Prognosis of transient new-onset atrial fibrillation during vascular surgery

[Perioperative atrial fibrillation : Diagnosis with underestimated relevance]

Atrial fibrillation (AF) is the most common cardiac arrhythmia in adults, both in general and perioperatively and is associated with significant morbidity and mortality. The age of the patients is a major risk factor. The prevalence of AF in noncardiac surgery (NCS) varies widely from 0.4% to 30% and for cardiac surgery, especially major combined procedures, up to approximately 50%. Ectopic excitation centers and reentry mechanisms at the atrial level are favored as the main process of uncoordinated electrical atrial activity. The loss of atrial contraction can lead to a reduction in cardiac output of up to 20-25%. The increased risk of thromboembolism due to AF extends beyond the perioperative period. Medication-based prevention strategies have not yet gained widespread acceptance. Treatment strategies include frequency and rhythm control as well as the avoidance of thromboembolisms through anticoagulation.

Atrial fibrillation in vascular surgery: a systematic review and meta-analysis on prevalence, incidence and outcome implications

AIMS

To know the prevalence of atrial fibrillation (AF), as well as the incidence of postoperative AF (POAF) in vascular surgery for arterial diseases and its outcome implications.

METHODS

We performed a systematic review and meta-analysis following the PRISMA statement.

RESULTS

After the selection process, we analyzed 44 records (30 for the prevalence of AF history and 14 for the incidence of POAF).The prevalence of history of AF was 11.5% [95% confidence interval (CI) 1-13.3] with high heterogeneity (I2 = 100%). Prevalence was higher in the case of endovascular procedures. History of AF was associated with a worse outcome in terms of in-hospital death [odds ratio (OR) 3.29; 95% CI 2.66-4.06; P < 0.0001; I2 94%] or stroke (OR 1.61; 95% CI 1.39-1.86; P < 0.0001; I2 91%).The pooled incidence of POAF was 3.6% (95% CI 2-6.4) with high heterogeneity (I2 = 100%). POAF risk was associated with older age (mean difference 4.67 years, 95% CI 2.38-6.96; P = 0.00007). The risk of POAF was lower in patients treated with endovascular procedures as compared with an open surgical procedure (OR 0.35; 95% CI 0.13-0.91; P = 0.03; I2 = 61%).

CONCLUSIONS

In the setting of vascular surgery for arterial diseases a history of AF is found overall in 11.5% of patients, more frequently in the case of endovascular procedures, and is associated with worse outcomes in terms of short-term mortality and stroke.The incidence of POAF is overall 3.6%, and is lower in patients treated with an endovascular procedure as compared with open surgery procedures. The need for oral anticoagulants for preventing AF-related stroke should be evaluated with randomized clinical trials.

Major Adverse Cardiac Events after Elective Infrarenal Endovascular Aortic Aneurysm Repair

OBJECTIVE

There is a significant cardiac morbidity and mortality after endovascular aneurysm repair (EVAR). However, information about long-term risk of cardiac events after EVAR and potential predictors is lacking. Therefore, the aim of this study was to determine incidence and predictors of major adverse cardiac events (MACE) at one- and five-years after elective EVAR for infrarenal abdominal aortic aneurysms.

METHODS

Baseline, perioperative and postoperative information of 320 patients was evaluated. The primary outcome was the incidence of MACE after EVAR, which was defined as acute coronary syndrome, unstable angina pectoris, de novo atrial fibrillation, hospitalization for heart failure, mitral valve insufficiency, revascularization (including PCI and CABG), as well as cardiovascular and non-cardiovascular death. Kaplan Meier analysis was performed to determine incidences of MACE, MACE excluding non-cardiovascular death and cardiac events by excluding non-cardiovascular and vascular death from MACE. Predictors of MACE were identified using univariate and multivariate binary regression analysis.

RESULTS

Through one- and five-years follow-up after EVAR, freedom from MACE was 89.4% (standard error (SE) 0.018) and 59.8% (SE 0.033), freedom from MACE excluding non-cardiovascular death was 94.7% (SE 0.013) and 77.5% (SE 0.030) and freedom from cardiac events was 96.0% (SE 0.011) and 79.1% (SE 0.030), respectively. Predictors for MACE within one-year were American Society of Anaesthesiologists (ASA) score 3 or 4 (OR, 3.17; 95% CI, 1.52-6.59) and larger abdominal aortic diameter (OR, 1.04; 95% CI, 1.01-1.08). History of atrial fibrillation (OR, 0.14; 95% CI, 0.03-0.60) was a negative predictor factor. Predictors for MACE through five-years were history of heart failure (OR, 4.10; 95% CI 1.36-12.32) and valvular heart disease (OR, 2.31; 95% CI, 0.97-5.51), ASA score 3 or 4 (OR, 1.66; 95% CI, 0.96-2.88) and older age (OR, 1.04; 95% CI, 1.01-1.08).

CONCLUSION

MACE is a common complication during the first five-years after elective EVAR. Cardiac diseases at baseline are strong predictors for long-term MACE and potentially helpful in optimizing future post-operative long-term follow-up.

Incidence, Risk Factors, and Outcomes of Perioperative Atrial Fibrillation following Noncardiothoracic Surgery: A Systematic Review and Meta-Regression Analysis of Observational Studies

Background

Atrial fibrillation (AF) occurs in 16-30% of patients after cardiac and thoracic surgery and can lead to serious complications like hypoperfusion of vital organs, pulmonary edema, and myocardial infarction. The evidence on risk factors and complications associated with perioperative AF after noncardiothoracic surgery is limited.

Methods

The primary objective was to determine demographic and clinical risk factors for new-onset atrial fibrillation associated with noncardiothoracic surgery. A secondary aim was to identify the incidence and odds of perioperative complications associated with the new-onset atrial fibrillation. A systematic search within multiple databases was conducted for studies that explicitly reported on new-onset atrial fibrillation after noncardiothoracic surgery. We reported data on demographics, comorbidities, and perioperative complications as mean difference (MD) or odds ratios (OR) and corresponding 95% confidence interval (CI) using random effects models. A two-sided P value of less than 0.05 was considered significant. We performed meta-regression and sensitivity analysis of various subgroups to confirm the inference of our findings.

Results

Eleven studies reporting on 121,517 patients were included, of whom 2,944 developed perioperative AF (incidence rate: 3.7%; 95% CI: 2.3%--6.2%). Advanced age (AF group versus control group: 69.36 ± 10.5 versus 64.37 ± 9.53 years; MD: 4.06; 95% CI: 1.67--6.44; P=0.0009), male gender (52.85% versus 43.59%; OR: 1.08; 95% CI: 0.54 to 1.62; I ²: 84%; P < 0.0001), preoperative hypertension (60.42% versus 56.51%; OR: 1.15; 95% CI: 1.08 to 1.23; I ²: 0%; P < 0.00001), diabetes mellitus (22.6% versus 23.04%; OR: 0.97; 95% CI: 0.89 to 1.05; I ²: 0; P < 0.00001), and cardiac disease (30.64% versus 8.49%; OR: 2.3; 95% CI: 0.28 to 4.31; I ²: 93%; P=0.03) were found to be significant predictors for perioperative AF. The AF group was at increased odds of developing postoperative cardiac complications (34.1% versus 5%; OR: 5.44; 95% CI: 0.49 to 10.39; I ²: 82%; P=0.03), postoperative stroke (0.5% versus 0.1%; OR: 3; 95% CI: 0.65 to 5.35; I ²: 0%; P=0.01), and mortality (7.40% versus 1.92%; OR: 3.58; 95% CI: 0.14 to 7.02; I ²: 0%; P=0.04). Study quality assessment by meta-regression and sensitivity analysis of the various subgroups did not affect the final inference of the results.

Conclusion

We identified advanced age, male gender, preoperative hypertension, diabetes mellitus, and cardiac disease as important risk factors for perioperative atrial fibrillation. The atrial fibrillation group was at increased odds for postoperative cardiac complications, stroke, and higher mortality, emphasizing the need for risk stratification and close monitoring.

Anticoagulant Use and the Risk of Thromboembolism and Bleeding in Postoperative Atrial Fibrillation After Noncardiac Surgery

BACKGROUND

An effective and safe oral anticoagulation (OAC) strategy for patients with new postoperative AF (POAF) after noncardiac surgery remains unclear. We aimed to determine the association between OAC use and 1) thromboembolic events and 2) major bleeding in patients with POAF after noncardiac surgery.

METHODS

A retrospective cohort (1999-2015) was used to identify patients with new POAF after inpatient noncardiac surgery. Initiation of OAC was defined as prescription of an OAC within 30 days following hospital discharge. Times to first hospital admission or emergency department visit for a thromboembolic or major bleeding event were compared using Cox proportional hazards models.

RESULTS

We identified 22,007 patients with new POAF after inpatient noncardiac surgery. The majority of patients had intermediate (CHA₂DS₂-VASc 2-3: 45%) to high (CHA₂DS₂-VASc ≥ 4: 42%) thromboembolic risk. During a mean follow-up of 4 years, a total of 1099 (5%) thromboembolic and 3250 (15%) bleeding events occurred. Compared with patients not on anticoagulation, anticoagulation did not reduce the risk for thromboembolic events (adjusted hazard ratio [aHR] 0.89, 95% CI 0.73-1.07). In patients initiated on anticoagulation, there was an association with a higher risk for major bleeding (aHR 1.14, 95% CI 1.04-1.25).

CONCLUSIONS

In patients with new POAF after noncardiac surgery, anticoagulation was not associated with a reduction in long-term thromboembolic events; however, this was accompanied by an overall increased risk for major bleeding. Future prospective clinical studies are needed to better address the role for anticoagulation therapy in the setting of POAF after noncardiac surgery to understand the efficacy and safety of treatment.

Postoperative Atrial Fibrillation Following Noncardiac Surgery Increases Risk of Stroke

BACKGROUND

New-onset postoperative atrial fibrillation is well recognized to be an adverse prognostic marker in patients undergoing noncardiac surgery. Whether postoperative atrial fibrillation confers an increased risk of stroke remains unclear.

METHODS

A systematic review and meta-analysis was performed to assess the risk of stroke after postoperative atrial fibrillation in noncardiac surgery. MEDLINE, Cochrane, and EMBASE databases were searched for articles published up to May 2019 for studies of patients undergoing noncardiac surgery that reported incidence of new atrial fibrillation and stroke. Event rates from individual studies were pooled and risk ratios (RR) were pooled using a random-effects model.

RESULTS

Fourteen studies of 3,536,291 patients undergoing noncardiac surgery were included in the quantitative analysis (mean follow-up 1.4 ± 1 year). New atrial fibrillation occurred in 26,046 (0.74%), patients with a higher incidence following thoracic surgery. Stroke occurred in 279 (1.5%) and 6199 (0.4%) patients with and without postoperative atrial fibrillation, respectively. On pooled analysis, postoperative atrial fibrillation was associated with a significantly increased risk of stroke (RR 2.51; 95% confidence interval, 1.76-3.59), with moderate heterogeneity. The stroke risk was significantly higher with atrial fibrillation following nonthoracic, compared with thoracic, surgery (RR 3.09 vs RR 1.95; P = .01).

CONCLUSION

New postoperative atrial fibrillation following noncardiac surgery was associated with a 2.5-fold increase in the risk of stroke. This risk was highest among patients undergoing nonthoracic noncardiac surgery. Given the documented efficacy of newer anticoagulants, randomized controlled trials are warranted to assess whether they can reduce the risk of stroke in these patients.

Major Adverse Cardiovascular Events Associated With Postoperative Atrial Fibrillation After Noncardiac Surgery

Background:

Postoperative atrial fibrillation (POAF) is a frequent occurrence after noncardiac surgery. It remains unclear whether POAF is associated with an increased risk of major adverse events. We aimed to elucidate the risk of stroke, myocardial infarction, and death associated with POAF following noncardiac surgery by a meta-analysis of randomized controlled studies and observational studies.

Methods:

We searched electronic databases from inception up to August 1, 2019 for all studies that reported stroke or myocardial infarction in adult patients who developed POAF following noncardiac surgery. We used random-effects models to summarize the studies.

Results:

The final analyses included 28 studies enrolling 2 612 816 patients. At 1-month (10 studies), POAF was associated with an ≈3-fold increase in the risk of stroke (weighted mean 2.1% versus 0.7%; odds ratio [OR], 2.82 [95% CI, 2.15–3.70]; P <0.001). POAF was associated with ≈4-fold increase in the long-term risk of stroke with (weighted mean, 2.0% versus 0.6%; OR, 4.12 [95% CI, 3.32–5.11]; P ≤0.001) in 8 studies with ≥12-month follow-up. There was a significant overall increase in the risk of stroke and myocardial infarction associated with POAF (weighted mean, 2.5% versus 0.9%; OR, 3.44 [95% CI, 2.38–4.98]; P <0.001) and (weighted mean, 12.6% versus 2.7%; OR, 4.02 [95% CI, 3.08–5.24]; P <0.001), respectively. Furthermore, POAF was associated with a 3-fold increase in all-cause mortality at 30 days (weighted mean, 15.0% versus 5.4%; OR, 3.36 [95% CI, 2.13–5.31]; P <0.001).

Conclusions:

POAF was associated with markedly higher risk of stroke, myocardial infarction, and all-cause mortality following noncardiac surgery. Future studies are needed to evaluate the impact of optimal cardiovascular pharmacotherapies to prevent POAF and to decrease the risk of major adverse events in these high-risk patients.

Preventing Postoperative Atrial Fibrillation After Noncardiac Surgery: A Meta-analysis

BACKGROUND

Although postoperative atrial fibrillation is common after noncardiac surgery, there is a paucity of data regarding prophylaxis. We sought to determine whether pharmacologic prophylaxis reduces the incidence of postoperative atrial fibrillation after noncardiac surgery.

METHODS

We performed an electronic search of Ovid MEDLINE, the Cochrane central register of controlled trials database, and SCOPUS from inception to September 7, 2016 and included prospective randomized studies in which patients in sinus rhythm underwent noncardiac surgery and examined the incidence of postoperative atrial fibrillation as well as secondary safety outcomes.

RESULTS

Twenty-one studies including 11,608 patients were included. Types of surgery included vascular surgery (3465 patients), thoracic surgery (2757 patients), general surgery (2292 patients), orthopedic surgery (1756 patients), and other surgery (1338 patients). Beta-blockers (relative risk [RR] 0.32; 95% confidence interval [CI], 0.11-0.87), amiodarone (RR 0.42; 95% CI, 0.26 to 0.67), and statins (RR 0.43; 95% CI, 0.27 to 0.68) reduced postoperative atrial fibrillation compared with placebo or active controls. Calcium channel blockers (RR 0.55; 95% CI, 0.30 to 1.01), digoxin (RR 1.62; 95% CI, 0.95 to 2.76), and magnesium (RR 0.73; 95% CI, 0.23 to 2.33) had no statistically significant effect on postoperative atrial fibrillation incidence. The incidence of adverse events was comparable across agents, except for increased mortality (RR 1.33; 95% CI, 1.03 to 1.37) and bradycardia (RR 2.74; 95% CI, 2.19 to 3.43) in patients receiving beta-blockers.

CONCLUSIONS

Pharmacologic prophylaxis with amiodarone, beta-blockers, or statins reduces the incidence of postoperative atrial fibrillation after noncardiac surgery. Amiodarone and statins have a relatively low overall risk of short-term adverse events.

Postoperative atrial fibrillation in patients undergoing non-cardiac non-thoracic surgery: A practical approach for the hospitalist

New postoperative atrial fibrillation (POAF) is the most common perioperative arrhythmia and its reported incidence ranges from 0.4 to 26% in patients undergoing non-cardiac non-thoracic surgery. The incidence varies according to patient characteristics such as age, presence of structural heart disease and other co-morbidities, as well as the type of surgery performed. POAF occurs as a consequence of adrenergic stimulation, systemic inflammation, or autonomic activation in the intra or postoperative period (e.g. due to pain, hypotension, infection) in the setting of a susceptible myocardium and other predisposing factors (e.g. electrolyte abnormalities). POAF develops between day 1 and day 4 post-surgery and it is often considered a self-limited entity. Its acute management involves many of the same strategies used in non-surgical patients but the optimal long-term management is challenging because of the limited available evidence. Several studies have shown an association between occurrence of POAF and in-hospital morbidity, mortality, and length of stay. Although, traditionally, POAF was considered to have a generally favorable long-term prognosis, recent data have shown an association with an increased risk of stroke at 1 year after hospitalization. It is unknown, however, whether strategies to prevent POAF or for rate/rhythm control when it does occur, lead to a reduction in morbidity or mortality. This suggests the need for future studies to better understand the risks associated with POAF and to determine optimal strategies to minimize long-term thromboembolic risks. In this article, we summarize the current knowledge on epidemiology, pathophysiology, and short- and long-term management of POAF after non-cardiac non-thoracic surgery with the goal of providing a practical approach to managing these patients for the non-cardiologist clinician.

What evidence is there for intraoperative predictors of perioperative cardiac outcomes? A systematic review

Background

Patients undergo cardiac preoperative evaluation to identify those at risk of adverse perioperative cardiac events. The Revised Cardiac Risk index is commonly used for this task, although it is unable to accurately risk stratify in all patients. This may be partly a result of intraoperative events which significantly modify preoperative risk.

Methods

We conducted a systematic review to identify independent intraoperative predictors of adverse cardiac events in patients undergoing non-cardiac surgery. Four databases (Ovid Healthstar 1966 to Jan 2012, Ovid Medline 1946 to 6 March 2012, EMBASE 1974 to March 05 2012 and The Cochrane Library to March 06 2012) were searched.

Results

Fourteen eligible studies were identified. The need for intraoperative blood transfusion (odds ratio (OR), 2.3; 95% confidence interval (CI), 1.4-3.3), vascular surgery (OR, 2.3; 95% CI, 1.2-3.4) and emergent/urgent surgery (OR, 2.3; 95% CI, 1.1-3.5) were the only independent intraoperative risk predictors identified in more than study. Other independent intraoperative factors identified included a >20 mmHg fall in mean arterial blood pressure for > 60 min (OR, 3.0; 95% CI, 1.8-4.9), >30% increase in baseline systolic pressure (OR, 8.0; 95% CI, 1.3-50), tachycardia in the recovery room (>30 beats per min (bpm) from baseline for >5 min) (OR, 7; 95% CI, 1.9-26), new onset atrial fibrillation (OR, 6.6; 95% CI, 2.5-20), hypothermia (OR, 2.2; 95% CI, 1.1-5) and remote ischemic preconditioning (OR, 0.22; 95% CI, 0.07-0.67). Other markers of surgical complexity were not independently associated with postoperative adverse cardiac outcomes. None of these studies controlled for blood transfusion.

Conclusions

Intraoperative events significantly increase the risk for postoperative cardiac complications, although only intraoperative blood transfusion has strong evidence supporting this finding. It is possible that modification of these intraoperative risk factors by anesthetists and surgeons may reduce postoperative cardiac events and improve outcome. The Vascular Events in Noncardiac Surgery Patients Cohort Evaluation (VISION) Study will add important information to understanding intraoperative risk factors for adverse cardiac events.