Acute coronary syndromes: the reperfusion era and beyond

The recent decade has enjoyed and provided major advances in our understanding of the pathophysiology and treatment of patients with acute coronary syndromes. The use of reperfusion therapy and acute mechanical intervention in patients with acute myocardial infarction has dramatically advanced our understanding of the mechanisms of acute coronary events. The disrupted unstable plaque is the proximate cause of acute coronary syndrome in the majority of patients, most experiencing the plaque rupture of a lipid-laden lesion. This results in a spectrum of clinical disease with clinical presentations ranging from unstable angina to ST-elevation myocardial infarction. Although a common aetiology exists, treatment is not uniform. The triage of patients and risk stratification are paramount to selecting the appropriate therapy at the right time for individual patients.     

Acute compartment syndromes

BACKGROUND: Acute compartment syndrome is both a limb- and life-threatening emergency that requires prompt treatment. To avoid a delay in diagnosis requires vigilance and, if necessary, intracompartmental pressure measurement. This review encompasses both limb and abdominal compartment syndrome, including aetiology, diagnosis, treatment and outcome. METHODS: A Pubmed and Cochrane database search was performed. Other articles were cross-referenced. RESULTS AND CONCLUSION: Diagnosis of limb compartment syndrome is based on clinical vigilance and repeated examination. Many techniques exist for tissue pressure measurement but they are indicated only in doubtful cases, the unconscious or obtunded patient, and children. However, monitoring of pressure has no harmful effect and may allow early fasciotomy, although the intracompartmental pressure threshold for such an undertaking is still unclear. Abdominal compartment syndrome requires measurement of intra-abdominal pressure because clinical diagnosis is difficult. Treatment is by abdominal decompression and secondary closure. Both types of compartment syndrome require prompt treatment to avoid significant sequelae.     

Acute foot compartment syndromes.

Twelve cases of compartment syndrome of the foot in 10 patients were retrospectively reviewed. All were high-energy injuries sustained in a fall from a height (six), crush (three), or motor vehicle accident (three). Bone injuries of the foot included five calcaneal fractures, three multiple metatarsal and/or phalangeal fractures, and two Lisfranc fracture-dislocations with multiple metatarsal neck fractures. The most consistent physical finding was tense swelling of the foot. The diagnosis was confirmed with compartmental pressure measurements in all cases. Decompressive fasciotomies were adequately performed by the medial approach of Henry or a combined approach with medial and dorsal incisions. An additional lateral incision was used in two instances.     

Urgent and emergency coronary artery bypass grafting for acute coronary syndromes

BACKGROUND: Urgent and emergency coronary artery bypass grafting may be associated with significant mortality and morbidity. We report our recent experience with this group of patients. METHODS: A retrospective analysis of 441 patients undergoing urgent and emergency surgery over a 3-year period was carried out. Multivariate analysis was used to identify subgroups of patients who were most at risk of death. RESULTS: The 30-day mortality was 3.3 and 16.3% in the urgent and emergency groups, respectively. Urgent surgery was associated with significantly shorter duration of ventilation (16 h vs 69 h) and stay at the intensive care unit (31 h vs 102 h). The incidence of pneumonia, pulmonary embolism, renal failure and neurological events were also less in the urgent group. The preoperative use of the intra-aortic balloon pump was low (0.8% in the urgent group and 4.8% in the emergency group). Multivariate analysis showed that patients over 70 years of age (odds ratio 3.2, 95% confidence interval 1.1-9.5) with left main stenosis (odds ratio 4.4, 95% confidence interval 1.5-12.4) complicated by cardiogenic shock (odds ratio 17.8, 95% confidence interval 5.2-61.1) were at highest risk of death. Patients transferred directly to theatre from cardiac catheter laboratory following failed percutaneous interventions were found to be most at risk. Mortality in this group was 29%, with 50% patients being in shock and 36% having left main stenosis. CONCLUSION: Satisfactory results have been obtained in urgent coronary artery bypass grafting, but acute coronary syndromes complicated by cardiogenic shock remain a high-risk group. Further studies are needed to define the optimal operative management in this group of patients.     

Acute and chronic pain syndromes after thoracic surgery

Pain is one of the most important considerations in the care of thoracic surgical patients. Failure in pain management is associated with increased mortality and morbidity. Acute pain management aspires to stop the painful stimuli before it is transferred to the CNS. The authors recommend (1) a thorough explanation of the operation and the expected outcome to the patient, (2) preoperative pulmonary rehabilitation for those with marginal lung function, (3) choosing the least painful surgical approach with acceptable exposure, (4) minimizing tissue trauma during surgery, (5) preemptive analgesia, and (6) early ambulation as prophylactic measures that should be employed during hospitalization. Good acute pain control should reduce the incidence of chronic pain. Mediansternotomy and VATS seem to be less acutely painful approaches than thoracotomy for most thoracic surgery. One should rule out recurrent malignancy as the etiology for chronic or recurrent pain. Opioids and NSAIDs are sufficient to produce optimal pain control in patients who undergo VATS and sternotomv. TEA is typically reserved for patients who have a thoracotomy. Opioid PCA can be used instead of-or after the discontinuation of-the epidural catheter. Chronic pain can be treated in many ways, and input from a pain clinic might be beneficial. The single best approach to chronic pain is to prevent it. This can be achieved by selecting the right incisional approach, instituting early physical therapy, and achieving optimal postoperative pain control.     

Acute coronary angiography after coronary artery bypass grafting

Objectives Coronary angiography is the golden standard when myocardial ischemia after CABG occurs. We summarize our experience of acute coronary angiography after CABG. Design All 4446 patients (mean age 68?±?9 years, 22% women) who underwent CABG 2007 to 2012 were included in this retrospective observational study. Incidence, indications, findings, measures of acute angiography after CABG was assessed. Outcome variables were compared between patients who underwent angiography and those who did not. Results Eighty-seven patients (2%) underwent acute coronary angiography. Patients undergoing angiography had ECG changes (92%), echocardiographic alterations (48%), hemodynamic instability (28%), angina (15%), and/or arrhythmia (13%). Positive findings were detected in 69% of the cases. Only ECG changes as indication for angiography had a moderate association with positive findings, but the precision increased if other sign(s) of ischemia were present. Thirty-day mortality (7% versus 2%, p?=?0.002) was higher and long-term-cumulative survival lower (77% versus 87% at five years, p?=?0.043) in angiography patients. Conclusions Acute angiography is a rare event after CABG. Postoperative myocardial ischemia leading to acute coronary angiography is associated with increased short-term and long-term mortality.     

The role of coronary artery spasm in anginal syndromes

The role of coronary artery spasm in the production of angina at rest is emphasized. Three case reports of variant angina are presented to illustrate the spectrum of presentation and to stress the principles underlying the therapy of coronary artery spasm. This entity should be suspected and diagnosed more frequently in order that patients may derive the benefit of relatively specific therapy which consists of calcium antagonists and long-acting nitrates.     

Acute coronary syndrome and heart failure

Acute coronary syndrome describes a range of clinical conditions that arise from acute myocardial ischaemia and includes unstable angina, non-ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI). It presents with chest pain, pressure, tightness, or heaviness that radiates to neck, jaw, shoulders, back, or one or both arms. Heart failure occurring in the environment of an acute coronary syndrome describes an inability of the heart to sustain adequate forward blood flow for metabolizing tissues. It may be a direct consequence of myocardial ischaemia or infarction with abnormal systolic function, or be secondary to acute valvular regurgitation or ventricular septal rupture. In its most severe form acute heart failure is termed cardiogenic shock. The priority of treatment in both conditions is to use ECG and biochemical cardiac markers to identify patients with STEMI who may benefit from immediate reperfusion therapy. In patients with STEMI, blood flow to the myocardium may be restored with thrombolytic therapy or percutaneous coronary intervention. Patients with unstable angina or NSTEMI require therapy to prevent progression to full-thickness myocardial infarction, with anti-platelet and anticoagulant medication and β-blockade. Patients who develop heart failure following myocardial ischaemia or infarction may be risk-stratified by measuring B-type natriuretic peptide. Once cardiogenic shock has developed the prognosis is poor, with an estimated mortality rate of 75%. Patients may require invasive monitoring, ventilatory support, cardiovascular support, or intra-aortic balloon counterpulsation.