Faculty Bibliography

BACKGROUND:We examined whether the radial artery diameter is correlated with body mass index (BMI) in patients undergoing transradial catheterization. METHODS:1706 patients undergoing trans-radial catheterization at three experienced, high-volume, radial centers were analyzed. Radial and ulnar artery diameters were determined by ultrasound in the distal third of the forearm one day post procedure. Pearson correlation test was used to measure the relationship between continuous variables. RESULTS:Radial diameter was larger than the ulnar artery [median 2.8mm (interquartile range (IQR): 2.4-3.1mm) vs. median 2.4mm (IQR: 2.1-2.6mm), p<0.001]. Women had smaller radial and ulnar arteries compared to men [median 2.6mm (IQR: 2.3-2.9mm) vs. median 2.8 (IQR: 2.4-3.2mm), p<0.001 and median 2.2mm (IQR: 2.0-2.5mm) vs. median 2.5mm (IQR: 2.2-2.7mm), p<0.001, respectively]. There was no correlation between radial diameter and BMI (Pearson correlation=0.003, p=0.88 (2-sided)), but a strong linear correlation between the radial and ulnar artery diameter existed (Pearson correlation=0.48, p<0.001 (2-sided)). After adjustment for clinical variables including diabetes, gender, and age, female gender was associated with smaller radial diameter (<2.8mm) (odds ratio 1.72; 95% CI 1.40-2.12, p<0.001). CONCLUSIONS:No correlation was observed between radial artery diameter and BMI, although female gender was associated with smaller radial diameter. This suggests catheterization can be performed without anthropometric consideration, although it should be recognized women may have smaller radial arteries. As the diameter of the radial is larger than the ulnar artery, the radial should remain the default catheterization access-site.

PURPOSE OF REVIEW:Patients with stable coronary artery disease (CAD) and a high risk of bleeding are not ideal candidates for a polymer-based drug-eluting stent (DES) because it requires 6-12 months of dual antiplatelet therapy (DAPT) following percutaneous coronary intervention (PCI). The purpose of this review is to assess the angiographic and clinical outcomes of polymer-free drug-coated stents (PF-DCS) in stable CAD patients with a high bleeding risk. RECENT FINDINGS:Several randomized controlled trials (RCTs) have compared angiographic and clinical outcomes of PF-DCS with bare-metal stents (BMS), permanent polymer (PP)-DES, or biodegradable polymer (BP)-DES. However, none of these studies particularly recruited patients with stable CAD and a high risk of bleeding. Furthermore, there are limited data available on duration of DAPT following PF-DCS placement. PF-DCS has a better efficacy and similar safety as compared with BMS. PF-DCS with dual drug is noninferior to currently available PP-DES. Further RCTs are needed to assess the safety and efficacy of PF-DCS to BP-DES and PP-DES comparing shorter to standard durations of DAPT.

BACKGROUND:Identification of the infarct-related artery (IRA) in patients with STEMI using coronary angiography (CA) is often based on the ECG and can be challenging in patients with severe multi-vessel disease. The current study aimed to determine how often percutaneous intervention (PCI) is performed in a coronary artery different from the artery supplying the territory of acute infarction on cardiac magnetic resonance imaging (CMR). METHODS:We evaluated 113 patients from the Reduction of infarct Expansion and Ventricular remodeling with Erythropoetin After Large myocardial infarction (REVEAL) trial, who underwent CMR within 4±2 days of revascularization. Blinded reviewers interpreted CA to determine the IRA and CMR to determine the location of infarction on a 17-segment model. In patients with multiple infarcts on CMR, acuity was determined with T2-weighted imaging and/or evidence of microvascular obstruction. RESULTS:A total of 5 (4%) patients were found to have a mismatch between the IRA identified on CMR and CA. In 4/5 cases, there were multiple infarcts noted on CMR. Thirteen patients (11.5%) had multiple infarcts in separate territories on CMR with 4 patients (3.5%) having multiple acute infarcts and 9 patients (8%) having both acute and chronic infarcts. CONCLUSIONS:In this select population of patients, the identification of the IRA by CA was incorrect in 4% of patients presenting with STEMI. Four patients with a mismatch had an acute infarction in more than one coronary artery territory on CMR. The role of CMR in patients presenting with STEMI with multi-vessel disease on CA deserves further investigation.

Percutaneous coronary intervention (PCI) induces thrombin generation and is associated with the risk of acute, subacute, or long-term ischaemic events. Therefore, intravenous anticoagulation is recommended to minimize thrombotic complications. The intensity and duration of anticoagulation needed are dependent on the clinical presentation (elective PCI for stable coronary artery disease, PCI for non-ST elevation acute coronary syndromes, or primary PCI for ST-segment elevation myocardial infarction) and procedural features. As both ischaemic and periprocedural bleeding complications are associated with acute and long-term mortality, the optimal level of anticoagulation and the best agents are a matter of debate. Despite a number of limitations and the lack of large randomized clinical trials, unfractionated heparin (UFH) is still been used in the majority of interventions. Intravenous enoxaparin, a low-molecular-weight heparin, leads to a more predictable level of anticoagulation and has been compared with UFH in patients with elective PCI and primary PCI with favourable results. The direct thrombin inhibitor bivalirudin has been studied in numerous trials and consistently shown to reduce bleeding complications when compared with UFH with or without glycoprotein IIb/IIIa inhibitors. This review will summarize the current status of anticoagulation for PCI and the results of most recent trials and give recommendations for different clinical scenarios.