MIAMI BEACH – Patients undergoing major vascular surgery showed a surprisingly high incidence of perioperative cardiac arrhythmias in a single-center, prospective study that so far includes 41 patients.
Dr. Hence J.M. Verhagen
Insertion of a continuous ECG monitor into patients starting about 2 weeks before they underwent major vascular surgery and continuing monitoring of each patient through about 2 months after surgery showed that 12 patients (29%) had some form of new-onset cardiac arrhythmia, Dr. Hence J.M. Verhagen said at ISET 2011, an international symposium on endovascular therapy. The study group included 13 patients (32%) undergoing open repair of an abdominal aortic aneurysm, 18 (44%) patients having an endovascular repair of an abdominal aortic aneurysm, and 10 patients (24%) having peripheral artery bypass surgery.
By using an inserted arrhythmia monitor to track incident arrhythmias for a prolonged period during and after surgery "we detected arrhythmias we were completely unaware of," said Dr. Verhagen, professor of surgery and chief of vascular surgery at Erasmus University Medical Center in Rotterdam, the Netherlands. "Many of these patients are completely asymptomatic," he noted in an interview. The most common arrhythmias were ventricular tachycardias, followed by atrial fibrillations, and supraventricular tachyarrhythmias. Most were paroxysmal.
Prior studies by Dr. Verhagen and his associates showed that vascular surgery patients who develop a cardiac arrhythmia following surgery have significantly worse outcomes. "This is a new opportunity to improve long-term outcomes," he said, but added that his group has not yet examined the impact that early treatment of the arrhythmias has on long-term consequences.
The earlier reports from Dr. Verhagen and his collaborators used externally worn Holter monitors to track cardiac arrhythmias in vascular surgery patients. Because these devices are intrusive for patients, monitoring lasted only 3 days. In one recently reported study, they assessed for 3 days 483 vascular surgery patients with Holter monitors and found new onset tachyarrhythmias in 33 (7%). They reported that the patients with these arrhythmias had a higher rate of reduced left ventricular ejection fraction and myocardial infarctions during the perioperative period. During a 2-year follow-up, their rate of sudden cardiac death was 2.6-fold higher than in the patients who did not have perioperative arrhythmias (J. Vasc. Surg. 2010 [doi:10.1016/j.jvs.2010.09.013]).
In another recent report, they presented findings from 72-hour Holter monitoring in 513 vascular surgery patients and found 55 (11%) with ventricular tachycardia, atrial fibrillation, supraventricular tachycardia, or ventricular fibrillation. Patients who had these arrhythmias had a 2.2-fold increased rate of cardiovascular events during an average follow-up of 1.7 years (Am. Heart J. 2010;159:1108-15).
The study using Holter monitoring included patients who had open or endovascular abdominal aortic aneurysm repair and peripheral artery bypass surgery as well as some patients who underwent carotid endarterectomy or endovascular carotid artery stenting.
The group’s more recent studies using longer-term monitoring with small, inserted devices showed that the incidence of new arrhythmias is much higher than the earlier studies had shown. The arrhythmic episodes seemed to be more common during the first couple of weeks following surgery, but several other episodes occurred several weeks after the vascular operation, Dr. Verhagen said. The pattern of arrhythmia episodes also appeared to have no relationship to whether surgery was done by open or endovascular procedures. His group will continue to collect data using inserted monitors from additional surgery patients, and future studies will need to address the impact that treatment of the arrhythmias has on long-term patient outcomes, Dr. Verhagen said.
Dr. Verhagen said that he has received research funding from and has served as a consultant to Medtronic. The insertable ECG monitors used in his study were Reveal XT models, a device marketed by Medtronic.