Changes in radial artery volume assessed using intravascular ultrasound: a comparison of two vasodilator regimens in transradial coronary interventions.
ABSTRACT This study used intravascular ultrasound (IVUS) to evaluate radial artery volume changes after intraarterial administration of nitroglycerin and/or verapamil.
Radial artery spasm, which is associated with radial artery size, is the main limitation of the transradial approach in percutaneous coronary interventions (PCI).
This prospective, randomized study compared the effect of two intra-arterial vasodilator regimens on radial artery volume: 0.2 mg of nitroglycerin plus 2.5 mg of verapamil (Group 1; n = 15) versus 2.5 mg of verapamil alone (Group 2; n = 15). Radial artery lumen volume was assessed using IVUS at two time points: at baseline (5 minutes after sheath insertion) and post-vasodilator (1 minute after drug administration). The luminal volume of the radial artery was computed using ECOC Random Fields (ECOC-RF), a technique used for automatic segmentation of luminal borders in longitudinal cut images from IVUS sequences.
There was a significant increase in arterial lumen volume in both groups, with an increase from 451 ± 177 mm³ to 508 ± 192 mm³ (p = 0.001) in Group 1 and from 456 ± 188 mm³ to 509 ± 170 mm³ (p = 0.001) in Group 2. There were no significant differences between the groups in terms of absolute volume increase (58 mm³ versus 53 mm³, respectively; p = 0.65) or in relative volume increase (14% versus 20%, respectively; p = 0.69).
Administration of nitroglycerin plus verapamil or verapamil alone to the radial artery resulted in similar increases in arterial lumen volume according to ECOC-RF IVUS measurements.
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ABSTRACT: OBJECTIVES: This "proof of concept" study sought to determine the magnitude of radial artery diameter change in 20 healthy subjects by induction of flow mediation dilatation (FMD) via reactive hyperemia. BACKGROUND: Transradial access in the cardiac catheterization laboratory is becoming more commonplace due to lower bleeding complications and increase in patient comfort. However, access to the radial artery can be challenging due to small vessel size. We sought to examine whether FMD can be used to increase radial artery diameter, potentially allowing improved transradial access. METHODS: We obtained baseline radial artery diameter via a high frequency ultrasound probe on 20 healthy subjects. A standard reactive hyperemia protocol was employed in the right arm, followed by successive measurements of the subject's radial artery at pre-specified intervals. Radial artery diameter measurements were performed offline by the sonographer and also a blinded reader to which agreement was sought. RESULTS: We found a mean increase in radial artery size of 0.48 ± 0.13 mm at peak reactive hyperemic states. This correlated to a mean increase in overall radial artery diameter of 21.7 ± 6.7%. The median time to peak dilation was 30 seconds (95% CI; 15-45 seconds), and the median duration of maximal dilation was 60 seconds (95% CI; 45-75 seconds). CONCLUSIONS: Among healthy subjects, we demonstrated a mean maximal increase in radial artery diameter of 21.7 ± 6.7% via FMD. This finding supports the notion that radial artery diameter can be increased noninvasively via a reactive hyperemia protocol.Journal of Interventional Cardiology 03/2013; · 1.50 Impact Factor
- International journal of cardiology 03/2014; · 6.18 Impact Factor
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ABSTRACT: Verapamil is traditionally applied prophylactically in transradial procedures to prevent radial artery spasm. However, verapamil may have side effects and is contraindicated in some clinical settings. During an investigator-initiated, randomized, double-blind trial, we evaluated the need for preventive verapamil administration. After vascular access was established, patients received either 5 mg verapamil (n=297) or placebo (n=294). We compared the rate of access site conversions as primary end point using a superiority margin of 5%. Occurrence of code breaks (composite of conversions and unplanned use of verapamil), overall verapamil use, procedural and fluoroscopic times, contrast volume, and subjective pain were investigated as secondary end points. The rate of access site conversions was not different in the 2 arms (placebo 1.7% versus verapamil 0.7%, P=0.28, difference 1.0%, 95% CI for the difference -1.1% to 3.3%). Proportion of code breaks was similar in the 2 groups (3.4% versus 1.3%, P=0.11), whereas overall verapamil use was markedly lower in the placebo arm (2.0% versus 100%, P<0.0001). Procedural time (median [IQR] 16.0 minutes [9.0 to 30.0 minutes] versus 17.0 minutes [10.0 to 31.0 minutes], P=0.37), fluoroscopic time (4.4 minutes [2.1 to 9.6 minutes] versus 4.8 minutes [2.4 to 10.7 minutes], P=0.28), contrast volume (72.5 mL [48.0 to 146.0 mL] versus 75.5 mL [47.0 to 156.5 mL], P=0.74), and pain score (P for trend=0.12) were comparable in the 2 groups. The preventive use of verapamil may be unnecessary for transradial procedures. The omission of prophylactic verapamil may not only reduce the rate of potential complications related to the drug but also allow the safe extension of the transradial method to those with contraindications to verapamil. http://www.clinicaltrials.gov. Unique identifier: NCT01402427.Journal of the American Heart Association. 01/2014; 3(2):e000588.