CAD in Patients at Risk of Reinfarction
How can you avoid a repeat of history?
Peter, aged 67, attends a routine appointment for blood pressure monitoring:
- He was diagnosed with hypertension 5 years ago and has since been receiving an ACE inhibitor
- At the same time, he started taking a statin to manage his lipid levels
- Despite these treatments, Peter had an NSTEMI 18 months ago
- Following a PCI, he received DAPT for 1 year and then aspirin alone for 6 months
Although Peter has experienced no further symptoms of CAD, he is concerned because a close friend recently died from a second MI and he is afraid of suffering the same fate.
Which measures should be implemented to reassure him whilst reducing his risk of reinfarction?
Most patients with stable CAD have already experienced an MI
Peter may be concerned, but he is far from alone. The CLARIFY registry found that 61.8% of outpatients with a diagnosis of chronic CAD have already had an MI.1 For these patients, the ESC treatment guidelines are clear, suggesting that they should receive long-term risk factor management with statins and antihypertensives.2,3 Furthermore, to reduce thrombotic risk, the guidelines suggest DAPT for 12 months after the event followed by long-term, low-dose aspirin.
However, data from the REACH registry show that even in patients with chronic CAD receiving a high standard of treatment, 18.3% of patients with a prior ischaemic event will experience another event over the following 4 years, compared with 12.2% of patients with stable CAD and no prior event.4
Recurrent events are a particular cause for concern. Not only do they show that management approaches may have been insufficient, but reinfarction more than doubles the mortality rate in the 3.9 years after an MI.5
Risk of reinfarction can be reduced with dual pathway inhibition
The COMPASS study evaluated the efficacy and safety of rivaroxaban 2.5 mg bid plus aspirin in a subanalysis of 24,824 patients with chronic CAD. Approximately 70% of patients with CAD had a history of MI, making the trial population consistent with the real-world population in the CLARIFY registry. COMPASS excluded patients with an indication for non-aspirin antiplatelet therapy; consequently, only 5% of patients with CAD had an MI within 1 year of randomization.6
A high standard of risk factor management was evident in the baseline characteristics of the patients enrolled in COMPASS, with over 90% of patients receiving a lipid-lowering drug and nearly three-quarters receiving an ACE inhibitor or ARB. However, on top of this treatment, rivaroxaban 2.5 mg bid plus aspirin reduced the risk of major adverse CV events (MACE; comprising MI, stroke or CV death) by 26% compared with aspirin alone (4.2% vs 5.6%; HR=0.74, 95% CI 0.65–0.86; p<0.0001), showing
These data have important implications for patients with prior MI. The treatment effect associated with rivaroxaban 2.5 mg bid plus aspirin versus aspirin alone was consistent in patients with and without a history of MI and was unaffected by the timing of the prior MI.
Consistent with the use of an additional antithrombotic, the risk of modified ISTH major bleeding was significantly higher in patients receiving rivaroxaban 2.5 mg bid plus aspirin versus aspirin alone, although there were no significant increases in the risks of fatal bleeding or ICH. History of MI did not significantly affect the increase in bleeding risk associated with rivaroxaban 2.5 mg bid plus aspirin versus aspirin alone.
So, is Peter right to worry? Overall, patients with CAD who have already experienced an MI do have a high risk of recurrent ischaemic events and, should they have another event, have a poor prognosis. However, as shown in the COMPASS study, rivaroxaban 2.5 mg bid plus aspirin offers a new approach to reducing the risk of these events with a consistent effect in patients with a history of MI and those who have not had an event. Furthermore, as Professor Sonia Anand explains in the video below,