FFR Accuracy, Prognostic Implications, and Limitations

The Following are key points to remember about the accuracy, prognostic implications and limitations of fractional flow reserve ( FFR) :

1-    FFR is an invasive procedure used during coronary angiography to determine the functional significance of coronary stenosis.
2-      Overall, FFR is a useful adjunct to coronary angiography that allows precise quantification of the degree of myocardial ischemia.
3-      0 Its use is particularly helpful in intermediate or angiographically ambiguous lesions in the absence of noninvasive functional studies.
4-      Randomized clinical trials have demonstrated improved clinical outcomes with the use of FFR to guide coronary revascularization, including a reduction in cardiac death or myocardial infarction, as well as costs with an FFR-based strategy compared with a conventional angiography-based approach.
5-      Current societal guidelines provide a class IIa recommendation to perform FFR in angiographically-intermediate stenosis in the absence of stress testing, or in the presence of discordant stress test and angiographic findings.
6-      The appropriate use criteria for coronary revascularization also endorse the concept of “functional percutaneous coronary intervention” with revascularization decision on the basis of hemodynamic significance rather than anatomic lesion severity.
7-      Nevertheless, important questions about FFR testing remain, including the interpretation of the results (dichotomous vs. continuous), the need for hyperemia and the best pharmacological agent to achieve it, and technical aspects of the measurement that can lead to misinterpretation of the results.

8-      Attention to detail is critical when performing the FFR test.
9-      In particular, FFR results should be interpreted with caution in patients with microvascular dysfunction and conditions that can lead to it, left ventricular hypertrophy, severe aortic stenosis, and severely elevated right atrial pressure, as FFR can be artificially elevated leading to an underestimation of lesion severity.
10-   Newer technologies, such as computed tomography-based and angiogram-based FFR where FFR is mathematically derived from a computed tomography or invasive coronary angiogram, may reduce the need for invasive FFR measurements in the future. 

    Dr.Debabrata Mukherjee