Deferral Versus Performance of PTCA in Patients Without Documented Ischemia - DEFER


The goal of the study was to compare routine versus fractional flow reserve (FFR)-directed percutaneous coronary intervention (PCI) for patients with coronary artery disease (CAD).

Contribution to the Literature: Deferring PCI based on FFR ≥0.75 is as safe and efficacious as performing PCI with low long-term event rates.

Study Design

- Patients Enrolled: 303
- Mean Follow-Up: Ongoing study; 12 months (planned); 5 years, 15 years

Patient Populations:

- Patients admitted for elective PCI of native coronary artery stenosis
- Reference diameter of at least 2.5 mm
- Stenosis of at least 50% by visual estimation


- Evidence of reversible ischemia during the previous 2 months

Primary Endpoints:

- Clinical outcomes

Drug/Procedures Used:

- FFR-guided conditional PCI vs. routine PCI; PCI was performed with either bare-metal stent or balloon PCI alone.

Principal Findings:

FFR is an invasive, lesion-specific index to demonstrate or to exclude whether a particular coronary stenosis can cause reversible ischemia. FFR can be determined “on the spot” immediately prior to planned intervention. An angiogram was performed and FFR was measured for each patient.

FFR was <0.75 for 144 patients, who received routine PCI. This was the reference group. The remaining 163 patients (with FFR ≥0.75) were randomized to intervention (“Perform” arm; n = 90) or optimal medical therapy (“Defer” arm; n = 91) in a 1:1 fashion. Baseline characteristics were fairly similar. About 12% had a history of diabetes mellitus. Mean ejection fraction was 67%. The mean reference vessel diameter was 2.97 mm and lesion length was 10 mm.

5-year follow-up: Event-free survival (freedom from all-cause mortality, myocardial infarction [MI], coronary artery bypass grafting, and coronary angioplasty) was not different between the Defer and Perform groups (80% and 73%, respectively; p = 0.52), but was significantly worse in the Reference group (63%; p = 0.03). The composite rate of cardiac death and acute MI in the Defer, Perform, and Reference groups was 3.3%, 7.9%, and 15.7%, respectively (p = 0.21 for Defer vs. Perform group; p = 0.003 for the Reference vs. both other groups). The percentage of patients free from chest pain at follow-up was not different between the Defer and Perform groups.

15-year follow-up: All-cause mortality for Defer vs. Perform vs. Reference: 33% vs. 31.1% vs. 36.1%, p = 0.79 for Defer vs. Perform. MI: 2.2% vs. 10% vs. 12.5%, p = 0.03 for Defer vs. Perform; repeat revascularization: 42.9% vs. 34.4% vs. 44.4%, p = 0.25 for Defer vs. Perform.


This is a landmark trial that helped establish the utility of FFR in patients with stable angina. Routine PCI in the setting of an FFR ≥0.75 is not superior to optimal medical therapy for cardiovascular events at 5 years, and at 15 years, appears to be associated with a higher risk of MI than medical management alone. This trial provides long-term data regarding the safety of an FFR-guided approach for the management of CAD. One limitation of this trial is that it enrolled patients with relatively simple lesions from a non-contemporary era (no drug-eluting stent, low use/doses of currently utilized medications for CAD).


Zimmermann FM, Ferrara A, Johnson NP, et al. Deferral vs. performance of percutaneous coronary intervention of functionally non-significant coronary stenosis: 15-year follow-up of the DEFER trial. Eur Heart J 2015;Sep 23:[Epub ahead of print].

Pijls NH, van Schaardenburgh P, Manoharan G, et al. Percutaneous coronary intervention of functionally nonsignificant stenosis: 5-year follow-up of the DEFER Study. J Am Coll Cardiol 2007;49:2105-11.

Presented at the XXth Congress of the European Society of Cardiology, Vienna, 1998.

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