By Dr Jonathan Shurlock
The results of the ISCHEMIA have been central to the discussion around management of chronic coronary artery disease since publication in 2020. More recently the author group have published interim results from their ongoing extended follow up period. The original ISCHEMIA trial randomised patients to an initial invasive strategy with guideline directed medical therapy or a conservative approach and included 5179 participants (Median age 65 years). The initial follow up was over a median of 3.2 years and did not find any evidence that initial invasive strategies reduced the risk of ischaemic cardiovascular events or all-cause mortality.
Interim results from ISCHEMIA-EXTENDED have demonstrated 557 deaths over a median follow up of 5.7 years, with 268 occurring during the extended follow up time period. 343 of these were classified as cardiovascular deaths.
The key takeaway finding is the lack of difference in all-cause mortality between the treatment groups (7-year rate 12.7% invasive group, 13.4% conservative group; adjusted hazard ratio (HR)=1.00, 95% CI: 0.85-1.18). This was accounted for, in part, by a lower 7-year rate cardiovascular mortality in the invasive group (6.4% vs. 8.6%, adjusted HR=0.78, 95% CI: 0.63-0.96) but a higher 7-year rate of non-cardiovascular mortality in this group (5.6% vs. 4.4%, adjusted HR=1.44, 95% CI: 1.08-1.91).
Though interim results, further findings seem likely to follow in the coming years. These results add important elements to the ongoing debate amongst cardiologists regarding best management of stable coronary artery disease, which seems sure to continue for the immediate future.