Performance and 12 month outcomes of a wire free fractional flow reserve system for assessment of coronary artery disease, first experience in south east asia

Funding Acknowledgements

Type of funding sources: None.

Background

Fractional flow reserve (FFR) using an invasive pressure wire has a Class 1A recommendation for guiding coronary revascularization in stable coronary artery disease (CAD). Angiography based ‘wire free’ FFR is an emerging technique which determines the physiological significance of a coronary lesion without requirement of a pressure wire or induction of hyperemia. It also eliminates potential complications associated with introduction of wires into the coronary arteries.

Objective

To assess the 12-month clinical outcomes of PCI deferral, guided by an angiography based fractional flow reserve (CAFFR) system. The primary end point was a composite of death from any cause, myocardial infarction (MI) or target vessel revascularization (TVR)

Methods

This was a prospective, single center study involving 69 patients (93 vessels) with angiographic stenosis of 30%-90%. Patients with CAFFR of <0.80 or poor image quality were excluded leaving 29 patients (31 vessels) for analysis. All recruited patients had a CAFFR >0.80 and thus, PCI deferral.

Wired FFR was done for comparison on 14 patients (48%) at the operator’s discretion.

Results

The mean age was 59 ± 12.6 years old. Majority of patients (83%) were male. 12 (42%) patients were diabetic, 18 (62%) were hypertensive, 17 (59%) had dyslipidemia and 18 (62%) had a smoking history. The mean LVEF was 52+/-11.4%. 72% of the patients had a recent acute coronary syndrome. We assessed the LAD artery in 15 (52%) vessels. The mean CAFFR and FFR was 0.87 ± 0.04 and 0.89 ± 0.05 respectively. The values showed agreement with each other with no statistically significant proportional bias on the Bland Altman plot (linear regression t test: t=-1.19, p = 0.257). CAFFR values >0.80 showed 100% correspondence to negative FFR values (>0.80). There were zero procedural complications from CAFFR measurement.

At 12 months, all 29 patients were alive. Only 1 patient (3.4%) met the primary end point (TVR for angina). 89.6% (26) patients remained in CCS class 1 on follow up.

Conclusion

CAFFR shows good agreement with wired FFR. The 12-month outcome data shows that CAFFR guided PCI deferral is safe and comparable to the gold standard of wired FFR guided PCI deferral. Further analysis with a larger patient pool and longer follow-up is warranted. Abstract Figure. Bland-Altman plot of FFR and CAFFR