Deferred versus Performed Percutaneous Coronary Intervention for Coronary Stenosis with Grey-Zone Fractional Flow Reserve Values

Abstract Background Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) has shown better clinical outcomes than conventional angiography-guided PCI. The optimal FFR cut-off value for revascularization is debated. With FFR ≤ 0.75, revascularization for coronary artery disease (CAD) stenosis is associated with improved clinical outcomes, whereas with FFR ≥ 0.8, medical treatment has been shown to result in favorable long-term outcomes. However, there has been controversy over revascularization decision-making for coronary stenosis with FFR between 0.75 and 0.80, the so-called grey zone. Objectives The present study aims to compare intermediate-term outcomes of performed versus deferred Percutaneous Coronary Intervention in moderate coronary stenosis with FFR values in the grey zone (0.75-0.80) and the primary outcome will be six months major adverse cardiac event (MACE). Methods A non-randomized prospective clinical study was conducted over 3 years period between January 2019 and January 2022. The study included stable CAD patients with coronary lesions between 40-70% diameter stenosis who underwent FFR study using intracoronary (IC) adenosine and had FFR values between 0.75-0.80 and were divided into two groups: group 1 who have undergone revascularization and group 2 who have undergone deferred revascularization. Results This study was conducted on 50 patients with moderate coronary artery stenosis with an FFR value in the grey zone undergoing performed or deferred revascularization. The age of the studied group ranged from 38-67 (mean 53.16 ± 7.83) years. The studied group included 12 females (24%) and 38 males (76%). 72% of the patients have diabetes, 70% hypertension, 94% dyslipidaemia and 52% were smokers. There was no significant difference between patients undergoing performed or deferred PCI as regard the risk factors (p-value 0.697). The most common culprit vessel is the left anterior descending (LAD) (64%) followed by right coronary artery (RCA) (20%) then left circumflex (LCX) (16%). 54% of the patients have undergone performed PCI while 46% have undergone deferred PCI with LAD (33.3% and 26.0%) followed by RCA (8.6% and 11.4%) then LCX (7.4% and 8.6%) respectively. There was no significant difference between patients undergoing performed or deferred PCI in regard to either the value of FFR or Culprit vessel (p-value 0.157, 0.232). 87.7% of the patients were asymptomatic after six months, stable and had no MACE. Six patients were symptomatic with MACE 6 patients had target vessel revascularization (TVR) (2 in group 1 and 4 in group 2) with 3 myocardial infarction (MI) (1 post-procedure in group 1 and 2 spontaneous in group 2) and one patient died after 3 months (group 1). No significant difference was found between patients undergoing performed or deferred PCI in regard either the clinical status, presentation & target coronary intervention, or MACE after three months (p-value 0.363) as well as after six months follow up (p-value 0.469). Conclusions Our study found that after 6 months follow-up period in patients with angiographically borderline coronary lesion with grey-zone FFR (0.75-0.8), either performing or deferring coronary intervention are effective and safe.