Ian C. Gilchrist

The Transradial Approach to Percutaneous Coronary Intervention: Historical Perspective, Current Concepts, and Future Directions

Periprocedural bleeding complications after percutaneous coronary intervention (PCI) are associated with increased short- and long-term morbidity and mortality. Although clinical trials have primarily assessed pharmacological strategies for reducing bleeding risk, there is a mounting body of evidence suggesting that adoption of a transradial rather than a transfemoral approach to PCI may permit greater reductions in bleeding risk than have been achieved with pharmacological strategies alone. However, despite a long history of use, a lack of widespread uptake by physicians coupled with the technological limitations of available devices has in the past confined transradial PCI to the status of a niche procedure, and many operators lack experience in this technique. In this review, we examine the history of the transradial approach to PCI and discuss some of the circumstances that have hitherto limited its appeal. We then review the current state of the peer-reviewed literature supporting its use and summarize the unresolved issues affecting broader application of this technique, including lack of operator familiarity and an insufficient evidence base for guiding practice. Finally, we describe potential directions for future investigation in the transradial realm.

Adoption of Radial Access and Comparison of Outcomes to Femoral Access in Percutaneous Coronary Intervention An Updated Report from the National Cardiovascular Data Registry (2007–2012)

Background— Radial access for percutaneous coronary intervention (r-PCI) is associated with reduced vascular complications; however, previous reports have shown that <2% of percutaneous coronary intervention (PCI) procedures in the United States are performed via the radial approach. Our aims were to evaluate temporal trends in r-PCI and compare procedural outcomes between r-PCI and transfemoral PCI. Methods and Results— We conducted a retrospective cohort study from the CathPCI registry (n=2 820 874 procedures from 1381 sites) between January 2007 and September 2012. Multivariable logistic regression models were used to evaluate the adjusted association between r-PCI and bleeding, vascular complications, and procedural success, using transfemoral PCI as the reference. Outcomes in high-risk subgroups such as age ≥75 years, women, and patients with acute coronary syndrome were also examined. The proportion of r-PCI procedures increased from 1.2% in quarter 1 2007 to 16.1% in quarter 3 2012 and accounted for 6.3% of total procedures from 2007 to 2012 (n=178 643). After multivariable adjustment, r-PCI use in the studied cohort of patients was associated with lower risk of bleeding (adjusted odds ratio, 0.51; 95% confidence interval, 0.49–0.54) and lower risk of vascular complications (adjusted odds ratio, 0.39; 95% confidence interval, 0.31–0.50) in comparison with transfemoral PCI. The reduction in bleeding and vascular complications was consistent across important subgroups of age, sex, and clinical presentation. Conclusions— There has been increasing adoption of r-PCI in the United States. Transradial PCI now accounts for 1 of 6 PCIs performed in contemporary clinical practice. In comparison with traditional femoral access, transradial PCI is associated with lower vascular and bleeding complication rates. # Clinical Perspective {#article-title-25}Background— Radial access for percutaneous coronary intervention (r-PCI) is associated with reduced vascular complications; however, previous reports have shown that <2% of percutaneous coronary intervention (PCI) procedures in the United States are performed via the radial approach. Our aims were to evaluate temporal trends in r-PCI and compare procedural outcomes between r-PCI and transfemoral PCI. Methods and Results— We conducted a retrospective cohort study from the CathPCI registry (n=2 820 874 procedures from 1381 sites) between January 2007 and September 2012. Multivariable logistic regression models were used to evaluate the adjusted association between r-PCI and bleeding, vascular complications, and procedural success, using transfemoral PCI as the reference. Outcomes in high-risk subgroups such as age ≥75 years, women, and patients with acute coronary syndrome were also examined. The proportion of r-PCI procedures increased from 1.2% in quarter 1 2007 to 16.1% in quarter 3 2012 and accounted for 6.3% of total procedures from 2007 to 2012 (n=178 643). After multivariable adjustment, r-PCI use in the studied cohort of patients was associated with lower risk of bleeding (adjusted odds ratio, 0.51; 95% confidence interval, 0.49–0.54) and lower risk of vascular complications (adjusted odds ratio, 0.39; 95% confidence interval, 0.31–0.50) in comparison with transfemoral PCI. The reduction in bleeding and vascular complications was consistent across important subgroups of age, sex, and clinical presentation. Conclusions— There has been increasing adoption of r-PCI in the United States. Transradial PCI now accounts for 1 of 6 PCIs performed in contemporary clinical practice. In comparison with traditional femoral access, transradial PCI is associated with lower vascular and bleeding complication rates.

Transradial arterial access for coronary and peripheral procedures: executive summary by the Transradial Committee of the SCAI.

In response to growing U.S. interest, the Society for Coronary Angiography and Interventions recently formed a Transradial Committee whose purpose is to examine the utility, utilization, and training considerations related to transradial access for percutaneous coronary and peripheral procedures. With international partnership, the committee has composed a comprehensive overview of this subject presented herewith.

A Registry-Based Randomized Trial Comparing Radial and Femoral Approaches in Women Undergoing Percutaneous Coronary Intervention : The SAFE-PCI for Women (Study of Access Site for Enhancement of PCI for Women) Trial

OBJECTIVES This study sought to determine the effect of radial access on outcomes in women undergoing percutaneous coronary intervention (PCI) using a registry-based randomized trial. BACKGROUND Women are at increased risk of bleeding and vascular complications after PCI. The role of radial access in women is unclear. METHODS Women undergoing cardiac catheterization or PCI were randomized to radial or femoral arterial access. Data from the CathPCI Registry and trial-specific data were merged into a final study database. The primary efficacy endpoint was Bleeding Academic Research Consortium type 2, 3, or 5 bleeding or vascular complications requiring intervention. The primary feasibility endpoint was access site crossover. The primary analysis cohort was the subgroup undergoing PCI; sensitivity analyses were conducted in the total randomized population. RESULTS The trial was stopped early for a lower than expected event rate. A total of 1,787 women (691 undergoing PCI) were randomized at 60 sites. There was no significant difference in the primary efficacy endpoint between radial or femoral access among women undergoing PCI (radial 1.2% vs. 2.9% femoral, odds ratio [OR]: 0.39; 95% confidence interval [CI]: 0.12 to 1.27); among women undergoing cardiac catheterization or PCI, radial access significantly reduced bleeding and vascular complications (0.6% vs. 1.7%; OR: 0.32; 95% CI: 0.12 to 0.90). Access site crossover was significantly higher among women assigned to radial access (PCI cohort: 6.1% vs. 1.7%; OR: 3.65; 95% CI: 1.45 to 9.17); total randomized cohort: (6.7% vs. 1.9%; OR: 3.70; 95% CI: 2.14 to 6.40). More women preferred radial access. CONCLUSIONS In this pragmatic trial, which was terminated early, the radial approach did not significantly reduce bleeding or vascular complications in women undergoing PCI. Access site crossover occurred more often in women assigned to radial access. (SAFE-PCI for Women; NCT01406236).

Phase 1b Randomized Study of Antidote-Controlled Modulation of Factor IXa Activity in Patients With Stable Coronary Artery Disease

Background— Whether selective factor IXa inhibition produces an appropriate anticoagulant effect when combined with platelet-directed therapy in patients with stable coronary artery disease is unknown. REG1 consists of RB006 (drug), an injectable RNA aptamer that specifically binds and inhibits factor IXa, and RB007 (antidote), the complementary oligonucleotide that neutralizes its anti-IXa activity. Methods and Results— We evaluated the safety, tolerability, and pharmacodynamic profile of REG1 in a randomized, double-blind, placebo-controlled study, assigning 50 subjects with coronary artery disease taking aspirin and/or clopidogrel to 4 dose levels of RB006 (15, 30, 50, and 75 mg) and RB007 (30, 60, 100, and 150 mg). The median age was 61 years (25th and 75th percentiles, 56 and 68 years), and 80% of patients were male. RB006 increased the activated partial thromboplastin time dose dependently; the median activated partial thromboplastin time at 10 minutes after a single intravenous bolus of 15, 30, 50, and 75 mg RB006 was 29.2 seconds (25th and 75th percentiles, 28.1 and 29.8 seconds), 34.6 seconds (25th and 75th percentiles, 30.9 and 40.0 seconds), 46.9 seconds (25th and 75th percentiles, 40.3 and 51.1 seconds), and 52.2 seconds (25th and 75th percentiles, 46.3 and 58.6) (P<0.0001; normal 25th and 75th percentiles, 27 and 40 seconds). RB007 reversed the activated partial thromboplastin time to baseline levels within a median of 1 minute (25th and 75th percentiles, 1 and 2 minutes) with no rebound increase through 7 days. No major bleeding or other serious adverse events occurred. Conclusions— This is the first experience of an RNA aptamer drug-antidote pair achieving inhibition and active restoration of factor IXa activity in combination with platelet-directed therapy in stable coronary artery disease. The preliminary clinical safety and predictable pharmacodynamic effects form the basis for ongoing studies in patients undergoing elective revascularization procedures.

Best practices for transradial angiography and intervention: a consensus statement from the society for cardiovascular angiography and intervention's transradial working group.

Duke University Medical Center, Durham, North Carolina Stanford University Medical Center, Palo Alto, California Penn State Hershey Medical Center, Hershey, Pennsylvania Brigham and Women’s Hospital, Boston, Massachusetts Mayo Clinic, Rochester, Minnesota University of Illinois at Chicago/Jesse Brown VA Medical Center, Chicago, Illinois First Coast Heart and Vascular Center, Jacksonville, Florida G.V. (Sonny) Montgomery VA Medical CenterJackson, Mississippi. Stern Cardiovascular Foundation, Memphis, Tennessee Reid Heart Center at FirstHealth of the Carolinas, Pinehurst, North Carolina Deborah Heart & Lung Institute, Browns Mills, New Jersey Duke University Medical Center, Durham, North Carolina Lahey Clinic, Burlington, Massachusetts Geisinger Medical Center, Danville, Pennsylvania Apex Heart Institute, Seth N.H.L. Municipal Medical College, Ahmedabad, Gujarat, India The Wright Center for Graduate Medical Education, The Commonwealth Medical College, Scranton, Pennsylvania

Sterile Inflammation Associated With Transradial Catheterization and Hydrophilic Sheaths

In 1999, we noted the development of inflammation and/or abscesses at the site of radial access in a group of patients. Over a 3‐year period, we noted this inflammation in 33 patients out of 2,038 (1.6%) who had catheterization via the radial approach. The radial abscesses occurred in 30 patients out of 1,063 (2.8%) in whom we could confirm the use of a hydrophilic‐coated sheath, but in no patient for whom we can document that an uncoated sheath was used. No infectious agent could be implicated, and the time course for the development of the abscess, typically 2 to 3 weeks, seemed long for a bacterial infection. Later patients had biopsies, and granulomatous reactions were seen in most. Additionally, a few of the biopsies showed an amorphous extravascular substance consistent with the catheter coating. All patients had good long‐term outcomes. Cathet Cardiovasc Intervent 2003;59:207–213.

Modifiable Risk Factors for Vascular Access Site Complications in the IMPACT II Trial of Angioplasty With Versus Without Eptifibatide

Abstract Objectives. This study was designed to identify potential predictors of vascular access site (VAS) complications in the large-scale Integrilin to Minimize Platelet Aggregation and Coronary Thrombosis (IMPACT) II trial, which studied angioplasty with versus without a new glycoprotein (GP) IIb/IIIa receptor inhibitor (eptifibatide). Background. GP IIb/IIIa receptor inhibition during coronary interventions has been associated with excess VAS complications. If other predictors of VAS complications could be identified, they might be manipulated to reduce complications. Methods. A total of 4,010 patients undergoing percutaneous transluminal coronary revascularization (PTCR) were randomized into one of three bolus/20- to 24-h infusion arms: placebo bolus/placebo infusion; 135-μg/kg body weight eptifibatide bolus/0.5-μg/kg per min eptifibatide infusion; or 135-μg/kg eptifibatide bolus/0.75-μg/kg per min eptifibatide infusion. Heparin during the procedure was weight adjusted and stopped 4 h before sheaths were removed. Logistic regression modeling was used to identify independent predictors of VAS complications. Results. VAS complications were more common in patients treated with eptifibatide (9.9% vs. 5.9% placebo-treated patients, p Conclusions. VAS complications may be reduced by early sheath removal, by avoiding placement of venous sheaths and by limiting heparin dosing to avoid excessive activated clotting times. Early sheath removal during inhibition of platelet aggregation by eptifibatide is feasible.

Clinical pharmacology of higher dose eptifibatide in percutaneous coronary intervention (the PRIDE study).

This study describes the dose-exploration phase of the PRIDE trial, an investigation of the clinical pharmacology of higher dose eptifibatide in patients who underwent elective percutaneous coronary intervention (PCI). Outcomes of treatment with the platelet glycoprotein IIb/IIIa inhibitors were dependent upon proper dosing selection. In this multicenter, placebo-controlled clinical study, 127 patients were randomized 1:1:2:2 into 1 of the following treatment groups: placebo; eptifibatide as a 135 microg/kg bolus followed by a 0.75 microg/kg/min infusion; eptifibatide as a 180 microg/kg bolus with a 2.0 microg/kg/min infusion; or eptifibatide as a 250 microg/kg bolus with a 3.0 microg/kg/min infusion. Light transmission aggregometry was used to determine platelet aggregation in response to 20 microM adenosine diphosphate, and platelet receptor occupancy was also determined. Eptifibatide exhibited linear pharmacokinetics over the dose range studied. Inhibition of platelet aggregation was greater in samples collected in sodium citrate compared with those collected in D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone. The 180/2.0 dosing regimen achieved 90% inhibition of platelet aggregation immediately (5 minutes) and at steady state (8 to 24 hours). At 1 hour, mean inhibition of platelet aggregation was 80%. Eptifibatide exhibited dose-dependent pharmacodynamics that were dependent upon choice of anticoagulant. A 180 microg/kg bolus followed by a 2.0 microg/kg/min infusion at steady state achieved >80% inhibition of platelet aggregation. With the single-bolus regimen, however, there was an early loss of the inhibition of platelet aggregation before steady state was reached. Additional dose-exploration studies may further optimize eptifibatide dosing.

Cardiac catheterization in morbidly obese patients

The safety and findings of cardiac catheterization and coronary angiography in morbidly obese patients with suspected coronary heart disease (CHD) have not been fully examined in the modern era. From a database of 4,978 patients undergoing diagnostic cardiac catheterization, we identified 110 with morbid obesity (body mass ≥ 145 kg and body mass index ≥ 40 kg/m2). Relative to all the other patients in this database, morbidly obese patients had a lower prevalence of CHD (45% vs. 72%; P < 0.05), reflecting a higher prevalence of false positive noninvasive tests. Overall, noninvasive tests were only 75% sensitive and 39% specific for CHD in this group. Use of radial access (66%) and femoral closure devices (24%) was much more frequent in the morbidly obese cohort. Complications were no more frequent in the morbidly obese group, with major (0 vs. 0.9%) and minor (4.7% vs. 3.5%) adverse outcomes being similar to the rest of the database. We conclude that cardiac catheterization using the radial artery or a femoral closure device is a safe and effective method of evaluating CHD in morbidly obese patients. In contrast, noninvasive testing is frequently not definitive and may be misleading. Cathet Cardiovasc Intervent 2002;56:174–177.