Imaging Modality Selection in Cardiac Ablation.

Catheter ablation as a treatment method for both ventricular and atrial arrhythmias has evolved significantly over the past 40 years since it was first performed in humans. This evolution has been paralleled by a similar expansion in both invasive and non-invasive imaging modalities directed at further elucidating cardiac morphology and arrhythmia substrate pathophysiology. Access to multimodality imaging options is a significant piece of the armamentarium available to interventional electrophysiologists who are tackling increasingly complex rhythm problems with catheter ablation. This presents a unique problem to the practicing electrophysiologist in selecting the most pertinent imaging modalities that will improve the safety and efficacy of a procedure and winnowing out potential imaging studies that offer minimal or marginal benefit. In this review, we evaluate the various modalities that are useful in planning and executing successful ablation and weigh the evidence for benefit.

Intraventricular Free-Floating Thrombus in an Impella-Supported Patient: Damage Control in a No-Win Scenario.

We describe the management and clinical decision making in a cardiogenic shock patient with a free-floating left ventricular thrombus found during temporary mechanical support with an Impella CP. The management of these patients can be challenging because there are no guidelines or data to support any particular treatment strategy. (Level of Difficulty: Intermediate.).

Reexamination of the UN10 Rule to Discontinue Resuscitation During In-Hospital Cardiac Arrest.

Importance: Several clinical decision rules (CDRs) have been developed to help practitioners know when to safely terminate resuscitative efforts after in-hospital cardiac arrest (IHCA). The UN10 rule, a CDR that uses 3 intra-arrest variables, has been shown to predict a poor chance of survival to discharge. However, its large-scale applicability in clinical settings remains unknown. Objective: To assess the performance of a parsimonious CDR in a national cohort of individuals with IHCA. Design, Setting, and Participants: This retrospective cohort study used a nationwide cohort from the American Heart Association Get With the Guidelines-Resuscitation IHCA registry to derive a sample of 96 509 patients from 716 US hospitals who experienced IHCA from January 1, 2000, to January 26, 2016. Data analysis began in January 2018 and concluded in June 2018. Exposures: The UN10 rule uses 3 variables: (1) unwitnessed arrest, (2) nonshockable rhythm, and (3) no return of spontaneous circulation within 10 minutes of resuscitative efforts. The CDR indicates futility if all 3 criteria are met. This CDR was analyzed according to the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) reporting guideline. Main Outcomes and Measures: The primary outcome was survival to hospital discharge following resuscitation. Favorable neurologic status at discharge was also assessed. Overall rates of survival and survival with favorable neurologic status (cerebral performance category score, 1 or 2) were compared with predicted values by the UN10 rule using 2 × 2 contingency tables. Results: Of 96 509 patients, 55 761 (57.8%) were men, and the mean (SD) age was 67.1 (15.3) years. In total, 18 713 patients (19.4%) survived to discharge, and 16 134 patients (16.7%) were discharged with a favorable neurologic status. Overall, 15 838 patients (16.4%) met all 3 criteria for futility in the UN10 rule. A total of 1005 patients (6.3%) who met the UN10 rule survived to discharge, and 754 (4.8%) survived with favorable neurologic status. The percentage of patients meeting the UN10 rule (ie, predicting futile resuscitation) who actually survived in our study cohort was substantially higher than the initial derivation cohort (0%) and single-center validation cohort (1.1%). The positive predictive value of the UN10 rule was 93.7% (95% CI, 93.3%-94.0%), which was lower than the initial derivation cohort (100%; 95% CI, 97.5%-100%) and validation cohort (98.9%; 95% CI, 96.5%-99.7%). Conclusions and Relevance: Patients who met the UN10 rule were associated with unfavorable neurologic status and low rates of survival after IHCA. Yet their survival rates are higher than reported in the initial validation study, raising the question of whether the UN10 rule may have limited utility as a definitive measure of futility during resuscitations in real-world clinical settings.

Usefulness of Blood Pressure Variability Indices Derived From 24-Hour Ambulatory Blood Pressure Monitoring in Detecting Autonomic Failure.

Background Increased blood pressure ( BP ) variability and nondipping status seen on 24-hour ambulatory BP monitoring are often observed in autonomic failure ( ATF ). Methods and Results We assessed BP variability and nocturnal BP dipping in 273 patients undergoing ambulatory BP monitoring at Southwestern Medical Center between 2010 and 2017. SD , average real variability, and variation independent of mean were calculated from ambulatory BP monitoring. Patients were divided into a discovery cohort (n=201) and a validation cohort (n=72). ATF was confirmed by formal autonomic function test. In the discovery cohort, 24-hour and nighttime average real variability, SD , and variation independent of mean did not differ significantly between ATF (n=25) and controls (n=176, all P>0.05). However, daytime SD, daytime coefficient of variation, and daytime variation independent of mean of systolic BP ( SBP ) were all significantly higher in patients with ATF than in controls in both discovery and validation cohorts. Nocturnal BP dipping was more blunted in ATF patients than controls in both cohorts (both P<0.01). Using the threshold of 16 mm Hg, daytime SD SBP yielded a sensitivity of 77% and specificity of 82% in detecting ATF in the validation cohort, whereas nondipping status had a sensitivity of 80% and specificity of 44%. The area under the receiver operator characteristic of daytime SD SBP was greater than the area under the receiver operator characteristic of nocturnal SBP dipping (0.79 [0.66-0.91] versus 0.73 [0.58-0.87], respectively). Conclusions Daytime SD of SBP is a better screening tool than nondipping status in detecting autonomic dysfunction.

Comparative Efficacy of Endovascular Revascularization Versus Supervised Exercise Training in Patients With Intermittent Claudication: Meta-Analysis of Randomized Controlled Trials.

OBJECTIVES: The authors performed a meta-analysis of randomized controlled trials to compare the efficacy of initial endovascular treatment with or without supervised exercise training (SET) versus SET alone in patients with intermittent claudication. BACKGROUND: Current guidelines recommend SET as the initial treatment modality for patients with intermittent claudication, in addition to optimal medical therapy. The role of endovascular therapy as primary treatment for claudication has been controversial. METHODS: The primary outcome was treadmill-measured maximal walk distance at the end of follow-up. Secondary outcomes included resting ankle brachial index (ABI) and treadmill-measured ischemic claudication distance on follow-up. Risk of revascularization or amputations was also compared. Pooled estimates of the difference in outcomes between endovascular therapy with or without SET and SET-only groups were calculated using fixed and random effects models. RESULTS: A total of 987 patients from 7 trials were included. In pooled analysis, compared with SET only (reference group), patients that underwent combined endovascular therapy and SET had significantly higher maximum walk distance (standardized mean difference 0.79 [95% confidence interval (CI): 0.18 to 1.39]; weighted mean difference 98.9 [95% CI: 31.4 to 166.4 feet], and lower risk of revascularization or amputation (odds ratio 0.19 [95% CI: (0.09 to 0.40]; p < 0.0001, number needed to treat = 8) over a median follow-up of 12.4 months. By contrast, revascularization was not associated with significant improvement in exercise capacity or risk of future revascularization or amputation, compared with SET alone. Follow-up ABI was significantly higher among patients that underwent endovascular therapy with or without SET as compared with SET alone. CONCLUSIONS: Compared with initial SET only, endovascular therapy in combination with SET is associated with significant improvement in total walking distance, ABI, and risk of future revascularization or amputation. By contrast, endovascular therapy-only was not associated with any improvement in functional capacity or clinical outcomes over an intermediate duration of follow-up.

Safety and Efficacy of Exercise Training in Patients With an Implantable Cardioverter-Defibrillator: A Meta-Analysis.

OBJECTIVES: In this study, the authors performed a meta-analysis of currently available comparative prospective studies to assess the efficacy and safety of exercise training in heart failure (HF) patients with implantable cardioverter-defibrillators (ICD). BACKGROUND: ICDs have been shown to improve survival in patients with HF. However, many patients with ICDs experience fear of shocks and avoid physical activity. Few data exist for efficacy and safety of exercise training in HF patients with ICDs. METHODS: Prospective parallel arm trials with control and exercise training groups that evaluated the efficacy of exercise training in patients with ICDs were included in the meta-analysis. Outcomes of interest were difference in the change in cardiorespiratory fitness (CRF) (ml/kg/min) between exercise and control group and the likelihood of ICD shocks among exercise training compared with that among control participants on follow-up. RESULTS: We included study level data from 6 trials (5 randomized controlled trials and 1 nonrandomized controlled trial). In the pooled analysis, ICD patients undergoing exercise training had significant improvement in CRF (weighted mean difference: 1.98 ml/kg/min; 95% confidence interval [CI]: 0.58 to 3.38). The likelihood of ICD shocks on follow-up was also significantly lower among exercise training than among control participants (pooled odds ratio: 0.47; 95% CI: 0.24 to 0.91). CONCLUSIONS: Among patients with HF and ICD implantation, exercise training was associated with significant improvement in CRF and lower likelihood of ICD shocks.

Conservative Management of an Epicardial Collateral Perforation During Retrograde Chronic Total Occlusion Percutaneous Coronary Intervention.

Coronary artery perforation is a highly feared complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and can lead to pericardial effusion, tamponade, and, rarely, emergent cardiac surgery. Perforation of epicardial collaterals during retrograde CTO-PCI may be particularly challenging to treat, as embolization from both sides of the perforation may be required to control the bleeding. However, conservative measures can occasionally be effective. We present a case of epicardial collateral vessel perforation that was managed conservatively with anticoagulation reversal.