Objective: To use novel statistical methods for analyzing the effect of lesion set on (long-standing) persistent atrial fibrillation (AF) in the Cardiothoracic Surgical Trials Network trial of surgical ablation during mitral valve surgery (MVS). Methods: Two hundred sixty such patients were randomized to MVS + surgical ablation or MVS alone. Ablation was randomized between pulmonary vein isolation and biatrial maze. During 12 months postsurgery, 228 patients (88%) submitted 7949 transtelephonic monitoring (TTM) recordings, analyzed for AF, atrial flutter (AFL), or atrial tachycardia (AT). As previously reported, more ablation than MVS-alone patients were free of AF or AF/AFL at 6 and 12 months (63% vs 29%; P < .001) by 72-hour Holter monitoring, without evident difference between lesion sets (for which the trial was underpowered). Results: Estimated freedom from AF/AFL/ATon any transmission trended higher after biatrial maze than pulmonary vein isolation (odds ratio, 2.31; 95% confidence interval, 0.95–5.65; P = .07) 3 to 12 months postsurgery; estimated AF/AFL/AT load (ie, proportion of TTM strips recording AF/AFL/AT) was similar (odds ratio, 0.90; 95% confidence interval, 0.57–1.43; P .6). Within 12 months, estimated prevalence of AF/AFL/AT by TTM was 58% after MVS alone, and 36% versus 23% after pulmonary vein isolation versus biatrial maze (P<.02). Conclusions: Statistical modeling using TTM recordings after MVS in patients with (long-standing) persistent AF suggests that a biatrial maze is associated with lower AF/AFL/AT prevalence, but not a lower load, compared with pulmonary vein isolation. The discrepancy between AF/AFL/AT prevalence assessed at 2 time points by Holter monitoring versus weekly TTM suggests the need for a confirmatory trial, reassessment of definitions for failure after ablation, and validation of statistical methods for assessing atrial rhythms longitudinally.

Heart rate volatility (HRVO) is hypothesized to be a physiological measure of sympathetic activity and is defined by the standard deviation (SD) of the heart rate (HR) in beats per minutes (BPM) over fixed time intervals. To investigate the relationship between low HRVO (SD < 0.5 BPM) during surgical procedures and mortality within 48 h post-procedure. We retrospectively reviewed all adult general surgical procedures performed at our center from January 1, 2003 through July 1, 2013 to identify patients who died within 48 h post-procedure. Demographic, heart rate, and mortality data were extracted from the electronic anesthesia record. Propensity score analysis was used to find matching controls based on age, gender, ASA score, anesthesia type, Charlson index, procedure type, emergency status, year, use of preoperative beta blocker, hypertension, diabetes, atrial fibrillation and heart failure. HRVO was calculated for each 5 min interval as the SD of all HR's within that interval. Negative binomial regression was then used to model the count of intervals with HRVO < 0.5 BPM for the duration of the surgery. During the 10 year study period, 283 patients died within 48 h of procedure finish. These patients were matched to 566 patients who did not die within 48 h after procedure. Patients who died had a 39 % increase in frequency of low HRVO episodes compared to patients who survived (RR 1.39, 95 % CI 1.13-1.72; p = 0.003). Low HRVO during surgical procedure is associated with increased mortality risk within 48 h after procedure. Strategies to identify HRVO early and modify it may lead to improvement in outcomes.

Our result provides additional evidence supporting previously published data indicating that autonomic nervous system measures such as HRVO could serve as important and useful clinical tools in the early triage of critically ill patients in the ED.