Statin treatment for primary and secondary prevention in elderly patients-a cross-sectional study in Stockholm, Sweden.

BACKGROUND: Age is a major risk factor for atherosclerotic cardiovascular disease (CVD) and death, but there has been a debate about benefit-risk of statin treatment in the elderly with limited evidence on benefits for primary prevention, while there is strong evidence for its use in secondary prevention. AIM: The aim of this study was to provide an overview of statin utilization in primary and secondary prevention for patients 75-84 years and ≥ 85 years in the Swedish capital Region Stockholm in 2019. METHODS: This is a cross-sectional study based on the regional healthcare database VAL containing all diagnoses and dispensed prescription drugs for all 174,950 inhabitants ≥ 75 years old in the Stockholm Region. Prevalence and incidence were analyzed by sex, age, cardiovascular risk, substance, and the intensity of treatment. RESULTS: A total of 35% of all individuals above the age of 75 in the region were treated with statins in 2019. The overall incidence in this age group was 31 patients per 1000 inhabitants. Men, individuals 75-84 compared to ≥ 85 years of age, and those with higher cardiovascular risk were treated to a greater extent. Simvastatin was used primarily by prevalent users and atorvastatin by incident users. The majority was treated with moderate-intensity dosages and fewer women received high intensity treatment. CONCLUSIONS: Statins are widely prescribed in the elderly. Physicians seem to consider individual cardiovascular risk when deciding to initiate statin treatment for elderly patients, but here may still be some undertreatment among high-risk patients (especially women and elderly 85 + years) and some overtreatment among patients with low-risk for CVD.

Trends in statin utilization and ischemic heart disease mortality in Lithuania and Sweden, 2000-2020.

Aims: To compare statin utilization and ischemic heart disease (IHD) mortality trends in Lithuania and Sweden and to assess correlations between the total utilization of statins and IHD mortality. Methods: An ecological study assessing time trends in statin utilization (DDDs per 1000 inhabitants per day; DDD/TID) and IHD mortality in Lithuania and Sweden between 2000 and 2020. Statin utilization data in Lithuania were wholesale trade data, and Swedish data were drugs dispensed at pharmacies. IHD mortality data were extracted from national databases as rates per 100 000 inhabitants. Associations between statin utilization and IHD mortality in Lithuania and Sweden were examined using Spearman's rank and Pearson's correlation coefficients, respectively. Results: Statin utilization increased from 16.8 to 135.8 DDD/TID in Sweden and from 0.2 to 61.8 DDD/TID in Lithuania between 2000 and 2020. Medium intensity was the most common statin dosage in Lithuania, while Sweden used more high intensity than moderate-intensity statins from 2017. IHD mortality in Lithuania remained high between 2000 and 2020 (from 359.1 to 508.8 deaths per 100 000 population), while it decreased markedly in Sweden (from 226.87 to 88.7 deaths per 100 000 population). IHD mortality and statin utilization were inversely correlated in Sweden (r = -0.993, P < 0.001), while a positive correlation was found in Lithuania (rs = 0.871, P < 0.001). Conclusion: Despite the growing statin utilization in both countries, Lithuania recorded a slight increase in IHD mortality rates unlike the situation in Sweden. This indicates room for improvement in the management of modifiable cardiovascular risk factors in Lithuania including how statins are prescribed and used in clinical practice.

Intensity of and adherence to lipid-lowering therapy as predictors of goal attainment and major adverse cardiovascular events in primary prevention.

BACKGROUND: The effectiveness of lipid-lowering therapy (LLT) for primary prevention of atherosclerotic cardiovascular disease (ASCVD) in routine care may depend on treatment intensity and adherence. METHODS: Observational study of adults with newly initiated LLT for primary prevention of ASCVD in Stockholm, Sweden, during 2017-2021. Study exposures were LLT adherence [proportion of days covered (PDC)], LLT intensity (expected reduction of LDL cholesterol), and the combined measure of adherence and intensity. At each LLT fill, adherence and intensity were calculated during the previous 12 months, and the patients estimated ASCVD risk was categorized. Study outcomes were major adverse cardiovascular events (MACE) and LDL-C goal attainment. RESULTS: Thirty-six thousand two hundred eighty-three individuals (mean age 63 years, 47% women, median follow-up 2 years), with a baseline low-moderate (40%), high (49%), and very-high (11%) ASCVD risk started LLT. Increases in LLT adherence, intensity, or adherence-adjusted intensity of 10% over 1 year were associated with lower risks of MACE (with hazard ratios of 0.95 [95% CI, 0.93-0.98]; 0.93 [0.86-1.00]; and 0.90 [0.85-0.95], respectively) and higher odds of attaining LDL goals. Patients with good adherence (≥80%) had similar risks of MACE and similar odds ratios for LDL-C goal attainment with low-moderate and high-intensity LLT. Treatment discontinuation was associated with increased MACE risk. The relative and absolute benefits of good adherence were greatest in patients with very high ASCVD risk. CONCLUSION: In routine-care primary prevention, better adherence to LLT was associated with a lower risk of MACE across all treatment intensities. Improving adherence is especially important among patients with very high ASCVD risk.

Cardiorenal Outcomes Among Patients With Atrial Fibrillation Treated With Oral Anticoagulants.

RATIONALE & OBJECTIVE: Direct oral anticoagulants (DOACs) have progressively replaced vitamin K antagonists (VKAs) for stroke prevention in patients with nonvalvular atrial fibrillation (AF). DOACs cause fewer bleeding complications, but their other advantages, particularly related to kidney outcomes, remain inconclusive. We studied the risks of chronic kidney disease (CKD) progression and acute kidney injury (AKI) after DOAC and VKA administration for nonvalvular AF. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Cohort study of Swedish patients enrolled in the Stockholm Creatinine Measurements (SCREAM) project with a diagnosis of nonvalvular AF during 2011-2018. EXPOSURE: Initiation of DOAC or VKA treatment. OUTCOME: Primary outcomes were CKD progression (composite of >30% estimated glomerular filtration rate [eGFR] decline and kidney failure) and AKI (by diagnosis or KDIGO-defined transient creatinine elevations). Secondary outcomes were death, major bleeding, and the composite of stroke and systemic embolism. ANALYTICAL APPROACH: Propensity score weighted Cox regression was used to balance 50 baseline confounders. Sensitivity analyses included falsification end points, subgroups, and estimation of per-protocol effects. RESULTS: We included 32,699 patients (56% initiated DOAC) who were observed for a median of 3.8 years. Their median age was 75 years, 45% were women, and 27% had an eGFR <60mL/min/1.73m2. The adjusted HRs for DOAC versus VKA were 0.87 (95% CI, 0.78-0.98) for the risk of CKD progression and 0.88 (95% CI, 0.80-0.97) for AKI. HRs were 0.77 (95% CI, 0.67-0.89) for major bleeding, 0.93 (95% CI, 0.78-1.11) for the composite of stroke and systemic embolism, and 1.04 (95% CI, 0.95-1.14) for death. The results were similar across subgroups of age, sex, and baseline eGFR when restricting to patients at high risk for thromboembolic events and when censoring follow up at treatment discontinuation or change in type of anticoagulation. LIMITATIONS: Missing information on time in therapeutic range and treatment dosages. CONCLUSIONS: Among patients with nonvalvular AF treated in routine clinical practice compared with VKA use, DOAC use was associated with a lower risk of CKD progression, AKI, and major bleeding but a similar risk of the composite of stroke, systemic embolism, or death.

Intensity of and Adherence to Lipid-Lowering Therapy as Predictors of Major Adverse Cardiovascular Outcomes in Patients With Coronary Heart Disease.

Background The effectiveness of lipid-lowering therapy (LLT) is affected by both intensity and adherence. This study evaluated the associations of LLT intensity, adherence, and the combination of these 2 aspects of LLT management with the risk of major adverse cardiovascular events (MACE) in people with coronary heart disease. Methods and Results This is an observational study of all adults who suffered a myocardial infarction or had coronary revascularization during 2012 to 2018 and initiated LLT in Stockholm, Sweden. Study exposures were LLT adherence (proportion of days covered), LLT intensity (expected reduction of low-density lipoprotein cholesterol), and the combined measure of adherence and intensity. At each LLT fill, adherence and intensity during the previous 12 months were calculated. The primary outcomes were MACE (nonfatal myocardial infarction or stroke and death); secondary outcomes were low-density lipoprotein cholesterol goal attainment and individual components of MACE. We studied 20 490 patients aged 68±11 years, 75% men, mean follow-up 2.6±1.1 years. Every 10% increase in 1-year adherence, intensity, or adherence-adjusted intensity was associated with a lower risk of MACE (hazard ratio [HR], 0.94 [95% CI, 0.93-0.96]; HR, 0.92 [95% CI, 0.88-0.96]; and HR, 0.91 [95% CI, 0.89-0.94], respectively) and higher odds of attaining low-density lipoprotein cholesterol goals (odds ratio [OR],1.12 [95% CI, 1.10-1.15]; OR, 1.42 [95% CI, 1.34-1.51], and OR, 1.16 [95% CI, 1.19-1.24], respectively). Among patients with good adherence (≥80%), the risk of MACE was similar with low-moderate and high-intensity LLT despite differences in the low-density lipoprotein cholesterol goal attainment with the treatment intensities. Discontinuation ≥1 year increased the risk markedly (HR,1.66 [95% CI, 1.23-2.22]). Conclusions In routine care, good adherence to LLT was associated with the greatest benefit for patients with coronary heart disease. Strategies that improve adherence and use of intensive therapies could substantially reduce cardiovascular risk.

Lipid-lowering treatment intensity, persistence, adherence and goal attainment in patients with coronary heart disease.

BACKGROUND: To examine patterns of lipid-lowering therapy (LLT) use, and persistence and adherence among patients with coronary heart disease and their associations with lipoprotein cholesterol (LDL-C) goal attainment. METHODS: Observational study among 26,768 patients who had suffered a myocardial infarction or had been revascularized in Stockholm during 2012 to 2018, and followed up through 2019. Outcomes included initiation of LLT, discontinuation, re-initiation, adherence to treatment and LDL-C goal attainment according to the European dyslipidaemia guidelines from 2011 and 2016 (mainly LDL-C <1.8 mmol/L). RESULTS: 82% of patients commenced or continued LLT within 90 days after discharge. Of those, 71% were dispensed an LLT prescription within 30 days (62% of them for high-intensity LLT). High-intensity LLT prescribing increased over time, from 12% in 2012 to 78% in 2018. During a median follow-up of 3 (IQR 2-5) years 73% continued to fill prescriptions for a statin, 26.3% temporarily or permanently discontinued, and 0.5% changed to non-statin LLT. Only 1.3% discontinued statin treatment permanently. Throughout observation, about 80% of patients showed good statin adherence (proportion of days covered ≥80%). LDL-C target attainment was 52% the first year and <50% during subsequent years. LDL-C goal attainment was highest among patients receiving high-intensity statin treatment and showing good treatment adherence. CONCLUSION: In secondary prevention for patients with established coronary heart disease, the proportion of LDL-C target attainment was low throughout the time period of the study, despite increasing use of high-intensity LLT and good treatment persistence and adherence.

Lessons from 20 years with COX-2 inhibitors: Importance of dose-response considerations and fair play in comparative trials.

Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit the enzyme cyclooxygenase (COX), which forms prostaglandins involved in pain and inflammation. COX inhibitors have analgesic and anti-inflammatory effects, but also increase risks for gastrointestinal ulcers, bleeding, and renal and cardiovascular adverse events. Identification of two isoforms of COX, COX-1 and COX-2, led to the development of selective COX-2 inhibitors, which were launched as having fewer gastrointestinal side effects since gastroprotective prostaglandins produced via COX-1 are spared. The balance between COX-1 mediated prothrombotic thromboxane and COX-2 mediated antithrombotic prostacyclin is important for thrombotic risk. An increased risk of suffering myocardial infarction and death with COX-2 inhibitor treatment is well established from clinical trials and observational research. Rofecoxib (Vioxx) was withdrawn from the market for this reason, but the equally COX-2 selective etoricoxib has replaced it in Europe but not in the United States. The "traditional" NSAID diclofenac is as COX-2 selective as celecoxib and increases cardiovascular risk dose dependently. COX inhibitor dosages should be lower in osteoarthritis than in rheumatoid arthritis. Randomized trials comparing COX-2 inhibitors with NSAIDs have exaggerated their gastrointestinal benefits by using maximal NSAID doses regardless of indication, and/or hidden the cardiovascular risk by comparing with COX-2 selective diclofenac instead of low-dose ibuprofen or naproxen. Observational studies show increased cardiovascular risks within weeks of treatment with COX-2 inhibitors and high doses of NSAIDs other than naproxen, which is the safest alternative. COX inhibitors are symptomatic drugs that should be used intermittently at the lowest effective dosage, especially among individuals with an increased cardiovascular risk.

Oral anticoagulants in patients with atrial fibrillation at low stroke risk: a multicentre observational study.

AIMS: There is currently no consensus on whether atrial fibrillation (AF) patients at low risk for stroke (one non-sex-related CHA2DS2-VASc point) should be treated with an oral anticoagulant. METHODS AND RESULTS: We conducted a multi-country cohort study in Sweden, Denmark, Norway, and Scotland. In total, 59 076 patients diagnosed with AF at low stroke risk were included. We assessed the rates of stroke or major bleeding during treatment with a non-vitamin K antagonist oral anticoagulant (NOAC), a vitamin K antagonist (VKA), or no treatment, using inverse probability of treatment weighted (IPTW) Cox regression. In untreated patients, the rate for ischaemic stroke was 0.70 per 100 person-years and the rate for a bleed was also 0.70 per 100 person-years. Comparing NOAC with no treatment, the stroke rate was lower [hazard ratio (HR) 0.72; 95% confidence interval (CI) 0.56-0.94], and the rate for intracranial haemorrhage (ICH) was not increased (HR 0.84; 95% CI 0.54-1.30). Comparing VKA with no treatment, the rate for stroke tended to be lower (HR 0.81; 95% CI 0.59-1.09), and the rate for ICH tended to be higher during VKA treatment (HR 1.37; 95% CI 0.88-2.14). Comparing NOAC with VKA treatment, the rate for stroke was similar (HR 0.92; 95% CI 0.70-1.22), but the rate for ICH was lower during NOAC treatment (HR 0.63; 95% CI 0.42-0.94). CONCLUSION: These observational data suggest that NOAC treatment may be associated with a positive net clinical benefit compared with no treatment or VKA treatment in patients at low stroke risk, a question that can be tested through a randomized controlled trial.

Non-vitamin K antagonist oral anticoagulants, proton pump inhibitors and gastrointestinal bleeds.

OBJECTIVE: To evaluate if proton pump inhibitor (PPI) treatment reduces the risk of upper gastrointestinal bleeding (UGIB) in patients with atrial fibrillation (AF) treated with non-vitamin K antagonist oral anticoagulants (NOACs). DESIGN: We used a common protocol, common data model approach to conduct a cohort study including patients with AF initiated on a NOAC in Stockholm, Denmark and the Netherlands from April 2011 until July 2018. The outcome of interest was a UGIB diagnosed in a secondary care inpatient setting. We used an inverse probability weighted (IPW) Poisson regression to calculate incidence rate ratios (IRRs), contrasting PPI use to no PPI use periods. RESULTS: In 164 290 NOAC users with AF, providing 272 570 years of follow-up and 39 938 years of PPI exposure, 806 patients suffered a UGIB. After IPW, PPI use was associated with lower UGIB rates (IRR: 0.75; 95% CI: 0.59 to 0.95). On an absolute scale, the protective effect was modest, and was found to be largest in high-risk patients, classified as age 75-84 years (number needed to treat for 1 year (NNTY): 787), age ≥85 years (NNTY: 667), HAS-BLED score ≥3 (NNTY: 378) or on concomitant antiplatelet therapy (NNTY: 373). CONCLUSION: Concomitant treatment with a PPI in NOAC-treated patients with AF is associated with a reduced risk of severe UGIB. This indicates that PPI cotreatment can be considered, in particular among the elderly patients, patients with a HAS-BLED score ≥3, and/or in patients on concomitant antiplatelet therapy.

Persistence and adherence to non-vitamin K antagonist oral anticoagulant treatment in patients with atrial fibrillation across five Western European countries.

AIMS: To assess persistence and adherence to non-vitamin K antagonist oral anticoagulant (NOAC) treatment in patients with atrial fibrillation (AF) in five Western European healthcare settings. METHODS AND RESULTS: We conducted a multi-country observational cohort study, including 559 445 AF patients initiating NOAC therapy from Stockholm (Sweden), Denmark, Scotland, Norway, and Germany between 2011 and 2018. Patients were followed from their first prescription until they switched to a vitamin K antagonist, emigrated, died, or the end of follow-up. We measured persistence and adherence over time and defined adequate adherence as medication possession rate ≥90% among persistent patients only. RESULTS: Overall, persistence declined to 82% after 1 year and to 63% after 5 years. When including restarters of NOAC treatment, 85% of the patients were treated with NOACs after 5 years. The proportion of patients with adequate adherence remained above 80% throughout follow-up. Persistence and adherence were similar between countries and was higher in patients starting treatment in later years. Both first year persistence and adherence were lower with dabigatran (persistence: 77%, adherence: 65%) compared with apixaban (86% and 75%) and rivaroxaban (83% and 75%) and were statistically lower after adjusting for patient characteristics. Adherence and persistence with dabigatran remained lower throughout follow-up. CONCLUSION: Persistence and adherence were high among NOAC users in five Western European healthcare settings and increased in later years. Dabigatran use was associated with slightly lower persistence and adherence compared with apixaban and rivaroxaban.

Association of preceding antithrombotic therapy in atrial fibrillation patients with ischaemic stroke, intracranial haemorrhage, or gastrointestinal bleed and mortality.

AIMS: To analyse 90-day mortality in atrial fibrillation (AF) patients after a stroke or a severe bleed and assess associations with the type of antithrombotic treatment at the event. METHODS AND RESULTS: From the Stockholm Healthcare database, we selected 6017 patients with a known history of AF who were diagnosed with ischaemic stroke, 3006 with intracranial haemorrhage, and 4291 with a severe gastrointestinal bleed (GIB). The 90-day mortality rates were 25.1% after ischaemic stroke, 31.6% after intracranial haemorrhage, and 16.2% after severe GIB. We used Cox regression and propensity score-matched analyses to test the association between antithrombotic treatment at the event and 90-day mortality. After intracranial haemorrhage, there was a significantly higher mortality rate in warfarin compared to non-vitamin K oral anticoagulant (NOAC)-treated patients [adjusted hazard ratio (aHR) 1.36, 95% confidence interval (CI) 1.04-1.78]. After an ischaemic stroke and a severe GIB, patients receiving antiplatelets or no antithrombotic treatment had significantly higher mortality rates compared to patients on NOACs, but there was no difference comparing warfarin to NOACs (aHR 0.84, CI 0.63-1.12 after ischaemic stroke, aHR 0.91, CI 0.66-1.25 after severe GIB). Propensity score-matched analysis yielded similar results. CONCLUSION: Mortality rates were high in AF patients suffering from an ischaemic stroke, an intracranial haemorrhage, or a severe GIB. NOAC treatment was associated with a lower 90-day mortality after intracranial haemorrhage than warfarin.

Long-term persistence and adherence with non-vitamin K oral anticoagulants in patients with atrial fibrillation and their associations with stroke risk.

AIMS: Studies on adherence and persistence with non-vitamin K oral anticoagulant (NOAC) treatment have relied on data from the early years of NOAC availability. We aimed to study long-term adherence and persistence with NOACs and their association with stroke risk. METHODS AND RESULTS: From the Stockholm Healthcare database, we included 21 028 atrial fibrillation patients claiming a first NOAC prescription from July 2011 until October 2018, with more than 1000 patients having more than 5 years of follow-up (median: 2.0, interquartile range: 1.0-3.2). Persistence rates, defined as continuing to claim NOAC prescriptions within a 90-day gap, decreased to 70% at the end of follow-up. However, 85% of the patients were treated at the end of the study due to reinitiations. Adherence, calculated as medication possession rate (MPR) in 3 and 6-month intervals among persistent users, remained stable at 90%, with 75% of patients having an MPR >95% throughout the study period. Using a case-control design, we calculated associations of persistence and adherence with stroke risk, adjusting for potential confounders. The outcome was a composite of ischaemic or unspecified stroke and transient ischaemic attack. Non-persistence and poor adherence were both associated with increased stroke risk [non-persistence adjusted odds ratio (aOR): 2.05; 95% confidence interval (CI): 1.49-2.82, 1% reduction MPR aOR: 1.03; CI: 1.01-1.05]. There was no association between non-persistence or poor adherence and the falsification endpoints; fractions and respiratory infections, indicating no 'healthy-adherer' effect. CONCLUSION: Persistence rates decreased slowly over time, but persistent patients had high adherence rates. Both non-persistence and poor adherence were associated with an increased stroke risk.

Guiding principles for the use of knowledge bases and real-world data in clinical decision support systems: report by an international expert workshop at Karolinska Institutet.

INTRODUCTION: Technical and logical breakthroughs have provided new opportunities in medicine to use knowledge bases and large-scale clinical data (real-world) at point-of-care as part of a learning healthcare system to diminish the knowledge-practice gap. AREAS COVERED: The article is based on presentations, discussions and recommendations from an international scientific workshop. Value, research needs and funding avenues of knowledge bases and access to real-world data as well as transparency and incorporation of patient perspectives are discussed. EXPERT OPINION: Evidence-based, publicly funded, well-structured and curated knowledge bases are of global importance. They ought to be considered as a public responsibility requiring transparency and handling of conflicts of interest. Information has to be made accessible for clinical decision support systems (CDSS) for healthcare staff and patients. Access to rich and real-world data is essential for a learning health care ecosystem and can be augmented by data on patient-reported outcomes and preferences. This field can progress by the establishment of an international policy group for developing a best practice guideline on the development, maintenance, governance, evaluation principles and financing of open-source knowledge bases and handling of real-world data.

Concomitant Anticoagulant and Antidepressant Therapy in Atrial Fibrillation Patients and Risk of Stroke and Bleeding.

We aimed to quantify the effects of antidepressant (AD) use in oral anticoagulant (OAC)-treated patients with atrial fibrillation (AF). Using the Stockholm Healthcare database, we analyzed AF patients initiated with an OAC. Outcomes were severe bleeds and strokes and were analyzed using Cox models. We included 17,210 patients claiming warfarin and 13,385 claiming a non-vitamin K OAC. The number of patients that claimed an AD during follow-up was 4,303. Concomitant OAC and AD use was associated with increased rates of severe bleeds (4.7 vs. 2.7 per 100 person-years) compared with OAC treatment alone (adjusted hazard ratio (aHR) 1.42, confidence interval (CI): 1.12-1.80), but not significantly associated with increased stroke rates (3.5 vs. 2.1 per 100 person-years, aHR 1.23, CI: 0.93-1.62). No significant differences in risks were observed between different OAC classes or different AD classes. In conclusion, concomitant use of an OAC and an AD is associated with an increased bleeding risk.

Lipid levels achieved after a first myocardial infarction and the prediction of recurrent atherosclerotic cardiovascular disease.

BACKGROUND: Low density lipoprotein cholesterol (LDL-C) goals post-myocardial infarction (MI) are debated, and the significance of achieved blood lipid levels for predicting a first recurrent atherosclerotic cardiovascular disease (rASCVD) event post-MI is unclear. METHODS: This was a cohort study on first-ever MI survivors aged ≤76 years attending 4-14 week revisits throughout Sweden 2005-2013. Personal-level data was collected from SWEDEHEART and linked national registries. Exposures were quintiles of LDL-C, high density lipoprotein cholesterol (HDL-C), total cholesterol (TC), and triglycerides (TGs) at the revisit. Group level associations with rASCVD (nonfatal MI or coronary heart disease death or fatal or nonfatal ischemic stroke) were estimated in Cox regression models. Predictive capacity was estimated by differences in C-statistic, integrated discriminatory improvement, and net reclassification improvement when adding each blood lipid to a validated risk prediction model. RESULTS: 25,643 patients, 96.9% on statin therapy, were followed during a mean of 4.1 years. rASCVD occurred in 2173 patients (8.5%). For LDL-C and TC, moderate associations with rASCVD were observed only in the 5th vs. the lowest (referent) quintiles. For TGs and HDL-C increased risks were observed in quintiles 3-5 vs. the lowest. Minor predictive improvements were observed when lipid fractions were added to the risk model but the discrimination overall was poor (C-statistics <0.6). CONCLUSIONS: Our data question the importance of LDL-C levels achieved at first revisit post-MI for decisions on continued treatment intensity considering the weak association with rASCVD observed in this post-MI cohort.

Meal intake increases circulating procoagulant microparticles in patients with type 1 and type 2 diabetes mellitus.

Diabetes mellitus (DM) is associated with prothrombotic alterations, and postprandial hyperglycemia is an independent risk factor for cardiovascular complications. We therefore investigated whether a standardized mixed meal alters circulating microparticles (MPs) and their procoagulant activity in DM patients. Patients with DM type 1 (T1DM, n = 11) and type 2 (T2DM; n = 9) were studied before and 90 min after a standardized meal (without premeal insulin). MPs in plasma derived from platelets (PMPs), endothelial cells (EMPs), or monocytes (MMPs) were measured by flow cytometry. MP-induced thrombin generation in plasma was assessed by a calibrated automated thrombogram. In the fasting state, MPs did not differ significantly between T1DM and T2DM. Meal intake increased the following microparticles: PMPs expressing phosphatidylserine (by 55%, on average), P-selectin (by 86%), and tissue factor (TF; by 112%); EMPs expressing E-selectin (by 96%) and MMPs expressing TF (by 164%), with no significant group differences between T1DM and T2DM. There were no increments in EMPs expressing phosphatidylserine or TF. Meal intake increased MP-induced thrombin generation similarly in T1DM and T2DM with increased endogenous thrombin potential (p = 0.02) and peak thrombin (p = 0.03) and shortened time to peak (p = 0.02). Phosphatidylserine inhibition by lactadherin completely abolished MP-induced thrombin generation, while an anti-TF antibody had no effect. In conclusion, meal intake increased several types of circulating MPs in patients with diabetes mellitus. These MPs have a procoagulant potential, which is related to phosphatidylserine expression and negatively charged MP surfaces rather than to TF.

Increased platelet reactivity and platelet-leukocyte aggregation after elective coronary bypass surgery.

Inflammatory mechanisms are activated, and thrombotic complications occur during the initial months after coronary artery bypass grafting (CABG). Therefore, changes over time of platelet activation and platelet-leukocyte interactions after CABG are of interest. Whole-blood flow cytometry was performed before, and 4-6 days, one month, and three months after elective CABG in 54 men with stable coronary artery disease treated with acetylsalicylic acid (ASA). Single platelets and platelet-leukocyte aggregates (PLAs) among monocytes (P-Mon), neutrophils (P-Neu), and lymphocytes (P-Lym) were studied without and with stimulation by submaximal concentrations of ADP, thrombin, and the thromboxane analog U46619. White blood cell counts were increased during the initial postoperative course, and platelet counts were increased after one month. Platelet P-selectin expression was significantly enhanced at one month when stimulated by thrombin and U46619 and at three months with ADP and thrombin. All PLAs subtypes were increased at one month without stimulation in vitro. P-Mon and P-Neu stimulated by ADP, thrombin, or U46619 were significantly increased one month after the operation but decreased compared to baseline at three months. Agonist stimulated P-Lyms were increased at one month and remained increased at three months after ADP stimulation. There was significant platelet activation and formation of PLAs unstimulated and after agonist stimulation by ADP, thrombin, and a thromboxane analog after CABG in patients with stable coronary artery disease irrespective of ASA treatment. Changes observed up to three months after CABG support further studies of the clinical implications of protracted increases in platelet activation and platelet-leukocyte interactions.