA or CTA using TTT is the optimal approach for the catheter ablation of AVNRT.

Impact of Diastolic Function Parameters on the Risk for Left Atrial Appendage Thrombus in Patients with Nonvalvular Atrial Fibrillation: A Prospective Study.

BACKGROUND: In patients with nonvalvular atrial fibrillation (NVAF), the impact of left ventricular diastolic function on the risk for left atrial appendage (LAA) thrombus has not been prospectively studied. METHODS: At two academic medical centers, patients with NVAF were prospectively enrolled to undergo investigational transthoracic echocardiography immediately before clinically indicated transesophageal echocardiography. Mitral inflow E velocity and tissue Doppler septal and lateral mitral annulus velocities (e') were measured, and E/e' ratios were calculated. RESULTS: Among 266 subjects (mean age, 65 years; 32% women), 17 (6.4%) had LAA thrombus. Patients with LAA thrombus had a higher mean CHA2DS2-VASc score (4.6 ± 1.7 vs 3.0 ± 1.8, P < .001), a higher mean lateral E/e' ratio (19.4 ± 10.1 vs 10.2 ± 5.6, P < .001), and a lower mean lateral e' velocity (7.0 ± 3.2 vs 10.4 ± 3.7 cm/sec, P = .001). There was a good discriminative capacity for E/e' (area under the curve, 0.83; P < .001) and e' velocity (area under the curve, 0.76; P = .001). None of the patients with normal E/e' ratios or normal e' velocities had LAA thrombus. Both E/e' (odds ratio, 1.13 per point; 95% CI, 1.06-1.20; P < .001) and e' velocity (odds ratio, 0.76 per 1 cm/sec; 95% CI, 0.63-0.92; P = .005) provided independent and incremental predictive value beyond the CHA2DS2-VASc score; however, E/e' provided greater incremental value than e' velocity (P = .036). Analyses using septal and averaged E/e' and septal e' velocity yielded similar results. Diastolic function parameters were also associated with the presence and intensity of left atrial spontaneous echo contrast, a precursor of LAA thrombus. CONCLUSIONS: This prospective and concomitant evaluation of diastolic function and LAA thrombus in patients with NVAF demonstrates that E/e' ratio and e' velocity are associated with LAA thrombus, independent of CHA2DS2-VASc score, and may play a role in identifying patients at low risk for LAA thrombus. These data suggest that diastolic function assessment may improve stroke prediction in patients with NVAF.

Impact of B-type natriuretic peptide level on the risk of left atrial appendage thrombus in patients with nonvalvular atrial fibrillation: a prospective study.

BACKGROUND: The impact of B-type natriuretic peptide (BNP) level on the risk of left atrial appendage (LAA) thrombus in patients with nonvalvular atrial fibrillation (NVAF) has not been prospectively studied. METHODS: In two academic medical centers, we obtained BNP levels immediately prior to transesophageal echocardiogram performed to exclude LAA thrombus in patients with NVAF. RESULTS: Among 261 subjects (mean age 65 ± 12 years; 30 % women) with NVAF, 17 (6.5 %) had LAA thrombus and 85 (32.6 %) had at least mild spontaneous echo contrast (SEC). Mean BNP level was significantly higher in patients with LAA thrombus [775 ± 678 vs. 384 ± 537, P = 0.001]. Receiver operator characteristics analysis demonstrated that BNP has a good discriminatory capacity for LAA thrombus (area under the curve, 0.74; 95 % confidence interval [CI], 0.63-0.85; P = 0.001); BNP ≥ 67 pg/mL was 100 % sensitive and 20 % specific for LAA thrombus. Multivariate logistic regression analysis demonstrated that BNP was not independently associated with LAA thrombus (odds-ratio, 1.05 per 100 pg/mL increment; CI, 0.99-1.12; P = 0.127) after adjusting for CHA2DS2-VASc score; while the latter was independently associated with LAA thrombus after adjusting for BNP level (odds-ratio, 1.46 per CHA2DS2-VASc point; CI, 1.09-1.96; P = 0.011). Nonetheless, BNP was associated with SEC in univariate and multivariate analysis, after adjusting for the CHA2DS2-VASc score, (odds-ratio, 1.08; CI, 1.02-1.14; P = 0.005). CONCLUSIONS: BNP is predictive of SEC. However, it does not provide significant incremental value in the prediction of LAA thrombus.

Nonfluoroscopic Ablation of Atrial Fibrillation Using Cryoballoon.

BACKGROUND: The conventional method of cryoballoon ablation of atrial fibrillation involves the use of fluoroscopy for visual guidance. The use of fluoroscopy is accompanied by significant radiation risks to the patient and the medical staff. Herein, we report our experience in performing successful nonfluoroscopic pulmonary vein isolation using cryoballoon ablation in 5 consecutive patients with paroxysmal atrial fibrillation. METHODS AND RESULTS: Five consecutive patients with paroxysmal atrial fibrillation underwent cryoballoon ablation for pulmonary vein isolation using a nonfluoroscopic approach. Pre-procedural cardiac computed tomography or cardiac magnetic resonance imaging was not performed in any patient. A total of twenty pulmonary veins were identified and successfully isolated (100%) with the guidance of intracardiac echocardiography and 3-dimensional electroanatomic mapping. No fluoroscopy was used for the procedures. There were no major procedural adverse events. CONCLUSION: In an unselected group of patients undergoing cryoballoon ablation, a nonfluoroscopic approach is feasible and can be performed safely and effectively while eliminating the risks associated with radiation to both the patient and the medical staff.

Nonfluoroscopic catheter ablation of cardiac arrhythmias in adults: feasibility, safety, and efficacy.

BACKGROUND: Catheter ablations are traditionally performed using fluoroscopic guidance, exposing both patients and medical staff to the risks of radiation. Nonfluoroscopic catheter ablation has been used successfully to treat limited types of arrhythmias in children, but whether this approach has broad application in adults is uncertain. The purpose of this study was to evaluate the feasibility, safety, and efficacy of fluoroless catheter ablation in adults being treated for a range of arrhythmias. METHODS AND RESULTS: Retrospective analysis was performed in 2 patient groups (both n = 60): (1) the nonfluoroscopy (NF) group consisting of consecutive adult patients, in which catheter positioning was accomplished exclusively with intracardiac electrograms (IE), electroanatomic mapping (EAM), and intracardiac echocardiography (ICE); and (2) the fluoroscopy (F) group, in which catheter positioning was additionally guided by fluoroscopy. The patients in the F group were selected to match the types of arrhythmias in the NF group. All ablation procedures were performed by one operator. The total procedure time did not differ between groups for any specific type of arrhythmia ablated. Acute procedural success was similar in both groups (NF, 59/60 [98%] and F, 60/60 [100%]). The complications were limited to a groin pseudoaneurysm in the NF group, and pericardial effusion and groin hematoma in the F group. CONCLUSION: Catheter ablations were efficiently and effectively performed in adults with a variety of arrhythmias using only IE, EAM, and ICE for catheter guidance. This nonfluoroscopic technique was feasible, posed no additional safety concerns, and should be readily implementable in most electrophysiology laboratories.

Survival benefit from early revascularization in elderly patients with cardiogenic shock after acute myocardial infarction: a cohort study.

OBJECTIVES: To assess if early revascularization offers any survival benefit in patients with cardiogenic shock (CS) complicating acute myocardial infarction (AMI) who are > or = 75 years of age. BACKGROUND: CS after AMI continues to pose formidable therapeutic challenges in elderly patients. METHODS: We conducted survival analyses of 310 consecutive subjects (including 80 patients > or = 75 years of age) who developed cardiogenic shock after AMI at two study centers - Rush University Medical Center and the John H. Stroger Jr. Hospital of Cook County (both in Chicago, Illinois). The data were collected over a 6-year period. Where appropriate, we used Kaplan-Meier survival plots, multivariate Cox proportional hazards modeling, stepwise multivariate Poisson regression analyses and unconditional logistic regression analysis. RESULTS: Early revascularization was associated with a statistically significant survival benefit both in patients < 75 years of age (relative hazard 0.40, 95% confidence interval [CI] 0.28-0.59; p < 0.001), as well as in patients > or = 75 years of age (relative hazard 0.56, 95% CI 0.32-0.99; p = 0.049). This benefit remained significant even after adjusting for the simultaneous effects of several putative confounders. In patients > or = 75 years of age, this survival benefit was evident very early and was sustained all through the period of follow up of the cohort. CONCLUSIONS: These retrospective data suggest a significant survival benefit of early revascularization in elderly patients > or = 75 years of age developing CS after AMI, albeit less as compared to those aged < 75 years.