COVID-Inflicted Coagulopathy: Expert Consensus on Management with Novel Oral Anticoagulants in India.

Coronavirus disease 2019 (COVID-19) is a highly hypercoagulable viral infection complicated as COVID-inflicted coagulopathy (CIC), that is associated with increased risk of morbidity and mortality. International guidelines recommend low molecular weight heparin (LMWH) to treat CIC in both in-hospital and in-home settings. However, in India, using subcutaneous LMWH may not be a feasible option for a vast majority of patients under home management. Additionally, while some evidence advocates the use of novel oral anticoagulants (NOACs), in hospitalized settings, most guidelines find no role of NOACs in hospital settings. On the other hand, the resource crunch faced in recent COVID-19 pandemic in India forced physicians to treat many patients in home settings. These patients had been usually prescribed NOACs for ease of administration and adherence. Therefore, there is a need to form a consensus on the use of NOACs to manage CIC in India.

Preclinical evaluation of a novel polyphosphazene surface modified stent.

BACKGROUND: Treatment options for patients with coronary artery disease at high risk for bleeding complications are limited. The aim of the current preclinical study was to evaluate neointimal coverage, endothelial recovery, inflammation and thrombogenicity in a novel thin-strut (71µm thickness) Cobalt Chromium (CoCr) stent modified with a nano-thin Polyzene®-F (PzF) surface coating. METHODS AND RESULTS: Twenty-eight single PzF nano-coated stents and 20 bare metal control stents (BMS) were implanted in the coronary arteries of 24 pigs, with scheduled 5- (n=5), 28- (n=13), and 90-day (n=6) follow-up in addition to overlapping configuration (n=6 each), examined at 28-days. Histomorphometric analysis showed significantly lower neointimal thickness in PzF nano-coated stents than BMS controls at both 28- and 90-days (p=0.023 and 0.005) and reduced inflammation (p=0.06 and 0.13). Endothelial coverage over luminal surfaces at all time points was similar between nano-coated stents and BMS controls. We conducted supplementary in-vitro experiments using human monocytes and an ex-vivo swine carotid-jugular arterio-venous shunt model to better understand the healing properties afforded by the PzF nano-coating. Overall, the PzF-nano-coating showed reduced monocyte adhesion and thrombus formation compared to the un-coated controls. CONCLUSIONS: Stents modified with a nano-thin PzF-coating implanted in healthy swine indicate favorable vascular healing properties shown by reduced neointimal hyperplasia and inflammation, along with resistance to thrombus formation in an ex-vivo shunt model over unmodified stents.

A clinical risk score for the prediction of very late stent thrombosis in drug eluting stent patients.

AIMS: Very late stent thrombosis (VLST; >1 year) is an infrequent but potentially serious complication, whose risk factors have not been fully elucidated. This investigation sought to develop a clinically useful risk stratification score for VLST following drug eluting stent (DES) placement. METHODS AND RESULTS: A Cox proportional hazards multivariate model of VLST was developed based on follow-up into a second year of patients enrolled in the ARRIVE registries, utilising readily available baseline clinical and angiographic characteristics. ST predictors between one and two years were identified among 7,459 consecutively enrolled patients who received a TAXUS® Express2™ (Boston Scientific, Natick, MA, USA) DES. Six significant predictors were found: presence of renal disease, prior myocardial infarction, multiple stenting, bifurcation lesions, prior CABG, and smoking at baseline. Each predictor was assigned a score, then summed for a maximum possible score of 10. Stratification into low and high risk groups revealed that VLST developed in 0.5% of 6,759 patients with scores<5, and 2.6% of 700 patients with scores≥5. CONCLUSIONS: We defined a VLST risk score for patients during the second year post DES-placement that provides a useful tool for risk stratification.

One-year outcomes from the TAXUS express stent versus cypher stent.

We compared 1-year outcomes in patients treated with paclitaxel-eluting stents (PESs) or sirolimus-eluting stents (SESs) in "real-world" clinical practice. Clinical outcomes were evaluated in 1,558 consecutive, unselected, retrospectively collected patients treated with drug-eluting stents (DESs; PES = 816, SES = 742) at 19 United States centers. The primary end point was 1-year target vessel revascularization (TVR). The study included a prespecified diabetic cohort (PES = 289, SES = 247), for which efficacy comparisons between DESs were analyzed according to vessel diameter and presence of chronic kidney disease. Baseline demographic, angiographic, and procedural characteristics were similar between patients treated with PESs and those treated with SESs. At 1 year, there were no overall statistical differences in death, myocardial infarction, TVR, or stent thrombosis. In the diabetic cohort, however, the cumulative incidence of TVR was significantly lower for patients treated with PESs (3%) compared with SESs (9%, p <0.01), which persisted after adjustment for baseline differences (hazard ratio 0.29, 95% confidence interval 0.12 to 0.67). This decrease in TVR with PES was similar in insulin- and noninsulin-requiring diabetic patients. In multivariate analysis, independent predictors of TVR included diabetes, bifurcation stenting, and overlapping stents; in the diabetic cohort, treatment with SESs was also a multivariate predictor of TVR. In conclusion, in this observational, retrospective analysis of DES-treated patients, PESs and SESs demonstrated similar overall safety and efficacy, but PESs were associated with a significant decrease in 1-year TVR rates in diabetic patients.

A clinical risk score for prediction of stent thrombosis.

The aim was to develop a clinically useful patient risk score predictive for stent thrombosis (ST). Using readily available baseline clinical and angiographic characteristics, a Cox proportional hazards multivariate model was used to identify significant (p <0.10) predictors of ST through 1 year in 2,487 patients receiving a TAXUS Express (Boston Scientific Corp., Natick, Massachusetts) drug-eluting stent (DES) in the ARRIVE 1 registry. Hazard ratios of significant predictors were rounded to an integer value ranging from 2 to 5. These values were summed for a maximum possible score of 24. The model was validated using 1-year data from a similar DES data set (ARRIVE 2, n = 4,820 patients). The 8 significant predictors found were thienopyridine therapy discontinuation before 6 months, insulin-requiring diabetes, smoker at baseline, left main stent placement, multiple stent placement, lesion length >28 mm, moderate to severe lesion calcification, and reference vessel diameter <3 mm. Model discrimination was high, indicated by an area under the receiver-operator characteristic curve of 0.819. Stratification of patients into low-, medium-, and high-risk groups showed that ST developed in 0.8% of patients with a score <6, 3.6% of patients with a score of 7 to 13, and 12.6% of patients with a score >or=14. In conclusion, using 8 readily available clinical and angiographic characteristics, we defined an ST risk score for patients receiving a DES during the first year. Analysis of patients from ARRIVE 1 and 2 showed that most (73%) were in the lowest risk category, with 25% in the moderate risk category. Less than 2% were at highest risk of developing ST.