Faculty Bibliography

INTRODUCTION/BACKGROUND:The presence of severe coronary artery calcification is associated with higher rates of angiographic complications during percutaneous coronary intervention (PCI), as well as higher major adverse cardiac events compared with non-calcified lesions. Incorporating orbital atherectomy (OAS) for effective preparation of severely calcified lesions can help maximize the benefits of PCI by attaining maximal luminal gain (or stent expansion) and improve long-term outcomes (by reducing need for revascularization). Areas covered: In this manuscript, the prevalence, risk factors, and impact of coronary artery calcification on PCI are reviewed. Based on current data and experience, the authors review orbital atherectomy technique and best practices to optimize lesion preparation. Expert Commentary: The coronary OAS is the only device approved for use in the U.S. as a treatment for de novo, severely calcified coronary lesions to facilitate stent delivery. Advantages of the device include its ease of use and a mechanism of action that treats bi-directionally, allowing for continuous blood flow during treatment, minimizing heat damage, slow flow, and subsequent need for revascularization. The OAS technique tips reviewed in this article will help inform interventional cardiologists treating patients with severely calcified lesions.

VA Cooperative Studies Program #571 (DIVA) was designed to evaluate the efficacy of drug-eluting stents (DES) for reducing aortocoronary saphenous vein bypass graft (SVG) failure when compared with bare-metal stents (BMS) in participants undergoing stenting of de novo SVG lesions. Participants undergoing clinically indicated stenting of de novo SVG lesions were randomized in a 1:1 ratio to DES or BMS. Randomization was stratified by presence/absence of diabetes mellitus and the number of target SVG lesions (1 vs ≥2) within each participating site. At sites that did not routinely administer 12-months of dual antiplatelet therapy after SVG stenting participants without acute coronary syndromes received 1 month of open-label clopidogrel, followed by 11 months of clopidogrel for those assigned to DES and 11 months of placebo for those assigned to BMS. The primary endpoint was the 12-month incidence of target-vessel failure (defined as the composite of cardiac death, target-vessel myocardial infarction, or target-vessel revascularization). Secondary endpoints included the incidence of other clinical endpoints and the incremental cost-effectiveness of DES relative to BMS. Due to lower-than-anticipated target-vessel failure rates, target enrollment was increased from 519 to 762. The study had randomized 599 participants when recruitment ended in December 2015. The DIVA trial will provide clarity on the appropriate stent type for de novo SVG lesions.

Dual-antiplatelet therapy (DAPT) is considered mandatory after new-generation drug-eluting coronary stent implantation to reduce ischemic complications such as stent thrombosis, but the need for DAPT makes the timing of elective surgery difficult. Interrupting DAPT places patients at risk for stent thrombosis, and surgery in the setting of DAPT may lead to bleeding. The 2016 American College of Cardiology/American Heart Association guideline recommends delaying elective noncardiac surgery for a minimum 6-month period to reduce ischemic risks after the implantation of a second-generation metallic drug-eluting stent (DES). However, the guideline fails to appropriately stratify surgical patients based on the indication for second-generation metallic DES implantation and other patient characteristics. The Absorb bioresorbable vascular scaffold (Abbott Vascular, Abbott Park, IL), which has a higher propensity for stent thrombosis compared with second-generation metallic DES, also produces DAPT management challenges in patients presenting for elective noncardiac surgery. Due to the novelty of bioresorbable vascular scaffold therapy, there are no guidelines available for the management of patients undergoing elective noncardiac surgery. This review addresses DAPT management in patients undergoing noncardiac surgery less than 12 months after new-generation metallic DES or bioresorbable vascular scaffold implantation and provides further guidance for anesthesiologists who encounter these challenging cases.

OBJECTIVES/OBJECTIVE:We sought to characterize how the perceived risk of early dual antiplatelet therapy (DAPT) discontinuation is incorporated into operator decision-making regarding stent choice, using a simple pre-procedure survey screening for clinical variables that may lead to early DAPT discontinuation. BACKGROUND:Understanding which factors influence operator decision-making regarding stent choice during percutaneous coronary intervention (PCI) could help identify areas for quality improvement. METHODS:We retrospectively identified 1202 patients who underwent PCI from July 2008 to January 2013 at the Durham Veterans Affairs Medical Center. We excluded patients without a complete pre-procedure survey within 14days of PCI, repeat procedures on the same patient and those who received both drug-eluting stents (DES) and bare-metal stents (BMS) or no stent during PCI, leaving 864 patients. The primary outcome was the independent association of "yes" responses to survey items with the odds of DES use during PCI. RESULTS:Of 864 patients, 661 received DES and 203 received BMS. A "yes" response to "planned major surgery or dental work in the next year" (OR 0.20, 95% CI 0.11-0.36, p<0.001), "recent bleeding event or bleeding diathesis" (OR 0.31, 95% CI 0.14-0.68, p=0.003) or "currently taking Coumadin" (OR 0.39, 95% CI 0.19-0.78, p=0.007) was independently associated with lower odds of DES use. CONCLUSIONS:Responses to 3 items on a simple pre-procedure survey screening for clinical variables that may lead to early DAPT discontinuation were independently associated with stent type used during PCI, suggesting the importance of these factors in an operator's stent choice.

BACKGROUND:Considerable variability remains as regards the appropriate and safe length of stay after elective PCI. We performed a survey of interventional cardiologists to identify current views on appropriate and safe length of stay after PCI. METHODS:We created an online survey using the commercially available SurveyMonkey application. This was sent to interventional cardiologists in the US, Canada and the UK with the assistance of the national interventional cardiology societies (SCAI, CAIC/CCS, BCIS/BCS) as well as being made available on the theheart.org website. RESULTS:505 interventional cardiologists responded, of which 237 were practicing in the US. Of those from the US, 52% were not aware of any guidelines for length of stay and 48% reported that their unit did not have a standard practice for length of stay. Same-day discharge after PCI was practiced as routine by 14% of cardiologists in the US versus 32% of cardiologists from Canada (P = 0.003) and 57% (P < 0.0001) from the UK. Amongst respondents, there was significant variation between respondents and divergence from published SCAI guidelines regarding appropriate length of stay for patient specific and procedural related clinical factors. CONCLUSIONS:There is considerable variation in practice patterns regarding length of stay after PCI. Whilst most cardiologists practice overnight observation, a significant minority utilize same-day discharge. There is also lack of familiarity with published guidelines. This variation and knowledge gap confirms an urgent need for updated guidelines and a concerted effort to educate cardiologists on appropriate post-PCI length of stay. © 2017 Wiley Periodicals, Inc.

OBJECTIVE:To compare the efficacies of various post-percutaneous coronary intervenetion (PCI) bivalirudin doses on net adverse clinical events (NACEs) and mortality. BACKGROUND:In primary PCI, lower risk of bleeding with bivalirudin (vs. unfractionated heparin [UFH]) is counterbalanced by an increased risk of acute stent thrombosis (ST). Several randomized clinical trials (RCTs) and a recent meta-analysis suggest that acute ST risk may be eliminated without compromising the bleeding benefit, but only if the full dose, not a low dose, of bivalirudin is continued post-PCI. However, it is not known whether this improved risk leads to lower rates of NACEs and mortality. METHODS:Scientific databases and Web sites were searched for RCTs. Trials were included if study patients were undergoing primary PCI for acute ST-segment elevation myocardial infarction and were randomly assigned to bivalirudin or UFH treatment. The bivalirudin arm was divided based on post-PCI bivalirudin dosage: The Biv-Full group received 1.75 mg/kg/h, the Biv-Low group, 0.25 mg/kg/h, and the Biv-No group, none. RESULTS:Six RCTs involving 16,842 patients were found. In pairwise meta-analysis, bivalirudin improved 30-day all-cause mortality by 35% and cardiac mortality by 32%, but did not yield a NACE rate better than that achieved with UFH. Subgroup analysis showed the Biv-Full group had a 46% lower NACE rate and 47% lower all-cause mortality than UFH. These effects were not seen in the other two groups. Network meta-analysis yielded similar results. At treatment ranking, the Biv-Full group yielded the best treatment efficacy. CONCLUSIONS:In primary PCI, full-dose bivalirudin infusion for 3-4 hr after PCI appeared to improve NACE rates compared to UFH. It also seemed to be the most effective strategy for improving cardiac mortality and all-cause mortality. © 2016 Wiley Periodicals, Inc.

BACKGROUND:Studies showing an advantage of transradial approach (TR) for coronary angiography and intervention (PCI) compared to the transfemoral approach (TF) predominantly included a younger population. Therefore, we conducted a meta-analysis of published studies to determine the efficacy of TR in the elderly population. METHODS AND RESULTS/RESULTS:A comprehensive search identified 16 studies [3 randomized controlled studies, 13 observational] comprising 777,841 elderly patients undergoing PCI. TR was used in 99,201 patients and TF in 678,640 patients. The results from observational studies showed that TR was associated with a lower rate of vascular complications (0.4% vs. 0.8%, OR 0.36, 95% CI 0.30-0.44), stroke (0.3% vs. 0.4%, OR 0.81, 95% CI 0.66-1.0) and death (2.0% vs. 2.2%, OR 0.51, 95% CI 0.41-0.63). RCTs confirmed findings from observational studies for both significant reduction in vascular complications (2.7% vs. 7%, OR 0.37, 95% CI 0.23-0.60) and stroke (0.4% vs. 1.4%, OR 0.31, 95% CI 0.10-0.97) but showed no effect on mortality (3.3% vs. 2.8%, OR 1.20, 95% CI 0.69-2.09). However, among patients with ST elevation myocardial infarction (STEMI), TR was associated with a mortality benefit (5% vs. 7%, OR 0.48, 95% CI 0.25-0.90, p=0.02). Access site crossover rate was higher for TR compared to the TF approach (11% vs. 3%, p=0.0003) but there was no difference in contrast media use, procedure duration, fluoroscopy time and door to balloon time for STEMI. CONCLUSION/CONCLUSIONS:TR for PCI in the elderly is associated with a reduced risk of stroke, lower rate of vascular complications overall and a mortality benefit for patients presenting with STEMI. The access site cross rate for TR is higher compared to TF but remains acceptably low. TR should be the preferred strategy for PCI in the elderly to optimize clinical benefit in this high-risk group.

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.