Non-ST elevation acute coronary syndromes: timing and selection of early invasive management, ECG monitoring need, DAPT duration, pathogenesis of recurrence and beware of delirium in the intensive/acute cardiac care unit!

The ESC guidelines on non-ST elevation acute coronary syndromes (NSTE-ACS) recommend a routine early invasive management in all patients with at least one high risk factor.1 This recommendation is challenging to implement when patients are presenting with a NSTE-ACS at remote non-PCI-capable hospitals. In an Italian registry, an early invasive strategy provided no benefit in outcome compared to an early conservative strategy performed at non-PCI capable hospitals intriguingly independent of the GRACE risk score.2 However, on per protocol analysis an early invasive strategy was superior indicating that cardiologists are very able to clinically risk stratify patients for early transfer to a PCI-capable hospital. On the other hand, the decision to perform early coronary angiography can already be taken in the pre-hospital setting based on the EKG and point of care troponin measurement as is demonstrated by a preliminary report from the in Denmark ongoing randomized acute versus subacute angioplasty in patients with NON-ST-Elevation Myocardial Infarction (NONSTEMI) trial.3 In most cases a correct diagnosis was made in the ambulance and the patients who were referred for immediate angiography had a significantly shorter hospital stay. That patients with suspected NSTE-ACS and a normal high sensitivity cardiac troponin (hscTnT) value may not benefit from a routine invasive strategy during hospital stay, provided they receive optimal pharmacotherapy and have the opportunity for invasive procedures at signs or symptoms of recurrent ischaemia is demonstrated by a substudy of the PLATO trial.4 Patients with a first myocardial infarction who are treated conservatively without coronary revascularisation may benefit from dual antiplatelet therapy (DAPT). However, analysis of nationwide Danish registers shows that DAPT use is less likely among elderly patients although similar effects regarding both risk and benefit were found in all age groups.5 Increased focus on initiating dual anti-platelet treatment in elderly, non-invasively treated myocardial infarction patients is therefore warranted. A systematic review suggests that prolongation of DAPT therapy beyond the standard 12 months period after an acute coronary syndrome may be beneficial but we need more evidence on the optimal duration and on which patients may benefit.6 The electrocardiogram is one of the cornerstones in the diagnosis and follow-up of patients with an acute coronary syndrome. Some NSTE-ACS patients develop a giant T wave inversion and an extreme QT prolongation when pain free in the subacute phase.7 Acute cardiac care cardiologists should be familiar with this characteristic ECG pattern. The ESC guidelines on NSTE-ACS recommend monitoring low-risk patients with NSTEMI for at least 24 hours (1). The finding of an elevated hs-cTnT may trigger a decision to send the patient to a coronary care unit or telemetry ward for 24 hour ECG rhythm monitoring even if the patients are at low risk of having an acute coronary syndrome. A study performed at the Mayo Clinic shows that patients who are admitted to a non-intensive care unit rhythm-monitored bed because of elevated troponin levels but without a STEMI or primary arrhythmia are at very low risk to develop life-threatening arrhythmias.8 Although the incidence of arrhythmias is high (36%), most often they are relatively benign and alterations in therapeutic management is infrequently required. Utilization of this expensive resource should therefore be re-evaluated in these patients, as it is not likely to be beneficial. Recurring acute coronary syndromes after a recent ST-segment elevation myocardial infarction (STEMI) despite optimal medical therapy continues to represent a relevant problem in clinical practice. A study performed at Catholic University of the Sacred Heart in Rome, Italy showed that STEMI patients who are seropositive for Helicobacter pylori cytotoxin-associated gene antigen (CagA) present more frequently with a previous history of acute coronary syndrome and experienced major adverse cardiovascular events during a 2-year follow-up.9 These observations suggest that CagA-positive strains of Helicobacter pylori may be involved in the pathogenesis of recurring acute coronary syndromes possible through an auto-immune response triggered by a chronic gastric infection with this pathogen. Delirium is a common problem in patients admitted to the intensive acute cardiac care unit (ICCU) especially among the elderly patients with multiple comorbidities. The incidence and of delirium and its impact on clinical outcome apparently depends on the illness severity on admission and level of care: 21.% of nonintubated acute cardiac patients admitted to the ICCU of the Kanazawa University Hospital in Japan developed delirium and this was associated with a an almost 300% increase of the 60 day mortality;10 conversely 8.3% of the patients admitted to the coronary care unit at the Mayo Clinic developed delirium and this was associated with a 50% increase of both in-hospital and one-year mortality.11 The safety of antipsychotic drugs in controlling delirium in acute cardiac patients remained uncertain as chronic use of these agents was associated with an increased incidence of sudden cardiac death possibly due to a proarrhytmogenic effect. From the registry of the Mayo Clinic we learn that treatment with low doses of haloperidol and quetiapine appears to be safe, without an increase in risk of sudden cardiac death, in-hospital mortality, or one-year mortality in carefully monitored patients.