Mark A. Kotowycz

Radial Artery Patency After Transradial Catheterization

The transradial approach to cardiac catheterization has many advantages over the transfemoral approach and is increasingly being used for both diagnostic coronary angiography and percutaneous coronary intervention (PCI). The technique is associated with fewer vascular access complications1–3 and has been shown to reduce major bleeding when compared with the femoral approach.4 Patients prefer the radial approach and score higher on quality-of-life questionnaires after transradial catheterization.3,5 Radial access allows for earlier patient ambulation and same-day hospital discharge in PCI patients4 – 6 and is associated with decreased cost.5,7,8 Radial artery occlusion (RAO) is a complication of transradial catheterization that can lead to permanent occlusion of the radial artery. Estimated to occur in 1–10% of cases,9–14 it has been described as the “Achilles’ heel” of the transradial technique.15 RAO is usually clinically silent because of the dual blood supply to the hand, and for this reason it is often overlooked. In fact, more than 50% of transradial operators do not routinely assess radial artery patency before hospital discharge.16 However, the complication is not benign, as hand ischemia resulting from RAO has been reported.17–19 Furthermore, once the artery is occluded, it cannot be used as an access site for future catheterization or as an arterial conduit for bypass surgery. RAO renders the ipsilateral ulnar artery unusable as well, because instrumenting and cannulating the ulnar would put the patient’s hand at risk of ischemia. In this report, we review the pathophysiology, clinical presentation, and risk factors for RAO, discuss prevention and treatment options, and suggest directions for future research aimed at minimizing this complication.

Predictors of Radial Artery Size in Patients Undergoing Cardiac Catheterization: Insights From the Good Radial Artery Size Prediction (GRASP) Study

BACKGROUND Radial artery occlusion occurs after transradial cardiac catheterization or percutaneous coronary intervention. Although use of a sheath larger than the artery is a risk factor for radial artery occlusion, radial artery size is not routinely measured. We aimed to identify bedside predictors of radial artery diameter. METHODS Using ultrasound, we prospectively measured radial, ulnar, and brachial artery diameters of 130 patients who presented for elective percutaneous coronary intervention or diagnostic angiography. Using prespecified candidate variables we used multivariable linear regression to identify predictors of radial artery diameter. RESULTS Mean internal diameters of the right radial, ulnar, and brachial arteries were 2.44 ± 0.60, 2.14 ± 0.53, and 4.50 ± 0.88 mm, respectively. Results for the left arm were similar. The right radial artery was larger in men than in women (2.59 vs 1.91 mm; P < 0.001) and smaller in patients of South Asian descent (2.00 vs 2.52 mm; P < 0.001). Radial artery diameter correlated with wrist circumference (r(2) = 0.26; P < 0.001) and shoe size (r(2) = 0.25; P < 0.001) and weakly correlated with height (r(2) = 0.14; P < 0.001), weight (r(2) = 0.18; P < 0.001), body mass index (r(2) = 0.07; P = 0.002), and body surface area (r(2) = 0.22; P < 0.001). The independent predictors of a larger radial artery were wrist circumference (r(2) = 0.26; P < 0.001), male sex (r(2) = 0.06; P < 0.001), and non-South Asian ancestry (r(2) = 0.05; P = 0.006; final model r(2) = 0.37; P < 0.001). A risk score using these variables predicted radial artery diameter (c-statistic, 0.71). CONCLUSIONS Wrist circumference, male sex, and non-South Asian ancestry are independent predictors of increased radial artery diameter. A risk score using these variables can identify patients with small radial arteries.

Angiographic and Echocardiographic Correlates of Suitable Septal Perforators for Alcohol Septal Ablation in Hypertrophic Obstructive Cardiomyopathy

BACKGROUND Myocardial contrast echocardiography during angiography is critical in identifying appropriate septal perforator(s) for alcohol septal ablation (ASA) in patients with hypertrophic obstructive cardiomyopathy. We evaluated whether there were other angiographic and/or echocardiographic markers that might identify patients who are anatomically suitable for ASA. METHODS We performed quantitative coronary angiographic analysis and echocardiographic assessment on 74 patients referred for ASA from January 2004 to July 2012 at the Peter Munk Cardiac Centre, University Health Network, Toronto, Ontario, Canada. Patients who proceeded to ASA were compared with those in whom ASA was aborted. RESULTS Of the 74 patients referred for ASA, 63 proceeded to ASA and in 11 patients ASA was aborted because of various anatomic and technical reasons. There were no clinically significant differences observed in quantitative angiographic and echocardiographic measurements between the 2 groups. The ratio of ostial left main (LM) to ablated septal distance on angiography vs the basal septum to the septum area where the mitral valve contacted the septum because of systolic anterior motion (SAM) was 1.53. In the whole cohort, a significant correlation was observed between the ostial LM to the target septal distance and the distance from basal septum to SAM-septal contact point on echocardiography (r = 0.39; P = 0.008). A stronger correlation was evident when analysis was restricted to patients undergoing ASA only (r = 0.44; P = 0.006). CONCLUSIONS Echocardiographic and angiographic assessments of the distance between the basal septum to SAM-septal contact point and ostial LM to the target septal distance might be useful in preprocedural selection of the appropriate septal perforator for ASA.

Long-term outcomes after percutaneous intervention of the internal thoracic artery anastomosis: the use of drug-eluting stents is associated with a higher need of repeat revascularization.

BACKGROUND There is a lack of data and absence of clear recommendations regarding the optimal treatment of lesions located at the anastomosis of internal thoracic artery (ITA) grafts and native coronary arteries (CAs). The objective of this study was to assess the long-term outcomes of percutaneous coronary intervention (PCI) at the ITA anastomosis according to delivered treatment, namely deployment of a drug-eluting stent (DES), bare-metal stent (BMS), or balloon angioplasty only (POBA). METHODS We used a prospective PCI registry at a large Canadian teaching hospital to identify all patients who underwent PCI at the ITA-CA anastomosis between June 2000 and June 2010. Our primary end point was repeat target lesion revascularization (TLR) at follow-up. RESULTS Of the 53 patients included in the study (mean age 67.1 ± 10.7; 84.9% males), 45 (84.9%) underwent a successful PCI procedure. Of these, 23 patients (51.1%) received DES, 18 (40%) BMS, and 4 (8.9%) POBA. After a median follow-up of 29.2 months (interquartile range, 11.1-77.7 months), TLR was 47.8% with DES, 7.1% with BMS, and 50% with POBA (P = 0.032). Patients who underwent repeat revascularization were more likely to have longer stents than those who did not (18.2 mm vs 14.2 mm, P = 0.043). CONCLUSIONS Deployment of a DES for the treatment of ITA anastomotic lesions appears to be associated with a higher rate of repeat revascularization compared with BMS. Further studies will be necessary to evaluate if the present results might reflect different underlying pathophysiology in anastomotic and native coronary atherosclerotic lesions.

Characteristics and outcomes of patients undergoing percutaneous coronary intervention within 1 year of coronary artery bypass graft surgery

The aim of this study was to examine the clinical and procedural outcomes of patients undergoing percutaneous coronary intervention (PCI) within 1 year of coronary artery bypass graft surgery (CABG).