Perceived contraindications to thrombolytic treatment in acute myocardial infarction. A survey at a teaching hospital

Intravenous thrombolysis in acute ischaemic stroke: from trial exclusion criteria to clinical contraindications. An international Delphi study

OBJECTIVE

Several studies indicate that only a small proportion of patients with acute ischaemic stroke are treated with intravenous thrombolysis. Indications and contraindications for this treatment are usually based on the inclusion and exclusion criteria of randomised clinical trials. The trial context of these criteria hampers implementation in real life settings. We therefore aimed to obtain specialist opinion in a Delphi consensus on these contraindications.

METHODS

We used the Delphi approach on an international group of specialists in the field of thrombolysis. Inclusion and exclusion criteria were reworded into 18 quantitatively phrased propositions. Feedback consisted of the median score, interquartile range and the panellist's own score in the previous round. For each item, we defined consensus as the achievement of an interdecile range within two prespecified clinically relevant units.

RESULTS

Thirty-one specialists participated in the first round and 30 completed all three rounds. Consensus was reached on 12 of the 18 propositions: previous ischaemic stroke, head trauma and gastrointestinal tract bleeding should not have taken place earlier than 1.5 months, 2 months and 14 days, respectively; the severity of the neurological deficit is defined as a National Institutes of Health Stroke Scale (NIHSS) score of 2-3 or more, and blood pressure level should not be >185/110 mmHg; platelet count should be >90x10(12)/l, glucose levels 2.7-22 mmol/l, international normalised ratio <1.5 and activated partial thromboplastin time <50 s. No consensus was reached on propositions concerning the stroke onset to treatment time, patient's age, recent medical procedures, spontaneous improvement rate and blood pressure treatment.

CONCLUSIONS

We present specialists' opinion on contraindications for intravenous thrombolysis in ischaemic stroke. The results of this study may be relevant for routine clinical practice as they may help to increase the number of treated patients.

Síndrome coronario agudo con elevación de ST durante el embarazo: descripción de un caso y revisión de las opciones terapéuticas

ST segment elevation acute coronary syndrome is a clinical condition that is rarely observed in pregnant women. However, its manifestation is a situation of high maternal-fetal risk. Pharmacotherapeutical management of these patients is difficult and requires individualized care by a multidisciplinary team since many of the standard treatments are included within the categories of teratogencity C or D of the Food and Drug Administration and experience with techniques such as coronary angioplasty with stent placement is scarce. The case of a 32-year woman who was 11 weeks pregnant and diagnosed of acute coronary syndrome with ST segment and its therapeutic approach are described. Furthermore, the information available on epidemiology, etiology and pathophysiology of acute coronary syndrome with ST segment during pregnancy and the specific role of the currently available treatment options are reviewed.

Valvular Heart Disease and Pregnancy

A large number of prosthetic heart valves (PHV) are being implanted in patients with both congenital and acquired valvular disease. Many of the recipients of such valves are women of childbearing age who desire to have children. The main issues involved with pregnancy in a patient with PHV include the selection of PHV in women during their childbearing age, risks to both the mother and the fetus associated with pregnancy and the management of the patients with PHV during gestation.

Systemic thrombolytic therapy after recent abdominal aortic aneurysm repair: an absolute contraindication?

Systemic thrombolysis in the early postoperative period can cause fatal hemorrhage. Systemic thrombolysis is often considered contraindicated after major vascular procedures; thus, experience with this scenario is limited. A 67-year-old man experienced massive pulmonary embolization after his abdominal aortic aneurysm was repaired with a bifurcated, woven Dacron graft. Because systemic thrombolysis was the only option for our patient's survival, he underwent this procedure with recombinant tis-sue-type plasminogen activator just 2 weeks after the Dacron graft repair of his abdominal aortic aneurysm. After clinical stabilization, abdominal and pelvic computed tomography showed no periprosthetic graft hemorrhage. The successful systemic thrombolysis suggests that this therapy may prove useful in extreme situations.

Value of the ECG in suspected acute myocardial infarction with left bundle branch block

Uncomplicated left bundle branch block (LBBB) is characterized by true ST-segment shifts resulting from delayed repolarization in the left ventricle with respect to the right ventricle. When acute coronary occlusions develop in the setting of previous or new LBBB, 12-lead eCG manifestations of injury may also appear. They consist of a more pronounced ST-segment elevation, of ST-segment deviations opposite to those of uncomplicated LBBB, or both. We have reported that the only 3 independent ECG signs of acute MI during LBBB among patients with chest pain or history of coronary disease are: ST elevation > or = 1 mm in leads with a positive QRS, ST-depression > or = 1 mm in V1 to V3, and ST elevation > or = 5 mm in leads with a negative QRS. In our study, the clinical prediction rule score values of these signs were 5; 3; and 2, respectively. A score > or = 3 made a diagnosis of MI with a 90% specificity and a score of 2 with > 80%, specificity. Recent validation studies have confirmed that the presence of any of these ECG signs is associated with a sensitivity of 44 to 79% and a specificity of 93 to 100%. Sensitivity increases if serial or previous ECGs are available for comparison. Interobserver agreement is very high. While current practice guidelines recommend thrombolysis for all patients with chest pain and LBBB, concern among physicians about hemorrhagic stroke prevents many of these patients from receiving timely treatment. In a population with LBBB and chest pain where our proposed ECG criteria were not ascertained, only 73% of eligible patients received thrombolysis; on the other hand, 48% of patients with no biochemical evidence of MI were thrombolyzed. For the latter group, the clinical prediction rule had a score of 0. Instead, 79% of patients with confirmed acute MI had a prediction rule score > or =2. Similar values applied to a subgroup of patients with serial ECGs. We propose that thrombolysis among patients with chest pain and LBBB be decided on the basis of a systematic ECG review to "rule patients in". This provision may result in both a significant reduction in the number of patients without infarction who receive thrombolysis and in timely treatment of those who do have MI.

Suspected myocardial infarction and left bundle branch block: electrocardiographic indicators of acute ischaemia

OBJECTIVES

To examine the use of thrombolytic treatment in patients with suspected acute myocardial infarction (AMI) and left bundle branch block (LBBB). To evaluate electrocardiographic criteria for the identification of AMI in the presence of LBBB, and examine the implications of using these criteria in the clinical setting.

METHODS

A retrospective study over two years, based in two Sheffield teaching hospitals. Patients presenting with LBBB and suspected AMI were studied by analysis of an AMI database. The proportion of patients with LBBB and AMI receiving thrombolysis, and the in-hospital delay before the start of treatment, were used as indicators of current performance. Three predictive criteria were applied to the electrocardiograms (ECGs) retrospectively, and their ability to identify acute ischaemic change assessed. The implications of using the predictive criteria in the clinical setting were explored.

RESULT

Twenty three per cent (5/22) of patients with LBBB and AMI did not receive thrombolysis, in the absence of documented contraindications. The mean in-hospital treatment delay for thrombolysed patients was 154 minutes. Forty eight per cent (16/33) of those thrombolysed did not have a final clinical diagnosis of AMI. In the majority of cases (8/12), the decision not to administer thrombolysis was based on a single ECG recording. The presence of any of the predictive electrocardiographic criteria was associated with a diagnosis of AMI, with a sensitivity of 0.79 (95% confidence interval 0.63 to 0.95), specificity 1, positive predictive value 1, and negative predictive value 0.79. The kappa scores between four independent observers showed either substantial or near perfect agreement.

CONCLUSION

Currently, thrombolytic treatment is under-utilised in patients with LBBB and AMI, and those who are thrombolysed endure lengthy delays before treatment. Patients with any of the predictive criteria should be thrombolysed immediately. When the diagnosis is in doubt, serial ECGs may demonstrate evolving ischaemic change.