Prognostic impact of angiographically determined diffuse phenotype in functionally non-significant coronary stenosis

Background Previous studies have shown that angiographic phenotype (diffuse or focal) was associated with adverse clinical outcomes after percutaneous coronary intervention. However, few studies have compared the long-term prognosis between diffuse and focal intermediate lesions which were deferred revascularization because of negative for ischemia using fractional flow reserve (FFR). Purpose This study aimed to explore the prognostic value of angiographic phenotype (focal or diffuse) of functionally non-significant coronary stenosis. Methods This retrospective study included 420 intermediate lesions, defined as a percent stenosis of 50% to 75% on visual estimation, from 370 patients with FFR >0.80 and deferred revascularization. Based on coronary angiography, focal coronary lesions were defined as a single intermediate lesion which lesion length of less than 20 mm in the target vessel, and any other lesions (2 or more intermediate lesions or intermediate lesions with a lesion length ≥20 mm) were defined as diffuse lesions. All intermediate lesions were evaluated using FFR in a standard manner. Physiologically significant stenosis was defined as FFR ≤0.80. Primary endpoint was target-vessel revascularization (TVR). Results Among the intermediate lesions, 152 were diffuse lesions, and 268 were focal lesions. Median FFR value in the lesions was 0.87 (interquartile range: 0.84 to 0.91). Patients (mean age was 71±9 years, 80% of patients were men) were followed for a median of 58 months. During this period, TVR occurred in 32 (8%) lesions. Patients with TVR, compared with those without, were younger (68±10 years vs. 72±9 years, p=0.020) and showed higher rates of dyslipidemia (87% vs. 64%, p=0.005), statin pretreatment (81% vs. 62%, p=0.031), lesions with lower FFR values (0.86±0.04 vs. 0.88±0.04, p=0.035) and diffuse intermediate lesions (75% vs. 33%, p<0.001). In the multivariate regression analysis, diffuse intermediate lesions were statistically associated with future TVR (Table). Kaplan-Meier analysis also revealed a significantly higher rates of TVR in diffuse intermediate lesions compared with focal lesions and the difference gradually widened overtime (p<0.001 for Log-rank) (Figure). Conclusions Diffuse intermediate lesions showed poorer outcomes (i.e., higher TVR rates) than focal intermediate lesions, even if FFR negative. Our findings may suggest the need for close follow-up and targeted medical treatments for this patient subsets.