ICD Shocks, Needed or Not, 'Trigger a Cascade of Procedures'

Larry Hand

February 17, 2017

STANFORD, CA — Almost half of shocks from implantable cardioverter-defibrillators are followed by procedures and other healthcare utilization related to the shock, including inpatient care in a large proportion, suggests an observational study [1]. The finding was the same for both appropriate and inappropriate shocks.

"Shocks, regardless of why they occur, increase healthcare utilization and trigger a cascade of procedures that otherwise might not have occurred at all," Dr Mintu P Turakhia (Stanford University, CA) told heartwire from Medscape. "It's important that we really think of the quality of device programming, not just whether eligible patients receive a device, and make sure that we use contemporary evidence-based programming to minimize all of the healthcare utilization that we've seen in this study."

Turakhia and colleagues conducted an analysis of newly linked data on 10,266 patients who had remote monitoring of ICDs and cardiac resynchronization therapy defibrillator devices (CRT-D) implanted between January 1, 2008 and December 31, 2010.

First, they retrieved patient information from the Medtronic Data Warehousing and Analytics Service (DWAS). They then linked that data to matching patient medical data in the Truven Health MarketScan Commercial Claims and Encounters Database and MarketScan Medicare Supplemental and Coordination of Benefits Database.

They identified patients with at least one shock event during a 24-hour period from the DWAS data. Among the 10,266 patients with successfully linked data, 1529 (14.9%) had at least one shock event, according to their article, published online February 14, 2017 in Circulation: Cardiovascular Quality and Outcomes.

They excluded 532 patients without continuous preimplant enrollment and 34 patients whose shock events took place while hospitalized, leaving 963 patients who had 1885 shock events. Patients, mostly male (81%), had a mean age of 61.3 years.

"There were high rates of preimplant ischemic heart disease or previous myocardial infarction (60%), ventricular arrhythmias (41%), and atrial arrhythmias (37%)," the researchers write. "In this cohort, 23% had single-chamber, 49% had dual-chamber, and 28% had cardiac-resynchronization ICDs."

Of patients receiving shocks, 43% experienced only appropriate ones, 42% had only inappropriate shocks, and 12% received both kinds; the rest of patients experienced only "indeterminate" shocks.

Almost 14% (259) of shock events led to inpatient healthcare use, and 32.2% (608) led to outpatient healthcare use. A little over half (1018, 54%) did not lead to shock-related healthcare use.

ECG was the most frequent inpatient procedure (85.3%), followed closely by chest X-ray (75.7%) and cardiac catheterization (75.7%).

The most common outpatient procedures included device interrogations (76.1%) and ECG (73.4%), while 61.4% of patients required ambulance transportation and 45.6% had an emergency-room visit.

Researchers found the mean expenditure for inpatient shock-related healthcare to be $15,756 ($14,914 appropriate and $11,383 inappropriate). They found the mean expenditure for outpatient shock-related healthcare to be $1300 ($1094 appropriate and $1656 inappropriate).

What cardiologists can do to reduce the amount of shock-related healthcare use, according to Turakhia, is to use contemporary high-rate cut-off, extended-duration detection settings that potentially avert shocks. He cited the MADIT-RIT trial[2] as describing the kind of programming needed.

"How a device is programmed should be part and parcel of quality of care, not different from making sure the right patients are getting them and making sure they're not getting complications at implant. I really see this as a continuum of quality," Turakhia told heartwire.

He pointed out that the findings may be limited because they studied only patients with Medtronic devices and who had remote monitoring.

"We already know that patients who don't have remote monitoring have more healthcare utilization. I'm interested to see whether contemporary programming strategies are used less, possibly, in those patients who don't have remote monitoring," he said.

He said researchers are now looking to expand the types of data to be analyzed in this area.

"Beyond the clinical data and device data that we've looked at, are there other data that you can pull in—whether it's environmental data, personal data, or laboratory data—that may be used to help reduce the risk of clinical events, whether a heart-failure hospitalization or the risk of stroke in patients who have atrial fibrillation," he said.

"Those are areas of active investigation where we're really attempting to pool all this data together and use a variety of methods ranging from traditional biostatistics all the way to deep learning."

Medtronic funded this research. Turakhia is a consultant for Medtronic and St Jude Medical. Disclosures for the coauthors are listed in the paper.

Follow Larry Hand on Twitter: @LarryHand16. For more from theheart.org, follow us on Twitter and Facebook.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: