Risk Factors and Outcome of New-Onset Cardiac Arrhythmias in Vascular Surgery Patients

Abstract

Conclusion: Perioperative arrhythmias are common after vascular surgeries. Elderly patients and those with reduced left ventricular function are particularly prone to postoperative arrhythmias. Summary: Cardiac arrhythmia occurring postoperatively can be seen in up to 20% of patients undergoing noncardiac surgery (Brathwaite D, et al, Chest 1998;114:462-8 and Walsh SR et al, Ann R Coll Surg Engl 2007;89:91-5). The risk of cardiovascular events is especially elevated in noncardiac vascular surgical patients (Schouten O et al, Eur Heart J 2008;29:283-4). Many events are asymptomatic and often transient and unpredictable, suggesting the true prevalence may be underestimated. The current study focused on vascular surgical patients and was designed to determine the true prevalence of cardiac arrhythmias in this population, identify operative risk factors leading to new-onset cardiac arrhythmias, and assess the impact of these new arrhythmias on postoperative outcome. The study included 515 vascular surgical patients without a history of arrhythmia. Assessed were left ventricular function (LVF), determined by N-terminal pro-B-type natriuretic peptide levels and echocardiography, inflammatory status, and cardiac risk factors. New onset arrhythmias and ischemia were identified with 72-hour continuous electrocardiographic recordings. Patients were evaluated for atrial fibrillation, sustained ventricular tachycardia, supraventricular tachycardia, and ventricular fibrillation. There was a new onset of arrhythmia in 55 patients (11%), including atrial fibrillation in 4%, ventricular tachycardia in 7%, supraventricular tachycardia in 1%, and ventricular fibrillation in 0.2%. Arrhythmia was preceded by ischemia in 10 of 55 patients. Reduced LVF and increased age were risk factors for development of arrhythmia. Multivariant analysis indicated that perioperative arrhythmias were associated with long-term cardiovascular events independent of perioperative ischemia (hazard ratio, 2.2; 95% confidence interval, 1.3-3.8; P = .004). Comment: More than 30 years ago, Goldman published a prospective series of patients undergoing major noncardiac surgery, and only 4% developed postoperative supraventricular arrhythmias (Goldman L, Chest 1978;73:450-4). One conclusion was that postoperative supraventricular arrhythmias were often transient, and the most important thing was to correct the cause of the arrhythmia. The number of each type of arrhythmia occurring in this study did not permit meaningful subset analysis. The association of arrhythmias with older age and preoperatively decreased LVF is not all that surprising. Currently, many vascular surgical patients are routinely subjected to telemetry monitoring. Given the number of arrhythmias identified in this study, the current data may question the use of such a blanket policy for patients without known preoperative left ventricular dysfunction.