Primary percutaneous coronary intervention for acute ST-segment elevation myocardial infarction: changing patterns of vascular access, radial versus femoral artery.

OBJECTIVE: To examine the safety and efficacy of emergency transradial primary percutaneous coronary intervention for ST-elevation myocardial infarction. DESIGN: Single-centre observational study with prospective data collection. SETTING: A regional cardiac centre, United Kingdom. PATIENTS: 1051 consecutive patients admitted with ST-elevation myocardial infarction, without cardiogenic shock, between November 2004 and October 2008. INTERVENTIONS: Percutaneous coronary interventions by radial and femoral access MAIN OUTCOME MEASURES: The primary outcome measures were procedural success, major vascular complication and failed initial access strategy. Secondary outcomes were in-hospital mortality and major adverse cardiac and cerebrovascular events, needle-to-balloon times, contrast volume used, radiation dose absorbed and time to discharge. Multiple regression analysis was used to adjust for potential differences between the groups. RESULTS: 571 patients underwent radial access and 480 femoral. A variable preference for radial access was observed among the lead operators (between 21% and 90%). Procedural success was similar between the radial and femoral groups, but major vascular complications were more frequent at the site of femoral access (0% radial versus 1.9% femoral, p = 0.001). Failure of the initial access strategy was more frequent in the radial group (7.7% versus 0.6%, p<0.001). Adjustment for other procedural and clinical predictors did not alter these findings. Needle-to-balloon time, as a measure of procedural efficiency, was equal for radial and femoral groups. CONCLUSIONS: In the setting of acute ST-elevation myocardial infarction without cardiogenic shock, transradial primary angioplasty is safe, with comparable outcomes to a femoral approach and a lower risk of vascular complications.

Radial artery anomaly and its influence on transradial coronary procedural outcome.

BACKGROUND: The transradial approach for percutaneous coronary procedures has the advantage of reduced access site complications but is associated with specific technical challenges in comparison with the transfemoral approach. Transradial procedure failures can sometimes be due to variation in radial artery anatomy. However, data describing such variations are limited. OBJECTIVE: To evaluate the incidence and impact of radial artery anomalies in patients undergoing transradial coronary procedures. METHODS: Retrograde radial arteriography was performed in all patients presenting for a first-time radial procedure. Patient characteristics, radial artery anatomy and procedural outcome were assessed. RESULTS: 1540 consecutive patients were studied, 70.6% male, mean (SD) age 63.6 (11.1) years. The overall incidence of radial artery anomaly was 13.8% (n = 212). 108 (7.0%) patients had a high-bifurcating radial origin, 35 (2.3%) had a full radial loop, 30 (2.0%) had extreme radial artery tortuosity and 39 (2.5%) had miscellaneous anomalies such as radial atherosclerosis and accessory branches. Overall transradial procedural success was 96.8%. Procedural failure was more common in patients with anomalous anatomy than in patients with normal anatomy (14.2% vs 0.9%, p<0.001). Procedural failure in patients with high radial bifurcation, radial loop, severe radial tortuosity and other anomalies was 4.6%, 37.1%, 23.3% and 12.9%, respectively. 15 (1%) vascular complications occurred, all of which were treated conservatively without ischaemic sequelae. CONCLUSION: Anomalous radial artery anatomy is relatively common and is a significant cause of procedural failure. Within each specific anomalous pattern there is a differential procedural failure rate. This has implications for clinical practice and suggests a need for imaging of the radial artery after sheath insertion.

Lignin signatures show the effects of changes in heather and bracken cover on the composition of organic matter in a moorland soil profile.

Bracken (Pteridium aquilinum) is aggressively displacing heather (Calluna vulgaris) on many moorlands in Britain. We investigated the use of lignin derivatives to identify the distribution of soil organic matter (SOM) derived from bracken in moorland soil profiles formed under heather. Phenylpropanoids extracted from recently senesced litters, roots and SOM, using alkaline CuO oxidation, showed distinct signatures for bracken and heather, with vanillyl moieties dominating bracken litter extracts and vanillyl and syringyl dominating heather litter extracts. Ratios of vanillyl and syringyl concentrations characterised the SOM derived from heather and bracken better than the concentrations of the individual moieties. The analysis showed up to a depth of 5 cm under pure bracken cover, and at the interface between heather and bracken, the SOM was largely derived from bracken litter but below that depth SOM was apparently derived from heather. The use of these methods to identify the plant origin of SOM not only enables understanding the effects of changing vegetation cover on organic matter dynamics in moorland soils but could also facilitate management techniques in moorland/heathland restoration which involve the removal of comparatively nutrient-rich SOM derived from bracken.