COVID-19: The crucial role of blood coagulation and fibrinolysis.

The overflow of studies in the recent literature on COVID-19 often gives provisional or contradictory results and therefore deserves pauses of reflection and reconsideration. In fact, knowledges of pathophysiology of this new disease are still in development and hence originate discussions and interpretations. Regarding the role of blood coagulation and fibrinolysis, these mechanisms should be considered as crucial especially in severe cases. It is proposed to consider two distinct phenotypes of thrombotic manifestations: the current "thromboembolic type" also occurring in other kinds of sepsis, and the diffuse micro-thrombotic type, prevailing in the lungs but sometimes extending to other organs. Both types can induce severe disease and are potentially lethal. The micro-thrombotic pattern, more specific for COVID-19, results from a massive activation of coagulation strictly coupled with a hyper-intense inflammatory and immune reaction. This results in widespread occlusive thrombotic micro-angiopathy with destruction of alveoli and obstructive neoangiogenesis. The involvement of fibrinolysis, often neglected, confers a double faceted process of activation/inhibition, finally conducive to a fibrinolytic shutdown that reinforces persistence of micro-thrombi. Considering these peculiar mechanisms, it seems evident that both prophylactic and therapeutic effects of current anti-thrombotic drugs cannot be taken for granted and need therefore new specific and rigorous controlled trials.

Why include the humanities in medical studies?

The relation between philosophy and biomedicine has been reassessed and rethought in the last few years: on the one hand, philosophy of science has paid increasing attention to actual modes of biomedical research and clinical practice; on the other, classes in philosophy, and more generally, in the humanities, have started entering medical curricula. However, the role of philosophy in medical education is not yet unanimously recognized, with situations differing significantly in various national and international contexts. In line with the tradition in Italy and other countries of reflecting on clinical methodology and with the recent initiatives at the crossroads between medicine and philosophy, this contribution aims to argue for the mutual relevance of medicine and philosophy in educational processes, and to suggest some possible forms of implementation of their interactions.

Use and Misuse of Aspirin in Primary Cardiovascular Prevention.

The use of low-dose aspirin in primary prevention of cardiovascular (CV) events in healthy or apparently healthy people is a widely debated topic. Many arguments indicate that "primary prevention" is only a conventional definition and that the transition from primary to secondary prevention represents a continuum of increasing levels of CV risk. Although there are no direct proofs of a different efficacy of aspirin at different CV risk levels, in low-risk populations aspirin will appear to be less efficient. In fact, the lower number of events occurring in patients at low risk yields lower absolute numbers of events prevented. As many as 6 meta-analyses of trials of primary CV prevention with aspirin versus placebo, performed between 2009 and 2016, confirmed the above concepts and showed a concordant, significant reduction in nonfatal myocardial infarction, with no significant effects on stroke, as well as on CV and all-cause mortality. The recent demonstration of a moderate protective effect of aspirin on cancer (especially colorectal) confers, however, additional value to the use of aspirin, although unusually long durations of treatment and optimal daily compliance seem to be necessary. Because aspirin increases the bleeding risk, the evaluation of its net clinical benefit is an important point of debate. Thus, it is justified to search for a cutoff level of global CV risk above which the net clinical benefit of aspirin becomes evident. Such a threshold value has been calculated considering the data of 9 primary prevention trials, by the Thrombosis Group of the European Society of Cardiology, and has been indicated as a risk value of 2 or more major CV events per 100 persons per year. Also, in the recent 2016 US Guidelines, the main criterion adopted for the indication of aspirin is the level of global CV risk (suggested cutoff is 1 or more major CV events per 100 persons per year). Beyond the different values selected, it is seems very important to introduce to clinical practice and future trials a new criterion based on the level of global CV risk.

Error, contradiction and reversal in science and medicine.

Error and contradictions are not "per se" detrimental in science and medicine. Going back to the history of philosophy, Sir Francis Bacon stated that "truth emerges more readily from error than from confusion", and recently Popper introduced the concept of an approximate temporary truth that constitutes the engine of scientific progress. In biomedical research and in clinical practice we assisted during the last decades to many overturnings or reversals of concepts and practices. This phenomenon may discourage patients from accepting ordinary medical care and may favour the choice of alternative medicine. The media often enhance the disappointment for these discrepancies. In this note I recommend to transfer to patients the concept of a confirmed and dependable knowledge at the present time. However, physicians should tolerate uncertainty and accept the idea that medical concepts and applications are subjected to continuous progression, change and displacement.

[Italian intersocietary consensus document on aspirin therapy in primary cardiovascular prevention]. / La terapia con aspirina nella prevenzione cardiovascolare primaria. Documento di consenso intersocietario italiano.

The indications for the use of aspirin in primary cardiovascular prevention continue to be a source of intense debate, with major international guidelines providing conflicting advices. This document, written by delegates of the main Italian scientific societies dealing with cardiovascular prevention and modeled on a similar document by the European Society of Cardiology Working Group on Thrombosis, reviews the evidence in favor and against the use of aspirin therapy in primary prevention based on data cumulated so far, including recent data linking aspirin with cancer protection. While awaiting the results of several ongoing studies, this document argues for a pragmatic approach to the use of low-dose aspirin in primary cardiovascular prevention, and suggests its use in patients at high cardiovascular risk, defined as ≥2 major cardiovascular events (death, myocardial infarction, or stroke) projected per 100 person-years, who are not at increased risk of bleeding.

Aspirin therapy in primary cardiovascular disease prevention: a position paper of the European Society of Cardiology working group on thrombosis.

Although the use of oral anticoagulants (vitamin K antagonists) has been abandoned in primary cardiovascular prevention due to lack of a favorable benefit-to-risk ratio, the indications for aspirin use in this setting continue to be a source of major debate, with major international guidelines providing conflicting recommendations. Here, we review the evidence in favor and against aspirin therapy in primary prevention based on the evidence accumulated so far, including recent data linking aspirin with cancer protection. While awaiting the results of several ongoing studies, we argue for a pragmatic approach to using low-dose aspirin in primary cardiovascular prevention and suggest its use in patients at high cardiovascular risk, defined as ≥2 major cardiovascular events (death, myocardial infarction, or stroke) projected per 100 person-years, who are not at increased risk of bleeding.

Anticoagulants (heparin, low molecular weight heparin and oral anticoagulants) for intermittent claudication.

BACKGROUND: Anticoagulant treatment for intermittent claudication might improve functional capacity and prevent acute cardiovascular complications caused by peripheral obstructive arterial disease. This is an update of the review first published in 2001. OBJECTIVES: To assess the effects of anticoagulant drugs (heparin, low molecular weight heparin (LMWH) and oral anticoagulants) in patients with intermittent claudication (Fontaine stage II) in terms of improving walking capacity (pain-free walking distance or absolute walking distance), mortality, cardiovascular events, ankle/brachial pressure index, progression to surgery, amputation-free survival and side effects of these drugs. SEARCH METHODS: For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched May 2013) and CENTRAL (2013, Issue 4). SELECTION CRITERIA: All randomised trials of anticoagulants used to treat patients with intermittent claudication. DATA COLLECTION AND ANALYSIS: Seven studies were included. Only three studies (two evaluating oral anticoagulants, one evaluating heparin) met the high quality methodological inclusion criteria and were included in the primary analysis. Four other studies were included in the sensitivity analysis. The authors extracted the data independently. MAIN RESULTS: No new studies were included for this update. Seven studies with a combined total of 802 participants were included in this review. No significant difference was observed between heparin treatment and control groups for pain-free walking distance or maximum walking distance at the end of treatment. There were no data to indicate that LMWHs benefit walking distance. Revascularisation or amputation-free survival rates were reported in one study only with a five year follow-up. No study reported a significant effect on overall mortality or cardiovascular events and the pooled odds ratios were not significant for these outcomes either. Major and minor bleeding events were significantly more frequent in the group treated with oral anticoagulants compared to control, with a non-significant increase in fatal bleeding events. No major bleeding events were reported in the study evaluating heparin, while a non-significant increase in minor bleeding events was reported. AUTHORS' CONCLUSIONS: The benefit of heparin, LMWHs and oral anticoagulants for treatment of intermittent claudication has not been established while an increased risk of major bleeding events has been observed, especially with oral anticoagulants. There is no clear evidence to support the use of anticoagulants for intermittent claudication at this stage.

New oral anticoagulants in atrial fibrillation: a reappraisal of trial results looking at absolute figures.

Three new oral anticoagulant agents were tested versus warfarin in separate, large phase III randomized clinical trials for prevention of any stroke and systemic embolism in atrial fibrillation. Dabigatran, a direct thrombin inhibitor, is at 110 mg bid non-inferior and at 150 mg bid superior to warfarin; rivaroxaban, a factor X inhibitor, is also non-inferior, and apixaban, also a factor X inhibitor, is superior to warfarin on the same efficacy end point. Statistical analysis of subgroups does not suggest, for any of the tested drugs, major differences in relation to different risk levels and history of previous stroke/TIA. This re-appraisal of data was undertaken in search for possible additional information, by considering the absolute differences in efficacy and safety events versus warfarin and the corresponding efficiency and number needed to treat, also with regard to secondary versus primary prevention. By this approach, it appears that for all drugs, equivalence or advantage versus warfarin on the efficacy end point is largely driven by a reduction in hemorrhagic rather than ischemic strokes. Dabigatran shows a balanced effect on ischemic and hemorrhagic strokes, and apixaban is most effective in sparing intracranial bleeding versus warfarin. In secondary prevention, better efficiency is shown by dabigatran 150 and apixaban, versus rivaroxaban, despite the higher proportion of post-stroke/TIA patients (55 %) in the ROCKET AF trial of rivaroxaban seemed to favor better results of this drug in secondary prevention. These and other results of our approach should not be directly translated into clinical practice. They may supply useful suggestions to be subsequently tested in specific trials, although head-to-head comparative studies of the three drugs remain unlikely.

Development and use of sulodexide in vascular diseases: implications for treatment.

Sulodexide (SDX), a sulfated polysaccharide complex extracted from porcine intestinal mucosa, is a blend of two glycosaminoglycan (GAG) entities, namely a fast-moving heparin (HP) fraction and a dermatan sulfate (DS; 20%) component. The compound is unique among HP-like substances in that it is biologically active by both the parenteral and oral routes. A main feature of the agent is to undergo extensive absorption by the vascular endothelium. For this reason, in preclinical studies, SDX administered parenterally displays an antithrombotic action similar to that of HPs but associated with fewer alterations of the blood clotting mechanisms and tests, thus being much less conducive to bleeding risk than HPs. When given orally, SDX is associated with minimal changes in classic coagulation tests, but maintains a number of important effects on the structure and function of endothelial cells (EC), and the intercellular matrix. These activities include prevention or restoration of the integrity and permeability of EC, counteraction versus chemical, toxic or metabolic EC injury, regulation of EC-blood cell interactions, inhibition of microvascular inflammatory and proliferative changes, and other similar effects, thus allowing oral SDX to be considered as an endothelial-protecting agent. The best available clinical evidence of the efficacy of SDX administered orally with or without an initial parenteral phase is the following: alleviation of symptoms in chronic venous disease and especially acceleration of healing of venous leg ulcers; prevention of cardiovascular events in survivors after acute myocardial infarction; marked improvement of intermittent claudication in patients with peripheral occlusive arterial disease; and abatement of proteinuria in patients with diabetic nephropathy that may contribute to the amelioration or stabilization of kidney function. Although further clinical trials are warranted, SDX is presently widely accepted in many countries as an effective and safe long-term, endothelial-protecting drug.

[Aspirin in primary prevention of cardiovascular diseases: how to balance risks and benefits]. / Aspirina nella prevenzione primaria delle malattie cardiovascolari: come bilanciare rischi e benefici.

While the use of aspirin in the secondary prevention of cardiovascular atherothrombotic disease is well established, many aspects of primary prevention are still unclear. Uncertainties mostly depend on a doubtful risk-benefit ratio, because of the low atherothrombotic risk of populations involved on the one hand, and the non-negligible bleeding risk of treatment on the other. Areas of specific doubt are those of diabetes and asymptomatic peripheral arterial disease, where neither single trials nor meta-analyses allow issuing high-grade specific recommendations at the moment. The present review aims at giving an account on this topic, highlighting areas for further studies, but also attempting at providing a rationale for what to do practically now, while awaiting more conclusive evidence. Based on the results of a number of clinical trials and meta-analyses, and especially considering the absolute figures of the benefit (major cardiovascular events avoided) and of the harm (major bleeding events occurred related to aspirin), the authors recommend to limit primary cardiovascular prevention with aspirin (in apparently healthy subjects with no previous cardiovascular events) to subjects with an estimated global cardiovascular risk ≥2 major cardiovascular events per 100 patients-year, as assessed by the risk score assessments proposed in the Italian "Progetto Cuore" (www.progettocuore.it). This cut-off should also be adopted for primary prevention in patients with type 2 diabetes and/or asymptomatic peripheral arterial disease.

Antiplatelet therapy: controversial aspects.

Although the efficacy of antiplatelet therapy is supported by numerous studies areas of uncertainty and doubt persist both in secondary and in primary prevention. In both settings it can be surmised that, with few exceptions, the relative risk reduction obtained, for instance, with aspirin, is rather uniform across the different clinical conditions and measures "efficacy" of the drug: while the absolute risk reduction varies according to the risk levels of the different conditions, and expresses the "efficiency" of the treatment. Especially in conditions at high risk as the acute coronary syndrome (ACS) the problem of "variability of response" or "resistance" to antiaggregating drugs is of remarkable importance. For aspirin resistance main factors are low compliance, interferences with other drugs, especially NSAIDS, diabetes and related glication phenomenon, and especially fast platelet turnover. Genetic polymorphism (C50T) of COX1 gene, has been described but its significance is debated. Regarding clopidogrel, drug interferences, diabetes mellitus, increased platelet turnover, and polymorphisms of the cytochrome P450 family are involved. A useful expression of antiplatelet resistance is "High on Treatment Platelet Reactivity" (HTPR). This entity has been found predictive of poor outcome in a number of studies of patients with ACS, but not in all. Similarly, genotyping patients for cytochrome P450 polymorphisms also shows predictivity, but not confirmed in all studies. Both genotyping and measuring HTPR can be useful for selection of high risk ACS patients and especially in clinical research. New antiplatelet drugs as prasugrel, ticagrelor, and the recent vorapaxar seem to overcome the problem of resistance. In primary prevention, even assuming a uniform efficacy of aspirin, the risk and hence the absolute number of events spared are much lower. Therefore, aspirin will be less efficient, and the net clinical benefit over the bleeding risk will be smaller. Inconclusive results have been found in healthy people as well as in people with diabetes but no prior cardiovascular event. However, in a recent meta-analysis including new trials bearing some factors of heterogeneity, a small but significant reduction in overall mortality suggests that, for aspirin in primary prevention, "the game is not over".

Antiplatelet drugs--do we need new options? With a reappraisal of direct thromboxane inhibitors.

This review describes the current status of antiplatelet therapy in prevention of cardiovascular events of an atherothrombotic nature. The efficacy of aspirin clearly outweighs bleeding risk in secondary prevention, with the relevant exception of patients with peripheral arterial disease (PAD). In trials of primary prevention, aspirin has a limited advantage, which is challenged by the risk of major bleeding. A typical example is primary prevention in type 2 diabetes mellitus, in which a number of trials and a recent meta-analysis have confirmed these limitations. In various settings, clopidogrel has been shown to be marginally more effective than aspirin. Despite a non-negligible bleeding risk, the combination of aspirin-clopidogrel has provided satisfactory results in conditions at high thrombotic risk but rather disappointing results in the long-term treatment of chronic stable cardiovascular disease. The combination of aspirin-dipyridamole was shown to be superior to aspirin alone and equivalent to clopidogrel alone for secondary prevention in cerebrovascular patients. Limitations in the efficacy of antiplatelet agents are partly inherent in their mechanism of action and should not be considered simply as 'treatment failures'. Among other factors, individual variability of response to antiplatelet drugs also plays a meaningful role. Variability of response and 'resistance' may result from drug interactions, baseline and residual platelet hyperactivity, increased platelet turnover, pharmacogenetic factors and others. Poor biological response to aspirin and/or clopidogrel is also frequent in clinical settings such as diabetes, obesity and acute coronary syndromes. The correlation between biological resistance and impaired clinical efficacy of aspirin, and especially clopidogrel, is currently accepted, although with limitations due to the different methods used to assess platelet response. Indeed, the concept of individual 'tailoring' of antiplatelet regimens on the basis of previous laboratory or 'point of care' platelet function tests has been validated in a number of recent trials. The search for and validation of new antiplatelet agents with already known, or totally new, mechanisms of action have also been undertaken with increasing eagerness. Among new adenosine diphosphate receptor antagonists, prasugrel is already registered, and ticagrelor and cangrelor are being developed. New mechanisms being explored are blockade of thrombin-induced platelet aggregation (vorapaxar [SCH 530398]), and inhibition of collagen and ristocetin-mediated platelet functions (DZ-697b). Reappraisal of the neglected class of direct thromboxane A(2) antagonists was followed with less interest. Besides blocking the effects of thromboxane produced from platelets, drugs of this class (such as terutroban sodium and picotamide) may also protect cells from thromboxane produced by sources other than platelets, and some of them may preserve or enhance prostacyclin production. Terutroban is presently being tested in PAD and stroke prevention. Picotamide, marketed in Italy, was shown to reduce cardiovascular events and mortality in studies of PAD patients with diabetes. The results available with thromboxane inhibitors are particularly interesting because they are being obtained in conditions, such as type 2 diabetes and PAD, which are known to be refractory to aspirin.

Approaches to prevention of cardiovascular complications and events in diabetes mellitus.

Diabetes mellitus affects about 8% of the adult population. The estimated number of patients with diabetes, presently about 170 million people, is expected to increase by 50-70% within the next 25 years. Diabetes is an important component of the complex of 'common' cardiovascular risk factors, and is responsible for acceleration and worsening of atherothrombosis. Major cardiovascular events cause about 80% of the total mortality in diabetic patients. Diabetes also induces peculiar microangiopathic changes leading to diabetic nephropathy conducive to end-stage renal failure, and to diabetic retinopathy that may progress to vision loss and blindness. In terms of major cardiovascular events, coronary heart disease and ischaemic stroke are the main causes of morbidity and mortality in diabetic patients. Peripheral arterial disease frequently occurs, and is more likely to be conducive to critical limb ischaemia and amputation than in the absence of diabetes. Although there are a number of differences in the pathogenesis and clinical features of diabetic macroangiopathy and microangiopathy, these two entities often coexist and induce mutually worsening effects. Endothelial injury, dysfunction and damage are common starting points for both conditions. Causes of endothelial injury can be distinguished into those 'common' to nondiabetic atherothrombosis, such as hypertension, dyslipidaemia, smoking, hypercoagulability and platelet activation; and those more specific and in some cases 'unique' to diabetes and directly related to the metabolic derangement of the disease, such as (i) desulfation of glycosaminoglycans (GAGs) of the vascular matrix; (ii) formation of advanced glycation end-products (AGE) and their endothelial receptors (RAGE); (iii) oxidative and reductive stress; (iv) decline in nitric oxide production; (v) activation of the renin-angiotensin aldosterone system (RAAS); and (vi) endothelial inflammation caused by glucose, insulin, insulin precursors and AGE/RAGE. Prevention of major cardiovascular events with the antithrombotic agent aspirin (acetylsalicylic acid) is widely recommended, but reportedly underutilised in patients with diabetes. However, some data suggest that aspirin may be less effective than expected in preventing cardiovascular events and especially mortality in patients with diabetes, as well as in slowing progression of retinopathy. In contrast, a recent study found picotamide, a direct thromboxane inhibitor, to be superior to aspirin in diabetic patients. Clopidogrel was either equivalent or less active in diabetic versus nondiabetic patients, depending upon different clinical settings.Recent studies have shown that some GAG compounds are able to reduce micro- and macroalbuminuria in diabetic nephropathy, and hard exudates in diabetic retinopathy, but it is as yet unknown whether these agents also influence the natural history of microvascular complications of diabetes. Lifestyle changes and physical exercise are also essential in preventing cardiovascular events in diabetic patients. Available data on the control of the metabolic state and the main risk factors show that careful adjustment of blood sugar and glycated haemoglobin is more effective in counteracting microvascular damage than in preventing major cardiovascular events. The latter objective requires a more comprehensive approach to the whole constellation of risk factors both specific for diabetes and common to atherothrombosis. This approach includes lifestyle modifications, such as dietary changes and smoking cessation and the use of HMG-CoA reductase inhibitors (statins), which are able to correct the lipid status and to prevent major cardiovascular events independently of the baseline lipidaemic or cardiovascular status. Tight control of hypertension is essential to reduce not only major cardiovascular events but also microvascular complications. Among antihypertensive measures, blockade of the RAAS by means of ACE inhibitors or angiotensin II receptor antagonists recently emerged as a potentially polyvalent approach, not only for treating hypertension and reducing cardiovascular events, but also to prevent or reduce albuminuria, counteract diabetic nephropathy and lower the occurrence of new type 2 diabetes in individuals at risk.

Evaluation of thermal water in patients with functional dyspepsia and irritable bowel syndrome accompanying constipation.

AIM: To evaluate the efficacy of water supplementation treatment in patients with functional dyspepsia or irritable bowel syndrome (IBS) accompanying predominant constipation. METHODS: A total of 3872 patients with functional dyspepsia and 3609 patients with irritable bowel syndrome were enrolled in the study by 18 Italina thermal centres. Patients underwent a first cycle of thermal therapy for 21 d. A year later patients were re-evaluated at the same centre and received another cycle of thermal therapy. A questionnaire to collect personal data on social and occupational status, family and pathological case history, life style, clinical records, utilisation of welfare and health structure and devices was administered to each patient at basal time and one year after each thermal treatment. Sixty patients with functional dyspepsia and 20 with IBS and 80 healthy controls received an evaluation of gastric output and oro-cecal transit time by breath test analysis. Breath test was performed at basal time and after water supplementation therapies. Gastrointestinal symptoms were evaluated at the same time points. Breath samples were analyzed with a mass spectometer and a gascromatograph. Results were expressed as T(1/2) and T-lag for octanoic acid breath test and as oro-cecal transit time for lactulose breath test. RESULTS: A significant reduction of prevalence of symptoms was observed at the end of the first and second cycles of thermal therapy in dyspeptic and IBS patients. The analysis of variance showed a real and persistant improvement of symptoms in all patients. After water supplementation for 3 wk a reduction of gastric output was observed in 49 (87.5%) of 56 dyspeptic patients. Both T(1/2) and T-lag were significantly reduced after the therapy compared to basal values [91 +/- 12 T(1/2) and 53 +/- 11 (T-lag), Tables 1 and 2] with results of octanoic acid breath test similar to healthy subjects. After water supplementation for 3 wk oro-cecal transit time was shorter than that at the beginning of the study. CONCLUSION: Mineral water supplementation treatment for functional dyspepsia or constipation accompanying IBS can improve gastric acid output and intestinal transit time.