According to a new study, the reduced bleeding and reduced mortality seen with the transradial approach in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) is also observed in patients with non-ST-segment elevation myocardial infarction (NSTEMI).
M Bilal Iqbal (Royal Brompton and Harefield NHS Foundation Trust, Harefield Hospital, Middlesex, UK) and others write in Circulation: Cardiovascular Interventions that the RIVAL (Radial versus femoral access for coronary intervention) study indicated that, unlike for STEMI patients, transradial access does not confer a mortality benefit for non-ST-segment elevation acute coronary syndromes (NSTEACS) patients undergoing PCI. However, Iqbal et al comment that only 62% of patients in this study had positive cardiac biomarkers and “whether transradial access confers prognostic benefit in the high-risk NSTEACS group, that is, with positive cardiac biomarkers, remains to be determined.” The aim of Iqbal et al’s study was to determine whether transradial access was associated with better clinical outcomes in patients with NSTEMI (NSTEACS with a positive troponin) treated with PCI.
Using data from their local British Cardiac Intervention Society database, the authors identified 10,095 consecutive patients with NSTEMI who underwent PCI at eight tertiary cardiac centres in London between 2005 and 2011. Of these patients, 7,820 had undergone transfemoral access and 2,275 had undergone transradial access.
Iqbal et al found, in a multivariate analysis, that transradial access was a significant predictor of reduced total bleeding (p=0.002), reduced major bleeding (p=0.009), reduced access-site bleeding (p=0.015), and reduced access-site complications (p=0.034). They also found that overall, transradial access was a significant predictor of reduced mortality at 30 days (p=0.021), six months (p=0.003), and at one year (p=0.017).
As well as reviewing the effect of transradial access on mortality during the overall study period, because of the learning curve with the approach and because expertise in performing it would have increased over time, Iqbal et al also examined the effect of transradial access on mortality for two time periods: 2005 to 2007 and 2008 to 2011. They found that transradial access was not a predictor of reduced mortality between 2005 and 2007 at any time point (30 days, six months, and one year), but was a predictor of reduced mortality at all of the study time points between 2008 and 2011. “Similarly, when comparing low versus high volume radial centres, the mortality benefit of transradial access was not seen at the low-volume centres but specifically seen in the high-volume radial centres,” Iqbal et al report.
The authors conclude: “This observational study suggests a clinical benefit of transradial access over transfemoral in patients NSTEMI. In addition to being associated with reduced bleeding and access-site complications, transradial access is associated with a mortality benefit. These data also demonstrate that the evolving learning curve, experience, and expertise may be important factors contributing to the prognostic benefit conferred with transradial access.”