Acute occlusion of left main coronary artery without ventricular damage

Primary Angioplasty in a Catastrophic Presentation: Acute Left Main Coronary Total Occlusion-The ATOLMA Registry

OBJECTIVES

To determine the outcome predictors of in-hospital mortality in acute total occlusion of the left main coronary artery (ATOLMA) patients referred to emergent angioplasty and to describe the clinical presentation and the long-term outcome of these patients.

BACKGROUND

ATOLMA is an uncommon angiographic finding that usually leads to a catastrophic presentation. Limited and inconsistent data have been previously reported regarding true ATOLMA, yet comprehensive knowledge remains scarce.

METHODS

This is a multicenter retrospective cohort that includes patients presenting with myocardial infarction due to a confirmed ATOLMA who underwent emergency percutaneous coronary intervention (PCI).

RESULTS

In the period of the study, 7930 emergent PCI were performed in the five participating centers, and 46 of them had a true ATOLMA (0.58%). At admission, cardiogenic shock was present in 89% of patients, and cardiopulmonary resuscitation was required in 67.4%. All the patients had right dominance. Angiographic success was achieved in 80.4% of the procedures, 13 patients (28.2%) died during the catheterization, and the in-hospital mortality rate was 58.6% (27/46). At one-year and at the final follow-up, 18 patients (39%) were alive, including four cases successfully transplanted. Multivariate analysis showed that postprocedural TIMI flow was the only independent predictor of in-hospital mortality (OR 0.23, (95% CI 0.1-0.36), p < 0.001).

CONCLUSIONS

Our study confirms that the clinical presentation of ATOLMA is catastrophic, presenting a high in-hospital mortality rate; nevertheless, primary angioplasty in this setting is feasible. Postprocedural TIMI flow resulted as the only independent predictor of in-hospital mortality. In-hospital survivors presented an encouraging outcome. ATOLMA and left dominance could be incompatible with life.

Electrocardiographic changes in patients with acute myocardial infarction caused by left main trunk occlusion

BACKGROUND

Left main trunk (LMT) occlusion is a rare angiographic finding. The primary purpose was to investigate the ECG pattern of patients with angiographic confirmation of LMT as culprit lesion.

METHODS

Forty-eight patients (32 men; mean age 73 years) with angiographic total (21 patients; 44%) or subtotal (27 patients; 56%) occlusion of the LMT were analyzed. Twenty patients (42%) were found to have concomitant coronary lesions. Eighteen patients (38%) required intra-aortic balloon pump support.

RESULTS

A significant left axis deviation was observed in 26 cases (54%) and an intraventricular conduction delay in 32 patients (67%). The average QRS width and QTc interval were 122 and 433 ms, respectively. ST-segment elevation in lead aVR occurred in 32 patients (67%). ST-segment elevation in leads V2-5 and in leads I and aVL [classic left anterior descending (LAD) type] was frequently observed (18 cases; 35%). In six patients (13%), a partial LAD type was observed with ST-segment elevation in leads I and aVL, but not in peripheral leads. The remaining patients showed ST-segment elevation only in peripheral leads (12 cases), in inferior leads III + aVF (six cases), whereas six patients had no ST-segment elevation. Diffuse ST-segment depression only (>6 leads) was observed in 15 cases (31%). Eighteen patients (38%) died during hospitalization.

CONCLUSION

ST-segment elevation in lead aVR or a LAD-type pattern can be associated with LMT disease. Other relevant aspects are the presence of cardiogenic shock at admission, the left axis deviation and marked prolongation of QTc interval and QRS width.

Left main coronary artery stenosis: state-of-the-art

Patients with stenosis of the left main coronary artery present difficult challenges. The risks associated with this lesion have been known since the early days of angiography when patients were found to have increased mortality during follow-up. This information led to the general guidelines that surgical revascularization should be considered the treatment of choice in patients with significant left main coronary artery stenosis. Current advances in invasive cardiology have brought important information to the field. Intravascular ultrasound is now used routinely to evaluate angiographically indeterminate lesions with criteria now set forward as to what constitutes an indication for revascularization. Stents have even further dramatically changed the landscape. There are substantial issues, however, that need to addressed. These include the following: (1) the effect of specific lesion location on outcome - it is known that patients with distal bifurcation left main disease have worse outcome; (2) the potential for subacute thrombosis of the left main coronary artery; (3) the impact of left ventricular function and patient comorbidities irrespective of the degree and location of left main coronary artery stenosis; and (4) the risk-benefit ratio of stenting versus coronary artery bypass graft surgery. These issues are currently being addressed in two seminally important trials including the SYNTAX trial, which randomizes patients with left main and/or three-vessel disease to either coronary artery bypass graft surgery or a TAXUS drug-eluting stent. This trial is in the final stages of patient recruitment and will have important implications for the field. The other trial is the COMBAT trial, which is focused exclusively on left main coronary artery stenosis and randomizes patients with left main coronary artery disease either to a Sirolimus-eluting stent (Cypher, Johnson and Johnson Cordis, USA) or to coronary artery bypass graft surgery. The field of left main coronary artery disease continues to expand in terms of the evidence available for optimal patient evaluation and selection of treatment modalities.

Reciprocal changes in 12-lead electrocardiography can predict left main coronary artery lesion in patients with acute myocardial infarction

Acute left main coronary artery (LMCA) occlusion may result in acute myocardial infarction (AMI) or sudden death. ST elevation in the aVR and V1 leads is reported to be valuable in recognizing LMCA occlusion. Early recognition of electrocardiogram (ECG) changes, such as reciprocal ST depression in other leads, is helpful in averting this disaster. This study aimed to determine the reciprocal ST segment depression of 12-lead ECGs associated with acute LMCA occlusion. From January 2000 to December 2004, 61 patients who underwent emergency percutaneous coronary intervention in 3 hospitals due to AMI associated with LMCA (n = 18) and a left anterior descending coronary artery (LADCA) (n = 43) proximal lesion were selected. Reciprocal ST segment depression occurred in leads aVF, V(2), V(3), V(4), V(5), and V(6) with significantly higher incidence in the LMCA group than in the LADCA group. Stepwise linear multivariate discriminant analysis indicated that ST segment depression in leads aVF, V(2), and V(4) could distinguish the LMCA group from the LADCA group. We concluded that reciprocal ST segment depression in leads V(2), V(4), and aVF of a 12-lead ECG is an important predictor of acute LMCA occlusion.

Prediction of acute left main coronary artery obstruction by 12-lead electrocardiography. ST segment elevation in lead aVR with less ST segment elevation in lead V(1)

OBJECTIVES

We sought to determine the electrocardiographic (ECG) features associated with acute left main coronary artery (LMCA) obstruction.

BACKGROUND

Prediction of LMCA obstruction is important with regard to selecting the appropriate treatment strategy, because acute LMCA obstruction usually causes severe hemodynamic deterioration, resulting in a less favorable prognosis.

METHODS

We studied the admission 12-lead ECGs in 16 consecutive patients with acute LMCA obstruction (LMCA group), 46 patients with acute left anterior descending coronary artery (LAD) obstruction (LAD group) and 24 patients with acute right coronary artery (RCA) obstruction (RCA group).

RESULTS

Lead aVR ST segment elevation (>0.05 mV) occurred with a significantly higher incidence in the LMCA group (88% [14/16]) than in the LAD (43% [20/46]) or RCA (8% [2/24]) groups. Lead aVR ST segment elevation was significantly higher in the LMCA group (0.16 +/- 0.13 mV) than in the LAD group (0.04 +/- 0.10 mV). Lead V(1) ST segment elevation was lower in the LMCA group (0.00 +/- 0.21 mV) than in the LAD group (0.14 +/- 0.11 mV). The finding of lead aVR ST segment elevation greater than or equal to lead V(1) ST segment elevation distinguished the LMCA group from the LAD group, with 81% sensitivity, 80% specificity and 81% accuracy. A ST segment shift in lead aVR and the inferior leads distinguished the LMCA group from the RCA group. In acute LMCA obstruction, death occurred more frequently in patients with higher ST segment elevation in lead aVR than in those with less severe elevation.

CONCLUSIONS

Lead aVR ST segment elevation with less ST segment elevation in lead V(1) is an important predictor of acute LMCA obstruction. In acute LMCA obstruction, lead aVR ST segment elevation also contributes to predicting a patient's clinical outcome.

Effect of primary angioplasty on total or subtotal left main occlusion: analysis of incidence, clinical features, outcomes, and prognostic determinants

BACKGROUND

Although acute left main coronary artery (LMCA) occlusion is a rare clinical entity, it carries a very high mortality rate. The purposes of this study were to evaluate the effect of primary angioplasty for a severely obstructed or totally occluded LMCA, and to determine the incidence, clinical features, outcome, and prognostic determinants in this clinical setting.

MATERIALS AND METHODS

Between May 1993 and July 2000, a total of 740 patients with acute myocardial infarction underwent primary angioplasty in our hospital. Eighteen of 740 patients (2.4%) with a severely obstructed or totally occluded LMCA constituted the population of this study.

RESULTS

Seventeen of 18 patients (94.4%) experienced pulmonary edema (including 14 patients in cardiogenic shock). Six patients (33.3%) sustained sudden death due to malignant ventricular tachyarrhythmias. Coronary angiography showed that there were variable grade flow of intercoronary collaterals in 12 patients (66.7%), a totally occluded LMCA in 8 patients (44.4%), an incompletely occluded LMCA in 10 patients (55.6%), and a dominant right coronary artery (RCA) in 16 patients (88.9%). Primary angioplasty of the LMCA was performed with a 72.2% procedural success rate. Four patients (22.2%) received coronary artery bypass surgery after angioplasty. Six patients (33.3%) died in the hospital. Two patients died after discharge. Ten of 18 patients (55.6%) survived in long-term follow-up (mean +/- SD, 44 +/- 14 months). Those patients who survived to be discharged had significantly higher combined coexisting incidence of intercoronary collaterals, dominant RCA, and incompletely occluded LMCA (100% vs 0.0%, p = 0.0006) than those patients who died in the hospital.

CONCLUSIONS

Acute obstructive LMCA disease generally presented as pulmonary edema, cardiogenic shock, or sudden death. Only those who had combined coexistence of intercoronary collaterals, a dominant RCA, and an incompletely occluded LMCA could survive to be discharged. Our experience suggests that primary LMCA angioplasty is a feasible and effective procedure, and it may save lives in this clinical setting.

[Direct dilatation and emergency bypass operation of main branch occlusion in acute anterior wall infarct and cardiogenic shock]

Occlusion of the left main coronary artery (LMCA) is the cause of myocardial infarction in about 0.04%. Those patients who do not die during the acute phase often do have a dominant right coronary artery with extensive collaterals to the left coronary artery. Because this is a very rare situation there are only some cases reports dealing with the management of these patients. A 60 years old woman was admitted to our hospital with the signs of an acute Q-wave anterior myocardial infarction. Within a few minutes after the arrival she developed a cardiogenic shock. Coronary angiography was performed immediately. The left main coronary artery was occluded and a big right coronary artery showed a significant stenosis. There were many collaterals from the right coronary artery supplying the left coronary artery. After information of the cardiac surgeons, primary angioplasty of the LMCA was performed in order to achieve hemodynamic stabilisation and to relieve symptoms. Reperfusion of the left anterior descendent coronary artery (LAD) could be achieved within 30 minutes. This led to hemodynamic stabilisation of the patient. But a significant residual stenosis of the LMCA remained and the circumflex artery was still occluded. In the meanwhile cardiac surgery was able to be performed and so the patient was transferred to surgery without further dilatation or stent implantation. Four venous grafts (LAD, first diagonal branch, circumflex artery and right coronary artery) were inserted. After 4 weeks the patient was in a good shape and could be discharged at home. Primary angioplasty seems to be an effective treatment in patients with acute myocardial infarction and an occlusion of the LMCA. But coronary bypass surgery is nearly almost necessary during the following period in order to achieve complete revascularisation and to improve survival.