The Transradial Approach is Associated with Lower Risk of Adverse Outcomes Following Percutaneous Coronary Intervention: A Single-Center Experience

ABSTRACT: Objective. We sought to test the hypothesis that the transradial approach is associated with lower risk of adverse outcomes following percutaneous coronary intervention (PCI) compared to the transfemoral approach, and to examine whether the adoption of the transradial approach could result in improved quality of care for PCI in a single-center practice. Background. Although previous research has suggested that the transradial approach is associated with lower risk of adverse outcomes following PCI, it is not widely used in the United States. Methods. We identified 462 transradial and 625 transfemoral PCI cases that were treated at our center between January 2007 and March 2009. The differences between the transradial and transfemoral approaches in risks of in-hospital mortality, bleeding, and vascular complications as well as post-procedural lengths of stay were examined. Results. The risk of bleeding was significantly lower in the transradial group (2.60%) than the transfemoral group (6.08%); the adjusted odds ratio (OR) was 0.34 [95% confidence interval (CI), 0.17–0.68; p = 0.002]. The risk of vascular complications was also significantly lower (0% versus 1.44%, respectively; OR, 0.11; 95% CI, 0–0.68; p = 0.01). The observed in-hospital mortality rate was lower for the transradial approach (0.87% versus 2.24%), but the difference was not statistically significant (adjusted OR, 0.55; 95% CI, 0.14–2.10; p = 0.38). Same-day discharges were more common in the transradial patients (14.2% versus 2.2%; adjusted OR, 15.6; 95% CI, 7.76–31.44; p Conclusion. The risks of bleeding and vascular complications are lower for the transradial approach. Adopting the transradial approach may lead to improved care for PCI. J INVASIVE CARDIOL 2011;23:88–92 Key words: transradial PCI; complications ——————————————————— Recent studies have shown that patients who received percutaneous coronary intervention (PCI) through radial arteries were less likely to develop bleeding and vascular complications compared to those who received PCI through femoral arteries.^1–5 The transradial approach was also found to be related to lower risk of mortality during 30-day and 1-year follow-up compared to the transfemoral approach.¹ In addition to being related to fewer adverse post-procedural outcomes, the transradial approach was reported to be related to shorter length of stay and lower cost of care for PCI.^3,6–8 Although the transradial approach appears to be associated with lower risk of adverse outcomes and lower cost of care, most PCI procedures are performed using the traditional transfemoral approach in the United States. A recent study showed that fewer than 2% of PCI procedures were performed using the transradial approach.² Therefore, given the potential benefit in patient outcomes and cost savings, the transradial approach could be a process that can be adopted in practice to improve the quality of care for PCI. The objective of this study is to evaluate the impact of the transradial approach on the quality of care for PCI in a single-center practice.

Methods

Database and study population. Beginning in 2007, the Penn State Milton S. Hershey Medical Center started to submit data to the CathPCI Registry, which is part of the National Cardiovascular Data Registry (NCDR).⁹ For each PCI procedure performed in the catheterization laboratory, patient demographic variables, pre-procedural risk factors, procedural information, and post-procedural outcomes, such as complications and death, were collected prospectively using the NCDR report form and instructions. From January 1, 2007 to March 31, 2009, a total of 1,113 PCI procedures were performed in the Medical Center. 462 procedures (41.5%) were performed via the transradial approach, 625 (56.2%) were transfemoral, and 26 cases (2.3%) were performed through other or multiple entry sites. The study population consisted of the 1,087 patients who underwent either transradial or transfemoral PCI. All procedures were done in a closed cardiac catheterization laboratory by one of the 4 interventional cardiologists, all of whom had at least 15 years of practice experience and 10 years experience with transradial catheterization. The transradial approach was brought to the Center after a visit to Montreal, Canada in 1995 by one of the interventionalists. The experience was disseminated to all interventionalists, but was utilized in an asymmetric fashion with 1 staff member using radial artery as default access, 1 staff member using femoral artery default access, and 2 other interventionalists split between transfemoral or transradial approaches without a strong preference. Outcomes. The main outcomes of interest in this study were post-procedural in-hospital death, bleeding, and vascular complications, which were reflective of the quality of care for PCI. Bleeding complications included percutaneous entry site, retroperitoneal, gastrointestinal, and genital-urinary bleeding, as well as bleeding at other sites that required a transfusion or prolonged hospital stay or resulted in a drop of hemoglobin by at least 3.0 g/dl. The NCDR Cath-PCI defines percutaneous entry-site bleeding as external bleeding or a hematoma > 2 cm for radial access or > 10 cm for femoral access.⁹ The primary outcome variable for bleeding complications is any bleeding complications regardless of the bleeding site. Secondary outcome variables for bleeding, which were defined based on the presence of entry-site bleeding, included entry-site bleeding only, entry-site bleeding with or without bleeding at other sites, and non-entry site bleeding. Vascular complications consisted of access-site occlusion, peripheral embolization, dissection, pseudoaneurysm, and arteriovenous fistula as defined in the NCDR Cath-PCI data instruments.⁹Statistical analysis. We first compared the distributions of baseline risk factors of patients who received transradial or transfemoral PCI. Such variables included demographic variables and preprocedural comorbiditiies, as well as medication use. For categorical variables, the Pearson’s Chi-square test was applied, and for continuous variables, the Student’s t-test was used. The differences in crude rates of in-hospital mortality, bleeding, and vascular complications between the transradial and transfemoral approaches were compared using the Pearson Chi-square test. Crude odds ratios (OR) for each adverse event (transradial versus transfemoral) and 95% confidence intervals (CI) were calculated. In addition, logistic (or exact logistic when appropriate) regression models were used to control for potential confounding due to the uneven distribution of baseline risk factors between the two treatment groups. The adjusted OR for each adverse event (transradial versus transfemoral) and 95% CI were then derived from respective logistic regression models.¹⁰ The post-procedure length of stay (calculated as the number of days between the dates of discharge and procedure) between the transradial and transfemoral approaches was compared among the patients who were alive at the time of discharge. Because the length of stay was not normally distributed, the unadjusted lengths of stay were compared using negative binomial regression with length of stay as the dependent variable and indicator of treatment as the only independent variable.¹¹ The adjusted lengths of stay were also compared by further controlling for baseline patient risk factors. Besides treating length of stay as a continuous variable, same-day discharge (defined as discharge on the same day of operation) was compared between the 2 treatment groups. Pearson’s Chi-square was used to test for crude association between same-day discharge and treatment approach, and multivariate logistic regression was used to control for confounding. All analyses were conducted using SAS version 9.1 (SAS Institute, Cary, North Carolina), and the significance of all statistical tests were 2-sided and determined at the 0.05 level.

Results

Table 1 shows that the patients who underwent transradial procedures were less likely to be female, to have history of diabetes and previous coronary artery bypass graft surgery, to have multi-vessel disease, and to be present with type C lesion. However, the transradial patients were more likely to have a history of myocardial infarction prior to procedures. In terms of medications on admission, the transradial patients were more likely to receive treatment with both unfractionated and low-molecular-weight heparin. As for intracoronary artery device use, the transradial patients were less likely to receive drug-eluting stents (40.0% versus 53.3%; p following PCI. The crude in-hospital mortality rates were 0.87% and 2.24% for the transradial and transfemoral approaches, respectively, but the difference was not statistically significant (p = 0.09). The difference in mortality between the transradial and transfemoral groups remained statistically nonsignificant when baseline risk factors were adjusted for in a logistic regression model with in-hospital death as the dependent variable (adjusted OR = 0.55; 95% CI, 0.14–2.10; p = 0.38). Table 2 shows that the crude rate of any bleeding complications was significantly lower for the transradial group compared to the transfemoral group (2.60% versus 6.08%, respectively; p = 0.009), and the difference remained statistically significant when adjusting for baseline risk factors (adjusted OR = 0.34; 95% CI, 0.17–0.68; p = 0.002). The adjusted OR of 0.34 indicated that the transradial approach was associated with a 66% lower risk of any bleeding complications. The number of patients needed to be treated by the transradial approach instead of the transfemoral approach to avoid 1 bleeding complication was 25 (95% CI, 20–51). When bleeding was categorized by bleeding site, the results showed that the transradial group was at lower risk of bleeding at entry site only (0% versus 1.12%; p = 0.04) and bleeding at entry site with or without bleeding at other sites (0.22% versus 2.56%; adjusted OR = 0.10; p = 0.03). There is also a trend toward a lower risk of non-entry site bleeding for the transradial approach (2.38% versus 3.52%; adjusted OR = 0.46; p = 0.06), but it is not statistically significant. We further compared the rate of non-entry site bleeding between the 2 entry approaches stratifying by warfarin use on admission and up to procedures. For the 412 transradial and 563 transfemoral cases who had not used warfarin from admission through procedure time, the rates of non-entry site bleeding were 2.18% and 2.31% for the transradial and the transfemoral patients, respectively (p = 0.90). For the 50 transradial and 62 transfemoral cases who received warfarin from admission and through procedures, the rates of non-entry site bleeding were 4.00% and 14.52% for transradial and transfemoral patients, respectively (p = 0.12). Regarding vascular complications, there was no vascular event in the transradial group, and the rate of vascular complication in the transfemoral group was 1.44%. The difference in rates of vascular complications was statistically significant (p = 0.01; Table 2). The post-procedural median length of stay for hospitalized patients was 1 day with an interquartile range of 1–3 days for both approaches. The unadjusted negative binomial regression results showed a 2% decrease in length of stay for the transradial group, but the difference was not statistically significant (p = 0.69). After adjusting for baseline risk factors, the adjusted length of stay was 10% shorter for the transradial group (rate ratio = 0.90; 95% CI, 0.81–0.99; p = 0.04) and the difference was statistically significant. Same-day discharge was more common among the transradial than the transfemoral patients (14.2% versus 2.2%, respectively; p Discussion In this study, we evaluated the impact of the transradial approach on major in-hospital adverse outcomes following PCI to explore its role as a process to improve the quality of care for PCI in a single-center practice. We observed a lower but non-significant risk of in-hospital mortality for the transradial approach compared to the transradial approach (adjusted OR = 0.55; p = 0.38). This trend is consistent with the findings that the transradial approach was related to lower risk of 30-day and 1-year mortality following PCI in a study by Chase et al¹ and that the transradial approach is related to a lower risk of bleeding, which predicts mortality.^12,13 We found that the transradial approach was associated with significantly lower risk of bleeding and vascular complications following PCI procedures. In addition to examining any bleeding complications, we found that the transradial approach was associated with lower risk of entry-site bleeding. We also found that the risk of bleeding without the involvement of the entry site was also lower for the transradial approach, but this finding was statistically nonsignificant (2.38% versus 3.52%; adjusted OR = 0.46; p = 0.06). This finding indicates that different approaches in using anticoagulant medications may put transfemoral patients at higher risk of bleeding at non-entry sites. For example, warfarin is usually discontinued prior to transfemoral PCI procedures and is replaced by another type of anticoagulant medication, but this is not the case for the transradial approach. Therefore, it is possible that the residual effect of warfarin in addition to the newly initiated anticoagulant medication used as an anticoagulant bridge may increase the risk of bleeding for transfemoral patients. To explore this hypothesis, we compared the rate of non-entry site bleeding between the 2 entry approaches stratifying by warfarin use on admission and up to the time of PCI. Although the difference in risk of non-entry site bleeding between the transradial and transfemoral approaches was not statistically significant (4.00% versus 14.52%, respectively; p = 0.12) for the patients who received warfarin possibly due to small sample size, it indicates a trend worthy of future investigation that the transradial approach is associated with lower risk of non-entry site bleeding. The finding in this study that the transradial approach was associated with lower risk of bleeding and vascular complications is consistent with a study by Rao et al.² However, it should be noted that our study consisted of more ST-elevation myocardial infarction (STEMI) patients (26.8%) compared to the study by Rao et al,² in which emergency or salvage cases were excluded and the prevalence of STEMI was 4.1%. Consequently, the bleeding rates and vascular complications for the transfemoral group in our study were 6.08% and 1.44%, respectively, and were higher than the rates of 1.83% for bleeding and 0.70% for vascular complications in the study by Rao et al.² The bleeding rate for the transradial approach was also higher in our study than the Rao study (2.60% versus 0.79%, respectively). However, there were no vascular complications in the transradial group in our study, likely because of limited sample size compared to 0.19% in the Rao study.² Besides being associated with fewer adverse in-hospital events, our study found that the post-procedural length of stay for the transradial patients was about 1 day shorter compared to the transfemoral group. The transradial patients were also more likely to be discharged on the same day of operation (14.2% versus 2.2% in the transfemoral group). This finding is consistent with other reports.^3,6–8 A recent article from Canada showed a 50% reduction in cost with same-day discharge.¹⁴ Extrapolation of this and similar savings to the United States has suggested that up to 1 billion healthcare dollars could be saved with widespread adaption of same-day discharge.¹⁵ Non-urgent PCI is no longer considered an inpatient procedure by Medicare and other payers, and is one of the potential targets of Medicare Recovery Audit Contractor (RAC) program audits. Under this shift in healthcare economics, United States cardiologists may finally shift toward the transradial approach in line with much of the rest of the international community. It has been our experience from over 10 years of same-day discharge that patients request and appreciate the opportunity to leave the same day as their procedure. They are all given the option of staying overnight, but it is extremely rare for the offer to be taken. All are contacted within 48 hours by a nurse practitioner to confirm prescription compliance and review discharge instructions with the patient rested and in the familiar surroundings of their home. While the so-called legal concerns are often raised whenever a new approach to healthcare is introduced, the evidence points clearly to safety when it is used in the transradial environment, and well-informed patients are always the best defense against an unusual adverse event. Given the lower risk of adverse post-procedural events and shorter post-procedural length of stay associated with the transradial approach, it is conceivable the transradial approach can become a process that can be used to improve the quality of care for PCI. The nationwide impact could be substantial in that about 1.2 million PCI procedures are performed annually and fewer than 2% of these use the transradial approach.¹⁶ However, it should be noted that there are challenges when PCI is performed through a radial artery. One challenge is that there is a learning curve for performing PCI through radial arteries, but this is not a barrier that cannot be overcome.^17,18 Another major concern is that the transradial approach may damage radial arteries because the catheters are close to the wall of a radial artery and the damaged radial artery may not be a good conduit for coronary artery bypass surgery or for renal dialysis.^19,20 However, future improvements in the transradial technique, such as advancements in equipments, may reduce the risk of damaging the radial artery. Study limitations. A few study limitations should be noted. First, this is a single-center study; therefore, its results may not be generalizable to other clinical settings. It is worth noting that the utilization rate of the transradial approach in our center is much higher than the national average. The transradial approach was used for about 40% of the PCI cases in our study, but it was used for less than 2% of the patients registered in the National Cardiovascular Data Registry.² Moreover, only 7 of the 606 centers that participated in the NCDR Cath-PCI registry and were included in the Rao study had performed PCI procedures using the transradial approach for at least 40% of their patients. The higher utilization rate of the transradial approach may particularly affect the generalizability of this study because there is a learning curve to master this approach. Nonetheless, our finding is consistent with another recent single-center study.²² Second, this is an observational study and the choice of entry approach was not random, but was based on a decision made by the operators and the patients. Therefore the study is possibly subject to selection bias. Nonetheless, we used multivariate analysis to control for the uneven distribution of baseline risk factors to reduce the impact of the non-random selection of cases into different treatment groups, though we could not eliminate selection bias. Last, this study examined in-hospital adverse outcomes but lacked longer-term data, which may help to better understand the impact of transradial versus transfemoral approaches.

Conclusion

In summary, the transradial approach has the potential to be a process of care that can improve the quality of care for PCI. Our study confirmed that the benefit of performing transradial PCI could be realized in a single center with annual PCI volume of about 500 cases. We look forward to more studies that attempt to examine the impact of increased use of the transradial approach on both short- and long-term outcomes in practices in which the transfemoral approach is currently primarily used. Acknowledgments. The authors would like to thank Teresa Hughes, Robert Steckbeck, and the physicians and staff of the catheterization laboratory for their efforts in data collection and management. Richard Evans and Terry Britton of the Department of Public Health Sciences also provided support in data management.

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———————————————————— From the Department of Public Health Sciences and ^§Penn State Heart and Vascular Institute, Penn State Hershey College of Medicine, Hershey, Pennsylvania. The preliminary results of this study were presented at the American Heart Association Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke 2010 Scientific Sessions, Washington DC, May 19–21, 2010. Disclosure: Dr. Gilchrist receives speaker honoraria from Terumo Medical, Inc. The other authors report no conflicts of interest regarding the content herein. Manuscript submitted October 27, 2010, provisional acceptance given November 29, 2010, final version accepted December 21, 2010. Address for correspondence: Chuntao Wu, MD, PhD, Assistant Professor, Department of Public Health Sciences, Penn State Hershey College of Medicine, 600 Centerview Dr., ASB 2200, A210, Hershey, PA 17033. E-mail: chuntao.wu@psu.edu