ISCHEMIA: balancing the risks and benefits of invasive procedures in stable ischemic heart disease patients

DM: Dr. Burzotta, you pointed out in your review of the ISCHEMIA trial that the results may pertain to only a proportion of patients presenting with a chronic coronary syndrome in everyday practice. How do you see the generalizability of the trial results, given that CCTA was used to exclude patients with left main disease and that the degree of ischemia on baseline stress testing did not impact the overall results?
FB: That’s a very important point! We knew that revascularization may impact the clinical outcome only in some patients with stable ischemic heart disease. Non-invasive tests to find ischemia are routinely done worldwide to find these patients. Yet, as ISCHEMIA results showed no benefit of invasive management in patients with positive tests, it is very difficult to understand the true clinical role of inducible ischemia. On the opposite, CCTA was feasible in such a huge study population and allowed to easily find patients with very high risk (like left main disease) and those with no benefit with invasive strategy (non-obstructive disease).

DM: Given that approximately 70% of patients in the invasive group had multivessel disease and that FFR was used in 20%, could an increased use of FFR/iFR guidance have had an impact on the study results?
FB: You have touched upon a very important issue: modern invasive management can no longer be ANGIOGRAPHY-BASED!!! We have efficient tools to establish if a coronary lesion induces significant ischemia in its territory (FFR, iFR). In the near future,  intracoronary imaging techniques (OCT) that are today able to perfectly define anatomic details will help select some higher risk patients. I think that the paradigm ‘significant inducible ischemia ->revascularization’ may strongly benefit from careful selection of lesions really deserving treatment.

DM: In patients treated with PCI, the authors report that in 5.4% stent was not deliverable, that POBA alone was used in 1.5% and that 1st generation DES was used in 1.9%. What is your estimate of the ability of contemporary evolving techniques for challenging subsets, such as calcified lesions, bifurcations and CTO, to decrease stent-related events and thereby improve the overall outcomes in PCI-treated patients?
FB: PCI is continuously improving. We need to continue working on that!
Stents have some minor room for improvement. On the contrary, novel devices may help deliver stents (guide cath extension) and appropriately expand them (lithotripsy, non compliant balloons). Furthermore, enhanced use of imaging may help optimize stent resulrs. Finally, best selection of PCI techniques in complex lesions like bifurcations and CTOs is known to have the potential to increase PCI efficacy.

DM: The results of the FORZA randomized trial, of which you were the lead author, suggested an important role of intracoronary imaging in improving outcomes in patients referred to coronary angiography. Do you think that intracoronary imaging could have been an effect modifier in the ISCHEMIA trial?
FB: Intracoronary imaging is the eye of the modern interventional cardiologist. These technologies are ready for prime time. A series of data is accumulating and will help react to what we see in the most efficient way. For instance, the non-emergent setting of invasive procedures in stable patients represents a natural environment for the refinement of image-guuded details .

DM: Dr. Burzotta, thank you very much for your thorough review of this important trial. In summary, in which aspects do you think the ISCHEMIA trial may or may not ultimately change the everyday practice for our community of interventional cardiologists around the world?
FB: In stable patients we should carefully balance risks and benefits of invasive procedures. The anticipated benefit of revascularization is, on average, low. Thus, careful selection of patients needing revascularization and adoption of PCI techniques able to reduce risks are pivotal.

Read this EAPCI/PCR Journal Club review of the ISCHEMIA Trial

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