Intracoronary Doppler- and quantitative coronary angiography-derived predictors of major adverse cardiac events after stent implantation

Abstract

Background - Distal coronary flow velocity reserve (CVR) is significantly improved after a successful balloon angioplasty (PTCA). Furthermore, a postinterventional CVR >2.5 and a percent diameter stenosis (%DS) ≤35% are predictive for a low incidence of major adverse cardiac events (MACE) at 6 months of 16%. Similar results are lacking for coronary stenting. Methods and Results - In 150 patients, baseline and hyperemic coronary flow velocities were recorded with a Doppler guidewire distal to the target lesion and in an unobstructed reference artery before and after PTCA, after stenting, and at 6 months. Distal CVR and relative CVR (CVRrel) were calculated. Logistic regression and receiver operating characteristic analyses were applied to determine prognostic cutoff values of CVR, CVRrel %DS, and minimal lumen diameter separately and in combination to predict MACE at 6 months. After stenting, CVR (2.96±0.87 versus 2.40±0.7; P=0.001), CVRrel (1.02±0.24 versus 0.81±0.24; P=0.001), and minimal lumen diameter (2.98±0.56 versus 2.11±0.74 mm; P=0.001) were significantly higher than after PTCA. Thirty-three patients developed MACE. A postinterventional CVRrel>0.88 was the best single predictor of MACE, with an incidence of 6.8%, whereas the combination of a CVRrel>0.88 and a %DS ≤11.2% predicted an incidence of MACE of 1.5%. Conclusions - Measurement of CVRrel and %DS after stent implantation are best suitable to predict MACE at 6 months.