Pretreatment with Intragraft Verapamil Prior to Percutaneous Coronary Intervention of Saphenous Vein Graft Lesions: Results of t

Volume 14 - Issue 6 - June, 2002
Posted on: 8/1/08
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Author(s):

Andrew D. Michaels, MD, *Mark Appleby, MD, Matthew H. Otten, BA, †Kent Dauterman, MD, Thomas A. Ports, MD, Tony M. Chou, MD, §C. Michael Gibson, MS, MD

Intracoronary calcium channel blockers have been administered during percutaneous coronary interventions (PCI) for the management of reduced coronary flow due to microvascular dysfunction.1–3 More recent studies have shown that intracoronary calcium antagonists may improve coronary and myocardial perfusion when given prophylactically prior to elective PCI,4,5 and in patients undergoing primary PCI for acute myocardial infarction.6 In addition to calcium channel blockers, other agents including abciximab,7 adenosine8 and the adenosine triphosphate-sensitive potassium channel opener nicorandil9 have been used to treat or prevent no-reflow.
No-reflow during PCI of degenerated saphenous vein grafts (SVGs) occurs in roughly 10–40% of cases. Intragraft adenosine8 and verapamil10 have been shown to be effective in treating no-reflow during PCI of SVGs, while nitroglycerin has no beneficial effect.10 No study, however, has assessed the efficacy of intragraft calcium antagonists in the prevention of no-reflow prior to SVG PCI. Accordingly, we randomized patients undergoing SVG PCI to receive intragraft verapamil or no verapamil prior to PCI in order to test the hypothesis that intragraft verapamil was effective in preventing no-reflow and improving graft and native coronary blood flow.

Methods

Patient selection. Patients enrolled in this study were candidates for PCI of an SVG. Patients with systolic blood pressure < 95 mmHg, heart rate < 50 beats per minute, and those on vasopressors were excluded. Patients with completely occluded SVGs on diagnostic angiography were also excluded. The study protocol was approved by the University of California at San Francisco Committee on Human Research, and informed written consent was obtained from all patients.

Study protocol. Eligible patients were randomized to receive 200 µg of intragraft verapamil through the guiding catheter or no verapamil prior to advancing the guidewire into the SVG. Coronary angiography was performed prior to and following PCI of the SVG. Cardiac enzymes (CK-MB or troponin I) were checked 6–12 hours post-PCI.