Nicardipine Protocol for CABG Using the Radial Artery Clinical and Angiographic Data

Abstract

The routine use of arterial grafts in coronary surgery is facilitated by peroperative adjunction of antispasmodic drug to reduce the event of spasm. Diltiazem has been favoured in most clinical studies devoted to the radial artery graft. The aim of this study was to assess the efficacy of a spasm preventing protocol associating hydrostatic dilation of the graft with a diluted solution of papaverine and nicardipine infusion, starting preoperatively and continued postoperatively in IV and per os forms.

Between September 1996 and March 1997, a consecutive series of 50 patients underwent myocardial revascularization using the radial artery. The radial artery was prepared by hydrostatic dilation with papaverine (1%) and nicardipine was administrated at 0.25 µg/kg/min and titrated according to the arterial systemic pressure. Operative mortality was 4% (sepsis). There was no evidence of perioperative MI nor hypoperfusion syndrome. Mean CKMB level at 18 hours was 36 µg/1. No ischaemic anomalies of the ECG were detected. Angiography performed in the last 20 patients showed a 98% (51/52) permeability rate for all grafts; 19/20 radial grafts (95%) were patent. One radial graft presented a 50% stenosis at the proximal anastomosis, and another a moderate spasm (40%) in the middle part of the conduit.

This study confirms that the radial artery conduit can be used with satisfactory results for routine coronary artery bypass. The use of nicardipine allows the control the vasoreactivity of the radial graft without totally obviating at least angiographic spasm. This drug is easy to titrate, and well tolerated in association to ß-blockers in the routine perioperative management of the coronary patients.

Key-words:

• Radial artery conduit
• coronary artery bypass grafting
• spasm
• nicardipine
• dihydropiridine
• calcium antagonists