Preventing spasm of the radial artery conduit during coronary artery bypass grafting: Nicardipine versus verapamil.

BACKGROUND AND AIM OF THE STUDY: In vitro studies have shown a reduction in radial artery spasm with the use of calcium antagonists. The purpose of this study was to evaluate the efficacy of topical treatment of the radial artery conduit using either verapamil or nicardipine before the anastomoses. METHODS: This prospective randomized study included 131 patients, who underwent coronary artery bypass grafting surgery with the use of the radial artery as a conduit. In 65 patients, the harvested radial artery was topically treated with verapamil and in 66 patients with nicardipine. After harvesting the radial artery, the direct flow through the conduit was measured in vitro before 5-minute incubation in nicardipine or verapamil and measured again after incubation. The flow before and after incubation was compared. Postincubation flow was also compared in the two groups. After performing the anastomosis, the flow through the radial artery was measured in vivo. RESULTS: The mean flow after NaCl incubation was 19.93 ± 12.66 mL/min and after incubation in the Ca+ channel blocker 47.16 ± 14.58 mL/min (P < .001). No significant difference in postincubation free flow was found between verapamil (46.29 ± 15.43 mL/min) and nicardipine (48.01 ± 13.77 mL/min; P = .503). CONCLUSION: Topical treatment with Ca+ channel blockers reduces radial artery spasm and significantly increases the free flow through the radial artery conduit. Nicardipine is a safe and effective alternative of verapamil in preventing spasm of radial artery conduit.

Conduction disorders and impact on survival after sutureless aortic valve replacement compared to conventional stented bioprostheses.

OBJECTIVES: Sutureless and rapid-deployment aortic valve prostheses are frequently used for the treatment of aortic stenosis. However, postoperative left bundle branch block (LBBB) and permanent pacemaker (PPM) implantation have emerged as frequent complications. The aim of this study was to compare the incidence of new-onset LBBB and PPM implantation after sutureless aortic valve replacement (sAVR) with stented bioprostheses, and the impact on postoperative survival. METHODS: Patients undergoing isolated surgical aortic valve replacement (AVR) or concomitant AVR with coronary artery bypass surgery between January 2010 and July 2017 were included in the study. Two groups were defined: sAVR and conventional AVR (cAVR). The findings of preoperative electrocardiograms were compared with postoperative electrocardiogram findings for both groups. The incidence of new-onset LBBB and the requirement for PPM implantation were recorded. The effect of these conduction disorders on late survival was analysed. RESULTS: A total of 987 patients were analysed, consisting of 132 sAVR and 855 cAVR patients. The sAVR group had an increased incidence of new-onset LBBB compared to the cAVR group (16.7% vs 2.3%, P < 0.001). A significantly higher rate of postoperative PPM implantation was found for sAVR patients compared to cAVR (6.8% vs 1.6%, P = 0.001). The multivariate Cox analysis revealed that neither postoperative new-onset LBBB nor PPM implantation was associated with increased mortality (hazard ratio 1.73, 95% confidence interval 0.74-4.03, P = 0.204). CONCLUSIONS: sAVR is associated with an increased risk of new-onset LBBB and PPM requirement compared to cAVR. In this population, postoperative conduction disorders did not affect the mid-term survival.