Background: Small coronary vessels supply small myocardial territories. The clinical significance of small-vessel stenoses is therefore questionable. Moreover, percutaneous coronary intervention (PCI) of nonfunctionally significant lesions does not improve clinical outcome and might be associated with potential procedural or stent related risks. The aim of this study was to assess the clinical outcome of fractional flow reserve (FFR)-guided PCI in the treatment of small coronary vessel lesions as compared with an angio-guided PCI.
Methods and results: From January 2004 to December 2008, all patients treated with PCI for stable or unstable angina in small native coronary vessels (reference vessel diameter and stent size <3 mm) were retrospectively analyzed. Patients were divided into angio-guided and an FFR-guided PCI groups. A total of 717 patients were enrolled (495 angio-guided, 222 FFR-guided). End points were death, nonfatal myocardial infarction (MI), combined death or nonfatal MI, target vessel revascularization (TVR), and procedure costs. Major adverse cardiac events (MACE) were defined as death, nonfatal MI, and TVR. Clinical follow-up was obtained in 97.5% (median follow-up: 3.3 [from 0.01-5] years) of the patients. Seventy-eight patients (35%) had a significant FFR (<0.80) and underwent PCI. Using a propensity score adjusted Cox analysis, patients treated with FFR-guided PCI had significantly lower combined death or nonfatal MI (hazard ratio [HR], 0.413; 95% confidence interval [CI], 0.227-0.750; P=0.004), nonfatal MI (HR, 0.063; 95% CI, 0.009-0.462; P=0.007), TVR (HR, 0.517; 95% CI, 0.323-0.826; P=0.006), and MACE (HR, 0.458; 95% CI, 0.310-0.679; P<0.001). No difference was observed in mortality alone (HR, 0.684; 95% CI, 0.355-1.316; P=0.255). Procedure costs were also reduced in the FFR guided strategy (3253±102 Euros versus 4714±37 Euros, P<0.0001).
Conclusions: FFR-guided PCI of small coronary arteries is safe and results in better clinical outcomes when compared with an angio-guided PCI.