Preprocedural β-Blockers in the Functional Assessment of Intermediate Coronary Lesions by Instantaneous Wave-Free Ratio

Aim: Instantaneous wave-free ratio (iFR) has emerged as the strategy of choice for the assessment of intermediate coronary lesions. The impact of preprocedural β-blockers therapy on the iFR was the aim of this study. Methods: We included patients undergoing functional assessment of intermediate (40%-70%) coronary lesions in 2 centers. The iFR measurement was performed by pressure-recording guidewire and calculated at the core laboratory using the manufacturers’ dedicated software. Minimal luminal diameter, reference diameter, percent diameter stenosis, and length of the lesion were measured. Positive iFR was considered for values <0.90. Results: We included 197 patients undergoing functional evaluation of 223 coronary lesions. Patients on β-blockers (69%) had more frequently hypertension (P =.05); previous myocardial infarction (P =.01); therapy with clopidogrel (P =.02), statins, and aspirin; and acute coronary syndrome at presentation (P <.001, respectively). Mean iFR values were slightly higher in patients on β-blockers (0.94 ± 0.06 vs 0.92 ± 0.06, P =.11). The rate of positive iFR was significantly lower with β-blockers (14.9% vs 27.5%, P =.04). On multivariate analysis, β-blockers use was a predictor of the significance of coronary stenoses (odds ratio [OR] = 0.48; 95% CI = 0.23-0.98; P =.05) together with lesion length (OR = 1.04; 95% CI = 1.01-1.07; P =.007). Conclusion: Among patients undergoing iFR, preprocedural β-blockers are associated with higher absolute values and a lower rate of positive iFR.