Atrial fibrillation is the most common arrhythmia. AF is the common cause of stroke/CVA. Conventionally anti coagulation with warfarin is preferred. Now left atrial appendage closure devices are also considered as a treatment strategy. Two RCT PROTECT AF and PREVAIL shows Non-inferiority compared to warfarin.
Three primary end points stroke (hemorrahagic or ischemic), systemic embolism and cardiovascular or unexplained death.
The choice to include CV/unexplained death, as an end point, an event unlikely to be affected by either treatment arm, biases towards non-inferiority. Due to so many loopholes in RCTs and higher rates complications with watchman, Anticoagulation is still considered as the first choice.
We need more number of large RCT to show that LAA Device closure is a feasible alternative.
3. Non-inferiority compared to warfarin.
Three primary end points stroke (hemorrahagic
or ischemic), systemic embolism and
cardiovascular or unexplained death.
The choice to include CV/unexplained death,
as an end point, an event unlikely to be
affected by either treatment arm, biases
towards non-inferiority
LAAC was noninferior to NOACs (Apixaban)
4. Sample size
NOACs vs Warfarin trials have
tens of thousands of patients
PROTECT AF- 730
PREVAIL- 382
PRAGUE-17 - 402
Lesser non-inferiority margins
RELY and ARISTOTLE trials used
a non-inferiority risk ratio of
1.46 and 1.44, respectively
PROTECT AF and PREVAIL
trials employed a lesser
margin of 2.0 and 1.75,
respectively
Rate of haemorrhagic stroke
In the warfarin arms of more
than 38,000 patients enrolled
in contemporary clinical trials
ranges from 0.36%-0.5%.
In PROTECT AF haemorrhagic
stroke with WATCHMAN vs
warfarin (0.2% vs 1.1%). 1.1%
rate of haemorrhagic stroke in
the warfarin arm is
unexpectedly very high.
5. Higher rates of ischaemic stroke as per PREVAIL trial
Warfarin group 1.3% Watchman group 2.5%
Major bleeding in different trials
Trials Device
group
PROTECT,
PREVAIL
Control
group
PROTECT,
PREVAIL
CAP
registry
AVERROES
Apixaban
AVERROES
Aspirin
Major
bleeding all
3.1% 3.5% 4% 1.4% 1.2%
Even after device implantation as
per PROTECT & PREVAIL
Warfarin plus ASA 75 mg for 45 days
DAPT 6 months
SAPT lifelong.
6. Warfarin Watchman
As per control group data of
PROTECT AF and PREVAIL trial
Major bleeding risk is 3.5% .
Access related- 0.6-13 %
Risk due to the use of large
delivery sheaths.
Device implantation related-
(as per PROTECT AF)
Residual peri-device leak- 32%
Device related thrombus- 4.2%
Cardiac tamponade- 2.8%
Associated stroke/TIA- 1.5%
Pericardial effusion (no
intervention needed)- 0.9%
Device migration (0.2%) or
embolization (0.6%)
7. Due to so many loopholes in RCTs and higher
rates complications with watchman,
Anticoagulation is still considered as the first
choice.
We need more number of large RCT to show
that LAA Device closure is a feasible
alternative.
