PROTECT-AF (LAA Closure with Watchman vs Warfarin in
AF and Stroke)
VY Reddy (Mount Sinai School of Medicine, New York, NY)
Heart Rhythm Society (HRS) 2013 Scientific Sessions
• A long-term (45-month) follow-up analysis of device therapy with Watchman vs
warfarin for LAA closure with respect to all-cause and CV mortality and
hemorrhagic stroke in patients with nonvalvular atrial fibrillation and stroke risk
factors
• Population and treatment:
800 patients followed up for a mean of 45 months, or an aggregate of 2621
patient-years, randomized to either the Watchman device or warfarin
• Primary end points:
Efficacy: Stroke, systemic embolism, or CV or unexplained death
Safety: A composite of serious pericardial effusion, major bleeding, procedurerelated stroke, hemorrhagic stroke, and device embolization
LAA=Left Atrial Appendage
PROTECT-AF: Results
•
•
•
The new data confirm that the Watchman is
noninferior and show for the first time that it
is superior to warfarin for the composite
primary efficacy end point of stroke,
systemic embolism, or cardiovascular or
unexplained death.
LAA closure with the Watchman device is
superior to warfarin with respect to all-cause
and CV mortality and hemorrhagic stroke in
patients with nonvalvular atrial fibrillation
and stroke risk factors.
The observed 40% drop in primary events
were fairly consistent throughout most of the
trial, but only with the latest long-term
analysis reached statistical superiority.
Rate ratios for primary efficacy and
safety end points and secondary end
points in PROTECT-AF, by intention to
treat
End points
RR (95%CI)
Primary efficacy end point:
Stroke, systemic embolism, or CV or
unexplained death
0.60 (0.41–1.05)
All-cause mortality
0.66 (0.45–0.98)
Cardiovascular mortality
0.40 (0.21–0.72)
Hemorrhagic stroke
0.15 (0.03–0.49)
Primary safety end point:
Serious pericardial effusion, major bleeding,
procedure-related stroke, hemorrhagic stroke,
and device embolization
1.17 (0.78–1.95)
PROTECT-AF: Commentary*
"This is statistically nonsignificant for the first time. The reason is, even though there
[was] a high number of [mostly procedure-related] events up front in the Watchman
group, there [were] cumulative events in the warfarin group. So by the time we have
the four-year analysis, the event rate is statistically similar.
"The difference is that the confidence intervals have narrowed, meaning, as we
have more data accumulated, we have become more and more confident that that
40% decrease is actually . . . a real end point, not just by chance. The amount of
benefit hasn't really changed; what has changed is our certainty that the number is
really true."
- Dr Vivek Y Reddy
*All comments from Long-term PROTECT-AF analysis: Watchman attains efficacy superiority over
warfarin in AF (http://www.theheart.org/article/1538469.do)