July 11th, 2014
Do FFR and IVUS Feed the Elephant?
Richard A. Lange, MD, MBA and L. David Hillis, MD
In an observational study of all patients who underwent PCI in National Health Service hospitals in London between January 1, 2004, and July 31, 2011 (n = 41,688), fractional flow reserve (FFR)-guided and intravascular ultrasonography (IVUS)-guided PCI were not associated with improved long-term survival when compared with standard angiography-guided PCI (performed on the basis of visual lesion assessment).
In an accompanying editorial, Aseem Malhotra remarks: “The elephant in the room is that randomized studies (including patients at low risk and high risk) have not demonstrated outcomes benefit for stenting stable coronary disease in addition to optimal medical therapy despite its widespread use.”
This follows on the heels of a recent Circulation paper by Hopkins cardiologist, Armin Arbab-Zadeh, who notes that “The rationale for the FFR concept…is based on a common misconception of the relationship between provocable myocardial ischemia and risk of adverse cardiac events.”
JOIN THE DISCUSSION
Does FFR/IVUS guided-PCI prevent MI or death?
Are FFR and IVUS overused or underused?
Do you ever discuss FFR or IVUS with your patients?
Does treating provocable ischemia with PCI prevent MI or death?
4 Responses to “Do FFR and IVUS Feed the Elephant?”
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In the management of that subset of patients with stable coronary artery disease on optimum medical therapy, the control of angina pectoris is a significant endpoint for the patient and their family. FFR measurement has provided a simple and reproducible tool for the assessment of multiple stenoses in series and, in its current form, results in a “minimalist” approach to the extent of stenting effected to achieve improved flow characteristics. IVUS has little utility in this regard.
The application of coronary artery stenting to the stable coronary artery disease patient to improve MACE has been, reliably in my opinion, shown to be a fallacious construct no matter the method of assessment.
What FAME 1 and 2 have elucidated is that the detection of an ischemic or non-ischemic segment of myocardiam based on either focal, diffuse and/or multisegmental coronary atherosclerosis does not manifest in the intermediate term as mortality or MI. FFR detected ischemia if left untended results in increase MACE driven by urgent unplanned revascularization and FFR deferred lesions in those trail populations had few and nonsignificant MI sequelae with no increased mortality signal.
FFR is be considered an in cath lab “stress test” as per derivation/validation studies such as DEFER.
Undoubtedly, FFR may help identifying the symptom producing lesion in some ambiguous situations. In my experience, these situations are the exception, not the rule. Furthermore, few patients have crippling symptoms that do not respond to medical therapy. The point is that despite widespread perception to the contrary, there is no evidence that FFR reduces hard events compared to standard approach – if you carefully review the FAME studies. What the FAME actually shows is that fewer PCIs resulted in improved patient outcome because the associated periprocedural events are not outweighed by benefit from PCI. There was no evidence provided in FAME that the FFR assessment contributed to this benefit (e.g., compared to randomly omitting PCI).
We need to do a better job conveying to patients and providers – backed by more explicit guideline statements – that the benefit of PCI in patients with stable symptoms is generally confined to faster symptom relief compared to medicine – which comes at the expense of procedure related risk and higher costs to our society.
Again revascularization provides no benefit. Sadly, this European study had no medical management arm.
How long are we going to continue the expensive insanity of stenting for no benefit other than more rapid reduction in angina compared to medical management.
We need to identify those at risk by a simple and inexpensive coronary calcium score and treat to plaque stability. This will reduce heart attacks and coronary death. All the FFR assessment in the world will make no difference for the patient.
If angina cannot be controlled medically, then stenting is appropriate regardless of FFR. If angina is controlled medically, then stenting is inappropriate regardless of FFR.