DIVISION OF RESEARCH
Re: Monthly Graphics for Sustainer Use and Stroke Prevention June 3, 2022
Hello RISTRA-AF Physicians!
Several of you have asked how we’re doing with implementing the principles of management from RISTRA-AF. Details on cardioversion are harder to capture, but we have been able to calculate use of sustainers for rate reduction and engagement with stroke prevention.
Below we explain why these two clinical components are important and how we went about our calculations.
1. Use of sustained rate-reduction medications
A. Clinical Importance
Sustainers produce long-lasting rate reduction, which facilitates discharge home and reduces the need for observation and hospitalization, according to several U.S. studies. Oral sustainers include metoprolol tartrate 50mg BID (the best of the bunch), metoprolol succinate XL 50mg daily, and diltiazem XL 120mg daily. We include atenolol daily on this list. It’s not as a good a choice as metoprolol but has a role in ED patients already taking it. IV sustainers include magnesium sulfate. Doses proven to be effective in randomized trials range from 3g to 9g often given over 30min. A small 2g dose has not been as well studied but might have some rate-reducing effect. We recommend 4g over 60min or longer.
We restricted our calculation to ED patients with primary AF or flutter, excluding those with common causes of secondary AF, e.g., sepsis, pneumonia, PE. The denominator is comprised of all those with primary AF or flutter who received ANY AV nodal blocker, long-acting, short-acting, oral, IV, whatever. The numerator includes those who received a sustainer, listed above. We included long-acting oral agents (metoprolol tartrate, metoprolol succinate, atenolol and diltiazem XL) of any dose, and MgSO4 of 2g or more. Dividing the numerator by the denominator gives us the % of rate-reducing recipients who received a sustainer. We include in the comparison all the KPNC EDs whose RISTRA-AF app is live, for whatever duration of time.
We report 3-month moving averages to smooth out the expected month-by-month variation.
The first month value following implementation is only for that month.
The second month value is the average of the first two months.
The third month value is the average of the first three months.
Months four and beyond are the average of the specific month under review and the prior two months.
In addition to our own ED’s %s, we report in the bar graph the 3 EDs with the highest rates. The numbers in the vertical bars denote the ED ranking from 1 on down.
2. Stroke prevention
A. Clinical Importance
AF and flutter are common causes of ischemic stroke, the effects of which can be devastating. Most patients who cross the risk threshold (using CHA2DS2-VASc) have a far greater net benefit of stroke prevention over bleeding risk. For some patients, the ED visit can be a turning point in stroke prevention. Here are two effective engagement strategies:
Explain the rationale for stroke prevention (the risk-specific handout is very helpful for this) and if the patient agrees, prescribe a 30-day course of anticoagulation. Continuation is in the hands of their clinic docs.
Without prescribing, you can introduce the topic and provide a nudge to get this process moving forward. Any of these three actions can increase the rate of OAC prescribing in the 30 days following discharge
a. Providing a patient handout and recommend they take it their next clinic appt.
b. eConsult Anticoag Management Services if the patient wants more information on OACs.
c. Send the PCP a note alerting them to the patient’s unaddressed elevated stroke risk.
The population (or denominator) for these calculations is comprised of those with primary AF or flutter (as above), who are Health Plan members, were discharged home directly from the ED and were thought to be eligible for OAC.
How did we estimate OAC eligibility? The patient crossed the stroke risk threshold on CHA2DS2-VASc (2 for men and 3 for women) and wasn’t already taking an OAC. These were determined using electronic HealthConnect data; these are not perfect, but fairly accurate. The numbers of eligible cases per month are so small we report only 3-month averages.
The first bar graph is the % of these OAC-eligible AF patients who were prescribed an OAC on ED discharge.
The second is the % of these OAC-eligible AF patients who were prescribed an OAC not on discharge but in the 30 days following discharge, something that may have been influenced by our nudges above (A2a-2c). These numbers are delayed by a month.
Let your site lead know if you have any questions.
Thanks for all you do for our AF patients.