ICD and Pacemaker Needs After Open Heart Surgery: Series Provides a Benchmark

Looking at a large cohort of patients undergoing various types of open heart surgery, investigators have provided contemporary data that can be used to inform patients about the risks of cardiac device implantation after their operation. The information also has importance in the context of developments in transcatheter technologies.

Overall, 4.1% of surgical patients required a new implant with either a pacemaker or implantable cardioverter defibrillator (ICD), lead author Newton Wiggins, MD (Cleveland Clinic, OH), and colleagues report in a study published online October 12, 2016, ahead of print in Europace. The rate varied widely across different types of operation, however, ranging from 1.2% for CABG alone to 25% for tricuspid valve replacement.

Senior author Khaldoun Tarakji, MD (Cleveland Clinic), pointed out the relevance of the findings for transcatheter procedures. Percutaneous approaches are becoming increasingly used, particularly for aortic valve replacement, but a major concern remains the high rates of device implantation after the procedures, he told TCTMD.

“So it is extremely important to have a benchmark for the same patients undergoing the same type of surgery, but one is through transcatheter [and the other through] surgical,” Tarakji said.

The authors note that the rate of device implantation after surgical aortic valve replacement in the current study was 6.2%, which is lower than the permanent pacemaker rates seen in TAVR registries; those range from 19.2% to 42.5% with CoreValve (Medtronic) and 7% to 22% with Sapien (Edwards Lifesciences).

But something to keep in mind, Tarakji said, is that TAVR technology is improving and pacemaker rates are falling with new-generation devices.

Survival Differs in Patients With Devices

Tarakji said that much of the information on the risks of device implantation after open heart surgery comes from studies that are decades old. In the modern era, surgeons are treating patients who are older and have more comorbidities, so updated data are needed, he said, also pointing out that there is little information available about long-term outcomes in those who receive devices.

For the current study, the investigators examined data on 39,546 patients without implanted devices who underwent cardiac surgery at the Cleveland Clinic between January 1996 and January 2008. In all, 2.8% required pacemaker implantation and 1.3% required ICD implantation after the operation, although rates varied substantially depending on the type of operation. The rate of device implantation also became increasingly frequent with each redo operation, reaching over 20% for patients undergoing a fifth repeat surgery.

Risk factors associated with the need for implantation included older age, LV dysfunction, valvular disease, a history of syncope, preoperative A-fib, and prior cardiac surgery.

Of note, survival differences emerged between patients who required a device after surgery and those who didn’t. After propensity adjustment, patients with a device were less likely than those without a device to die within the first year of follow-up (HR 0.38; 95% CI 0.22-0.65) but more likely to die beyond 1 year (HR 1.3; 95% CI 1.2-1.5).

Tarakji said the survival differences were a little surprising and raise some hypotheses that need to be tested. The early advantage for patients with devices could be indicative of the need to monitor rhythms longer after operations to ensure that all patients who require support receive it, he said.

Different issues are raised by the long-term survival disadvantage among device-implanted patients, according to Tarakji. Decisions about who should get a device are made shortly after the operation, but the situation can change over time, he noted. It could be that someone who initially requires pacing of the right ventricle no longer needs it a few weeks later, he said, adding that unnecessary pacing can be detrimental to patients. The disadvantage in long-term survival could also be related to complications like infections associated with battery changes, device changes, and upgrades, he pointed out.

Those findings, though hypothesis-generating, highlight the importance of careful follow-up for patients, Tarakji said. “Not only do they need to be followed up with a cardiologist but also with an electrophysiologist [who can] reassess their device, reassess their patient needs, and make the necessary adjustment if appropriate.”

‘Extremely Valuable Data’

Commenting for TCTMD in an email, Isaac George, MD (Columbia University Medical Center, New York, NY), called this analysis “a very comprehensive and enlightening study regarding the need for a device after cardiac surgery. . . . This is extremely valuable data that should be used as benchmark data, particularly in the setting of evolving transcatheter therapies.”  

The analysis of risk factors for device implantation “unfortunately does not provide much useful information as to who will or will not require a device, as the data do not have enough granularity to investigate this on an anatomic level,” he said. “However, further studies mapping out how anatomical, pathological, and surgical details affect this primary outcome will be interesting and very useful in the development of transcatheter techniques as well as for refinement of surgical technique.”

The findings also “suggest that pacemaker rates in recent valve studies may suffer from too much medicine,” he said. “In an effort to minimize length of stay and treat conduction disturbances early, we implant early. The approach of waiting and watching, as is done more frequently in clinical practice and in surgical valve replacement, may reduce implantation but at the cost of a longer hospital stay.”

It is difficult to interpret the clinical impact of device implantation because of the lack of data on long-term cardiac function and the need for a device after discharge, George pointed out.

“Nonetheless,” he concluded, “this is an excellent review of a large series that provides a nice overview of the topic.”