Anticoagulation in new-onset postoperative atrial fibrillation: An analysis from the Society of Thoracic Surgeons Adult Cardiac Surgery Database.

Background: New-onset postoperative atrial fibrillation (POAF) is the most common complication after cardiac surgery and is associated with increased long-term stroke and mortality. Anticoagulation has been suggested as a potential therapy, but data on safety and efficacy are scant. Objectives: To determine the association between anticoagulation for POAF and long-term outcomes. Methods: Adult patients with POAF after isolated coronary artery bypass surgery (CABG) were identified through the Society of Thoracic Surgeons Adult Cardiac Surgery Database and linked to the Medicare Database. Propensity-matched analyses were performed for all-cause mortality, stroke, myocardial infarction, and major bleeding for patients discharged with or without anticoagulation. Interaction between anticoagulation and CHA2DS2-VASc score was also assessed. Results: Of 38,936 patients, 9861 (25%) were discharged on oral anticoagulation. After propensity score matching, discharge anticoagulation was associated with increased mortality (hazard ratio [HR] 1.16, 95% confidence interval [CI] 1.06-1.26). There was no difference in ischemic stroke between groups (HR 0.97, 95% CI 0.82-1.15), but there was significantly higher bleeding (HR 1.60, 95% CI 1.38-1.85) among those discharged on anticoagulation. Myocardial infarction was lower in the first 30 days for those discharged on anticoagulation, but this effect decreased over time. The incidence of all complications was higher for patients with CHA2DS2-VASc scores ≥5 compared to patients with scores of 2-4. Anticoagulation did not appear to benefit either subgroup. Conclusion: Anticoagulation is associated with increased mortality after new-onset POAF following CABG. There was no reduction in ischemic stroke among those discharged on anticoagulation regardless of CHA2DS2-VASc score.

Attitudes toward anticoagulation for postoperative atrial fibrillation: A nationwide survey of VA providers.

INTRODUCTION: Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery. Though often felt to be self-limited, this complication has been associated with increases in both short and long-term stroke and mortality. Several studies have also shown a high rate of AF recurrence. Optimal treatment strategy is not yet defined, and the role of anticoagulation (AC) is unclear. Our objective was to determine provider attitudes toward management of this common complication. METHODS: A survey consisting of 15 multiple choice questions was distributed to providers at Veterans Healthcare Administration hospitals nationwide. RESULTS: The majority of respondents were cardiologists. Practices varied drastically with respect to AC use for patients with POAF who were discharged in normal sinus rhythm. Less variability existed for patients discharged in AF. There was no clear consensus regarding other factors to consider when deciding on AC therapy, including length of episode, or risk factors for stroke such as CHA2 DS2 -VASc score. There was also no consensus on duration of therapy or need for post discharge cardiac monitoring. CONCLUSION: Our data indicate a wide variability in the management of POAF. This reflects conflicting recommendations in the guidelines, as well as a paucity of prospective treatment trials in this field. Nevertheless, a growing evidence base suggests that this complication carries potentially serious long-term morbidity and mortality, and better evidence for its management is needed.

Incidence of Early Atrial Fibrillation After Transcatheter versus Surgical Aortic Valve Replacement: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Post-operative atrial fibrillation (POAF) is common after aortic valve replacement (AVR) and is associated with worse outcomes. We performed a meta-analysis of randomized controlled trials comparing Surgical Aortic Valve Replacement (SAVR) and Transcatheter Aortic Valve Replacement (TAVR) for incidence of POAF at 30 days. METHODS: We searched databases from 1/1/1990 to 1/1/2020 for randomized studies comparing TAVR and SAVR. POAF was defined as either worsening or new-onset atrial fibrillation. Random effects model was used to estimate the risk of POAF with TAVR vs SAVR in all trials, and in subgroups (low, intermediate, high risk, and in self-expandable vs balloon expandable valves). Sensitivity analysis was performed including only studies reporting new-onset atrial fibrillation. RESULTS: Seven RCTs were identified that enrolled 7,934 patients (3,999 to TAVR and 3,935 to SAVR). The overall incidence of POAF was 9.7% after TAVR and 33.3% after SAVR. TAVR was associated with a lower risk of POAF compared with SAVR (OR 0.21 [0.18-0.24]; P < 0.0001). Compared with SAVR, TAVR was associated with a significantly lower risk of POAF in the high-risk cohort (OR 0.37 [0.27-0.49]; P < 0.0001), in the intermediate-risk cohort (OR 0.23 [0.19-0.28]; P < 0.0001), low-risk cohort (OR 0.13 [0.10-0.16]; P < 0.0001). Sensitivity analysis of 4 trials including only new-onset POAF showed similar summary estimates (OR 0.21, 95% CI [0.18-0.25]; P< 0.0001). CONCLUSIONS: TAVR is associated with a significantly lower risk of post-operative atrial fibrillation compared with SAVR in all strata. Further studies are needed to identify the contribution of post-operative atrial fibrillation to the differences in clinical outcomes after TAVR and SAVR.

Contemporary Anticoagulation Practices for Postoperative Atrial Fibrillation: A Single Center Experience.

AIMS: Postoperative atrial fibrillation (POAF) is a frequent in-hospital complication after cardiac surgery. Surprisingly, despite its prevalence, management of this condition has not been well studied. One promising approach that has been evaluated in a limited number of studies is use of anticoagulation. However, the trends and patterns of real-world use of anticoagulation in POAF patients has not been systemically investigated. In this study, we aimed to determine real-world patterns of anticoagulation use for patients with POAF. METHODS: We identified 200 patients undergoing coronary artery bypass (CABG) or cardiac valve surgery at University Hospitals Cleveland Medical Center over a 2 year period beginning January 2016 with new onset POAF. We reviewed charts to verify candidacy for inclusion in the study and to extract data on anticoagulation use, adverse outcomes, and CHA2DS2-VASc scores. RESULTS: Anticoagulation use was low after CABG, but high after bioprosthetic valve surgery. The most common anticoagulant used was warfarin. Anticoagulation use was not correlated with CHA2DS2-VASc score or cardioversion. Stroke and mortality were higher among patients not receiving anticoagulation, however, confirmation of this finding in larger randomized studies is warranted. CONCLUSIONS: Anticoagulation use is low after CABG and this practice does not appear to be affected by CHA2DS2VASc score or cardioversion. This differs with previously reported provider attitudes towards management of this condition. Stroke and mortality appear to be elevated for patients not receiving anticoagulation but further investigation is required to confirm this observation.

Revisiting an Underrecognized Strategy for Rhythm Management: Hybrid Therapy for Patients who Convert from Atrial Fibrillation to Flutter on Antiarrhythmic Drugs.

Atrial fibrillation (AF) is often treated with antiarrhythmic drugs (AADs) or catheter ablation. In a unique subset of patients, AF can convert to atrial flutter (AFL) after the initiation of an AAD. It has previously been shown that, in this subset of patients, cavotricuspid isthmus (CTI) ablation followed by the continuation of the AAD regimen has an unusually high rate of successfully maintaining sinus rhythm. This is an underrecognized approach toward rhythm management in such patients. However, the reason(s) for such a high degree of efficacy with this hybrid therapeutic approach are unclear. We suggest that conversion from AF to AFL selects for a group of patients in whom AF is particularly responsive to the effects of the AAD. Since CTI ablation is essentially curative of AFL, the combination of both techniques results in a high efficacy of sinus rhythm maintenance. Further investigation is required to confirm these hypotheses.

Recent heart rate history affects QT interval duration in atrial fibrillation.

QT interval prolongation is associated with a risk of polymorphic ventricular tachycardia. QT interval shortens with increasing heart rate and correction for this effect is necessary for meaningful QT interval assessment. We aim to improve current methods of correcting the QT interval during atrial fibrillation (AF). Digitized Holter recordings were analyzed from patients with AF. Models of QT interval dependence on RR intervals were tested by sorting the beats into 20 bins based on corrected RR interval and assessing ST-T variability within the bins. Signal-averaging within bins was performed to determine QT/RR dependence. Data from 30 patients (29 men, 69.3±7.3 years) were evaluated. QT behavior in AF is well described by a linear function (slope ~0.19) of steady-state corrected RR interval. Corrected RR is calculated as a combination of an exponential weight function with time-constant of 2 minutes and a smaller "immediate response" component (weight ~ 0.18). This model performs significantly (p<0.0001) better than models based on instantaneous RR interval only including Bazett and Fridericia. It also outperforms models based on shorter time-constants and other previously proposed models. This model may improve detection of repolarization delay in AF. QT response to heart rate changes in AF is similar to previously published QT dynamics during atrial pacing and in sinus rhythm.

Drug-Induced QTc Prolongation.

QTc prolongation has a high prevalence of and is associated with increased all-cause mortality. Nonetheless, QTc prolonging medications are often used during patient hospitalizations despite baseline prolongation and QTc changes. Data regarding the real-world relative risk of QTc prolongation in the hospital setting are lacking. In this study, we sought to quantify the degree and relative risk of QTc prolongation in patients receiving Arizona Center for Education and Research on Therapeutics (AzCERT) "known risk" medications. Electronic medical records of patients receiving an electrocardiogram at the University of Chicago, admitted in 2011 were analyzed. The longest QTc interval and medications administered within the preceding 24 hours were evaluated. Medications were classified into 4 categories according to the AzCERT classification. Of a total of 14,804 patients, mean QTc intervals were 485 versus 454 ms for men and 469 versus 453 ms for women receiving known risk medications compared with those receiving no risk medications (p <0.001). The rate of QTc prolongation was 71% versus 48% for men and 50% versus 34% for women, respectively. There was no significant increase in QTc prolongation for patients administered multiple QT-relevant medications or for those administered only conditional or possible risk medications. In conclusion, the prevalence of significant QTc prolongation in patients receiving AzCERT known risk medications is high. This may be a reflection of inadequate awareness or overall quality inadequacies.

Provider Response to QTc Prolongation on Standard 12-Lead EKG: Do We Notice or Do We Care?

BACKGROUND: Drugs and electrolyte imbalances are widely recognized as common triggers of a prolonged QT interval. We conducted a chart review to assess provider response to prolonged QT reported on a standard 12-lead electrocardiogram (EKG). METHODS: We identified all Veterans Affairs Pittsburgh Healthcare System patients in a 6-month period with an EKG reporting a corrected QT (QTc) >500 ms. We excluded confounding or uninterpretable EKGs. Charts were reviewed to assess medications and electrolytes at the time of the EKG as well as the setting (inpatient vs outpatient) in which the EKG was obtained. Provider documentation of QTc and any corrective measures were sought. RESULTS: After exclusions, 106 patients were included in this analysis (87 [82%] inpatient and 19 [18%] outpatient). Most were male (101, 95%) with a mean age of 63.5 ± 10.6 years. At the time of index EKG, most patients were receiving at least one (72, 68%), and frequently two or more (35, 33%), QTc prolonging medications. Providers documented QTc prolongation in 20 inpatients (19%). Drugs were adjusted or discontinued in only two inpatients (2%). There were 14 patients (14%) with potassium level <3.6 mmol/L and 10 of 69 (14%) patients had a magnesium level <1.7 mg/dL. CONCLUSION: Patients with prolonged QTc on EKG were more likely to be inpatients than outpatients. Inpatients were more likely to be receiving multiple types and classes of QTc prolonging medications. In the vast majority of cases, providers did not address the prolonged QTc and only rarely initiated remedial actions.

Bleeding and infection with external ventricular drainage: a systematic review in comparison with adjudicated adverse events in the ongoing Clot Lysis Evaluating Accelerated Resolution of Intraventricular Hemorrhage Phase III (CLEAR-III IHV) trial.

BACKGROUND: Retrospective series report varied rates of bleeding and infection with external ventricular drainage (EVD). There have been no prospective studies of these risks with systematic surveillance, threshold definitions, or independent adjudication. OBJECTIVE: To analyze the rate of complications in the ongoing Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage Phase III (CLEAR III) trial, providing a comparison with a systematic review of complications of EVD in the literature. METHODS: Patients were prospectively enrolled in the CLEAR III trial after placement of an EVD for obstructive intraventricular hemorrhage and randomized to receive recombinant tissue-type plasminogen activator or placebo. We counted any detected new hemorrhage (catheter tract hemorrhage or any other distant hemorrhage) on computed tomography scan within 30 days from the randomization. Meta-analysis of published series of EVD placement was compiled with STATA software. RESULTS: Growing or unstable hemorrhage was reported as a cause of exclusion from the trial in 74 of 5707 cases (1.3%) screened for CLEAR III. The first 250 patients enrolled have completed adjudication of adverse events. Forty-two subjects (16.8%) experienced ≥1 new bleeds or expansions, and 6 of 250 subjects (2.4%) suffered symptomatic hemorrhages. Eleven cases (4.4%) had culture-proven bacterial meningitis or ventriculitis. CONCLUSION: Risks of bleeding and infection in the ongoing CLEAR III trial are comparable to those previously reported in EVD case series. In the present study, rates of new bleeds and bacterial meningitis/ventriculitis are very low despite multiple daily injections, blood in the ventricles, the use of thrombolysis in half the cases, and generalization to >60 trial sites.