Citations

AbstractIntroductionReticulated platelet (RP) content is increased in nonvalvular atrial fibrillation (NVAF). The purpose of this study was to determine if platelet content, morphology, and RP proportion are modulated by platelet genes.Methods and resultsExpression of six platelet‐predominate genes impacting platelet formation and release, platelet count, and RP content was assessed in NVAF patients before and 3–4 months after pulmonary veins isolation (PVI) and compared to normal sinus rhythm (NSR) controls. RNA from isolated platelets was reverse‐transcribed assayed against selected genes utilizing real‐time qPCR, and expressed as mean cycle threshold (ΔCt) using beta‐2‐microglobulin as endogenous control. RP content was assessed by flow cytometry. A fourfold lower expression of CFL1 gene coding for nonmuscle cofilin (7.8 ± 0.9 vs. 5.7 ± 1.6, P < 0.001) and twofold lower expression of four other genes were associated with similar platelet counts but fourfold higher (28.7+7.0 vs. 6.7+5.4, P < 0.001) RP content (%) in 97 NVAF cases compared to 51 NSR controls. Three to 4 months after PVI, RP decreased by 28%, while CFL1 gene expression increased over twofold but TUBA4A gene expression decreased almost twofold; NFE2 and MYL6 gene expression remained unchanged.ConclusionsNVAF is associated with notable downregulation of genes directing platelet production and size but increased RP content. PVI impacts the expression of many of these genes, implying a direct relationship between atrial fibrillation and platelet biogenesis.

AbstractPurposeTesticular vein thrombosis (TVT) etiology, recurrence, and survival were compared with lower extremity deep vein thrombosis (DVT) in order to determine whether treatment guidelines for DVT could be applied to TVT.Patients and MethodsAn inception cohort of patients with confirmed TVT (January 1995‐October 2015) was compared to a control group of patients with lower extremity DVT matched by age, gender, and diagnosis date.ResultsThirty‐nine men with TVT were identified; 15 (38%) with isolated TVT. Left testicular vein was affected in 77% patients; there were no cases of bilateral TVT. Cancer was over twofold more common in TVT patients (59% vs 28%, P = .01). Most cancers (78%) involved organs in proximity to the testicular vein. Although TVT patients were less frequently treated with anticoagulants (49% vs 97%, P = .0001), recurrence rates were similar to DVT group (TVT 4.2 vs DVT 1.1 per 100 patient‐years, P = .11). Despite higher cancer prevalence, survival rates were similar between groups (31% vs 28%; P = .34). Major bleeding events were rare (one patient per group).ConclusionsIdentifying TVT should prompt a search for a regional malignancy. Despite the high cancer prevalence and low utilization of anticoagulants, recurrent venous thrombosis and mortality rates are similar to DVT patients.

AbstractAimsvon Willebrand factor (VWF) is an independent risk factor for adverse events in patients with non‐valvular atrial fibrillation (NVAF). However, it is unclear if VWF level remains elevated and predictive of stroke during entire course of NVAF.Methods and ResultsIn order to determine if VWF is a time‐dependent blood variable, VWF antigen measured by latex immunoassay in 425 NVAF patients and 100 controls with normal sinus rhythm (NSR) was analyzed according to NVAF duration (<1 month: n = 76, 1‐12 months: n = 98, and >12 months: n = 251). The mean VWF antigen level in NVAF patients with <1‐month duration (167 ± 59%) was not different compared to those with 1‐12 months (157 ± 50%, P = .24) and >12 months duration (156 ± 54%, P = .11) but higher compared to NSR controls (143 ± 48%, P = .003). Higher VWF level correlated with higher CHADS2 scores and with progressing intensity of blood stasis in the left atrium and thrombus formation in all three time periods of atrial fibrillation duration. Patients not treated with warfarin had VWF 30% higher in the first month compared to following months.Conclusionsvon Willebrand Factor is steadily elevated throughout the course of dysrhythmia in NVAF patients treated with warfarin and in those with higher intensity of left atrium blood stasis.

AbstractAimsPlatelets retain cytoplasmic messenger RNA and are capable of protein biosynthesis. Several diseases are known to impact the platelet transcriptome but the effect of non‐valvular atrial fibrillation (NVAF) on platelet RNA transcript is essentially unknown. The aim of this study was to evaluate the impact of NVAF on platelet RNA transcript by measuring platelet genes expression in consecutive NVAF patients before and 3‐4 months after pulmonary vein isolation (PVI) and compared to normal sinus rhythm controls (NSR).Methods and ResultsRNA from isolated platelets were reverse transcribed, assayed against 15 genes using real‐time qPCR, and expressed as mean cycle threshold (ΔCt) using beta‐2‐microglobulin as endogenous control. Expression of all evaluated genes, except cathepsin A gene, was significantly lower (higher ΔCt) in 103 NVAF patients compared to 55 NSR controls. Insulin‐like growth factor binding protein acid labile subunit gene (IGFALS) had expression more than 16 fold‐lower (17.0±2.8 vs 12.5±3.8, P<.001), follow by genes encoding for prostacyclin receptor, and for von Willebrand factor which had fourfold lower expression compared to NSR controls. Gender, type of atrial fibrillation, heart failure, hypertension, prior stroke, diabetes mellitus, and atherosclerosis were associated with different gene expression. Following PVI, expression of four genes significantly increased, particularly IGFALS gene (increased 256‐fold) and ADAMT gene increased 16‐fold); expression of three genes significantly decreased, and expression of eight genes has not changed.ConclusionsPlatelets are capable to respond to the circulatory environment of NVAF by altering transcript and changing prothrombotic status. This shows platelet potential for molecular “reprogramming” possibly induced by flow disturbances of NVAF.

Background: Prophylactic exclusion of the left atrial appendage (LAA) is often performed during cardiac surgery ostensibly to reduce the risk of stroke. However, the clinical impact of LAA closure in humans remains inconclusive. Methods: Of 10 633 adults who underwent coronary artery bypass grafting and valve surgery between January 2000 and December 2005, 9792 patients with complete baseline characteristics, surgery procedure, and follow-up data were included in this analysis. A propensity score–matching analysis based on 28 pretreatment covariates was performed and 461 matching pairs were derived and analyzed to estimate the association of LAA closure with early postoperative atrial fibrillation (POAF) (atrial fibrillation ≤30 days of surgery), ischemic stroke, and mortality. Results: In the propensity-matched cohort, the overall incidence of POAF was 53.9%. In this group, the rate of early POAF among the patients who underwent LAA closure was 68.6% versus 31.9% for those who did not undergo the procedure ( P <0.001). LAA closure was independently associated with an increased risk of early POAF (adjusted odds ratio, 3.88; 95% confidence interval, 2.89–5.20), but did not significantly influence the risk of stroke (adjusted hazard ratio, 1.07; 95% confidence interval, 0.72–1.58) or mortality (adjusted hazard ratio, 0.92; 95% confidence interval, 0.75–1.13). Conclusions: After adjustment for treatment allocation bias, LAA closure during routine cardiac surgery was significantly associated with an increased risk of early POAF, but it did not influence the risk of stroke or mortality. It remains uncertain whether prophylactic exclusion of the LAA is warranted for stroke prevention during non–atrial fibrillation-related cardiac surgery.

Embolic protection devices are occasionally employed during endovascular interventions to prevent complications caused by embolic debris. However, these devices have imperfect efficacy, confer risk of endovascular trauma, and are expensive. We report a patient with giant cell arteritis and symptomatic axillary artery stenosis, with a perceived elevated risk of distal embolization during endovascular intervention. We describe a straightforward embolic protection technique of brachial pressure cuff inflation during endovascular intervention and aspiration of displaced thrombotic material from the static column of blood. This novel, effective, and cost-free technique could also be employed in other vascular beds during endovascular intervention.