Using an insertable cardiac monitor to identify atrial fibrillation in patients with cryptogenic stroke is cost-effective, at least from a UK healthcare system’s perspective. The results are likely to catch the eye of the FDA, too, the lead researcher told Cardiovascular Business.
“The management of cryptogenic stroke patients is currently very difficult and often they don’t get anticoagulated until they have had a second stroke,” said Klaus Witte, MD, an associate professor and cardiologist at the University of Leeds in the UK and Leeds Teaching Hospitals National Health Service Trust. “The standard of care is aspirin, which we know is effectively pointless in a lot of cases, particularly if there is arrhythmia.”
Witte presented the results Feb. 11 at the American Stroke Association’s 2015 International Stroke Conference (ISC) in Nashville, Tenn. The cost-effectiveness analysis used data from the CRYSTAL AF (Cryptogenic Stroke and Underlying AF) trial, which randomized 441 patients with cryptogenic stroke or transient ischemic attack to either long-term electrocardiographic monitoring with an insertable cardiac monitor (REVEAL XT, Medtronic) or conventional follow-up.
At six months, atrial fibrillation was detected in 8.9 percent of the device group vs. 1.4 percent in the standard-care group. At 12 months, the detection of atrial fibrillation was seven time higher in the insertable cardiac monitor group compared with the control, and it continued to climb up to three years.
The cost-effectiveness model assumed that all patients with detected atrial fibrillation received anticoagulation of either a novel oral anticoagulant (NOAC) or warfarin. For risks, they included cerebrovascular events and treatment-related adverse events.
Patients treated with NOACs tallied an incremental cost-effectiveness ratio (ICER) of $28,308 (£17,184) and those receiving warfarin had an ICER of $21,903 (£13,296). Both anticoagulation approaches fell within the accepted range of value in the UK and the U.S., and also skimmed in below a lower threshold.
“We wanted to use the potential lower cutoff value that they [policy makers] might impose at some point in the future,” Witte explained. While the British standard of acceptability now sits at £30,000, it may drop to £20,000. “I suspect if NICE [National Institute of Clinical Excellence] goes for £20,000, and they are likely to, then the U.S. system will probably follow suit.”
Witte pointed out that the NOACs were more expensive but he characterized them as safer and more effective. Warfarin’s higher risk counteracted its much lower cost. “[The ICER] is still less than the NOACs but not as much less as you would expect, given the difference in price,” he said.
The FDA gave the green light to the Reveal LINQ insertable cardiac monitor system and the device is reimbursed under existing coding. In the UK, hospitals can make a case for reimbursement but there as yet are no strict guidelines from NICE. “The first stage now will be to go to NICE in the UK with our data and apply for reimbursement for this indication, and I suspect following that we will go to the FDA,” he said.
Medtronic sponsored CRYSTAL AF.