Learning Objective - how to prevent and how to handle major bleeding in ACS? What are the true indications of blood transfusion in 2015
- Risk factors for bleeding include age, renal impairment and prior haemorrhage
- Bleeding mainly influences short-term outcome
- Restrictive transfusion seems superior in ACS patients
- In intra cranial haemorrhage after ACS, rapid blood pressure control (target 140/90 mmHg) is essential
Incidence of bleeding and outcomes in ACS - Prof Sigrum Halvorsen, Oslo
We know the incidence and importance of bleeding, and complications of bleeding, in patients treated for Acute Coronary Syndromes (ACS). A number of well-publicised studies of large and disparate populations of ACS patients paint a reasonably consistent picture in terms of incidence, magnitude and impact on outcome. We have reasonable and widely accepted standards for seriousness of bleeding in terms of site, extent and impact, and these tools can be used to monitor bleeding complications in what is an ever-changing field in terms of antithrombotic and anticoagulant drugs, in many permutations and combinations. Clearly, bleeding is increased in invasive treatment options compared to more conservative management, and the impact of co-morbidity is well demonstrated - so increased age, renal impairment, female sex, prior exposure to anti platelet therapy (ATP) and prior haemorrhage all increase the likelihood of haemorrhage during ACS. Furthermore, the occurrence of bleeding complications during ACS has a clear impact on increased risk of death - partly due to direct consequences of major haemorrhage and its treatment, but possibly also because of interference with, or deviation from the optimum use of APT and anticoagulation to prevent coronary and non-coronary thrombotic complications. Clearly, details of procedural technique can have a positive impact, and radial access has a consistently lower incidence of access site haemorrhage than femoral access - challenging wider use of radial access where possible and appropriate. However, not all bleed are access-site-related and furthermore, significant non-access-site-related haemorrhage has an even worse outcome, both in terms of mortality and long term disability than access site bleeds. The good news is that bleeding appears to only influence short term (30 day) outcomes - with longer term outcomes less affected by peri-ACS haemorrhage. This is clearly a great challenge to get things totally right in the acute phase.
Hemovigilance: the risks and benefits of RBC transfusion. Prof Johanne Silvain Paris
This presentation summarised some of the history of blood transfusion and brought us right up to date with the confusing and sometimes conflicting evidence for the benefits and risks of transfusion in a variety of clinical situations related to the management of ACS. We know that transfusion is not infrequent in ACS, with an incidence of around 1 to 5%, and the general transfusion knowledge base, as well as knowledge more specific to ACS, share some increasing concerns of outcomes being independently adversely affected in patients exposed to even small quantities of allogeneic transfusion of red blood cells and other blood products. Clearly, transfusion can be immediately life-saving in massive haemorrhage, but it is on the more difficult range of when to transfuse in anaemia that most of the debate centres. The TRICC study, Hebert et al, NEJM 1999 was an extremely important evidence milestone demonstrating virtually equivalent outcomes for a large number of patients in different critical care contexts treated with traditional and "liberal" transfusion threshold (Hb 100 g/L) compared to "restrictive" (70 g/L). In many cases, the outcomes appear superior in the restrictive group - in many cases there are also no differences to justify the expense and other risks of transfusion. The TRICC study hinted at a special case for patients with coronary disease perhaps needing a higher haemoglobin concentration, but many subsequent studies have failed to demonstrate this with statistical significance. Recent studies have questioned the previous association with older blood donations (time from collection to transfusion) impacting on a range of adverse outcomes such as death, tumour recurrence and infection. Prof Silvain highlighted the current absence of a large randomised controlled trial of transfusion in ACS and announced the imminent commencement of exactly such a trial at his institution. The results are eagerly awaited.
How to prevent bleeding in ACS? Prof Joao Morais Leira, Portugal
We are still looking for the "Sweet Spot" - there is a constant real world conflict between the risk of thrombotic complications such as stent thrombosis and thrombotic stroke, vs the risk of bleeding complications occurring in between 1 to 20% of ACS patients subjected to the typical range of treatment options. It should surely be possible using evidence in trials and specific factors observed in individual patients to achieve a better balance, more of the time in this clinical conundrum. But the reality is more complex and clinical pressures still have a confusing impact. However, we know that risk of bleeding is directly related to increasing potency of anticoagulant and anti-platelet therapy and also to increased potency from their combination in various permutations. We also see an impact on bleeding from prior and repeat exposure to agents and the unpredictability of individual sensitivity to platelet modulation. Also, there are clear risk factors for serious haemorrhage such as age, renal impairment, prior haemorrhage etc which should be taken into account individually in aiming for the sweet spot and minimising serious complications whilst ensuring best ACS related outcome. The bottom line of the presentation is to ensure benefits related to procedural elements (e.g. use radial rather than femoral access where possible), use the right (or best for individual) drugs in the right combinations, avoid unnecessary (or unproven) drugs and treatments, protect the gut (we now have a much clearer picture of what protection agents - eg specific proton pump inhibitors - work best in relation to which style of anti-platelet therapy) - giving the opportunity and challenge to achieve a degree of "personalised" medicine in some of the details of ACS management.
How to prevent and manage brain haemorrhage? Prof Pierre Amarenco, Paris, France
Intracranial haemorrhage (ICH) is a rare but devastating complication of acute coronary syndrome (ACS) with only around 1 to 4% ACS patients affected, but around a third to half of these will die. The presentation summarised the evidence for this, as well as important and current (2015) guidelines for management of ICH in ACS from the American Heart Association. The guidelines are all sensible and common sense and supportive in nature, but the challenge remains enormous in health and health-economic terms: non-fatal ICH is obviously associated with significant disability and healthcare dependency. One thing that has come out of the various observational studies is the powerful prognostic effect of a prior stroke - significantly increasing the risk of incidence and severity of a new stroke in ACS. This has to be taken into account when balancing potency of anti-thrombotic benefits against bleeding risk - yet clearly there is current evidence of patients with prior stroke presenting with ACS and being treated inappropriately with dual anti-platelet therapy. Again, this calls for a better degree of personalised medicine. With regard to management of ICH after ACS, the key elements are mostly general and supportive with active control of hypertension crucial. Systolic pressure needs to be quickly and safely reduced to around 140 mmHg - with appropriate monitoring. There is rarely any indication for surgery and little evidence for active reversal of anti-platelet therapeutic effect - but careful and timely re-introduction of anticoagulation and anti-thrombotic therapy is crucial to avoid the ever-present threat of thrombotic disasters.