Faculty Bibliography

BACKGROUND/UNASSIGNED:Randomized trials comparing radial and femoral access report access site crossover rates of 3% to 9% for radial access and 1% to 3% for femoral access. However, contemporary real-world crossover rates are not well characterized. The aim was to evaluate contemporary trends and predictors of vascular access site crossover during percutaneous coronary intervention (PCI). METHODS/UNASSIGNED:We analyzed index PCI procedures recorded in the National Cardiovascular Data Registry CathPCI Registry from 2018 to 2024. Access site crossover was identified using documented access data, with radial-to-femoral crossover inferred when the final successful access site was femoral. Temporal trends and clinical predictors of crossover were examined. Operator experience was assessed using cumulative total and radial PCI volumes from 2011 to 2024 as captured in CathPCI Registry versions 4 and 5. RESULTS/UNASSIGNED:Among 3 861 790 index PCIs, 192 902 (5.0%) involved access site crossover, with a modest increase over time. Radial-to-femoral crossover accounted for 81.2% of crossover events. Factors independently associated with crossover included older age, female sex, higher body mass index, and peripheral vascular disease. Operators with the lowest total PCI volume and the lowest radial PCI volume experienced the highest crossover rates. Notably, operators with low radial PCI volume demonstrated a substantial decline in radial-to-femoral crossover over the study period. CONCLUSIONS/UNASSIGNED:In contemporary clinical practice, access site crossover rates are consistent with those reported in randomized trials. Although crossover occurs more frequently among lower-volume operators, rates decline with increasing operator experience, supporting the presence of a radial access learning curve and improvement in procedural performance over time.

Invasive coronary function testing (CFT) allows comprehensive assessment of the mechanisms of angina with nonobstructive coronary arteries, which can include coronary microvascular dysfunction, coronary vasospasm, endothelial dysfunction, or myocardial bridging. There is significant heterogeneity in approaches to CFT, including in the selection of arterial access site for the procedure. Transradial arterial access is associated with less bleeding and fewer vascular complications, but can be challenging in patients with chest pain and nonobstructive coronary arteries, as they are disproportionately of female sex, with higher risks of radial spasm and crossover. Radial vasodilators for radial spasm prophylaxis may lower the diagnostic yield of CFT. In this review, we highlight strategies to ensure diagnostic fidelity while enabling radial-first CFT, including conscious sedation, left radial arterial access, atraumatic wire advancement, pressure-mediated vasodilation using a saline "mocktail," selective use of short-acting arterial vasodilators when needed, mother-and-daughter catheter advancement, balloon-assisted tracking techniques, and the use of long hydrophilic sheaths. A pragmatic approach to radial vasodilators is reasonable when CFT is performed ad hoc, whereas withholding prophylactic radial vasodilators is preferred in patients electively referred for definitive CFT. Although the access site should be selected based on anatomic considerations and patient preference, a cocktail-free radial-first strategy is feasible for most patients undergoing CFT.

BACKGROUND:Coronary microvascular dysfunction (CMD) is a mechanism of ischemia with nonobstructive coronary arteries (INOCA) diagnosed by invasive coronary function testing (CFT). It is unknown whether CMD reflects a systemic microcirculatory disorder. Sidestream darkfield (SDF) microscopy permits noninvasive imaging of red blood cells (RBCs) in the sublingual microcirculation. OBJECTIVES/OBJECTIVE:We sought to evaluate whether SDF microscopy identifies sublingual microvascular abnormalities in patients with INOCA due to CMD. METHODS:Adults with INOCA underwent CFT for CMD, defined by abnormal coronary flow reserve <2.5 or index of microcirculatory resistance ≥25. Sublingual SDF microscopy was performed to determine the endothelial glycocalyx perfused boundary region (PBR), RBC filling percentage (%RBC), and perfused microvascular density (PMVD). RESULTS:A total of 135 participants with INOCA (mean age 59.3 ± 12.1 years, 80% female) underwent CFT and sublingual SDF microscopy. CMD was present in 63 participants (46.7%). The median PBR was 1.96 (IQR: 0.4), median %RBC was 72.6 (IQR: 8.0), and median PMVD was 406 (IQR: 141). No differences in sublingual PBR, %RBC, and PMVD were observed by CMD status. No correlations between sublingual parameters and continuous measures of coronary flow reserve or index of microcirculatory resistance were observed. CONCLUSIONS:Noninvasive SDF microscopy did not identify sublingual microvascular abnormalities in INOCA patients with CMD.

BACKGROUND:Myocardial injury after percutaneous coronary intervention (PCI) is common and associated with adverse outcomes. Contemporary definitions of periprocedural myocardial infarction require biomarker elevation with or without ischemic electrocardiographic (ECG) findings. However, the incremental prognostic value of ECG beyond biomarker-defined injury alone remains uncertain. OBJECTIVES/OBJECTIVE:To determine the incidence and independent prognostic value of ischemic ECG changes after elective PCI. METHODS:Consecutive adults age ≥ 18 years undergoing elective PCI at NYU Langone Health between 2011 and 2020 were included. Creatine kinase-myocardial band (CKMB) concentrations were measured at 1 and 3 h post-PCI. Among patients with myocardial injury, baseline and post-PCI ECGs (within 24 h) were reviewed to identify development of ischemic ECG changes (ST segment abnormalities, T wave abnormalities, and Q waves). Relationships between ischemic ECG findings and mortality were evaluated in Cox proportional hazards models adjusted for age, sex, and assay-normalized CKMB. RESULTS:Among 10,735 patients, 1741 (16.2%) developed post-PCI myocardial injury. New ischemic ECG changes occurred in 18.4% of patients with myocardial injury and increased stepwise with higher concentrations of CKMB. New T wave abnormalities were most common (11%), followed by ST depressions (4.9%), Q waves (3.0%), and ST elevations (1.5%). Over a median follow-up of 5.3 years, new ischemic ECG changes were not independently associated with increased mortality among patients with myocardial injury (aHR 1.27, 95% CI 0.82-1.96). CONCLUSIONS:Among patients with myocardial injury after elective PCI, new ischemic ECG changes were uncommon and did not confer independent prognostic value for long-term mortality.

BACKGROUND:Myocardial infarction with non-obstructive coronary arteries (MINOCA) has several underlying causes, including mimicking conditions in some cases. Imaging is recommended to identify MINOCA etiologies, but it remains unclear which patients are most likely to have abnormal findings. We characterized MINOCA mechanisms, analyzed predictors of imaging abnormalities and explored sex differences. METHODS:We enrolled patients with clinical diagnosis of MI in an international, prospective, diagnostic study at 28 sites in US, Canada and UK. After a women-only phase, we included both sexes. Individuals with ≥50% diameter stenosis or coronary dissection on angiography, or alternate causes for the clinical presentation, were excluded. Participants had multi-vessel coronary optical coherence tomography (OCT) during index coronary angiography and cardiac magnetic resonance imaging (CMR) within one week. Independent core laboratories interpreted imaging, blinded to other results. RESULTS:Among 754 patients enrolled, 389 had MINOCA and 336 with MINOCA underwent OCT (270 women and 66 men); CMR was completed in 284 (85%). An OCT-defined culprit lesion was identified in 45% (116/270 women [43% ] and 35/66 men [53%], p=0.18). CMR demonstrated an ischemic pattern in 114/284 (40%), similar by sex (96/225 women [43%] vs. 18/59 men [31%], p=0.12). A non-ischemic pattern was observed in 23% (23% of women, 25% of men, p=0.78). We identified a cause of the clinical presentation in 79% of patients with both tests completed: 59% had an ischemic cause of MINOCA and 20% had a non-ischemic mimicking condition. OCT alone found a MINOCA etiology in 151/336 (45%) and CMR alone in 180/284 (63%). Predictors of an OCT culprit lesion included age, abnormal angiogram, and number of vessels imaged, but 27% of normal angiograms harbored a culprit lesion. Predictors of abnormal CMR were peak troponin, shorter time to CMR, and non-Asian race, but CMR was abnormal in 40% when troponin was <4-fold above the upper reference limit. CONCLUSIONS:The combination of multi-vessel coronary OCT and CMR in patients with a clinical diagnosis of MINOCA confirmed MI in 59% and identified an alternate cause (MINOCA mimic) in 20%. Clinical factors had limited utility to predict imaging abnormalities. No sex differences in imaging results were detected.

BACKGROUND:Modern coronary physiology in the cardiac catheterization laboratory has evolved from a solely wire-based approach to a broader portfolio that now includes coronary computed tomography angiography, angiography-derived physiology, and microcatheter-derived physiology. Limited data exists on real-world practice patterns and perspectives among interventional cardiologists. METHODS:A web-based 76-item international survey was distributed to attending interventional cardiologists via email and social media from April to July 2024. RESULTS:In total, 206 interventional cardiologists completed the survey. Respondents represented diverse global regions, with 55% based in the United States. Most operators performed both percutaneous coronary intervention (PCI) and structural interventions (34%) or only PCI (25%). Nearly all respondents (98%) had access to invasive coronary physiology tools, with non-hyperemic pressure ratios (NHPR) usage being favored over fractional flow reserve (FFR) by operators (60% vs. 40%), particularly in US centers. Pressure-wire pullback was routinely performed by 44% of operators. Angiography-derived FFR was used by 33%, with lack of access being the primary barrier to adoption. Coronary microvascular dysfunction (CMD) evaluation was performed or referred by 39%, primarily using bolus thermodilution (78%) followed by continuous thermodilution in 22%. CONCLUSIONS:This multinational survey demonstrates substantial heterogeneity and marked geographic variation in the use of modern coronary physiology tools. Although important advances have broadened the coronary physiology toolkit, their routine use remains limited and inconsistent. These findings provide valuable insights into how novel modalities are being integrated into practice, including notable geographic differences.

BACKGROUND:Microvascular density and endothelial glycocalyx function may provide insights into early atherosclerosis and cardiovascular disease (CVD) risk. Sublingual sidestream darkfield (SDF) microscopy permits imaging of red blood cells (RBC) to assess the microcirculation. We sought to define reference ranges for SDF microscopy parameters in healthy populations and individuals with coronary artery disease (CAD) and to assess factors correlated with microcirculatory abnormalities. METHODS:Adults with and without CVD risk factors and epicardial CAD underwent SDF microscopy using a CapiScope Handheld Video Capillaroscopy System and Glycocheck analytic software to measure the perfused boundary region (a measure of RBC glycocalyx penetration), percent RBC filling (%RBC, a measure of microvascular perfusion) and microvascular density. RESULTS:<0.0001), though values overlapped substantially; after adjustment for demographics and CVD risk factors, obstructive CAD was not independently associated with sublingual microvascular parameters. CONCLUSIONS:Obstructive CAD was not associated with sublingual microvascular parameters after accounting for demographics and CVD risk factors. The overlap of microvascular parameters in patients with and without CAD limits the clinical utility of SDF microscopy to identify traditional CVD.