Effect of coronary revascularization on long-term clinical outcomes in patients with ischemic cardiomyopathy and recurrent ventricular arrhythmia.

BACKGROUND: Patients with ventricular tachycardia (VT) postmyocardial infarction (MI) are a higher risk group with significant morbidity and mortality. We examined the impact of prior coronary revascularization on clinical outcomes in patients with ischemic cardiomyopathy and VT. METHODS: The VANISH trial randomized 259 patients with prior MI and antiarrhythmic drug-refractory VT to receive escalated medical therapy or catheter ablation. Clinical outcomes were compared according to whether patients have undergone prior revascularization procedures. The primary outcome was a composite of death, appropriate implantable cardiac defibrillator (ICD) shock, or VT storm. The secondary outcomes included elements of the primary outcome, hospitalization, and any ventricular arrhythmia. RESULTS: 190 patients (73%) had prior coronary revascularization. Revascularization group had more men (97% vs 83%; P  =  0.0003) and patients in that group were older (mean age 69.3 ± 7.6 vs 66.7 ± 9.2; P  =  0.04), had more renal insufficiency (22.6% vs 8.7%; P  =  0.01), and were more likely to have an implanted cardiac resynchronization device (23% vs 10%, P  =  0.03) as compared with the nonrevascularized patients. There were no significant differences in baseline medication use. There was a trend toward fewer hospitalizations in the revascularization group (64% vs 77%; P  =  0.07); there were no differences in the individual outcomes of mortality, VT storm, ICD shocks, recurrent MI, or cardiac failure. CONCLUSIONS: In this cohort of patients with an ischemic cause for VT, a history of prior coronary revascularization was not associated with a reduction in ventricular arrhythmia or mortality.

Prospective Assessment of an Automated Intraprocedural 12-Lead ECG-Based System for Localization of Early Left Ventricular Activation.

BACKGROUND: To facilitate ablation of ventricular tachycardia (VT), an automated localization system to identify the site of origin of left ventricular activation in real time using the 12-lead ECG was developed. The objective of this study was to prospectively assess its accuracy. METHODS: The automated site of origin localization system consists of 3 steps: (1) localization of ventricular segment based on population templates, (2) population-based localization within a segment, and (3) patient-specific site localization. Localization error was assessed by the distance between the known reference site and the estimated site. RESULTS: In 19 patients undergoing 21 catheter ablation procedures of scar-related VT, site of origin localization accuracy was estimated using 552 left ventricular endocardial pacing sites pooled together and 25 VT-exit sites identified by contact mapping. For the 25 VT-exit sites, localization error of the population-based localization steps was within 10 mm. Patient-specific site localization achieved accuracy of within 3.5 mm after including up to 11 pacing (training) sites. Using 3 remotes (67.8±17.0 mm from the reference VT-exit site), and then 5 close pacing sites, resulted in localization error of 7.2±4.1 mm for the 25 identified VT-exit sites. In 2 emulated clinical procedure with 2 induced VTs, the site of origin localization system achieved accuracy within 4 mm. CONCLUSIONS: In this prospective validation study, the automated localization system achieved estimated accuracy within 10 mm and could thus provide clinical utility.

The Effect of Cardiac Rehabilitation and a Specialized Clinic on Outcomes of Patients With Atrial Fibrillation.

BACKGROUND: Cardiac rehabilitation (CR) intervention programs are currently not part of management in patients with atrial fibrillation (AF). We sought to determine the effect of CR compared with a specialized AF clinic (AFC) and usual care on outcomes in patients with AF. METHODS: This was a single-centre retrospective cohort study that was carried out using 3 databases: the Hearts in Motion database (2010-2014), prospectively collected data in an AFC (2011-2014), and a retrospective chart review for patients in usual care (2009-2012). Three care pathways were compared: (1) CR; (2) AFC; and (3) usual specialist-based care. The main outcome was AF-related emergency department visits and cardiovascular hospitalizations. RESULTS: Of 566 patients with newly diagnosed AF, 133 (23.5%) patients underwent CR, 197 patients (34.8%) attended the AFC, whereas the remaining 236 (41.7%) were followed in a usual specialist-based care clinic. At 1 year, AF-related emergency department visits and cardiovascular hospitalization rates occurred in 7.5% in the CR group, 16.8% in the AFC group, and 29.2% in usual care. After a propensity matched analysis, usual care was associated with the highest rate of the main outcome (odds ratio, 4.91; 95% confidence interval, 2.09-11.53) compared with CR, as did the AFC compared with CR (odds ratio, 2.75; 95% confidence interval, 1.14-6.6). CONCLUSIONS: Among patients with AF, CR was associated with a lower risk of AF-related outcomes. These findings support further study of the use of CR in the management of these patients to determine the optimal model of care for AF patients.