Updated to include comments from the principal investigator.

A new study has found that use of the Boston Scientific (NYSE:BSX) Watchman left atrial appendage closure (LAAC) device to treat atrial fibrillation costs less than existing and novel anticoagulant drugs over five years.
Researchers conducted the analysis using an Excel-based simulation model developed to assess the cost-effectiveness of LAAC using pooled data from a pair of clinical trials involving the Watchman device. The PROTECT AF study measured Watchman’s effectiveness in preventing embolism, while the PREVAIL 5-year, pivotal clinical trial compared its use to long-term treatment with the anticoagulant drug warfarin.
The new study was published in the Journal of the American Heart Association. It followed thousands of patients who were at moderate risk for stroke and bleeding. LAAC was cost‐effective relative to warfarin by year 7 and became more effective and less costly by year 10, the study showed. LAAC became cost‐effective and dominant compared with novel oral anticoagulant drugs (NOACs) by year 5. Over a lifetime, LAAC provided 0.60 more quality‐adjusted life‐years than warfarin and 0.29 more than NOACs.
“This comprehensive assessment uses the most complete body of clinical evidence for LAAC in an attempt to more definitively evaluate the therapy’s economic value and provide guidance for future analyses,” the study’s authors wrote.
Treating patients with AF adds an estimated $26 billion to U.S. healthcare costs, predominantly due to AF-related stroke, according to the heart association.
“A significant cost is the cost of stroke over the course of clinical experience,” principal investigator Dr. Vivek Reddy told MassDevice in an interview. Reddy is a professor of medicine and cardiology at Mount Sinai Hospital in New York City and a paid consultant to Boston Scientific, Abbott and Biosense Webster.
Those costs also depend upon the stroke’s severity, so the researchers took that into account, and also reported results on a year-by-year basis rather than the more common method of reporting long-term results, Reddy said. Using year-by-year reporting allowed them to determine when the individual treatment methods became more or less cost-effective, he added.
Marlborough, Mass.-based Boston Scientific said in May that it has begun a new study of the safety and efficacy of the next-generation Watchman FLX device compared with first-line oral anticoagulants (OAC) — including direct oral anticoagulants (DOAC), NOACs and warfarin — for stroke risk reduction in patients with non-valvular atrial fibrillation (AF) who undergo a cardiac ablation procedure.
Securing enough data to make a clinically significant direct comparison of Watchman to NOACS alone comparison will take five to six years, according to Reddy.
“From a clinician perspective, the trials that are needed in the field are appendage closure versus NOACs,” Reddy said. “It will be years before we have definitive data on that.”