Histologic evidence of distal coronary thromboembolism. A complication of acute proximal coronary artery thrombolysis therapy

Thrombus aspiration before primary angioplasty improves myocardial reperfusion in acute myocardial infarction: the DEAR-MI (Dethrombosis to Enhance Acute Reperfusion in Myocardial Infarction) study

OBJECTIVES

This study sought to test the hypothesis that thrombus removal, with a new manual thrombus-aspirating device, before primary percutaneous coronary intervention (PPCI) may improve myocardial reperfusion compared with standard PPCI in patients with ST-segment elevation acute myocardial infarction (STEMI).

BACKGROUND

In STEMI patients, PPCI may cause thrombus dislodgment and impaired microcirculatory reperfusion. Controversial results have been reported with different systems of distal protection or thrombus removal.

METHODS

One-hundred forty-eight consecutive STEMI patients, admitted within 12 h of symptom onset and scheduled for PPCI, were randomly assigned to PPCI (group 1) or manual thrombus aspiration before standard PPCI (group 2). Patients with cardiogenic shock, previous infarction, or thrombolytic therapy were excluded. Primary end points were complete (>70%) ST-segment resolution (STR) and myocardial blush grade (MBG) 3.

RESULTS

Baseline clinical and angiographic characteristics were similar in the 2 groups. Comparing groups 1 and 2: complete STR 50% versus 68% (p < 0.05); MBG-3 44% versus 88% (p < 0.0001); coronary Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 78% versus 89% (p = NS); corrected TIMI frame count 21.5 +/- 12 versus 17.3 +/- 6 (p < 0.01); no reflow 15% versus 3% (p < 0.05); angiographic embolization 19% versus 5% (p < 0.05); direct stenting 24% versus 70% (p < 0.0001); and peak creatine kinase-mass band fraction 910 +/- 128 mug/l versus 790 +/- 132 mug/l (p < 0001). In-hospital clinical events were similar in the 2 groups. After adjusting for confounding factors, multivariate analysis showed thrombus aspiration to be an independent predictor of complete STR and MBG-3.

CONCLUSIONS

Manual thrombus aspiration before PPCI leads to better myocardial reperfusion and is associated with lower creatine kinase mass band fraction release, lower risk of distal embolization, and no reflow compared with standard PPCI. (Thrombus Aspiration Before Standard Primary Angioplasty Improves Myocardial Reperfusion in Acute Myocardial Infarction; http://clinicaltrials.gov/ct/show/NCT00257153).

Distal protection in native coronary arteries during primary angioplasty in acute myocardial infarction: Single-center experience

Distal embolization of plaque or thrombotic debris is one of the mechanisms involved in the ischemia/reperfusion injury during primary percutaneous intervention for acute occlusion of a native coronary artery. We tested the clinical application of maximal antiplatelet therapy with abciximab combined with one of two different systems of mechanical distal protection: balloon occlusion and aspiration (PercuSurge) in 24 cases and a distal filter (FilterWire Ex) in 10 cases. Feasibility, technical limitations, and pitfalls are described.

Adjunctive thrombus aspiration and mechanical protection from distal embolization in primary percutaneous intervention for acute myocardial infarction

Primary percutaneous intervention for acute occlusion of a native coronary artery may be complicated by distal embolization of plaque or thrombotic debris, with infarct extension. We tested the clinical application of a new therapeutic strategy combining maximal antiplatelet therapy, with glycoprotein IIb/IIIa inhibition, and adjunctive mechanical protection from distal embolization and direct aspiration of thrombus with a new balloon and catheter system (PercuSurgetrade mark). Successful aspiration of thrombus could be obtained in 7 out of 8 attempted procedures, with inability to negotiate the angulated take-off of the circumflex coronary artery in one patient. The current mechanical characteristics of the device, primarily developed for use in larger saphenous vein grafts, and certain caveats and limitations are discussed. New dedicated systems should be available in the near future for the native coronary circulation. Excellent immediate angiographic results were obtained in all treated patients, without evidence of loss of distal branches and no intraprocedural complications.

Coronary artery and saphenous vein graft remodeling: a review of histologic findings after various interventional procedures--Part IV

Catheter balloon angioplasty is a well accepted form of nonsurgical treatment of acutely and chronically obstructed coronary artery vessels. It is also the centerpiece for various new intervention techniques. Their morphologic effects on the site of obstruction has been termed "remodeling." Part IV of this six-part series focuses on morphologic correlates of coronary angiographic patterns of remodeling after balloon angioplasty and discusses effects of angioplasty on adjacent, nondilated vessels.

Coronary embolization after balloon angioplasty or thrombolytic therapy: an autopsy study of 32 cases

OBJECTIVES

This study was undertaken to examine the nature, extent and clinical relevance of coronary embolism after balloon angioplasty or thrombolytic therapy, or both.

BACKGROUND

Histopathologic documentation of postinterventional coronary embolization has been reported in only 10 patients from five studies.

METHODS

This retrospective autopsy-based study included 32 patients, treated with balloon angioplasty or thrombolysis, or both, who died within 3 weeks of the procedure and underwent autopsy at the Mayo Clinic. Clinical variables included patient age and gender, artery treated, site and type of obstruction, type of intervention, success of the procedure, and postprocedural changes in the electrocardiogram (ECG), cardiac enzymes and hemodynamic status. Histopathologic variables included characteristics of treated plaques, acutely infarcted myocardium and coronary microemboli. Associations between microemboli and clinical and microscopic factors were evaluated by t tests and simple and multiple linear regression.

RESULTS

Emboli were observed in 26 (81%) of the 32 patients. Among 83 emboli, 95% were thrombotic or atheromatous. The presence of microemboli was associated statistically with the development of postprocedural infarct extension, new myocardial infarction or new ECG abnormalities. Moreover, the greatest number of microemboli were associated with intervention in the left anterior descending coronary artery, multiple interventional sites, postprocedural medial dissection and plaque rupture or extrusion.

CONCLUSIONS

Among patients undergoing balloon angioplasty or thrombolytic therapy who die and undergo autopsy, coronary microemboli occur in a substantial percent. The frequency in survivors is unknown. However, in living patients who develop acute myocardial ischemia or new ECG abnormalities after these interventions, coronary microembolization should be considered a potential cause.

Spontaneous coronary artery dissection in a young man with anterior myocardial infarction

A case of spontaneous coronary artery dissection in a young male with subsequent myocardial infarction is reported. In addition, distal vessel occlusion is noted, presumably from embolization of thrombotic material originating from the site of dissection. Postulated mechanisms of this uncommon cause of myocardial infarction and subsequent therapeutic options are reviewed.