On-treatment platelet reactivity before coronary artery bypass surgery is associated with in-hospital major bleeding

Abstract

obtained or calculated: average peak velocity (APV), renal flow reserve (RFR), and resistive index (RI). Measurements were obtained at baseline and under hyperemic condition induced by a bolus of dopamine (50 μg/kg) given intrarenally. RFR was calculated as the ratio of hyperemic to basal peak velocity. RI was estimated as (peak systolic velocity−end-diastolic velocity)/peak systolic velocity. APV, RFR, and RI were measured before and after RSD and 1 month later. The RSD was achieved via the lumen of the main renal artery with the catheter connected to a radiofrequencygenerator fromSt. JudeMedical according to prespecified algorithm. Samples for plasma norepinephrine were collected at baseline and at 1 month after ablation. Results: In the acute phase, APV increased by 300% postablation 300% higher (65.16±39.78 vs. 21.79±8.53 cm/s, Pb.0001). Similarly, RFR decreased by 50% and RI decreased by 30% (RFR 1.51±0.59 vs. 2.96±1.33, Pb.0001 and RI 0.66±0.07 vs. 0.74±0.07, P=.003). At 1 month after RSD compared to APV remained significantly higher (30.21±13.14 vs. 21.79±8.53 cm/s, P=.035) compared to baseline. Radiofrequency RSD resulted in reduced RFR (1.36±0.25 vs. 2.96±1.33, Pb.0001), RI (0.48±0.15 vs. 0.74±0.07, P=.003), and plasma norepinephrine levels (11.08±6.19 vs. 17.76±11.9 pg/ml, P=.045). Conclusions: Catheter-based RSD results in acute increase in RBF and decrease in RFR, RI, and plasma catecholamines. These results are maintained at 1 month postablation. The acute findings can potentially be used as a measure of successful renal denervation.