Phosphatidylthreonine is a procoagulant lipid detected in human blood and elevated in coronary artery disease.

Aminophospholipids (aPL) such as phosphatidylserine are essential for supporting the activity of coagulation factors, circulating platelets, and blood cells. Phosphatidylthreonine (PT) is an aminophospholipid previously reported in eukaryotic parasites and animal cell cultures, but not yet in human tissues. Here, we evaluated whether PT is present in blood cells and characterized its ability to support coagulation. Several PT molecular species were detected in human blood, washed platelets, extracellular vesicles, and isolated leukocytes from healthy volunteers using liquid chromatography-tandem mass spectrometry. The ability of PT to support coagulation was demonstrated in vitro using biochemical and biophysical assays. In liposomes, PT supported prothrombinase activity in the presence and absence of phosphatidylserine. PT nanodiscs strongly bound FVa and lactadherin (nM affinity) but poorly bound prothrombin and FX, suggesting that PT supports prothrombinase through recruitment of FVa. PT liposomes bearing tissue factor poorly generated thrombin in platelet poor plasma, indicating that PT poorly supports extrinsic tenase activity. On platelet activation, PT is externalized and partially metabolized. Last, PT was significantly higher in platelets and extracellular vesicle from patients with coronary artery disease than in healthy controls. In summary, PT is present in human blood, binds FVa and lactadherin, supports coagulation in vitro through FVa binding, and is elevated in atherosclerotic vascular disease. Our studies reveal a new phospholipid subclass, that contributes to the procoagulant membrane, and may support thrombosis in patients at elevated risk.

Iatrogenic Radial Recurrent Artery Perforation in Coronary Intervention.

An 80-year-old man underwent percutaneous coronary intervention of the left anterior descending coronary artery for intractable angina. During catheter advancement, he experienced an iatrogenic perforation of the radial recurrent artery that was successfully managed by covered stent placement in the radial artery, effectively occluding the radial recurrent branch. (Level of Difficulty: Intermediate.).

Post-Procedural Bivalirudin Infusion Following Primary PCI to Reduce Stent Thrombosis.

BACKGROUND: Prolonging infusions may abrogate the acute stent thrombosis (ST) associated with bivalirudin use during primary PCI but at an increased cost. We hypothesized that continuing the bivalirudin infusion commenced during the procedure at the PCI recommended dose until infusion end would prevent excess early ST. METHODS: Baseline demographics, procedural data and outcomes were gathered prospectively on 1395 consecutive patients undergoing primary PCI. The choice of bivalirudin versus heparin was at the cardiologist's discretion. Local protocol recommended continuation of the procedural bivalirudin at the PCI dose until infusion end. RESULTS: Patients' mean age was 62.8 ± 13.1years with 11.4% presenting with shock. The majority of patients underwent PCI using bivalirudin with fewer using heparin (87.7 vs. 12.3%, P < 0.0001). Glycoprotein inhibitor bailout rates were 6.1% with bivalirudin and 36.3% with heparin (P < 0.0001). Calculated on an individual patient basis the median intra-procedure duration of the bivalirudin infusion was 30(IQR 21-43) minutes and post-procedure 49(32-66) minutes. The acute (<24-hours) ST rates were 4/1224 with bivalirudin ± GPI (0.3%) and 0/171 with heparin ± GPI (0%, P = 0.41). The sub-acute (24-hours to 30-days) ST rates were 3/1224 for bivalirudin ± GPI (0.3%) and 2/171 with heparin ± GPI (1.2%, P = 0.11). In total the early (<30-days) ST rates were 7/1224 for bivalirudin ± GPI (0.6%) and 2/171 with heparin ± GPI (1.2%, P = 0.31). Acute ST was significantly more likely to occur in clopidogrel-loaded patients than prasugrel/ticagrelor patients (2.7 vs. 0.5%, P = 0.003). CONCLUSION: Continuing the bivalirudin infusion commenced during the procedure at the PCI recommended dose until infusion end combined with potent P2 Y12 inhibitors ameliorates excess early stent thrombosis.

Rotational Atherectomy in a Dissected Coronary Artery That Propagated Into the Sinus of Valsalva: Is This the Last Hope?

Percutaneous coronary intervention (PCI) of a resistant, undilatable lesion can result in coronary dissection. Retrograde propagation of a dissection flap into the sinus of Valsalva is a rare phenomenon. It is commonly seen at the time of PCI to a right coronary artery (RCA) and is associated with potentially fatal consequences. Use of rotational atherectomy (RA) is contraindicated in the presence of a coronary dissection. Coronary dissection with preserved flow in asymptomatic patients should be managed conservatively until the dissection heals, but in the case presented here, as coronary flow was compromised, the patient complained of chest pain and ST elevation was observed on electrocardiogram.

Femoral Access PCI in a Default Radial Center Identifies High-Risk Patients With Poor Outcomes.

BACKGROUND: Increasingly the trans-radial route (TRR) is preferred over the trans-femoral route (TFR) for PCI. However, even in high volume default TRR centers a cohort of patients undergo TFR PCI. We examined the demographics, procedural characteristics, and outcomes of patients undergoing PCI via the TF. METHODS: The patient demographics, procedural data, and outcomes of 5,379 consecutive patients undergoing PCI at a default radial center between 2009 and 2012 were examined. Major bleeding (MB) was classified by ACUITY and BARC definitions. RESULTS: A total of 559 (10.4%) patients underwent PCI via the TFR and 4,820 patients via the TRR (89.6%). Baseline variables associated with TFR were shock, previous CABG, chronic total occlusion intervention, rotablation/laser use, female sex, and renal failure. Sixty-five patients of the TFR cohort (11.6%) experienced MB with 27 (41.5%) being access site related. MB was significantly more frequent than in the radial cohort. The variables independently associated with MB in the TFR cohort were renal failure, acute presentation, shock, and age. In the TFR, patients with MB mortality was high at 30 days (17.2% vs 2.6% for no MB, P < 0.0001) and at 1 year (37.6% vs 5.0%, P < 0.0001). Shock and MB were highly predictive of 30 day and 12 month mortality. CONCLUSION: In a default radial PCI center 10% of patients undergo PCI via the femoral artery. These patients have high baseline bleeding risk and undergo complex interventions. As a result the incidence of major bleeding, transfusion and death are high. Alternative strategies are required to optimize outcomes in this select group.

Interaction between access choice and pharmacotherapy for coronary intervention: the results of a UK survey.

INTRODUCTION: Percutaneous coronary intervention (PCI) has changed significantly over the past decade with the uptake of radial access and the development of newer and more potent antiplatelets and safer antithrombins. This survey examined the default access route and pharmacology choice and their interaction in UK interventional practice. METHODS: An email-based survey invited interventional cardiologists to answer questions regarding arterial access and pharmacology use during PCI. Respondents were categorised into femoral, radial and radial(+) (if the other radial was used rather than femoral if the right radial attempt failed). Data were analysed using χ(2) or the Student t test. RESULTS: 81% of the 204 respondents reported the radial artery as their default access site with a significant interaction between years since qualification and access choice (21.1 years for radial(+) vs 23 years for radial (p=0.027) vs 26.6 years for femoral (p=0.013) vs radial (p=0.0005) vs radial(+)). There were 19 different combinations of access and pharmacology reported. For non-ST elevation myocardial infarction PCI, there was a significant trend for radial(+) and radial operators to favour ticagrelor or tailored therapy versus femoral operators (54.8% vs 47.8% vs 35%, respectively, p=0.018). For primary PCI (PPCI), radial(+) and radial operators were much more likely to choose ticagrelor or prasugrel than femoral operators (77.2% (p<0.001) vs 73.9% (p=0.023) vs 50%, respectively (p<0.0001) for trend). For PPCI, glycoprotein inhibitor use was similar between groups (26.1% vs 25%, not significant); radial operators were much more likely to choose bivalirudin (52.8% vs 10%, p<0.0001) and much less likely to use heparin only (19.8% vs 65%, p<0.0001) than femoral operators. CONCLUSIONS: There is a significant interaction between years since qualification and access choice. Although there is no established consensus on access site or drugs, default radial operators are significantly more likely to utilise new generation antiplatelets and bivalirudin than femoral operators.